Return to 1-chloro-1,1-difluoroethane Index Page

ACTIVITY: Propellent, US EPA List 2 Inert
Structure:

Adverse Effects:
Bone
Cancer - potential
Endocrine: Thyroid
Lung
Tremors
Environmental

Bone (click on for all fluorinated pesticides)

Damske et al. (1978) exposed 20 pregnant CRL:COBS CD (SD) BR rats to 0, 3259, or 9420 ppm HCFC-142b (0, 13,460, or 38,905 mg/cu.m, respectively) for 6 hours/day on gestation days 6-15. Dams were sacrificed on day 20, and the fetuses were weighed, sexed, and examined for external malformations... Some skeletal variations described by the study authors were classified as "commonly encountered" or "unusual skeletal variations", but no further information is given. Reduced ossification was described for several areas, including the interparietal and supraoccipital bones of the skull and the hyoid bone.."
Ref: US EPA IRIS, CASRN 75-68-3.
http://www.fluoridealert.org/pesticides/1-Chloro-1.1-difluoroe.IRIS.htm

Cancer (click on for all fluorinated pesticides)

Two short-term in vitro tests for mutagenicity (Salmonella reverse mutation and BHK21 cell transformation) were conducted on a series of fluorocarbons. Some of these materials (FC22, FC31, FC142b, FC143 and FC143a) were found to be positive in 1 or both of the tests and could therefore be considered as being potentially carcinogenic to animals.
Ref: Longstaff E et al. (1984). Genotoxicity and carcinogenicity of fluorocarbons: Assessment by short-term in vitro tests and chronic exposure in rats. TOXICOL APPL PHARMACOL; 72 (1). 15-31.
From Toxline at TOXNET

Lung (click on for all fluorinated pesticides)

Lester and Greenberg (1950) conducted whole-body exposures in 10 rats (sex and strain unspecified) to 100,000 ppm (413,100 mg/cu.m) for 16 hours/day. All animals died within nine exposures: 6 in 7 days, 2 in 8 days, and 2 in 9 days. All animals were examined grossly, and sections of lung and liver were examined for histopathology. Lungs of all animals showed signs of severe irritation, having extensive consolidation and advanced lobar pneumonia. In a subsequent experiment, five rats were exposed to 10,000 ppm (41,310 mg/cu.m), 16 hours daily for a period of 2 months, with no apparent effects. The lungs of 2/5 of these animals revealed evidence of inflammation, but sufficient information is not given to conclude that this effect was treatment related. These studies have a number of significant experimental (apparently no control animals were used) and reporting deficiencies that preclude their use in quantitative risk assessment.
Ref: US EPA IRIS for 1-Chloro-1,1-difluoroethane CASRN 75-68-3.
http://www.fluoridealert.org/pesticides/1-Chloro-1.1-difluoroe.IRIS.htm

-- RESPIRATORY. ACUTE EXPOSURE. Pulmonary irritation, bronchial constriction, cough, dyspnea, and chest tightness may develop after inhalation. Chronic pulmonary hyperreactivity may occur. Adult respiratory distress syndrome has been reported following acute inhalational exposures. Pulmonary edema is an autopsy finding in fatal cases.
-- Populations at Special Risk: THERE ARE ISOLATED REPORTS OF POISONING FROM EXPOSURE TO FLUOROCARBON PROPELLANTS & SOME STUDIES SHOWING A HIGHER INCIDENCE OF CORONARY HEART DISEASE AMONG HOSPITAL PERSONNEL & REFRIGERANT MECHANICS EXPOSED TO FLUOROCARBONS. ADDITIONAL INVESTIGATION IS REQUIRED TO ESTABLISH CAUSAL RELATIONSHIP BETWEEN FLUOROCARBONS & CARDIOVASCULAR & BRONCHOPULMONARY DISEASES AMONG EXPOSED WORKERS. THE HIGH INCIDENCE OF CANCER AMONG HOSPITAL PERSONNEL REPEATEDLY EXPOSED TO FLUORINE-CONTAINING GENERAL ANESTHETICS RAISES A FUNDAMENTAL NEED TO EXAMINE OTHER FLUOROCARBON-EXPOSED WORKERS FOR SIMILAR EFFECTS. /FLUOROCARBONS/ [Clayton, G.D., F.E. Clayton (eds.) Patty's Industrial Hygiene and Toxicology. Volumes 2A, 2B, 2C, 2D, 2E, 2F: Toxicology. 4th ed. New York, NY: John Wiley & Sons Inc., 1993-1994. 1209]
Ref: TOXNET profile from Hazardous Substances Data Bank for 1-Chloro-1,1-Difluoroethane.
http://www.fluoridealert.org/pesticides/1-Chloro-1,1,-Difluo.TOXNET.htm

Endocrine: Thyroid (click on for all fluorinated pesticides)

Inhalation rat; lowest published toxic concentration: 500 gm/m3/4 hour/4 week- intermittent; Endocrine: Evidence of thyroid hypofunction.
Ref: Toksikologiya Novykh Promyshlennykh Khimicheskikh Veshchestv. Toxicology of New Industrial Chemical Substances. For English translation, see TNICS*. (Izdatel'stvo Meditsina, Moscow, USSR) No.1- 1961-
As cited by The Registery of Toxic Effects of Chemical Substances (RTECS)
http://www.cdc.gov/niosh/rtecs/kh74bad0.html#TPKVAL

Tremors (click on for all fluorinated pesticides)

EARLY ... HUMAN EXPERIENCE INDICATED THAT HIGH VAPOR CONCN (EG, 20%) MAY CAUSE CONFUSION, PULMONARY IRRITATION, TREMORS & RARELY COMA, BUT THAT THESE EFFECTS WERE GENERALLY TRANSIENT & WITHOUT LATE SEQUELAE. ... CAUSE OF DEATH /FROM ABUSE OF FLUOROCARBONS/ IS IN CONSIDERABLE DOUBT. FREEZING OF AIRWAY SOFT TISSUES CAN PROBABLY BE ELIMINATED AS A CAUSE OF DEATH EXCEPT IN CASES WHERE THE PRODUCT WAS SPRAYED DIRECTLY INTO THE MOUTH FROM ITS CONTAINER OR FROM A BALLOON CONTAINING SOME LIQUID. LARYNGEAL SPASM OR EDEMA, OXYGEN DISPLACEMENT, OR SENSITIZATION OF MYOCARDIUM TO ENDOGENOUS CATECHOLAMINES WITH SUBSEQUENT VENTRICULAR FIBRILLATION APPEAR TO BE REASONABLE POSSIBILITIES. /FLUOROCARBON REFRIGERANTS & PROPELLANTS/ [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. II-159]
Ref: TOXNET profile from Hazardous Substances Data Bank for 1-CHLORO-1,1-DIFLUOROETHANE
http://www.fluoridealert.org/pesticides/1-Chloro-1,1,-Difluo.TOXNET.htm