CAS No. 68359-37-5
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Adverse Effects

ACTIVITY: Insecticide (Pyrethroid)

CAS NAME: cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate

Note: CAS No. 68359-37-5 for cyfluthrin and beta-cyfluthrin is the same


2004-2006 - US EPA CHEERS study in Jacksonville, Duval County, Florida.
This 2-year study of children's exposure to selected pesticides and chemicals has ignited enormous controversy. Cyfluthrin
(I, II, III, IV, total) was one of 16 pesticides selected to be monitored in children (ages 0-3 years). See FAN's updates on this study. Also, 4-fluoro-3-phenoxybenzoic acid, (CAS No. 77279-89-1), a metabolite of Cyfluthrin, will be analyzed in biological media. It's molecular structure is

[Note: the CDC's "Third National Report on Human Exposure to Environmental Chemicals," expected to be released sometime in 2005, includes 4-fluoro-3-phenoxybenzoic acid in its list of chemicals.]

•• Abstract on 4-fluoro-3-phenoxybenzoic acid:

Toxicology Letters Volume 134, Issues 1-3 , 5 August 2002, Pages 141-145

Pyrethroid exposure of the general population—is this due to diet
Thomas Schettgen (a), Ursel Heudorf (b), Hans Drexler (a) and Jürgen Angerer (a)

(a) Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, Friedrich-Alexander-University of Erlangen-Nürnberg, Schillerstraße 25/29, D-91054, Erlangen, Germany
(b) Public Health Department of the City of Frankfurt am Main, Braubachstr. 18–22, D-60311, Frankfurt am Main, Germany
Received 21 September 2001;  accepted 20 February 2002.  Available online 13 September 2002.

Inhabitants (1177) of a residential area in Frankfurt/Main have been investigated with respect to internal exposure to pyrethroids. Biological monitoring revealed a body burden of pyrethroids. The 95th‰ for the urinary metabolites of pyrethroids, such as permethrin and cypermethrin, cis and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-DCCA and trans-DCCA), was determined to be 0.5 and 1.4 g/l, respectively. 95th‰ for cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (DBCA), a specific metabolite of deltamethrin, and 4-fluoro-3-phenoxybenzoic acid (F-PBA), a metabolite of cyfluthrin, were 0.3 and 0.27 g/l, respectively. The metabolic pattern found for these samples points out that pyrethroids are probably ingested orally with daily diet.


Am J Rhinol. 2005 Mar-Apr;19(2):141-51.
Genotoxic effects of pentachlorophenol, lindane, transfluthrin, cyfluthrin, and natural pyrethrum on human mucosal cells of the inferior and middle nasal conchae.

Tisch M, Faulde MK, Maier H.

Department of Otorhinolaryngology, Head and Neck Surgery, Bundeswehr Hospital, Ulm, Germany.

BACKGROUND: Animal experiments and epidemiological studies suggest that pentachlorophenol (PCP) and gamma-hexachlorocyclohexane (lindane) should be classified as possible human carcinogens. In the past, both have had a variety of applications in the civilian and military sectors and in forestry. They have, e.g., been used to impregnate and treat uniforms and other fabrics and to control human lice. Animal experiments indicate that PCP in particular causes mutations and chromosome aberrations and thus DNA damage. Studies on whether or not this also applies to newer substances and especially to natural type I and type II pyrethroids still are not available. What is particularly lacking are data on the genotoxic effects of these substances on human target cells. Our study describes the genotoxic effects of PCP, lindane, transfluthrin, cyfluthrin, and natural pyrethrum on human mucosal cells of the inferior and middle nasal conchae.
METHODS: Epithelial cells were isolated from nasal mucosa, which was removed in the surgical treatment of chronic sinusitis and nasal concha hyperplasia. After the cells had been tested for vitality using the trypan blue exclusion test, the short-term culture method was used. The material was incubated with PCP (0.3, 0.75, and 1.2 mmol), lindane (0.5, 0.75, and 1.0 mmol), transfluthrin (0.05, 0.1, 0.5, 0.75, and 1.0 mmol), cyfluthrin (0.05, 0.1, 0.5, 0.75, and 1.0 mmol), natural pyrethrum (0.001, 0.005, 0.01, 0.05, and 0.1 mmol), and N-methyl-N'-nitro-N-nitrosoguanidine for 60 minutes. Substance-induced DNA damage (single-strand and double-strand breaks) were determined using single-cell microgel electrophoresis. A fluorescence microscope was used together with an image processing system to analyze the results obtained.
RESULTS: After exposure to all tested substances, a high percentage of the cells of the middle nasal concha in particular were found to have severely fragmented DNA as a result of strong genotoxic effects. Although the reaction of the cells of the inferior nasal concha was significantly less strong (p < 0.001), the tested substances were nevertheless found to have a notable genotoxic effect on these cells too.
CONCLUSION: Our study strongly suggests that exposure to PCP, lindane, transfluthrin, cyfluthrin, and natural pyrethrum has a genotoxic effect on the epithelial cells of human nasal mucosa. In addition, we have shown that nasal structures differ in susceptibility to the various pesticides used in the tests. Thus, the study provides new evidence supporting the biological plausibility of PCP- and lindane-induced effects, thereby helping evaluate potential PCP- and lindane-induced mucous membrane carcinomas of these parts of the nose. In addition, our study shows that other substances that today are widely used for controlling pests have a considerable genotoxic effect on human target cells. The results obtained indicate the need for additional studies on the genotoxicity of these substances and their adverse effects on human health.

PMID: 15921213 [PubMed - in process]

From Toxline at Toxnet

Fetal exposure to environmental toxins & infant outcome

Year of Publication: 2002



Source: Crisp Data Base National Institutes of Health


DESCRIPTION (provided by applicant): The exposure of pregnant women to environmental toxins is of major concern because of their potential harm on the fetus. However, the detection of fetal exposure to environmental toxins still remains a major challenge. We propose that meconium analysis is a promising tool to meet this challenge.
(1) To compare the prevalence and amount of fetal exposure to environmental toxins through the analysis of meconium, cord blood and neonatal hair and to determine the degree of agreement among these three methods,
(2) to determine the relationship between the prevalence and amount of maternal exposure to environmental toxins during pregnancy, as determined by serial analyses of maternal hair and blood, to the prevalence and amount of fetal exposure to environmental toxins as determined by meconium, cord blood and neonatal hair analyses, and
(3) to compare adverse immediate (birth weight, length, head circumference, gestational age) and long term (postnatal growth and neurobehavioral development up to 2 yrs from enrollment) outcomes that are associated with antenatal exposure to environmental toxins as determined by maternal blood, maternal hair, meconium, cord blood and neonatal hair analyses.
Study design: Pregnant women (n=750) will be recruited, at midgestation, from the Outpatient Clinic of the Bulacan Provincial Hospital, Philippines and their blood and hair will be obtained at the time of recruitment and at delivery. Umbilical cord blood, meconium and neonatal hair will also be obtained. The samples will be analyzed, by atomic absorption spectrometry, for lead, mercury and cadmium and by gas chromatography/mass spectrometry for the following pesticides and their metabolites: propoxur, transfluthrin, Malathion, DDT, chlorpyrifos, bioallethrin, pretilachlor, lindane, cyfluthrin and cypermethrin. Pertinent maternal and infant data will be obtained after birth. The infants will be subsequently followed up at scheduled intervals for 2 years, to study their physical growth and neurobehavioral development using a battery of tests.
Data analysis: The relationship between the presence/amount of environmental toxins in meconium, maternal blood, maternal hair, cord blood or neonatal hair to the immediate and two year outcome in the infants will be studied, while controlling for potential confounders. The presence/amount of environmental toxins in maternal blood, hair, cord blood, meconium and neonatal hair will be also evaluated to determine which substrate (s) provide(s) the best index of exposure for a given toxin.
Expected benefits: Meconium analysis may provide a powerful tool to study the prevalence and degree of fetal exposure to environmental toxins and its associated adverse effects. This project can also serve as a model for the study of environmental pollutant problems during pregnancy at a local, national or global level.

Neurotoxicology 2004 Jun;25(4):720

Meconium - The Best Matrix To Detect Fetal Exposure To Environmental Pesticide/Herbicide.

Ostrea EM Jr, Bielawski DM, Posecion NC Jr, Corrion ML, Seagraves JJ

Dept of Pediatrics, Wayne State University,, Detroit MI.

The exposure of pregnant women to environmental toxins is of major concern because of their potential harm on the fetus. The aim of this study was to determine the best matrix to detect fetal exposure to pesticide/herbicide. Methods: Pregnant women were prospectively recruited at midgestation from an agricultural site in the Philippines where our preliminary survey showed a significant use at home and in the ricefields of the following pesticide/herbicide: cyfluthrin/propoxur (73%), chlorpyrifos (37%), cypermethrin(31%), pretilachor (28%), bioallethrin (26%), malathion (15%), diazinon (12%), transfluthrin (11%). Maternal hair and blood were obtained upon recruitment [hair (n=272), blood (283)] and at birth [hair (n=176), blood (174)]. Neonatal cord blood (n=159), hair (n=171) and meconium (n=166) were obtained at birth. All samples were analyzed for the above compounds and their known metabolites by GCMS.
Results: Analysis of meconium detected the highest fetal exposure rate (% positive) to the various toxicants: propoxur =32.53%, malathion= 1.2%, bioallethrin 0.60%, pretilachlor (1.81%), DDT (1.81%) cyfluthrin (0.60%), cypermethrin (6.02%). Cord blood and infant hair were only positive for propoxur (6.94% and 0.58%, respectively). Pesticide metabolites were not seen in meconium nor cord blood. Maternal hair showed the next highest exposure rate: propoxur (13.12%), malathion (2.84%) chlorpyrifors (0.35%), bioallethrin (16.67%) and pretilachlor (0.35%). Conclusion: Prenatal exposure to environmental toxicants are best detected by the analysis of meconium and maternal hair. However, since meconium is fetal in origin, it represents the best matrix to detect for fetal exposure to various toxicants.

From Toxline at Toxnet

PESTICIDE SCIENCE; 52 (1). 1998. 3-20.

Research into fluorinated pyrethroid alcohols: An episode in the history of pyrethroid discovery.


Landwirtschaftszentrum Monheim, Bayer AG, D-51368 Leverkusen, Germany.

Abstract: An account of pyrethroid research from 1975 to 1985 at Bayer AG is given. The exploitation of fluorine chemistry for this purpose led to increased activity of known 3-phenoxybenzyl pyrethroid esters and to the commercialization of the broad-spectrum insecticide cyfluthrin, the particularly tick-toxic flumethrin and the rapid-acting household insecticides fenfluthrin and transfluthrin. The last two constituted in 1976 a novel type of pyrethroid, based on polyfluorinated benzyl alcohols, off the mainstream of published pyrethroid research. Transfluthrin, the single isomer (1R)trans-permethric acid ester of 2,3,5,6-tetrafluorobenzyl alcohol has just been introduced to the market. The history of its discovery and structure-activity data as well as resistance considerations regarding cyfluthrin, are presented.

Reports available from
The National Technical Information Service

Order from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5285 Port Royal Road, Springfield, VA, 22161, USA.
Order No. Title Abstract / Keywords
NTIS/01710194 42p

2000 - Dermal Transfer Efficiency of Pesticides from Turf Grass to Dry and Wetted Palms.

Authors: Clothier KM

Southwest Research Inst., San Antonio, TX.

Supporting Agency: Environmental Protection Agency, Research Triangle Park, NC. National Exposure Research Lab.

Project rept. Mar-Aug 99.
See also PB2000-105542. Sponsored by Environmental Protection Agency, Research Triangle Park, NC. National Exposure Research Lab.
This report presents results of a study to determine the transfer of three pesticide commonly used in residential lawn care from turf grass to human skin. Formulations of the insecticides chlorpyrifos and cyfluthrin and the fungicide chlorothalonil were applied to St. Augustine grass and allowed to dry for 4 and 24 hours. After 24 hours, adult volunteers performed hand presses (left and right hands, palm only) with either dry or wetted skin. The mean (six presses) transfer efficiencies for chlorpyrifos were 0.115% for water-wetted, 0.156% for saliva-wetted, and 0.046% for dry skin. Transfer efficiencies for the other two pesticides were much higher (3.06%, 2.72%, and 1.29% for chlorothalonil and 4.02%, 4.18%, and 2.93 for cyfluthrin, respectively), but the same relationship were observed; no essential differences between saliva- and water-wetted skin and substantially lower transfer efficiencies for dry skin.
Turf grasses
*Pesticide residues
*Environmental exposure pathway

• Note from FAN: Under "Keywords" they forgot to add "Human exposure experiment" -EC.



1995 - Pesticide Fact Sheet: MAT 7484 Technical Insecticide; Aztec 2.1% Granular (the End-Use Product Consisting of Two Active Ingredients, This New Chemical and the Registered Chemical, Cyfluthrin).

Environmental Protection Agency, Washington, DC. Office of Prevention, Pesticides and Toxic Substances.

This document contains up-to-date chemical information, including a summary of the Agency's regulatory position and rationale, on a specific pesticide or group of pesticides. A Fact Sheet is issued after issuance or reissuance of registration standard.

MAT 7484


EPA/OTS; Doc #88-920008987



CAS Registry Numbers: 68359-37-5


EPA/OTS; Doc #88-920006738



CAS Registry Numbers: 68359-37-5


EPA/OTS; Doc #88-920009431



CAS Registry Numbers: 68359-37-5


EPA/OTS; Doc #88-920009430



CAS Registry Numbers: 68359-37-5


EPA/OTS; Doc #88-920007047



FCR 1272
CAS Registry Numbers:


EPA/OTS; Doc #88-920006696

CAS Registry Numbers: 68359-37-5



1987 - Pesticide Fact Sheet Number 164: Cyfluthrin.

Environmental Protection Agency, Washington, DC. Office of Pesticide Programs.

The document contains up-to-date chemical information, including a summary of the Agency's regulatory position and rationale, on a specific pesticide or group of pesticides. A Fact Sheet is issued after one of the following actions has occurred. (1) Issuance or reissuance of a registration standard, (2) Issuance of each special review document, (3) Registration of a significantly changed use pattern, (4) Registration of a new chemical, or (5) An immediate need for information to resolve controversial issues relating to a specific chemical or use pattern.



1987 - Effects of Type I and II Pyrethroids on Motor Activity and the Acoustic Startle Response in the Rat (Journal Version).

Authors: Crofton KM, Reiter LW

Health Effects Research Lab., Research Triangle Park, NC. Neurotoxicology Div.

Two behavioral tests, locomotor activity and the acoustic startle response (ASR), were utilized to separate the behavioral actions of Type I and II pyrethroids using permethrin, RU11679, cypermethrin, RU26607, fenvalerate, cyfluthrin, flucythrinate, fluvalinate and p,p'-DDT. Dosage-effect functions for all compounds were determined for both figure-8 maze activity and the ASR in the rat. All compounds were administered po in 1 ml/kg corn oil 1.5 - 3 hr prior to testing. The Type I compounds permethrin RU11679, along with p,p'-DDT, increased amplitude and had no effect on latency to onset of the ASR. In contrast, the Type II pyrethroids cypermethrin, cyfluthrin, and flucythrinate decreased amplitude and increased the latency to onset the ASR. Fenvalerate increased the amplitude, had no effect on latency, but unlike the other compounds tested, increased ASR sensitization. Fluvalinate had no effect on any measure of the ASR. The data provide further evidence of the differences between the in vivo ef [abstract truncated]


Full report available at Science Direct

International Immunopharmacology
Volume 5, Issue 2 , February 2005, Pages 263-270

Influence of pyrethroids and piperonyl butoxide on the Ca2+-ATPase activity of rat brain synaptosomes and leukocyte membranes

Nina Grosman (a), , and Friedhelm Diel (b)
aDepartment of Pharmacology, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
bDepartment of Biochemistry, IUG and University of Applied Sciences, FH Fulda, Petersgasse 27, D-36037 Fulda, Germany

Pyrethroids are widely used insecticides of low acute toxicity in mammals but the consequences of long-term exposure are of concern. Their insecticidal action is related to neurotoxicity and, in addition, there are indications of mammalian immunotoxicity. In order to clarify structure–activity relationships of the membrane interactions of pyrethroids, the present study compared the influence of selected pyrethroids, i.e. permethrin and the more water soluble esbiol (S-bioallethrin), both type I, and cyfluthrin, type II, on the Ca2+-ATPase activity of rat brain synaptosomes and peritoneal leukocyte membranes. The pyrethroids were tested alone as well as mixed with the enhancing substance piperonyl butoxide (PBO) at concentration ratios of 1:5 and 1:10. At the highest concentration tested, permethrin (10 ?M) alone inhibited the ATPase activity of leukocyte membranes by 20%, whereas the synaptosomes were affected less. Esbiol and cyfluthrin alone did not affect either membrane preparation significantly, whereas PBO (50 ?M) alone caused 10–15% inhibition. Mixtures of either pyrethroid with PBO inhibited the ATPase activity of both types of membranes (up to 40% inhibition) in a synergistic manner, which always tended to be supra-additive. With esbiol a true potentiation took place. The synergistic interaction between pyrethroid and PBO was most apparent with mixtures of a concentration ratio of 1:5. The ATPase activity of leukocyte membranes tended to be more susceptible to inhibition than that of synaptosomes. The results are in accordance with the assumption that the mammalian toxicity of pyrethroids can be ascribed to a general disturbance of cell membrane function in neuronal tissue. The results indicate that it may also be the case in the immune apparatus.

Full report available at Science Direct

Environmental Toxicology and Pharmacology
Volume 20, Issue 2 , September 2005, Pages 279-282

Investigation of acute toxicity of cyfluthrin on tilapia fry (Oreochromis niloticus L. 1758)

Aysel Caglan Karasu Benli,

Department of Fisheries and Aquaculture, Faculty of Agriculture, Ankara University, Diskapi, 06110 Ankara, Turkey

Cyfluthrin, a synthetic pyrethroid pesticide contaminating aquatic ecosystems as a potential toxic pollutant, was investigated in the present study for acute toxicity. Tilapia fry (Oreochromis niloticus L. 1758) was selected for the bioassay experiments. The 48 and 72 h LC50 was determined for the tilapia fry. The experiments were repeated three times. The static test method of acute toxicity test was used. In addition, behavioral changes at each cyfluthrin concentration were determined for the individuals. Data obtained from the cyfluthrin acute toxicity tests were evaluated using the Probit Analysis Statistical Method. The 48 and 72 h LC50 value for tilapia fry were estimated as 25.82 ?g/L (95% confidence limits: 20.92–43.26) and 21.07 ?g/L (95% confidence limits: 16.21–30.39), respectively.

Conclusion. Cyfluthrin is a highly toxic synthetic pyrethroid pesticide widely used in agriculture. Here special attention is drawn to its heavy use in mosquito and cockroach control programs which necessitates in-depth sub-chronic and chronic toxicity tests to fish species and to non-target species to be undertaken to assess possible ecological risk assessment of cyfluthrin. In addition, potential risk from cyfluthrin metabolites should be investigated to get a more complete picture in terms of toxicity. Margni et al. (2002) and Pennington (2003) reported acute LC50 and chronic (NOEC) ecotoxicity data not being suitable for inter-species extrapolation. Comparisons using measures such as the HC5, the hazardous concentration at which 5% of the species in a multiple species system are presumed to be stressed, are discussed.
Synergistic interactions between the active ingredient and other components of the formulation should be taken into consideration when evaluating toxicity.

Full report available at Science Direct

Science of The Total Environment
Volume 341, Issues 1-3 , 1 April 2005, Pages 109-117

Differential sensitivity of three cyanobacterial and five green algal species to organotins and pyrethroids pesticides

Jianyi Ma, a, b,
aDepartment of Plant Protection, Henan Institute Science and Technology, Xinxiang, 453003, People's Republic of China
bSchool of Life Sciences, Zhejiang Forestry College, Lin-An 311300, People's Republic of China

In this work, five organotins and pyrethroids pesticides were tested to examine their effects on the three cyanobacteria Anabaena flos-aquae, Microcystis flos-aquae, Mirocystis aeruginosa and on the five green algae Selenastrum capricornutun, Scenedesmus quadricauda, Scenedesmus obliqnus, Chlorella vulgaris, Chlorella pyrenoidosa through 96 h acute toxicity tests. The results indicated that:
(1) the decreasing order of the average acute toxicity to cyanobacteria and green algae of five dissimilar organotins and pyrethroids pesticides was: fentin hydroxide>cyhexatin>azocyclotin>fenbutatin oxide>beta-cyfluthrin.
(2) Wide variations occurred in response to the tested pesticides among the eight individual species of cyanobacteria and green algae. The sensitivity of various species of algae exposed to fenbutatin-oxide varied over one order of magnitude, exposed to cyhexatin/fentin-hydroxide/beta-cyfluthrin varied over two orders of magnitude and exposed to azocyclotin varied three orders of magnitude.
(3) In contrast with the sensitivity of cyanobacteria and green algae, cyanobacteria were much less sensitive to beta-cyfluthrin than green algae. The pollutants may result in a shift of green algal and cyanobacterial group structure, especially in a shift from dominance by green algae to dominance by cyanobacteria, and may sustain cyanobcterial blooms during the special period. Thus, the decreasing order of the aquatic ecological risk was: beta-cyfluthrin>fentin hydroxide>cyhexatin>azocyclotin>fenbutatin oxide. There was a strong variance between toxicity and ecological risk, i.e. “low toxicity” does not automatically imply “low ecological risk”. The toxicity of pyrethroids pesticides was lower than that of organotins pesticides, whereas the aquatic ecological risk of pyrethroids pesticides was higher than that of organotins pesticides.


Toxicol Appl Pharmacol. 2005 Jul 25; [Epub ahead of print]
Structure-activity relationships for the action of 11 pyrethroid insecticides on rat Na(v)1.8 sodium channels expressed in Xenopus oocytes.

Choi JS, Soderlund DM.

Department of Entomology, New York State Agricultural Experiment Station, Cornell University, P. O. Box 462, Geneva, NY 14456, USA.

Pyrethroid insecticides bind to voltage-sensitive sodium channels and modify their gating kinetics, thereby disrupting nerve function. This paper describes the action of 11 structurally diverse commercial pyrethroid insecticides on the rat Na(v)1.8 sodium channel isoform, the principal carrier of the tetrodotoxin-resistant, pyrethroid-sensitive sodium current of sensory neurons, expressed in Xenopus laevis oocytes. All 11 compounds produced characteristic sodium tail currents following a depolarizing pulse that ranged from rapidly-decaying monoexponential currents (allethrin, cismethrin and permethrin) to persistent biexponential currents (cyfluthrin, cyhalothrin, cypermethrin and deltamethrin). Tail currents for the remaining compounds (bifenthrin, fenpropathrin, fenvalerate and tefluthrin) were monoexponential and decayed with kinetics intermediate between these extremes. Reconstruction of currents carried solely by the pyrethroid-modified subpopulation of channels revealed two types of pyrethroid-modified currents. The first type, found with cismethrin, allethrin, permethrin and tefluthrin, activated relatively rapidly and inactivated partially during a 40-ms depolarization. The second type, found with cypermethrin, cyfluthrin, cyhalothrin, deltamethrin, fenpropathrin and fenvalerate, activated more slowly and did not detectably inactivate during a 40-ms depolarization. Only bifenthrin did not produce modified currents that fit clearly into either of these categories. In all cases, the rate of activation of modified channels was strongly correlated with the rate of tail current decay following repolarization. Modification of Na(v)1.8 sodium channels by cyfluthrin, cyhalothrin, cypermethrin and deltamethrin was enhanced 2.3- to 3.4-fold by repetitive stimulation; this effect appeared to result from the accumulation of persistently open channels rather than preferential binding to open channel states. Fenpropathrin was the most effective compound against Na(v)1.8 sodium channels from the perspective of either resting or use-dependent modification. When use dependence is taken into account, cypermethrin, deltamethrin and tefluthrin approached the effectiveness of fenpropathrin. The selective expression of Na(v)1.8 sodium channels in nociceptive neurons suggests that these channels may be important targets for pyrethroids in the production of paresthesia following dermal exposure.

PMID: 16051293 [PubMed - as supplied by publisher]


Int J Hyg Environ Health. 2005;208(3):193-9.

Pyrethroids used indoor-ambient monitoring of pyrethroids following a pest control operation.

Leng G, Berger-Preiss E, Levsen K, Ranft U, Sugiri D, Hadnagy W, Idel H.

Institute of Hygiene, Heinrich-Heine-University Dusseldorf, Germany. gabriele.leng.gl@bayerindustry.de

House dust and airborne particles (PM) were sampled before (T1) and 1 day (T2), 4-6 months (T3) as well as 10-12 months (T4) after a pest control operation (PCO). Cyfluthrin was applied in 11, cypermethrin in 1, deltamethrin in three and permethrin in four interiors. The pyrethroid concentrations in house dust and PM were measured by GC/MS with a detection limit for all pyrethroids of 0.5 mg/kg house dust and of 1 ng/m3 PM for deltamethrin and permethrin and 3 ng/m3 PM for cyfluthrin and cypermethrin. A general background concentration of permethrin (95th percentile: 5.9 mg/kg) and cyfluthrin (95th percentile: 34.9 mg/kg) in house dust was found. In general, an appropriately performed PCO lead to an increase of pyrethroids in house dust as well as in PM, in some cases up to 1 year after application. One day after the application the cyfluthrin concentration increased significantly from 0.25 (T1) to 33.8 mg/kg house dust (T2) and up to 4.9 ng/m3 in PM. The permethrin concentration increased significantly from 4.3 to 70 mg/kg in house dust and up to 18.1 ng/m3 in PM, deltamethrin increased to 54.5 mg/kg and 20.8 ng/m3 and cypermethrin to 14 mg/kg and 45.7 ng/m3. Thereafter a continuous decrease could be observed during the time course of 1 year. After 1 year the permethrin concentration in house dust was still 1/5 of the T2 concentration, whereas for cypermethrin and cyfluthrin only 1/14 and 1/23 of the T2 concentration were found. Deltamethrin was not detected at all after T2. Moreover, the data of this study showed significant, positive correlations between pyrethroids in house dust and in airborne particles especially one day after PCO.

PMID: 15971858 [PubMed - indexed for MEDLINE]



Clin Exp Pharmacol Physiol. 2004 Mar;31(3):134-44.
Differential effects of pyrethroids on volume-sensitive anion and organic osmolyte pathways.

Culliford SJ, Borg JJ, O'Brien MJ, Kozlowski RZ.

Department of Pharmacology, School of Medical Sciences, University of Bristol, Bristol and Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, UK.

1. There are no effective ways of screening for potential modulators of volume-regulated anion channels in their native cell type. Generally, cell lines are used for this purpose. Using HeLa and C6 glioma cells, we identified the pyrethroids as a novel class of compounds that inhibit taurine efflux through volume-regulated anion transport pathways in these cells. Subsequently, we examined their effects on volume-regulated anion channels in guinea-pig ventricular myocytes to determine whether results obtained using cell lines could be extrapolated to other tissues.
2. Tetramethrin inhibited taurine efflux in both HeLa and C6 glioma cells with Ki values of approximately 26 and 16 micro mol/L, respectively. Bioallethrin and fenpropathrin inhibited volume-sensitive taurine efflux from C6 glioma cells, but not from HeLa cells. The Ki values for bioallethrin and fenpropathrin were 70 and 59 micro mol/L, respectively.
3. Volume-sensitive I- efflux was observed in HeLa cells but not in C6 glioma cells, suggesting that the taurine efflux pathway in C6 glioma cells may be different to that of the I- efflux pathway. Cyfluthrin, tetramethrin, fenpropathrin, tefluthrin and bioallethrin all significantly inhibited volume-sensitive I- efflux from HeLa cells at 100 micro mol/L.
4. Patch-clamp experiments have shown inhibition of ICl,vol in guinea-pig ventricular myocytes by fenpropathrin, but not tetramethrin or cypermethrin, at 100 micro mol/L. This revealed that further differences exist between ICl,vol in guinea-pig ventricular myocytes and the anion transport pathways in C6 glioma and HeLa cells.
5. In conclusion, we have shown that pyrethroids differentially inhibit volume-regulated anion and taurine efflux in a number of cell types. Because these compounds have different effects in different cells, it is likely that: (i) more than one pathway is involved in the volume-sensitive transport of anions and organic osmolytes; and (ii) the molecular identities of the channels underlying anion transport are different. Finally, for the reasons given above, care should be taken when extrapolating data from one cell type to another. However, in the absence of an existing high-throughput screen, taurine efflux still represents a viable route for the identification of potential modulators of volume-regulated ion channels.

PMID: 15008955 [PubMed - indexed for MEDLINE]


J Econ Entomol. 2004 Apr;97(2):496-502.

Contact and leaf residue activity of insecticides against the sweet Corn pest Euxesta stigmatias (Diptera: Otitidae).

Nuessly GS, Hentz MG.

Everglades Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, 3200 E. Palm Beach Road, Belle Glade, FL 33430-4702, USA.

Damage by Euxesta stigmatias Loew larvae to sweet corn renders the ears unmarketable. This report evaluates the efficacy of insecticides labeled for armyworm control in Florida sweet corn against E. stigmatias adults. Tests were performed in controlled settings by using direct contact and dried plant residues of esfenvalerate, cyfluthrin, lambda-cyhalothrin, chlorpyrifos, methyl parathion, methomyl, and thiodicarb. Direct application of all insecticides except thiodicarb quickly killed or caused incapacitating sublethal affects (uncoordinated movement, uncontrolled twitching, and hyperextension of mouthparts and ovipositor) to > 75% of the flies. Low rates (0.56 kg [AI]/ha) of chlorpyrifos and methyl parathion provided the most efficient control, killing 100 and 93%, respectively, within 2 h of direct contact. Low rates of pyrethroids induced low mortality but high sublethal effects that together immobilized nearly 100% of adults within 1 h of exposure. Mortality reached 95% within 2 h of direct contact in flies treated with high rates of pyrethroids. Methomyl killed as many as 94%, but required 24 h to reach this level after direct treatment. Residues on dipped leaves and field-treated plants of all tested insecticides except methyl parathion were less effective at killing adults compared with direct contact tests. Pyrethroid residues (particularly cyfluthrin) on field planted sweet corn induced significantly higher levels of sublethal effects (57-70%), and for a longer period of time, compared with materials in the other classes of chemistry.

PMID: 15154473 [PubMed - indexed for MEDLINE]


Mem Inst Oswaldo Cruz. 2004 Jun;99(4):433-7.

Insecticide and community interventions to control Triatoma dimidiata in localities of the State of Veracruz, Mexico.

Wastavino GR, Cabrera-Bravo M, Garcia De La Torre G, Vences-Blanco M, Hernandez AR, Torres MB, Gomez YG, Mesa A, Schettino PM.

Departamento de Microbiologia y Parasitologia, Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico, DF, Mexico. daglo@servidor.unam.mx

Three different interventions to control Triatoma dimidiata in the State of Veracruz were implemented: X-1 = whole dwelling spraying, X-2 = middle wall spraying, X-3 = household cleaning. Cyfluthrin was sprayed 3 times with 8 month intervals. After each spraying, insects were collected and sent to the laboratory to be recorded and to determine genus and species of the adult triatomine bugs, and nymphs were counted. Trypanosoma cruzi presence was determined. With X-1, the infestation, colonization, and natural infection indexes were reduced to 0% in the 3 localities, with respect to t0. With X-2, the infestation index was reduced to 10% at t3 in 3 localities; the colonization index was reduced to 0% in only 1 locality at t3, and the natural infection index was reduced to 0% at t3. With X-3 the 3 indexes were not effectively reduced but they decreased with respect to the baseline study. Insecticide application to the whole dwelling is a more efficient intervention than its application to only the lower half of the walls and to the cleaning of houses.

PMID: 15322635 [PubMed - in process]


Mem Inst Oswaldo Cruz. 2004 May;99(3):253-6.
Re-infestation of houses by Triatoma dimidiata after intra-domicile insecticide application in the Yucatán peninsula, Mexico.

Dumonteil E, Ruiz-Pina H, Rodriguez-Felix E, Barrera-Perez M, Ramirez-Sierra MJ, Rabinovich JE, Menu F.

Laboratorio de Parasitologia, Centro de Investigaciones Regionales Dr Hideyo Noguchi, Universidad Autonoma de Yucatan, Yucatan, Mexico. oliver@tunku.uady.mx

In most countries, Chagas disease transmission control remains based on domestic insecticide application. We thus evaluated the efficacy of intra-domicile cyfluthrin spraying for the control of Triatoma dimidiata, the only Chagas disease vector in the Yucatan peninsula, Mexico, and monitored potential re-infestation every 15 days for up to 9 months. We found that there was a re-infestation of houses by adult bugs starting 4 months after insecticide application, possibly from sylvatic/peridomicile areas. This points out the need to take into account the potential dispersal of sylvatic/peridomestic adult bugs into the domiciles as well as continuity action for an effective vector control.

PMID: 15273795 [PubMed - in process]


Onderstepoort J Vet Res. 2004 Mar;71(1):41-51.

Development of a novel self-medicating applicator for control of internal and external parasites of wild and domestic animals.

Burridge MJ, Simmons LA, Ahrens EH, Naude SA, Malan FS.

Department of Pathobiology, College of Veterinary Medicine, University of Florida, P. O. Box 110880, Gainesville, Florida 32611-0880, USA.

Four trials, three in the United States and one in South Africa, were conducted to evaluate the potential value of a novel self-medicating applicator in the passive control of gastrointestinal nematodes in cattle and deer, and of files and ticks on cattle using oil-based treatments. The results of the trials demonstrated that this applicator is an effective and practical device for the passive treatment of both deer and cattle for trichostrongyle infections using the endectocide, moxidectin (Cydectin. Fort Dodge Animal Health, USA), of cattle for hom fly (Haemotobia irritans) infestations using the insecticide, cyfluthrin (CyLence, Bayer AG, Germany) and of cattle for tick infestations (in particular Amblyomma hebraeum and Rhipicephalus appendiculatus) using the acaricides deltamethrin and amitraz (Delete All, Intervet, South Africa).

PMID: 15185574 [PubMed - indexed for MEDLINE]


J Econ Entomol. 2004 Apr;97(2):601-5.

Impacts of residual insecticide barriers on perimeter-invading ants, with particular reference to the odorous house ant, Tapinoma sessile.

Scharf ME, Ratliff CR, Bennett GW.

Center for Urban and Industrial Pest Management, Department of Entomology, Purdue University, West Lafayette, IN 47907-2089, USA. scharfm@purdue.edu

Three liquid insecticide formulations were evaluated as barrier treatments against perimeter-invading ants at a multifamily housing complex in West Lafayette, IN. Several ant species were present at the study site, including (in order of abundance) pavement ant, Tetramorium caespitum (L.); honey ant, Prenolepis imparis (Say); odorous house ant, Tapinoma sessile (Say); thief ant, Solenopsis molesta (Say); acrobat ant, Crematogaster ashmeadi (Mayr); crazy ant, Paratrechina longicornis (Latrielle), field ants, Formica spp.; and carpenter ant Camponotus pennsylvanicus (DeGeer). Studies began in May 2001 and concluded 8 wk later in July. Individual replicate treatments were placed 0.61 in (2 feet) up and 0.92 m (3 feet) out from the ends of 46.1 by 10.1-m (151 by 33-foot) apartment buildings. Ant sampling was performed with 10 placements of moist cat food for 1 h within treatment zones, followed by capture and removal of recruited ants for later counting. All treatments led to substantial reductions in ant numbers relative to untreated controls. The most effective treatment was fipronil, where 2% of before-treatment ant numbers were present at 8 wk after treatment. Both imidacloprid and cyfluthrin barrier treatments had efficacy comparative with fipronil, but to 4 and 2 wk, respectively. Odorous house ants were not sampled before treatment. Comparisons of ant species composition between treatments and controls revealed an increase in odorous house ant frequencies at 1-8 wk after treatment in treated locations only. These results demonstrate efficacy for both nonrepellent and repellent liquid insecticides as perimeter treatments for pest ants. In addition, our findings with odorous house ant highlight an apparent invasive-like characteristic of this species that may contribute to its dramatic increase in structural infestation rates in many areas of the United States.

PMID: 15154488 [PubMed - indexed for MEDLINE]


J Am Mosq Control Assoc. 2004 Mar;20(1):55-63.

Bioefficacy of cyfluthrin (SOLFAC EW050) impregnated bed-nets against Anopheles gambiae in southern Cameroon.

Etang J, Chandre F, Manga L, Bouchite B, Baldet T, Guillet P.

Institute of Medical Research and Studies on Medicinal Plants, PO Box 6163, Yaounde, Cameroon.

The bioefficacy of cyfluthrin-impregnated bed-nets was evaluated in the agro-industrial town of Mbandjock (southern Cameroon). The objectives were to assess the knockdown and mortality rates, the protection against bloodfeeding mosquitoes, and the irritant effect of cyfluthrin (SOLFAC EW050)-impregnated bed-nets against a susceptible strain of Anopheles gambiae. Polyester bed-nets were impregnated and distributed to inhabitants of Mbandjock for use, then nets were retreated after 6 months. The uptake of active ingredient on nets ranged from 30.8 mg/m2 to 75.1 mg/m2 at the initial treatment and from 131.0 mg/m2 to 225.0 mg/m2 at retreatment. The susceptible Kisumu reference strain of Anopheles gambiae reared in our laboratory was used for bioassays. The knockdown rate on freshly treated nets (2 wk after treatment) ranged from 93 to 96% and the mortality rate ranged from 52 to 70%. During the 12-month trial, knockdown and mortality rates showed 2 peaks, respectively, in the 4th month (94-97% knockdown and 61-96% mortality) and 7th month (i.e., soon after retreatment; 89-98% knockdown and 86-100% mortality), separated by breakdowns on the 5th through 6th and 12th months (46-77% knockdown and 8-69% mortality). Knockdown and mortality rates decreased faster on the lower part of nets than on the top, suggesting that some external factors such as dirt and daily hand manipulation could impede the efficacy of treated nets. Exceedingly dirty nets were less effective than clean nets. The protective rate against bloodfeeding mosquitoes ranged from 60 to 100% during the 1st 4 months and decreased at 40-70% during the 5th and 6th months after the initial treatment. After retreatment, the protective rate ranged from 50 to 90% for the 1st 5 months and from 35 to 64% at the 6th month. More than 70% of mosquitoes that attempt to feed through treated or retreated nettings died within 24 h after contact. Cyfluthrin was found to be mildly irritant during the whole evaluation. This trial reveals that cyfluthrin EW050-treated nets were effective against a susceptible strain of An. gambiae.

PMID: 15088705 [PubMed - indexed for MEDLINE]


Trop Anim Health Prod. 2004 Jan;36(1):33-43.

A large-scale trial to evaluate the efficacy of a 1% pour-on formulation of cyfluthrin (Cylence, Bayer) in controlling bovine trypanosomosis in Eastern Zambia.

Van den Bossche P, Munsimbwe L, Mubanga J, Jooste R, Lumamba D.

Institute of Tropical Medicine, Veterinary Department, Antwerpen, Belgium. pvdbossche@itg.be

A trial to evaluate the efficacy of a 1% cyfluthrin pour-on formulation (Cylence, Bayer) in reducing the incidence of bovine trypanosomosis was conducted in an area of ca. 2000 km2 of the Eastern Province of Zambia. The trial area was cultivated and carried a cattle population of approximately 11 animals/km2. Cattle were the main host of tsetse. Following the free of charge treatment of the adult cattle at intervals of 7 weeks and at a dosage of 15 ml/100 kg body weight, there was an increase in the average packed cell volume in the herd although the decline in the incidence of trypanosomal infections was more prolonged. The monthly incidence of trypanosomal infections started to decline substantially 8 months after the treatments were initiated. No trypanosomal infections were detected from 10 months after the start of the trial.

PMID: 14979556 [PubMed - indexed for MEDLINE]


J Agric Food Chem. 2004 Feb 25;52(4):755-61.

Separation and analysis of diastereomers and enantiomers of cypermethrin and cyfluthrin by gas chromatography.

Liu W, Gan JJ.

Department of Environmental Sciences, University of California, Riverside, California 92521, USA.

Synthetic pyrethroid (SP) insecticides are of environmental significance because of their high aquatic toxicity. Due to their chirality, SP compounds contain multiple diastereomers and enantiomers. However, due to great structural similarities and lack of isomer standards, gas chromatographic (GC) analysis of SP diastereomers or enantiomers is poorly developed. In this study, we used a HP-5 column to separate the diastereomers and a beta-cyclodextrin-based enantioselective column (BGB-172) to separate the enantiomers of cypermethrin (CP) and cyfluthrin (CF). Resolved peaks were identified by comparing chromatograms of isomer-enriched CP products. Diastereomers of both CP and CF were separated on the HP-5 column. On the BGB-172 column, enantiomers of all cis diastereomers were separated, while those of trans diastereomers were not separated. The elution order appears to be regulated by configuration, a finding which may allow peak identification in the absence of isomer standards. When coupled with electron capture detection, the developed methods had low detection limits and may be used for analysis of SP diastereomers and enantiomers in environmental samples.

PMID: 14969527 [PubMed - indexed for MEDLINE]


Environ Toxicol Chem. 2003 Jun;22(6):1330-4.

Pyrethroid stimulation of ion transport across frog skin.

Cassano G, Bellantuono V, Ardizzone C, Lippe C.

Dipartimento di Fisiologia Generale ed Ambientale dell'Universita di Bari, Via Amendola 165/A, 70126 Bari, Italy. cassano@biologia.uniba.it

Pyrethroids are grouped into two classes (types I and II) because of the absence or presence of an alpha-cyano substituent and the production of a different intoxication syndrome in rodents. In this study, we investigated the effect of pyrethroids on the ion transport across frog skin (Rana esculenta). The short-circuit current value (estimate of ion transport) was increased by each of the eight pyrethroids tested, with the following order of potency: lambda-cyhalothrin > deltamethrin > alpha-cypermethrin = beta-cyfluthrin > bioallethrin > permethrin > bioresmethrin > phenothrin. The first four compounds are type II pyrethroids. Therefore, ion transport is stimulated more by type II pyrethroids than by type I. Experiments performed in the presence of amiloride support the conclusion that pyrethroids mainly increase Na+ absorption and to a lesser extent Cl- secretion. In these experiments, no systematic difference between type I and II pyrethroids was found. Finally, the stimulation by pyrethroids was inhibited by indomethacin and W7 (inhibitors of cyclooxygenases and the Ca2+/calmodulin system, respectively). These observations suggest that pyrethroids do not directly affect the epithelial Na+ channel (ENaC) but indirectly influence an intracellular event involved in ENaC modulation and linked to the Ca2+ signaling cascade.

PMID: 12785591 [PubMed - in process]


Bull Environ Contam Toxicol. 2003 Jun;70(6):1143-50.

No Abstract available

Maximum Residue Limit and Risk Assessment of Beta-Cyfluthrin and Imidacloprid on Tomato ( Lycopersicon esculentum Mill).

Dikshit AK, Pachauri DC, Jindal T.

Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi 110012, India.

PMID: 12756452 [PubMed - in process]


Bull Environ Contam Toxicol. 2003 Jun;70(6):1136-42.

No Abstract available

Evaluation of Beta-cyfluthrin: protection of cole crops, dietary intake, and consumer risk assessment.

Borah S, Dikshit AK, Lal OP, Singh R, Sinha SR, Srivastava YN.

Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi 110012, India.

PMID: 12756451 [PubMed - in process]

Full free report available at http://jeq.scijournals.org/cgi/content/full/32/2/447

J Environ Qual. 2003 Mar-Apr;32(2):447-55.

Risk assessment of pesticide runoff from turf.

Haith DA, Rossi FS.

Biological and Environmental Engineering, Riley-Robb Hall, Cornell Univ., Ithaca, NY 14853, USA. dah13@cornell.edu

The TurfPQ model was used to simulate the runoff of 15 pesticides commonly applied to creeping bentgrass (Agrostis stolonifera L.) fairways and greens on golf courses in the northeastern USA. Simulations produced 100-yr daily records of water runoff, pesticide runoff, and pesticide concentration in runoff for three locations: Boston, MA, Philadelphia, PA, and Rochester, NY. Results were summarized as annual and monthly means and annual maximum daily loads (AMDLs) corresponding to 10- and 20-yr return periods. Mean annual pesticide runoff loads did not exceed 3% of annual applications for any pesticide or site, and most losses were substantially less than 1% of application. However, annual or monthly mean concentrations of chlorothalonil, iprodione, and PCNB in fairway runoff often exceeded concentrations that result in 50% mortality of the affected species (LC50) for aquatic organisms. Concentrations of azoxystrobin, bensulide, cyfluthrin, and trichlorfon in extreme (1 in 10 yr or 1 in 20 yr) events often approached or exceeded LC50 levels. Concentrations of halofenozide, mancozeb, MCPP, oxadiazon, propiconazole, thiophanate-methyl, triadimefon, and trinexapac-ethyl were well below LC50 levels, and turf runoff of these chemicals does not appear to be hazardous to aquatic life in surface waters.

PMID: 12708667 [PubMed - in process]


Int J Hyg Environ Health. 2003 Mar;206(2):85-92.

Pyrethroids used indoors--biological monitoring of exposure to pyrethroids following an indoor pest control operation.

Leng G, Ranft U, Sugiri D, Hadnagy W, Berger-Preiss E, Idel H.

Institute of Hygiene, Heinrich-Heine-University, Dusseldorf, Germany. gabriele.leng.gl@bayer-ag.de

A prospective epidemiological study with respect to pyrethroid exposure was carried out combining clinical examination, indoor monitoring and biological monitoring. The results of the biological monitoring are presented. Biological monitoring was performed in 57 persons before (T1) as well as 1 day (T2), 3 days (T3), 4-6 months (T4), and 10-12 months (T5) following a pest control operation (PCO) with pyrethroid containing products such as cyfluthrin, cypermethrin, deltamethrin or permethrin. Pyrethroids in blood were measured by GC-ECD. The respective metabolities cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (DBCA), 3-phenoxybenzoic acid (3-PBA) and fluorophenoxybenzoic acid (FPBA) were measured in urine using GC/MS. For all cases the concentrations of pyrethroids in blood were found to be below the detection limit of 5 micrograms/l before and after the PCO. With a detection limit of 0.2 microgram/l of the investigated metabolites, the percentage of positive samples were 7% for cis-DCCA, 3.5% for trans-DCCA and 5.3% for 3-PBA before PCO. One day after PCO (T2) the percentage of positive samples increased remarkably for cis-DCCA (21.5%), trans-DCCA (32.1%) and 3-PBA (25%) showing significantly increased internal doses as compared to pre-existing values. This holds also true for T3, whereas at T4 and T5 the significant increase was no more present. FPBA and DBCA concentrations were below the respective detection limit before PCO and also in most cases after PCO. In 72% of the subjects the route of pyrethroid uptake (measured by determining the DCCA isomeric ratio) was oral/inhalative and in 28% it was dermal. Based on the biological monitoring data it could be shown that appropriately performed pest control operations lead to a significant increase of pyrethroid metabolite concentration in the early phase (1 and 3 days) after pyrethroid application as compared to the pre-exposure values. However, evaluated metabolite concentrations 4-6 months after PCO did not exceed values of published background levels.

PMID: 12708229 [PubMed - in process]


J Expo Anal Environ Epidemiol. 2003 Mar;13(2):112-9.

Human exposure to indoor residential cyfluthrin residues during a structured activity program.

Williams RL, Bernard CE, Krieger RI.

Personal Chemical Exposure Program, Department of Entomology, and Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA.

Estimations of absorbed daily dosage (ADD) of chemicals following contact with treated surfaces may be required for risk assessment and risk management. Measurements of ADD based upon biomonitoring are a more reliable data than estimates of ADD from environmental measurements since they require fewer default assumptions. Study participants performed a structured activity program (SAP) 24-h after an application of Tempo((R)) 20 WP (cyfluthrin; 3-(2,2-dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylic acid cyano(4-fluoro-3-phenoxy-phenyl)-methyl ester) on a medium pile, plush nylon carpet. Measurements of total cyfluthrin residue and transferable cyfluthrin residue (cotton cloth and CDFA roller; personal sock and short dosimetry) were made at 3, 7, 12, 23, 47.5, and 407.5 h. Total cyfluthrin residue extracted from (Soxhlet extraction) carpet was 11.1+/-2.7 microg/cm(2) 1 h prior to the SAP. Transferable cyfluthrin residue obtained through analysis of cotton cloths rolled with a weighted 30-pound cylinder was 0.11 microg/cm(2). Cyfluthrin residues from socks and shorts were 0.74+/-0.23 and 0.15+/-0.03 microg/cm(2), respectively. Urine was collected at 12-h intervals during a 72-h period following the SAP and was analyzed for the cyfluthrin biomarker, 4-fluoro-3-phenoxybenzoic acid (FPBA). The mean cyfluthrin equivalents excreted were 8.4+/-5.7 microg/person (yielding an absorbed dosage of 0.10 microg/kg; n=7). The elimination half-life was 16+/-5 h. All predicted ADDs based upon environmental measurements overestimated the ADDs measured by urinary excretion.

PMID: 12679791 [PubMed - in process]


Bull Environ Contam Toxicol. 2002 Jul;69(1):54-8.

No Abstract available

Evaluation of residues of beta-cyfluthrin on cotton.

Mukherjee I, Gopal M, Kusum.

Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi 110012, India.

PMID: 12053257 [PubMed - indexed for MEDLINE]


J Environ Sci Health B. 2000 Jul;35(4):477-89.

A preliminary examination of the translocation of microencapsulated cyfluthrin following applications to the perimeter of residential dwellings.

Stout DM 2nd, Leidy RB.

National Exposure Research Laboratory, U.S. EPA, Research Triangle Park, NC 27711, USA. stout.dan@epa.gov

Methods have been developed to monitor the translocation of microencapsulated cyfluthrin following perimeter applications to residential dwellings. A pilot study was implemented to determine both the potential for application spray to drift away from dwellings and the intrusion of residues into homes following perimeter treatments. Residential monitoring included measuring spray drift using cellulose filter paper and the collection of soil samples from within the spray zone. In addition, interior air was monitored using fiberglass filter paper as a sorbent medium and cotton ball swabs were used to collect surface wipes. Fortification of matrixes resulted in recoveries of > 90%. Spray drift was highest at the point of application and declined to low but measurable levels 9.1 m from the foundations of dwellings. Soil residues declined to low, but measurable levels by 45 days post-application. No cyfluthrin was measured from indoor air; however, some interior surfaces had detectable levels of cyfluthrin until three days post-application. Findings indicate that spray drift resulting from perimeter applications might contaminate non-target surfaces outside the spray zone. Soil borne residues may serve as persistent sources for human exposure and potentially intrude into dwellings through the activities of occupants and pets. Residues do not appreciably translocate through air and consequently inhalation is not a likely route for human exposure. Surface residues detected indoors suggest that the physical movement of residues from the exterior to the interior might be a viable route of movement of residues following this type of application.

PMID: 10874624 [PubMed - indexed for MEDLINE]


J Med Entomol. 2000 Jan;37(1):201-4.

Relative efficacy of insecticide treated mosquito nets (Diptera: Culicidae) under field conditions.

Ansari MA, Razdan RK.

Malaria Research Centre (ICMR), Madhuban, Delhi, India.

The relative efficacy of insecticide treated mosquito nets was evaluated under field conditions in Dehra village of Dhaulana PHC, District Ghaziabad, U.P., India, during 1996. Nylon nets were impregnated with deltamethrin, cyfluthrin, lambdacyhalothrin, and etofenprox at 25 mg/m2 by standard methods. Repellent, excito-repellency, killing, and airborne actions were monitored from dusk to dawn by hourly collection of mosquitoes that entered and rested in rooms and also females that landed on treated and untreated mosquito nets. Results revealed 15.3-22.9% repellent action, 98.3-99.3% excito-repellency action, and 100% mortality of females that landed on treated fabrics. No significant differences were observed in the efficacy of different synthetic pyrethroids against anophelines. However, against Culex quinquefasciatus Say there was a significant difference between deltamethrin and etofenprox. Control of anophelines was more pronounced than Cx. quinquefasciatus. There was no pronounced airborne action with any insecticide tested. Synthetic pyrethroids with strong airborne action may be more appropriate for impregnation of mosquito nets.

PMID: 15218929 [PubMed - indexed for MEDLINE]


Occup Environ Med. 1999 Jul;56(7):449-53.

Role of individual susceptibility in risk assessment of pesticides.

Leng G, Lewalter J.

Institute of Hygiene, Heinrich-Heine-University Dusseldorf, Germany.

OBJECTIVES: This study presents criteria for assessing the individual pesticide burden of workers in the chemical industry.
METHODS: A group of 1003 workers exposed to methylparathion or ethylparathion (alkyl phosphates), propoxur (carbamate), or cyfluthrin (pyrethroid) was investigated. After exposure to methylparathion or ethylparathion the methylparathion or ethylparathion and methylparaoxon or ethylparaoxon concentrations in plasma, the p-nitrophenol concentration in urine, and the activities of cholinesterase and acetylcholinesterase were measured. For exposure to propoxur the propoxur concentration in plasma, the 2-isopropoxyphenol concentration in urine, and the cholinesterase and acetylcholinesterase activities were measured. For exposure to cyfluthrin the cyfluthrin concentration in plasma was measured.
RESULTS: At the same propoxur concentration only workers with a low individual acetylcholinesterase activity reported symptoms. Workers who metabolised cyfluthrin rapidly reported less symptoms than workers with a lower rate of metabolism. This tendency was also evident in cases of mixed exposure (cyfluthrin and methylparathion).
CONCLUSIONS: In the assessment of exposure to pesticides susceptibility of the individual person has to be considered.

PMID: 10472315 [PubMed - indexed for MEDLINE]


Toxicol Lett. 1999 Jun 30;107(1-3):123-30.

The influence of individual susceptibility in pyrethroid exposure.

Leng G, Lewalter J, Rohrig B, Idel H.

Institute of Hygiene, Heinrich-Heine-University Dusseldorf, FRG. leng@uni-duesseldorf.de

The aim of this study was to find a suitable biomarker for pyrethroid adverse effects. It was shown that there is a correlation between the half-life time (t(1/2)) of pyrethroids in plasma and the clinical findings. We hypothized that this finding indicates an interindividual different amount of total esterase activity or even a polymorphism. By in vitro experiments it was demonstrated that pyrethroids are cleaved by carboxylesterases. After it turned out that carboxylesterase activity in human plasma is too low for detection, a method for specific determination of carboxylesterase activity in human isolated lymphocytes was developed. As a substrate for carboxylesterase activity, cyfluthrin was added to the lymphocyte suspension. As a proof for cyfluthrin degradation by carboxylesterases the produced hydrocyanic acid was determined by GC/MS. First hints for interindividual differences in carboxylesterase activity in lymphocytes were found.

PMID: 10414789 [PubMed - indexed for MEDLINE]


Toxicol Lett. 1999 Jun 30;107(1-3):81-7.

Induction of mitotic cell division distrubances and mitotic arrest by pyrethroids in V79 cell cultures.

Hadnagy W, Seemayer NH, Kuhn KH, Leng G, Idel H.

Institute of Hygiene, Heinrich-Heine University Dusseldorf, Germany.

Five pyrethroids (fenvalerate, deltamethrin, cypermethrin, permethrin, cyfluthrin) differing in their chemical purity were investigated on their cytotoxic effects, especially on their ability to induce mitotic cell division disturbances using Chinese hamster lung cells of line V79. The colony forming ability (CFA) resulted in distinct differences of the cytotoxic effect of the tested pyrethroids, whereby permethrin was found to be most toxic. With the exception of fenvalerate all tested pyrethroids gave rise to inhibition of cell cycle progression as shown by G2/M-arrest of synchronized V79 cells by flow cytometry as well as by the increase of the mitotic index as evaluated by light microscopy. The mitotic arresting activity could be attributed to the occurrence of abnormal mitotic figures such as initial and full C-metaphases. The results however indicate, that pyrethroids per se do not contribute to the cytotoxic effects but that other factors such as chemical impurities, source as well as manufacturing process and isomer composition may be responsible for the observed cytotoxic effects.

PMID: 10414784 [PubMed - indexed for MEDLINE]


Toxicol Lett. 1998 Aug;96-97:361-8.

Assessment of pyrethroid-induced paraesthesias: comparison of animal model and human data.

Pauluhn J, Machemer LH.

Institute of Toxicology, Bayer AG, Wuppertal, Germany.

The quantification of upper respiratory tract (URT) sensory irritation is considered to be important in rodent inhalation studies, since it may be also used as an endpoint mimicking trigeminal paraesthesias observed in humans. URT sensory irritation is known to be associated with rodent-specific secondary physiological effects such as depression of body temperature and changes in heart rate. In acutely exposed rats, these endpoints have been addressed by telemetrical measurements. The analysis of the ventilation pattern during acute inhalation studies of rats exposed to the alpha-cyano-pyrethroid cyfluthrin demonstrates that concentration-dependent URT sensory irritation was associated with a hypothermic response. The no-effect levels (NO(A)EL) based on the URT sensory irritation endpoint following acute inhalation exposure for 1 h and following a repeated 4-week or 13-week inhalation exposure for 6 h/day on 5 days week were virtually identical (approximately 0.1 mg/m3 air). An additional objective was to examine whether human volunteers experience comparable signs when acutely exposed for 1 h to airborne concentrations slightly above or in the range of the NO(A)EL. In human volunteers there were no clinically significant or pyrethroid related abnormalities in vital signs, ECG's or in any clinical laboratory tests after either exposure, although transient effects related to URT (sensory) irritation were reported. In conclusion, an initial actual exposure concentration of approximately 0.1 mg cyfluthrin/m3 air appears to be in the range of the sensory irritant threshold concentration for both rats and humans. Thus, with regard to physiological afferent portal-of-entry effects, the interspecies response was consistent.

PMID: 9820689 [PubMed - indexed for MEDLINE]


World Health Organ Tech Rep Ser. 1998;879:i-vi, 1-73.

Evaluation of certain veterinary drug residues in food. Forty-eighth report of the Joint FAO/WHO Expert Committee on Food Additives.

[No authors listed]

This report presents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of residues of certain veterinary drugs in foods and to recommend maximum levels for such residues in food. The first part of the report considers standards for the performance of studies, residues at the injection site, and several initiatives to promote transparency of the process for setting Maximum Residue Limits (MRLs). A summary follows of the Committee's evaluations of toxicological and residue data on a variety of veterinary drugs: two anthelminthic agents (moxidectin and tiabendazole), eight antimicrobial agents (ceftiofur, danofloxacin, dihydrostreptomycin, streptomycin, enrofloxacin, flumequine, gentamicin and spiramycin), one glucocorticosteroid (dexamethasone), and two insecticides (cyfluthrin and fluazuron). Annexed to the report are a summary of the Committee's recommendations on these drugs, including Acceptable Daily Intakes and MRL's and further toxicological studies and other information required.

Publication Types: * Technical Report

PMID: 9727328 [PubMed - indexed for MEDLINE]


Bull Environ Contam Toxicol. 1998 Jun;60(6):837-44.

No Abstract available

Effects of pyrethroid insecticides on pest control operators.

Wieseler B, Kuhn K, Leng G, Idel H.

Institute of Hygiene, Heinrich-Heine-University Dusseldorf, Moorenstrasse 5, 40225 Dusseldorf, Germany.

PMID: 9606258 [PubMed - indexed for MEDLINE]


Gesundheitswesen. 1998 Feb;60(2):95-101.

[Pyrethroids in house dust of the German housing population--results of 2 nationwide cross-sectional studies]

[Article in German]

Friedrich C, Becker K, Hoffmann G, Hoffmann K, Krause C, Nollke P, Schulz C, Schwabe R, Seiwert M.

Institut fur Wasser-, Boden- und Lufthygiene des Umweltbundesamtes, Berlin.

As a part of the German Environmental Surveys performed in 1985/86 (West Germany), 1990/91 (West Germany) and 1991/92 (East Germany), dust samples were collected in the households of about 1600 randomly selected adults (25 to 69 years) and an analysis of these samples was performed in respect of their content of 8 different pyrethroids and of the synergist piperonyl butoxide (PBO). In the 1990-92 survey about 90% of the samples contained permethrin in concentrations above the limit of quantification. This showed permethrin to be the most widespread of the 8 compounds investigated. The geometric mean of the permethrin content in domestic dust was 0.22 mg/kg. Only about 8% of the samples contained one or more of the other investigated substances (cyfluthrin, lambda-cyhalothrin, cypermethrin, alpha-cypermethrin, deltamethrin, empenthrin, d-phenothrin) in quantifiable amounts. About 76% of the samples contained quantifiable amounts of PBO. In East Germany the geometric mean of the PBO content (0.21 mg/kg) was significantly higher than in West Germany (0.07 mg/kg), but no difference for permethrin was found. Significant associations could be shown for the permethrin content and the application of biocides as well as for the PBO content and regional factors (size of community, type of dwelling area). Samples collected in 1985/86 (West Germany) showed a geometric mean for permethrin of 0.06 mg/kg and for PBO of 0.07 mg/kg. Comparing the values of 1985/86 and 1990/91, a significant increase can be observed for permethrin, whereas the PBO concentration remained constant.

PMID: 9553309 [PubMed - indexed for MEDLINE]


Xenobiotica. 1997 Dec;27(12):1273-83.

Human dose-excretion studies with the pyrethroid insecticide cyfluthrin: urinary metabolite profile following inhalation.

Leng G, Leng A, Kuhn KH, Lewalter J, Pauluhn J.

Institute of Hygiene, Heinrich-Heine-University Dusseldorf, Germany.

1. Nine male volunteers were exposed to the pyrethroid insecticide cyfluthrin. The study was performed in an exposure room, where an aerosol containing cyfluthrin was sprayed to obtain atmospheres with mean cyfluthrin concentrations of 160 and 40 micrograms/m3. Four volunteers were exposed for 10, 30 and 60 min at 160 micrograms/m3 and another five volunteers were exposed for 60 min at 40 micrograms/m3. For 160 micrograms/m3 exposure urine samples were collected before and immediately after exposure as well as for the periods 1-2, 2-3, 3-4, 4-5, 5-6, 6-12 and 12-24 h after exposure. For 40 micrograms/m3 exposure urine samples were collected before and 2 h after exposure.
2. The main urinary cyfluthrin metabolites, cis-/trans-3-(2,2-dichlorovinyl)-2,2-dimethylycyclopropane carboxylic acid (DCCA) and 4-fluoro-3-phenoxybenzoic acid (FPBA), were determined. The limit of detection (LOD) for all metabolites was 0.0025 microgram in an urine sample of 5 ml (0.5 microgram/l). After inhalative exposure of 40 micrograms cyfluthrin/m3 air for 60 min, the amount of metabolites in urine collected in the first 2 h after exposure was less than the LOD, namely 0.14 microgram for cis-DCCA, 0.15-0.28 microgram for trans-DCCA and 0.12-0.23 microgram for FPBA.
3. Of the metabolites, 93% was excreted within the first 24 h (peak excretion rates between 0.5 and 3 h) after inhalative exposure of 160 micrograms/m3. The mean half-lives were 6.9 h for cis-DCCA, 6.2 h for trans-DCCA and 5.3 h for FPBA.
4. The mean trans-:cis-DCCA ratio was 1.9 for the time course as well as for each subject.
5. The amount of metabolites in urine depends on the applied dose, on the exposure time and shows interindividual differences.

Publication Types: * Clinical Trial * Controlled Clinical Trial

PMID: 9460232 [PubMed - indexed for MEDLINE]


Bull Environ Contam Toxicol. 1997 Nov;59(5):681-7.

No Abstract available

Evaluation of possible toxic effects of cyfluthrin during short-term, relevant community exposure.

Satpathy SK, Tyagi PK, Das BS, Srivastava P, Yadav RS.

Department of Internal Medicine and Biochemistry, Ispat General Hospital, Rourkela 769005, India.

PMID: 9323214 [PubMed - indexed for MEDLINE]


Toxicol Lett. 1996 Nov;88(1-3):215-20.

Biological monitoring of pyrethroid metabolites in urine of pest control operators.

Leng G, Kuhn KH, Idel H.

Institute of Hygiene, Heinrich-Heine-University Dusseldorf, Germany.

Due to their low mammalian toxicity but high insectical activity, pyrethroids are increasingly used for pest control. The objective of the present study was the development of a biological monitoring program to determine exposure to pyrethroids. A diastereoselective detection of the major pyrethroid metabolites cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid, cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-phenoxybenzoic acid and fluorophenoxybenzoic acid by capillary gas chromatography in combination with mass selective detection was applied. The limits of determination ranged between 0.5 and 1 microgram/l urine, depending on the metabolite concerned. It was demonstrated that pyrethroid metabolites were detectable in urine for a period of elimination up to 3.5 days after exposure to cyfluthrin. Fluorophenoxybenzoic acid was shown to be a suitable biomarker for exposure to cyfluthrin. The presented method was adequate for monitoring pyrethroids in occupationally exposed subjects.

PMID: 8920739 [PubMed - indexed for MEDLINE]


Gesundheitswesen. 1996 Oct;58(10):551-6.

[Toxicologic evaluation of pyrethroids in indoor air: demonstrated with the example of cyfluthrin and permethrin]

[Article in German]

Pauluhn J, Steffens W, Haas J, Machemer L, Miksche LK, Neuhauser H, Schule S.

Bayer AG, Institut fur Toxikologie, Wuppertal.

Pyrethroids have varying activities depending on vehicle or route of administration (oral, dermal, inhalational). Specific features like the sensory irritation potential of the alpha-cyano-pyrethroids on the respiratory tract can only be quantified adequately by inhalation testing. Thus equitoxic dosages can vary between inhalative and oral application, especially for alpha-cyano-pyrethrolds. The no-effect values for chronic exposures derived for permethrin (type I pyrethroid) and cyfluthrin (type II pyrethroid) show clearly, that each pyrethroid has to be considered as an individual substance toxicologically, and that any extrapolation from the oral to the inhalative route should only be done after a thorough assessment of the specific toxicological profile. The study of simulated pest control measures on carpets pretreated with permethrin showed, that no significant enrichment of permethrin in total dust could be seen from a carpet additionally treated with pyrethroids. The missing correlation between absolute (mg pyrethroid/m3 air) and relative (mg pyrethroid/kg dust) concentrations in air-borne dust as well as the low degree of translocation of pyrethroids from carpets (only about 0.044% x m(-2) x h(-1) of the cyfluthrin applied to the carpet can be regarded as possibly respirable) prove, that analyses of pyrethroids in household sedimented dust ("vacuum cleaner bag analyses") without knowing the absolute surface concentration and respective air concentrations are of little value for risk assessment. The data allow the conclusion, that a scientific assessment of health risks is only possible based on absolute concentrations of pyrethroids in indoor air.

PMID: 9035787 [PubMed - indexed for MEDLINE]


J Med Entomol. 1997 Sep;34(5):552-8.

Pesticide use by licensed applicators for the control of Ixodes scapularis (Acari: Ixodidae) in Connecticut.

Stafford KC 3rd.

Department of Entomology, Connecticut Agricultural Experiment Station, New Haven 06504, USA.

To assess the use of insecticides for tick control by commercial applicators in Connecticut, a questionnaire was mailed to 897 individuals and businesses with ornamental and turf pesticide applicator licenses. In total, 348 completed surveys were returned (38.8%). The majority of the respondents considered themselves lawn care (41.1%), landscape (31.3%) or tree care (12.6%) providers. Tick control services were offered by 16.4% (n = 57) of the respondents, all of whom apply insecticides for tick control, mainly for Ixodes scapularis Say. Over half (n = 33) also treat for the American dog tick, Dermacentor variabilis (Say). Most respondents (66.7%) began applying pesticides for the control of I. scapularis during the period from 1990 to 1996. The principal acaricide used for tick control was cyfluthrin (n = 21), with chlorpyrifos 2nd (n = 18), carbaryl 3rd (n = 12), and fluvalinate (n = 4) 4th. When asked about what other pesticides were used for tick control, the top 3 chemicals also were the principal alternatives. Past success with a product was the dominant factor in selecting a pesticide, but information provided by the Connecticut Agricultural Experiment Station (New Haven), Cooperative Extension (University of Connecticut, Storrs), and scientific studies were important. Half of the respondents (49.1%) indicated that their tick control business had increased slightly or dramatically since 1991, although tick control comprises < 5% of their overall business for 63.1% of these applicators. Residential properties comprised 90% of the business for half of those treating for ticks, and the median charge for 0.4 ha was $180. Many respondents (43.8%) also indicated that they planned to expand their tick control services. Tick control represents a small but growing business in Connecticut.

PMID: 9379461 [PubMed - indexed for MEDLINE]


Med Vet Entomol. 1996 Jan;10(1):1-11.

Comparison of different insecticides and fabrics for anti-mosquito bednets and curtains.

Curtis CF, Myamba J, Wilkes TJ.

London School of Hygiene and Tropical Medicine, U.K.

Various formulations of six insecticides (a carbamate and five pyrethroids), were impregnated into bednets and curtains made from cotton, polyester, polyethylene or polypropylene fabric. For bioassays of insecticidal efficacy, female Anopheles gambiae mosquitoes were made to walk on the fabrics for 3 min and mortality was scored after 24 h. The main concentrations tested were: bendiocarb 400 mg/m2, cyfluthrin 30-50 mg/m2, deltamethrin 15-25 mg/m2, etofenprox 200 mg/m2, lambda-cyhalothrin 5-15 mg/m2 and permethrin 200-500 mg/m2. Field trials in Tanzania used experimental huts (fitted with verandah traps) entered by wild free-flying Anopheles gambiae, An.funestus and Culex quinquefasciatus mosquitoes. Results of testing the impregnated fabrics in experimental huts showed better personal protection provided by bednets than by curtains. Permethrin cis:trans isomer ratios 25:75 and 40:60 were equally effective, and the permethrin rate of 200 mg/m2 performed as well as 500 mg/m2. Bioassay data emphasized the prolonged insecticidal efficacy of lambda-cyhalothrin deposits, except on polyethylene netting. Most of the impregnated nets (including the 'Olyset' net with permethrin incorporated during manufacture of the polyethylene fibre) and an untreated intact net performed well in preventing both Anopheles and Culex mosquitoes from feeding on people using them overnight in the experimental huts. Anopheles showed high mortality rates in response to pyrethroid-treated nets, but only bendiocarb treated curtains killed many Culex. Holed nets treated with either cyfluthrin (5 EW formulation applied at the rate of 50 mg a.i./m2) or lambda-cyhalothrin (2.5 CS formulation at 10 mg a.i./m2) performed well after 15 months of domestic use. Treatment with deltamethrin SC or lambda-cyhalothrin CS at the very low rate of 3 mg/m2 gave good results, including after washing and re-treatment.

PMID: 8834736 [PubMed - indexed for MEDLINE]


Bull Environ Contam Toxicol. 1995 Jul;55(1):142-8.

No Abstract available

Cyfluthrin persistence in soil as affected by moisture, organic matter, and redox potential.

Smith S Jr, Willis GH, Cooper CM.

USDA-ARS, National Sedimentation Laboratory, Oxford, Mississippi 38655-1157, USA.

PMID: 7663084 [PubMed - indexed for MEDLINE]


J Am Mosq Control Assoc. 1993 Jun;9(2):210-20.

Indoor low-volume insecticide spray for the control of Anopheles albimanus in southern Mexico. Village-scale trials of bendiocarb, deltamethrin and cyfluthrin.

Arredondo-Jimenez JI, Rodriguez MH, Bown DN, Loyola EG.

Centro de Investigacion de Paludismo, Direccion General de Epidemiologia, Secretaria de Salud, Tapachula, Chiapas, Mexico.

A comparative insecticide village-scale trial was carried out to determine the efficacy of low-volume (LV) indoor spray of bendiocarb, deltamethrin and cyfluthrin for the control of Anopheles albimanus in a coastal plain of southern Mexico. Low-volume spray was conducted with knapsack mist-blowers, giving an average discharge rate of 215 ml/min, which deposited droplets of 50-100 microns. Using this technique, 25 houses were treated/sprayman/day as compared with 8 houses/sprayman/day using conventional hand compression pumps. Indicators of LV mortality showed a residual activity of 10 wk as compared with 13 wk of activity for wettable powder (WP) (bendiocarb). When comparing expenditures, LV spray costs were 43% less when using bendiocarb, 83% less with deltamethrin and 74% less with cyfluthrin with respect to the conventional WP spray of the same insecticides. Low-volume spray time was reduced by one-third, with respect to WP. Malaria incidence was reduced by 53 and 56%, respectively, in the bendiocarb LV and deltamethrin LV treated villages as compared with the untreated village.

PMID: 8350078 [PubMed - indexed for MEDLINE]


Southeast Asian J Trop Med Public Health. 1992 Jun;23(2):318-23.

Beta-cyfluthrin, a synthetic pyrethroid for mosquito control.

Vasuki V, Rajavel AR.

Vector Control Research Centre, Indian Council of Medical Research, Pondicherry.

Beta-cyfluthrin (OMS 3051), a new synthetic pyrethroid and one of the stereoisomers of cyfluthrin, was studied for insecticidal activity against eight mosquito species. Its larvicidal activity with LC50 values of 5.62 x 10(-5) and 1.19 x 10(-4) mg/l respectively for Culex quinquefasciatus and Aedes aegypti was comparable with that of deltamethrin. This pyrethroid was more effective against the larvae of Armigeres subalbatus (LC50 - 7.76 x 10(-7)) and the adults of Anopheles culicifacies LT50 - 27.76 min at 2.0 mu/cm2) than the other species tested. Residual efficacy at 50 mg(ai)/m2 was more persistent (for 14-25 weeks) on thatch and asbestos among the four treated surfaces. This compound also elicited oviposition deterrent activity at 0.001 mg/l against Cx.quinquefasciatus. beta-cyfluthrin is a good insecticide for mosquito control. However, care should be exercised while using it as a larvicide in breeding habitats considering its toxicity to fish.

PMID: 1359650 [PubMed - indexed for MEDLINE]


Bull Environ Contam Toxicol. 1991 Sep;47(3):355-61.

No Abstract available

Pyrethroid insecticides and formulations as factors in residues remaining in apparel fabrics after laundering.

Laughlin J, Newburn K, Gold RE.

University of Nebraska-Lincoln 68583-0802.

PMID: 1768948 [PubMed - indexed for MEDLINE]


Fundam Appl Toxicol. 1988 May;10(4):624-34.

The effects of type I and II pyrethroids on motor activity and the acoustic startle response in the rat. Crofton KM, Reiter LW.

Neurotoxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711.

Recent data have demonstrated that the in vivo effects of low dosages of two pyrethroids, cismethrin and deltamethrin, can be differentiated. Two behavioral tests, locomotor activity and the acoustic startle response (ASR), were utilized to separate the behavioral actions of Type I and II pyrethroids using permethrin, RU11679, cypermethrin, RU26607, fenvalerate, cyfluthrin, flucythrinate, fluvalinate and p,p'-DDT. Dosage-effect functions for all compounds were determined for both figure-eight-maze activity and the ASR in the rat. All compounds were administered po in 1 ml/kg corn oil 1.5-3 hr prior to testing. All compounds produced dosage-dependent decreases in locomotor activity. The Type I compounds, permethrin and RU11679, along with p,p'-DDT, increased amplitude and had no effect on latency to onset of the ASR. In contrast, the Type II pyrethroids, cypermethrin, cyfluthrin, and flucythrinate, decreased amplitude and increased the latency to onset of the ASR. Fenvalerate increased the amplitude, had no effect on latency, but unlike the other compounds tested, increased ASR sensitization. Fluvalinate had no effect on any measure of the ASR. These data provide further evidence of the differences between the in vivo effects of low dosages of Type I and II pyrethroids, and extend the findings of our previous work to other representatives of the two classes of pyrethroids.

PMID: 3396790 [PubMed - indexed for MEDLINE]


Z Lebensm Unters Forsch. 1988 Feb;186(2):125-9.

[Residue analysis of pyrethroid insecticides in cereal grains, milled fractions and bread]

[Article in German]

Dicke W, Ocker HD, Thier HP.

Institut fur Lebensmittelchemie der Universitat Munster, Bundesrepublik Deutschland.

A procedure is described for the residual analysis of eight pyrethroid insecticides at levels of 2-5 micrograms/kg. Residues are extracted from cereal grains, flour or bread with a mixture of acetonitrile/water (2 + 1) and are partitioned into petroleum ether. Clean-up is performed by gel permeation chromatography on Bio-Beads S-X3 and an additional Florisil column. Electron capture gas liquid chromatography on a non-polar SE-30 capillary column separates the isomers of the compounds. Under the conditions used in the experiments with cyfluthrin, cypermethrin, deltamethrin, fenvalerate, and permethrin, the compound levels in rye and wheat did not decrease significantly. Losses during milling and baking were small. Consequently, pyrethroid insecticides remain effective in grain stored over a long period of time. However, considerable residues result in the milled fractions as well as in different types of bread.

PMID: 3354265 [PubMed - indexed for MEDLINE]


J Vector Ecol. 2002 Dec;27(2):230-4.

Field evaluation of cypermethrin and cyfluthrin against dengue vectors in a housing estate in Malaysia.

Sulaiman S, Pawanchee ZA, Othman HF, Shaari N, Yahaya S, Wahab A, Ismail S.

Department of Biomedical Science, Faculty ofAllied Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.

Cynoff 25ULV (cypermethrin 25 g/l) and Solfac UL015 (cyfluthrin 1.5% w/v) were evaluated against the sentinel sugar-fed adults and 4th-instar larvae of Aedes aegypti in a housing estate endemic of dengue in Malaysia. The impact of both pyrethroids on field populations of Aedes albopictus and Aedes aegypti larvae was monitored weekly using bottle containers. Both Cynoff 25ULV and Solfac UL015 showed adulticidal effects and larvicidal effects. This field trial using Cynoff 25ULV against dengue vectors showed its potential for use in dengue vector control programs.

PMID: 12546459 [PubMed - indexed for MEDLINE]


Med Vet Entomol. 2002 Dec;16(4):356-63.

Domestic scorpion control with pyrethroid insecticides in Mexico.

Ramsey JM, Salgado L, Cruz-Celis A, Lopez R, Alvear AL, Espinosa L.

Centre for Infectious Disease Research, National Institute for Public Health, Cuernavaca, Morelos, Mexico. jramsey@insp.mx

Scorpion stings cause more morbidity in Mexico than any other country, leading to about 100 deaths annually. In 1999, the State of Morelos reported nine deaths among 30663 cases of scorpion sting. To replace lindane used for scorpion control, field trials of pyrethroid pesticides were undertaken in Morelos during 1998-2000 at the village of Chalcatzingo (population initially with 2760 inhabitants and 530 houses). Pre-intervention surveys detected scorpions (Scorpiones: Buthidae) of two species in the majority of houses: Centruroides limpidus limpidus Karsch outnumbering Vaejovis mexicanus smithi Koch. Scorpion prevalence was assessed, pre- and post-spray, directly by searching (40 min/house) and by householder reports of sightings inside houses. Pre-intervention perceptions of scorpion abundance were similar for all areas, with sightings in 12-18% of houses, whereas daytime searches detected more infestations in eastern parts of the village (prevalence 17% indoors, 22% outdoors) than in other sectors (9% indoors, 14% outdoors). Pyrethroids were evaluated as residual treatments in separate sectors of Chalcatzingo, with almost complete coverage indoors and peridomestically, using the following four formulations: bifenthrin 10% wettable powder (WP) applied at 50mg a.i./m2, cyfluthrin 10% WP (Solfac 10 WP) at 44-55 mg a.i./m2, deltamethrin 2.5% suspension concentrate (Biothrin 25 SC) at 11 mg a.i./m2 and 5% WP (K-Othrine 50 WP) at 35 mg a.i./m2. Phase 1 compared bifenthrin 10 WP, Solfac 10 WP and Biothrin 25 SC sprayed in December 1998; phase 2 compared Solfac 10 WP and K-Othrine 50 WP sprayed in June and again in December 2000, with follow-up surveys of scorpions one month post-spray and subsequently. Scorpion prevalence was reduced by 64-77% peridomestically one month post-spray and by 83, 46 and 15% in houses sprayed with cyfluthrin WP, bifenthrin WP or deltamethrin SC, respectively. Householder reports of sighting scorpions indoors were 33-85% below pre-intervention levels. Cumulative effects of the three spray-rounds over 3 years reduced scorpion prevalence by approximately 60% in the deltamethrin WP re-sprayed area and by approximately 90% in the cyfluthrin WP re-sprayed area. Householder sightings also fell by 67 and 28% in the cyfluthrin and delta-methrin re-sprayed areas, respectively. Operational efficacy of these products against scorpions at the dosages applied was ranked as cyfluthrin WP > bifenthrin WP > deltamethrin SC > WP. Reported cases of scorpion sting intoxication fell by 17% during this study after having risen by approximately 40% over four previous years.

Publication Types: * Evaluation Studies

PMID: 12510887 [PubMed - indexed for MEDLINE]


Pest Manag Sci. 2002 Dec;58(12):1259-65.

Persistence and leaching of beta-cyfluthrin in alluvial soil of India.

Gupta S, Gajbhiye VT.

Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi, 110 012, India.

Persistence as affected by rate of application and moisture regimes and leaching of beta-cyfluthrin was studied in alluvial soil under laboratory conditions. The effects of rate of application and moisture regimes on persistence were studied by incubating fortified soil at 0.1, 1.0 and 10.0 mg kg(-1) under air-dry, field capacity and submerged moisture regimes. The initial deposits of 0.09, 1.11 and 10.1 mg kg(-1) dissipated with time and 78.4-100% loss was recorded at 90 days. The half-life values varied from 7.8 to 41.8 days. The rate of dissipation decreased as the rate of application increased under field capacity and submerged conditions. However, under air-dry conditions, the effect was less pronounced, and half-life values showed a reverse trend. Persistence of beta-cyfluthrin under different moisture regimes followed the trend: air-dry > field capacity > submerged. The trend could be attributed to the effect of moisture on number and type of microbes. Leaching was studied in a packed soil column under saturated flow conditions. beta-Cyfluthrin was found to be highly immobile in alluvial soil. No residues were detected in any leachate fraction under the experimental conditions. In column soil, residues were detected at 0-10 cm depth and the major amount (>99%) was recovered from 0-5 cm depth. Although beta-cyfluthrin showed moderate persistence in alluvial soil, the possibility of its leaching to ground water is negligible as a result of its immobility.

PMID: 12477001 [PubMed - indexed for MEDLINE]


Arch Inst Pasteur Madagascar. 2000;66(1-2):9-12.

[Xenopsylla cheopis (Siphonaptera: Xenopsyllinae), fleas in rural plague areas of high altitude Madagascar: level of sensitivity to DDT, pyrethroids and carbamates after 50 years of chemical vector control]

[Article in French]

Ratovonjato J, Duchemin JB, Duplantier JM, Chanteau S.

Institut Pasteur de Madagascar, BP 1274-101 Antananarivo-Madagascar.

The resistance of Xenopsylla cheopis from urban area to pyrethroids, to DDT, and their susceptibility to carbamate are known. We have evaluated the susceptibility of X. cheopis collected from three rural localities: Ambodisiarivo (district of Antananarivo Avaradrano), Mandoto (district of Betafo), Analaroa (district of Anjozorobe) in the province of Antananarivo and in Besoa (district of Ambalavao) in the province of Fianarantsoa. The standard WHO protocol was used and four insecticides were tested: deltamethrin 0.025%, cyfluthrin 0.15% (pyrethroids), DDT 4% (organochlorine), propoxur 1% and bendiocarb 0.1% (carbamate). X. cheopis has been shown resistance to DDT 4%, to deltamethrin 0.025% but was susceptible in the rural area around Antananarivo City. They were tolerant to deltamethrin 0.025% and cyfluthrin 0.15% but susceptible to propoxur 0.1% and bendiocarbe 1% in the districts of Betafo and Anjozorobe. In Besoa, X. cheopis was resistant to DDT 4%, tolerant to deltamethrin 0.025% and cyfluthrin 0.15% but susceptible to propoxur 0.1% and bendiocarbe 1%. These results indicate that DDT and pyrethroids can not be recommended any more for the vector control in the rural area around the capital. The use of pyrethroids in the other districts of the central highland must be joined with a X. cheopis susceptibility control. In case of resistance to pyrethroids, carbamates would be proposed to control plague vector in the rural area. The high level of resistance to DDT and pyrethroid in the rural area around the capital confirms the importance of studying the flea population in different area of Madagascar and the possibility of the gene resistance propagation.

PMID: 12463026 [PubMed - indexed for MEDLINE]

From Toxline at Toxnet

JOURNAL OF VECTOR ECOLOGY; 23 (1). 1998. 69-73.

Field evaluation of cyfluthrin and malathion 96 TG ULV spraying at high-rise flats on dengue vectors in Malaysia.


Dep. Biomed. Sci., Fac. Allied Health Sci., Univ. Kebangsaan Malaysia, Kuala Lumpur, Malaysia.

Cyfluthrin (Solfac ULO15) and malathion 96 TG were evaluated against sentinel sugar-fed adults and 4th-instar larvae of Aedes aegypti at high-rise flats in Malaysia by ULV spraying. The impact of both insecticides on field populations of Aedes spp. (Ae. aegypti and Ae. albopictus) larvae were monitored weekly using containers. Both cyfluthrin and malathion 96 TG showed adulticidal effects but cyfluthrin showed more significant larvicidal effect than malathion 96 TG (P<0.05).

From Toxline at Toxnet


The residual effects of the synthetic pyrethroids lambda-cyhalothrin and cyfluthrin against Aedes aegypti (L.) in wooden huts in Malaysia.


Dep. Parasitol. Med. Entomol., Fac. Med., Natl. Univ. Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia.

Lambda-cyhalothrin and cyfluthrin synthetic pyrethroids were evaluated for their residual effect against bloodfed females Aedes aegypti in wooden huts in Malaysia. At a concentration of 0.05 gm ai/m2, 100% knockdown was obtained at 28 days after residual spraying with lambda-cyhalothrin compared to cyfluthrin which did not produce 100% knockdown for more than 1 day posttreatment. However, both pyrethroid seemed to cause high mortalities up to 7 days posttreatment at the concentration of 0.01 gm ai/m2 and 56 days at 0.05 gm ai/m2.

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