CAS No. 83121-18-0


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Advese Effects

ACTIVITY: Insecticide (benzoylurea)

CAS Name: N-[[(3,5-dichloro-2,4-difluorophenyl)amino]carbonyl]-2,6-difluorobenzamide


Adverse Effects:

Lymph node haemangiomas

Environmental Effects:

Highly toxic to aquatic crustacean invertebrates

Persistent in sediment

A chemical used on salmon farms to rid fish of sea lice. Allegations of damage to small crustaceans and other marine wildlife, which could be crucial to the survival of other species.

Regulatory Information
(only comprehensive for the US)
US EPA Registered: No 
US EPA PC Code: 129048 
Registered use in
(includes only a limited list of countries)

Denmark, Germany, Hungary, Japan, Netherlands, Philippines, Portugal, UK
Africa: Burkina Faso, Cape Verde, Chad, Gambia, Guinea-Bissau, Madagascar, Mali, Mauritania, Niger, Senegal, South Africa

Japan's Maximum Residue Levels (MRLs)

Apple, Apricot, Asparagus, Barley, Broccoli, Brussel sprouts, Buckwheat, Burdock, Button mushroom, Cabbage, Cauliflower, Cherry, Corn, Cucumber, Eggplant, Grape, Grapefruit, Lemon, Lettuce, Lime, Melons, Multiplying onion (inc Shallot), Natsudaidai (whole), Nectarine, Other Cereal grains, Other Citrus fruits, Other Cruciferous vegs, Pear, Peach, Pimento, Plum, Potato, Pumpkin (inc Squash), Quince, Radish, Rice, Rye, Soybeans, Strawberry, Sugar beet, Sweet Potato, Tea, Tomato, Unshu orange, Welsh (inc Leek), Wheat

- Note the very high levels - 20 ppm - for Tea (Green, Black, Oolong, Wulung) 

Other Information
Molecular Formula: C14H6Cl2 F4 N2O2 
Entry Year: 1987  
Manufacturers: Cyanamid
Nutreco ARC Ltd.
Other Names: Calicide
Of special interest:
PAN Data
2002 - Review and synthesis of the environmental impacts of aquaculture. The Scottish Association for Marine Science and Napier University. Scottish Executive Central Research Unit. 
April 25, 2002 - Leaked government report reveals fish farm damage. Press release from Friends of the Earth, Scotland. 
July 1999 - Calicide (Teflubenzuron) - Authorisation for use as an in- feed sea lice treatment in marine cage salmon farms. Risk Assessment, EQS and Recommendations. Policy No. 29. Scottish Environment Protection Agency (SEPA), Fish Farming Advisory Group. Also available at http://www.sepa.org.uk/policies/pdf/29.pdf 
January 1999 - Summary Report (Part 2). Committee for Veterinary Medicinal Products. The European Agency for the Evaluation of Medicinal Products. See also Part 1 of the report published in 1997 at http://www.emea.eu.int/pdfs/vet/mrls/022197en.pdf 
Report that details metabolites, mechanism of action, and residue levels reported from several different countries at http://www.fao.org/ag/agp/agpp/pesticid/jmpr/Download/96/tefluben.pdf 
Pesticide Residues in Food. FAO & WHO report - 1996. 
Experimental Insect Growth Regulator. Article: Fire Ants: a look at new and old approaches to control. By Sean Adams - USDA ARS News and Information. January 30, 1997. 
Glossary of Pesticide Chemicals, October 2001. A listing of pesticides subject to analysis of residues in foods and feeds by the US Food and Drug Administration.  

Leaked Report Claims Toxins Are Hitting Marine Food Chain Fish Farming Today

Fish Farming Today
Published on: April 25, 2002

TOXIC chemicals used on salmon farms could be killing off key elements of the marine food chain, according to a report leaked to a leading scientific magazine.

New Scientist magazine has obtained a copy of a 178-page report which forms part of the ongoing 4 million study into the industry, which was launched by the UK government in 1999. In the leaked document it is alleged that chemicals such as cypermethrin, azamethiphos or teflubenzuron are damaging small crustaceans and other marine wildlife, which could be crucial to the survival of other species. These chemicals are often used by farmers to rid fish of sea lice.

The report also claims that many fish farmers seriously hampered the researchers in their efforts to collect information. Project leader Kenny Black from Dunstaffnage Marine Laboratory, which has been carrying out much of the research, described problems in getting access to sites and information as "very frustrating".

Friends of the Earth, who have campaigned against the industry for many years, welcomed the report. Chief executive Kevin Dunion said: "These worrying findings suggest that the impact of salmon farming may not be localised, as the industry and authorities have so far claimed. Despite being withheld from the public these findings must be passed to the current Parliamentary inquiry into the aquaculture industry."

But the director at Dunstaffnage, Graham Shimmield, stresses that the research is still in progress and that the impact may not be as large as some have suggested.

"Laboratory experiments so far suggest that fish-farm chemicals may have an effect," he said. "The challenge now is to quantify that effect."

Big Catch - Fish farming is flourishing at the expense of other marine life

From New Scientist 27 April 2002.

TOXIC chemicals used by salmon farms could be killing off tiny animals that are vital to the marine food chain, scientists warn in a confidential report for the British government leaked to New Scientist.

Salmon farming is one of the world's fastest growing food production industries. For the first time, the total amount of Atlantic salmon reared in cages in Norway, Chile, Scotland, Canada and elsewhere is expected to top one million tonnes this year.

But as the industry has grown, so have concerns about the pollution, disease and genetic contamination it may spread. Now, evidence from one of the biggest scientific investigations to date suggests that the pesticides applied at hundreds of salmon farms may be harming the marine environment.

The fish are fed or bathed in cypermethrin, azamethiphos or teflubenzuron to kill the sea lice that plague them. The lice damage the health of the fish, and in turn the salmon farming business. But shellfish farmers and environmentalists have long suspected that the chemicals could be harming other marine wildlife.

These fears prompted the British government to launch a £750,000 study in 1999, involving regulatory agencies, marine laboratories and the salmon farming industry. New Scientist has seen the 178-page second annual progress report of this study, dated April 2001.

The report includes the interim results of a study by the Plymouth Marine Laboratory, which surveyed small invertebrates around salmon farms in Loch Sunart and Loch Craignish on the west coast of Scotland. The researchers found a drop in the number of nematode worms in the sediment close to the fish farms. They were also worried about "the almost complete absence" of copepods, tiny crustaceans that are an important source of food for young fish. Although this could be partly explained by poor sampling, they believe it "suggests the possibility of a large-scale effect that may be related to the use of chemicals on the fish farms".

Lab experiments at the Dunstaffnage Marine Laboratory near Oban back this up. They show that the chemicals either kill or deform copepods at concentrations as low as 100 nanograms a litre. So far, however, the Dunstaffnage researchers have not been able to find the effect in the wild.

In the past, the research effort was hampered by a lack of cooperation from fish farmers. Dunstaffnage 's project leader, Kenny Black, described this as "very frustrating" in the leaked report. Now, though, relations are said to be much improved.

The salmon industry 's critics have seized upon the new findings. Friends of the Earth Scotland says they suggest that salmon farming is having a much wider impact than previously realised. "This report reveals that salmon farming is a very dirty business," adds Alan Berry, a former shellfish farmer who voiced some of the original fears.

But Dunstaffnage 's director, Graham Shimmield, stresses that the research is still in progress. "Laboratory experiments so far suggest that fish-farm chemicals may have an effect," he says. "The challenge now is to quantify that effect." He cautions that the impact on marine wildlife may not be as large as many critics suggest.
Rob Edwards

US Federal Register
August 1993

-- FR Doc. 93-18589 Filed 8-3-93; 8:45 am Filing.
Initial Filing of Pesticide Petition: Teflubenzuron 1. PP 3E4209. Biologic, Inc., 11 Lake Ave. Extension, Danbury, CT 06811, has submitted to EPA a petition for the insect growth regulator teflubenzuron technical to establish an import tolerance for various agricultural commodities as follows:
cabbage at .4 ppm
pome fruits at .7 ppm
potatoes at .05 ppm
meat, meat byproducts, fat, kidney, and liver of cattle, goats, hogs, horses, and sheep at .01 ppm
meat, meat byproducts, fat, kidney, and liver of poultry at .05 ppm
eggs at .05 ppm

milk at .01 ppm.

Fluoride Action Network | Pesticide Project | 315-379-9200 | pesticides@fluoridealert.org