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Dichlorofluoromethane. TOXNET profile from Hazardous Substances Data Base.


See for Updates: http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB

DICHLOROFLUOROMETHANE
CASRN: 75-43-4
For other data, click on the Table of Contents

Human Health Effects:

Human Toxicity Excerpts:

IN HIGH CONCN, IT MAY CAUSE CENTRAL NERVOUS DEPRESSION.
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. II-159]**PEER REVIEWED**

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]**PEER REVIEWED**

Although toxicity due to acute inhalation is low, CFC-21 is appreciably more toxic than related difluorinated methanes such as dichlorodifluoromethane or chlorodifluoromethane. The chronic toxicity of CFC-21 is markedly different from these compounds, and appears to be more similar to chloroform.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**

Manufacturing processes use hydrofluoric acid from fluorospar in the production of most fluorine containing organic compounds. Some processes use carbon tetrachloride from carbon disulfide or as a co-product of perchloroethylene and chlorination of propylene, or chloroform from chlorination of methanol. At the outset, it is important to emphasize that most fluorine containing compounds (CFC, HCFC, and HFC) are less toxic than any of the process materials used in their manufacture. The major hazards relate primarily to the inadvertent release of hydrofluoric acid or carbon tetrachloride, rather than to the manufactured final product. /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. 1194]**PEER REVIEWED**

A SPECIAL CLASS OF CHEMICALS SUBJECT TO ABUSE BY INHALATION ARE THE FLUOROHYDROCARBONS, SUCH AS ... DICHLOROFLUOROMETHANE ... THE "SNIFFING" OF SUCH AEROSOL SPRAYS IS HAZARDOUS PRACTICE. ... 110 "SUDDEN SNIFFING DEATHS" /HAVE BEEN IDENTIFIED/ ... IN EACH CASE THE VICTIM SPRAYED THE AEROSOL INTO A PLASTIC BAG, INHALED THE CONTENTS, BECAME EXCITED, RAN 90 M OR SO, COLLAPSED, & DIED. NECROPSY FINDINGS WERE LARGELY NEGATIVE ... ALTHOUGH AMOUNT OF PROPELLANT ABSORBED INTO BLOOD FROM USE OF HAIRSPRAY, COSMETIC, HOUSEHOLD, & MEDICATED AEROSOLS MUST VARY WITH CIRCUMSTANCES, PHYSICIAN IS ADVISED TO COUNSEL ... PATIENT ON POTENTIAL DANGERS, PARTICULARLY FROM THEIR USE IN POORLY VENTILATED CONFINED AREAS. /FLUOROHYDROCARBONS/
[Goodman, L.S., and A. Gilman. (eds.) The Pharmacological Basis of Therapeutics. 5th ed. New York: Macmillan Publishing Co., Inc., 1975. 910]**PEER REVIEWED**

EXCESSIVE SKIN CONTACT WITH LIQUID FLUOROCARBONS SHOULD BE MINIMIZED TO PREVENT DEFATTING OF SKIN ... /FLUOROCARBONS/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 897]**PEER REVIEWED**

... LOWER IN TOXICITY THAN CORRESPONDING CHLORINATED OR BROMINATED HYDROCARBONS. ... ASSOC WITH GREATER STABILITY OF C-F BOND; & PERHAPS ALSO WITH LOWER LIPID SOLUBILITY ... TOXIC EFFECTS FROM REPEATED EXPOSURE, SUCH AS LIVER OR KIDNEY DAMAGE, HAVE NOT BEEN PRODUCED BY FLUOROMETHANES ... /FLUOROCARBONS/
[International Labour Office. Encyclopaedia of Occupational Health and Safety. 4th edition, Volumes 1-4 1998. Geneva, Switzerland: International Labour Office, 1998.,p. 104.184]**PEER REVIEWED**

... ATTENTION /HAS BEEN DRAWN/ TO PROMINENT CARDIOTOXIC EFFECTS, MANIFESTED IN ARRHYTHMIAS, THAT ARE ASSOC WITH PULMONARY EXPOSURE TO ... FLUOROCARBON 21 ... TACHYCARDIA, MYOCARDIAL DEPRESSION, & HYPOTENSION HAVE BEEN DESCRIBED.
[Hamilton, A., and H. L. Hardy. Industrial Toxicology. 3rd ed. Acton, Mass.: Publishing Sciences Group, Inc., 1974. 293]**PEER REVIEWED**

Inhalation of vapors should be avoided. Forced air ventilation at the level of vapor concentration together with the use of individual breathing devices with independent air supply will minimize the risk of inhalation.
[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. 1195]**PEER REVIEWED**

The toxicity of Chlorofluorocarbons (CFCs) had been considered to be low; it is absorbed via the lungs and undergoes little subsequent biotransformation. In the United States when sudden unexplained deaths of aerosol "sniffers" were reported they were considered to be possibly due to cardiac arrhythmias induced by the CFC propellants. /CFCs/
[Rom, W.N. (ed.). Environmental and Occupational Medicine. 2nd ed. Boston, MA: Little, Brown and Company, 1992. 1299]**PEER REVIEWED**

Skin, Eye and Respiratory Irritations:

Refrigerant 21 vapor is respiratory irritant ...
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 1]**PEER REVIEWED**

On contact with liquid /dichlorofluoromethane/: frostbite
[International Labour Office. Encyclopaedia of Occupational Health and Safety. 4th edition, Volumes 1-4 1998. Geneva, Switzerland: International Labour Office, 1998.,p. 104.188]**PEER REVIEWED**


Medical Surveillance:

Consider the points of attack /respiratory system, lung, cardiovascular system/ in preplacement and periodic physical examinations.
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 325]**PEER REVIEWED**


Populations at Special Risk:

IT IS POSSIBLE THAT PT WITH CARDIAC OR RESP DISORDERS MAY PROVE ESP SUSCEPTIBLE. /FLUOROCARBONS/
[Goodman, L.S., and A. Gilman. (eds.) The Pharmacological Basis of Therapeutics. 5th ed. New York: Macmillan Publishing Co., Inc., 1975. 910]**PEER REVIEWED**


Probable Routes of Human Exposure:

Inhalation, ingestion, eye and skin contact.
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 325]**PEER REVIEWED**

Occupational exposure to manufactured fluorocarbons occurs in the manufacture, use, servicing, and disposal of refrigeration units, solvent applications, and plastic foam blowing. Cylinder packers and shippers; occassional high exposure to tank truck and tank car fillers; maintenance operators; lab analysts. /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. 1195]**PEER REVIEWED**

NIOSH (NOES Survey 1981-1983) has statistically estimated that 12,182 workers (1,640 of these are female) are potentially exposed to dichlorofluoromethane in the US(1). Occupational exposure to dichlorofluoromethane may occur through inhalation of this compound at workplaces where dichlorofluoromethane is produced or used(SRC).
[(1) NIOSH; National Occupational Exposure Survey (NOES) (1983)]**PEER REVIEWED**

Personal air samples were collected from firefighters in Buffalo, NY while responding to 3 wood-frame building structure fires and one car fire; the range of dichlorofluoromethane detected in the breathing space varied from 0.67 to 12.1 ppm(1).
[(1) Brandt-Rauf PW et al; Br J Ind Med 45: 606-12 (1988)]**PEER REVIEWED**


Body Burden:

Dichlorofluoromethane was found in the expired air of 2 of 8 male volunteers; the amounts exhaled in these two subjects were 0.14 and 0.062 fg/hr(1). Dichlorofluoromethane was detected, but not quantified, in the expired air of a nonsmoking population of 62 males and females, suburban and urban residents(2). The percentage of subjects whose breath contained dichlorofluoromethane was not reported.
[(1) Conkle JP et al; Arch Environ Health 30: 290-5 (1975) (2) Krotoszynski BK, O'Neill HJ; J Environ Sci Health A17: 855-83 (1982)]**PEER REVIEWED**


Emergency Medical Treatment:

Emergency Medical Treatment:

EMT Copyright Disclaimer:
Portions of the POISINDEX(R) database are provided here for general reference. THE COMPLETE POISINDEX(R) DATABASE, AVAILABLE FROM MICROMEDEX, SHOULD BE CONSULTED FOR ASSISTANCE IN THE DIAGNOSIS OR TREATMENT OF SPECIFIC CASES. Copyright 1974-1998 Micromedex, Inc. Denver, Colorado. All Rights Reserved. Any duplication, replication or redistribution of all or part of the POISINDEX(R) database is a violation of Micromedex' copyrights and is strictly prohibited.

The following Overview, *** FLUORINATED HYDROCARBONS ***, is relevant for this HSDB record chemical.

Life Support:
  o   This overview assumes that basic life support measures
      have been instituted.                           
Clinical Effects:
  SUMMARY OF EXPOSURE
   0.2.1.1 ACUTE EXPOSURE
     o   LOW CONCENTRATION - Inhalations such as those caused by
         leaking air conditioners or refrigerators usually
         result in transient eye, nose, and throat irritation.
         Palpitations,  light headedness, and headaches are also
         seen.
     o   HIGH CONCENTRATION - Inhalation associated with
         deliberate abuse, or spills or industrial use occurring
         in poorly ventilated areas has been associated with
         ventricular arrhythmias, pulmonary edema and sudden
         death.
  HEENT
   0.2.4.1 ACUTE EXPOSURE
     o   EYES - Eye irritation occurs with ambient exposure.
         Frostbite of the lids may be severe.  Ocular
         instillation results in corneal burns in rabbits.
     o   NOSE - Nasal irritation occurs with ambient exposure.
     o   THROAT - Irritation occurs.  Frostbite of the lips,
         tongue, buccal  mucosa and hard palate developed in a
         man after deliberate inhalation.
  CARDIOVASCULAR
   0.2.5.1 ACUTE EXPOSURE
     o   Inhalation of high concentrations is associated with
         the development of refractory ventricular arrhythmias
         and sudden death, believed to be secondary, primarily,
         to myocardial sensitization to endogenous
         catecholamines.  Some individuals may be susceptible to
         arrhythmogenic effects at lower concentrations.
  RESPIRATORY
   0.2.6.1 ACUTE EXPOSURE
     o   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.
  NEUROLOGIC
   0.2.7.1 ACUTE EXPOSURE
     o   Headache, dizziness, and disorientation are common.
         Cerebral edema may be found on autopsy.  A syndrome of
         impaired psychomotor speed, impaired memory and
         learning, and emotional lability has been described in
         workers with chronic occupational exposure to
         fluorinated hydrocarbons.
  GASTROINTESTINAL
   0.2.8.1 ACUTE EXPOSURE
     o   Nausea may develop.  Ingestion of a small amount of
         trichlorofluoromethane resulted in necrosis and
         perforation of the stomach in one patient.
  HEPATIC
   0.2.9.1 ACUTE EXPOSURE
     o   Jaundice and mild elevations in transaminases may
         develop after  inhalational exposure or ingestion.
         Hepatocellular coagulative necrosis has been observed
         on liver biopsy.
  DERMATOLOGIC
   0.2.14.1 ACUTE EXPOSURE
     o   Dermal contact may result in defatting, irritation or
         contact dermatitis.  Severe frostbite has been reported
         as an effect of freon exposure.  Injection causes
         transient pain, erythema and edema.
  MUSCULOSKELETAL
   0.2.15.1 ACUTE EXPOSURE
     o   Rhabdomyolysis has been reported in a worker
         susceptible to malignant hyperthermia after exposure to
         fluorinated hydrocarbons and also following intentional
         freon inhalation.  Compartment syndrome is a rare
         complication of severe exposure.
  REPRODUCTIVE HAZARDS
    o   Dichlorodifluoromethane was not teratogenic in rats and
        rabbits.
    o   The reproductive effects of 1,1,1,2-tetrafluoroethane
        were studied in rats.  No adverse effects on
        reproductive performance was noted or on the
        development, maturation or reproductive performance of
        up to two successive generations.
  GENOTOXICITY
    o   The hydrochlorofluorocarbons, HCFC-225ca and HCFC-225cb,
        were not mutagenic in the Ames reverse mutation assay,
        or clastogenic in the chromosomal  aberration assay with
        Chinese hamster lung cells.  Neither induced unscheduled
        DNA synthesis in liver cells.  Both of these agents were
        clastogenic in the chromosomal aberration assay with
        human lymphocytes.                        
Laboratory:
  o   Fluorinated hydrocarbons plasma levels are not clinically
      useful.
  o   No specific lab work (CBC, electrolyte, urinalysis) is
      needed unless otherwise indicated.
  o   Obtain baseline pulse oximetry or arterial blood gas
      analysis.
Treatment Overview:
  SUMMARY EXPOSURE
    o   Monitor EKG and vital signs carefully.  Cardiopulmonary
        resuscitation may be necessary.
  ORAL EXPOSURE
    o   These substances may cause frostbite to the upper airway
        and gastrointestinal  tract after ingestion.  Administer
        oxygen and manage airway as clinically  indicated.
        Emesis, activated charcoal, and gastric lavage are not
        recommended.
  INHALATION EXPOSURE
    o   MONITOR ECG and VITAL SIGNS carefully.  Cardiopulmonary
        resuscitation may be necessary.  AVOID CATECHOLAMINES.
    o   PROVIDE A QUIET CALM ATMOSPHERE to prevent adrenaline
        surge if the patient is seen before the onset of cardiac
        arrhythmias.  Minimize physical exertion.
    o   MONITOR pulse oximetry or arterial blood gases.
    o   Provide symptomatic and supportive care.
    o   These substances may cause frostbite of the upper airway
        with the potential for  severe edema.  Administer oxygen
        and manage airway early in patients with evidence  of
        upper airway injury.
    o   PULMONARY EDEMA (NONCARDIOGENIC):  Maintain ventilation
        and oxygenation and evaluate with frequent arterial
        blood gas or pulse oximetry monitoring.  Early use of
        PEEP and mechanical ventilation may be needed.
  EYE EXPOSURE
    o   DECONTAMINATION:  Irrigate exposed eyes with copious
        amounts of tepid water for at least 15 minutes.  If
        irritation, pain, swelling, lacrimation, or photophobia
        persist, the patient should be seen in a health care
        facility.
    o   Ophthamologic consultation should be obtained in any
        symptomatic patients.
  DERMAL EXPOSURE
    o   DECONTAMINATION:  Remove contaminated clothing and wash
        exposed  area thoroughly with soap and water.  A
        physician may need to  examine the area if irritation or
        pain persists.
    o   If frostbite has occurred, refer to dermal treatment in
        the main body of this document for rewarming.
Range of Toxicity:
  o   Freons are very toxic when inhaled in high concentrations
      and/or for extended periods.  At lower concentrations or
      brief exposure, freons may cause transient eye, nose, and
      throat irritation.  There is significant interpatient
      variation and it is difficult to predict which patient
      will exhibit symptoms following exposure.            

[Rumack BH: POISINDEX(R) Information System. Micromedex, Inc., Englewood, CO, 2001; CCIS Volume 110, edition exp November, 2001. Hall AH & Rumack BH (Eds):TOMES(R) Information System. Micromedex, Inc., Englewood, CO, 2001; CCIS Volume 110, edition exp November, 2001.] **PEER REVIEWED**

Antidote and Emergency Treatment:

IF INHALATION OCCURS, EPINEPHRINE OR OTHER SYMPATHOMIMETIC AMINES & ADRENERGIC ACTIVATORS SHOULD NOT BE ADMIN SINCE THEY WILL FURTHER SENSITIZE HEART TO DEVELOPMENT OF ARRHYTHMIAS. /FLUOROCARBONS/
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 3101]**PEER REVIEWED**

Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations as needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Minimize physical activity and provide a quiet atmosphere. Monitor for pulmonary edema and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. Rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . Treat frostbite with rapid rewarming techniques ... . /Chlorinated fluorocarbons (CFCs) and related compounds/
[Bronstein, A.C., P.L. Currance; Emergency Care for Hazardous Materials Exposure. 2nd ed. St. Louis, MO. Mosby Lifeline. 1994. 192]**PEER REVIEWED**

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious or in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . Treat seizures with diazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Chlorinated fluorocarbons (CFCs) and related compounds/
[Bronstein, A.C., P.L. Currance; Emergency Care for Hazardous Materials Exposure. 2nd ed. St. Louis, MO. Mosby Lifeline. 1994. 192]**PEER REVIEWED**


Animal Toxicity Studies:

Non-Human Toxicity Excerpts:

WHEN GUINEA PIGS WERE EXPOSED UP TO 2 HR ... @ CONCN RANGING FROM 1.2-10.2% BY VOL (12,000-102,000 PPM), CONCN OF 5.2% & HIGHER PRODUCED SIGNS OF IRRITATION, TREMORS, INCOORDINATION, & IRREGULAR BREATHING.
[American Conference of Governmental Industrial Hygienists. Documentation of the Threshold Limit Values for Substances in Workroom Air. Third Edition, 1971. Cincinnati, Ohio: AmericanConference of Governmental Industrial Hygienists, 1971. (Plus supplements to 1979) 81]**PEER REVIEWED**

/GUINEA PIGS/ ... EXPOSED /UP TO 2 HR/ @ CONCN OF 10.2% DIED &, ON AUTOPSY, CONGESTED LUNGS, CONGESTED KIDNEYS, CONGESTED LIVER, DISCOLORED SPLEEN, & HIGHLY CONTRACTED HEART WERE FOUND.
[American Conference of Governmental Industrial Hygienists. Documentation of the Threshold Limit Values for Substances in Workroom Air. Third Edition, 1971. Cincinnati, Ohio: AmericanConference of Governmental Industrial Hygienists, 1971. (Plus supplements to 1979) 81]**PEER REVIEWED**

Exposure to 100,000 ppm killed rats and guinea pigs within an hour. Clinical signs included loss of coordination, tremors ... /CNS depression/ and prostration; limited pathologic examination, partly obscured by post-mortem change, revealed lung and liver changes.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**

Repeated exposures have produced marked hepatic damage or failure. Ten rats exposed at 10,000 ppm CFC-21, 6 hours per day, 5 days per week for 2 weeks, all survived, but their livers were grossly pale and heavy. Histopathologic examination showed centrilobular necrosis with related changes. In comparable 90-day series of exposure at 5000 and 1000 ppm levels, rats showed bilateral hair loss and excessive mortality (20 of 54 died at 1000 ppm, 15 of 54 at 5000 ppm). Four dogs exposed at both levels showed weight loss. Cirrhosis was evident in rats exposed at both levels, but with dogs histopathologic changes in the liver were mild and evident only at the 5000 ppm.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**

CFC-21 has produced "pre-implantation" loss in pregnant rats exposed at 10,000 ppm. After exposure for 6 hr daily, on days 6 to 15 of gestation, 15 or 25 pregnant females had no viable fetuses or implantation sites on the uterine wall. Pregnancy outcome and fetal development in the other 10 rats were unaffected.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**

When admin alone to anesthetized mice at concn of 100,000 ppm, CFC-21 induced arrhythmia and sensitized the heart to epinephrine. Tachycardia with hypotension was observed in both monkeys and dogs that were anesthetized and exposed at 50,000-100,000 ppm. Bronchoconstriction was noted at 25,000 ppm.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**

EARLY ANIMAL ... 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. /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]**PEER REVIEWED**

... Chlorofluorocarbons could sensitize the canine myocardium to adrenaline, resulting in serious cardiac arrhythmias. /CFCs/
[Rom, W.N. (ed.). Environmental and Occupational Medicine. 2nd ed. Boston, MA: Little, Brown and Company, 1992. 1300]**PEER REVIEWED**

Non-Human Toxicity Values:

LC50 Rat /inhalation/ 49,900 ppm/4 hr exposure.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**


TSCA Test Submissions:

A subchronic inhalation toxicity study was conducted with groups of male (35) and female (35) albino rats (strain not reported) receiving whole body exposure to dichloromonofluoromethane at a nominal concentration of 0, 50, 150 or 500ppm in a dynamic air flow chamber for 6 hours per day, five days per week for approximately 90 days. On day 45 and day 90, 5 animals per sex and 20 animals per sex, respectively were sacrificed. The remaining animals were observed for an additional 30 days and then sacrificed. Four high dose males were found dead during the exposure period and one female and six males from the high dose group were found dead during the recovery period. High dose rats were observed to have statistically significant (p < 0.01) lower body weights than controls during the exposure period, but were comparable after the 30 day recovery period. Hematology, clinical chemistry and urine analysis values were similar between all dosed animals and control animals, with the exception of a slightly higher total blood leukocytes counts and elevated mean SAP and SGPT values for high dose animals at approximately 45, 90 and 120 days. A dose related increase in urine fluoride levels was also observed. Histopathology evaluation of treated animals revealed portal cirrhosis of the liver, interstitial edema of the pancreas and degeneration of the seminiferous epithelium. Three cases of leukemia were observed in high dose male rats.
[Industrial Bio-Test Laboratories; Subacute Inhalation Toxicity Study with Genetron 21 in Albino Rats, (1979), EPA Document No. FYI-OTS-0779-0045, Fiche No. OTS0000045-0 ] **UNREVIEWED**


Metabolism/Pharmacokinetics:

Metabolism/Metabolites:

The pharmacokinetics of dichlorofluoromethane (CFC-21) ... /was/ investigated in rats. Male Wistar rats were placed in a desiccator containing soda lime and connected to a pressureless oxygen supply. ... Test substances were monitored in the gas phase by gas chromatography. Animals were injected intraperitoneally with CFC-21 ... and placed in the closed chamber. Some animals were pretreated with 80 mg/kg phenobarbitol followed by 3 days of treatment with 0.1% phenobarbital in drinking water or with 200 mg/kg DDT 1 week before the experiments. Exhalation curves were examined using a standard procedure. Kinetic parameters of metabolic transformation after inhalation were calculated based on two compartment open pharmacokinetic models. ... Injected CFC-21 was only partially exhaled and then showed a consistent decline. Total clearance ... /value was/ ... calculated as 4,400 ml/3 hr/kg ... for CFC-21. ... The clearance from an unoccupied system was approximately ... 250 mg/hr/kg for ... CFC-21. ... The static equillibrium control constant was ... 6.0 for ... CFC-21.
[Peter H et al; Archives of Toxicology 58 (4): 282-83 (1986)]**PEER REVIEWED**


Absorption, Distribution & Excretion:

... MAIN FACTOR AFFECTING FATE OF FLUOROCARBONS IS BODY FAT, WHERE THEY ARE CONCENTRATED & SLOWLY RELEASED INTO BLOOD @ CONCN THAT SHOULD NOT CAUSE ANY RISK OF CARDIAC SENSITIZATION. /FLUOROCARBONS/
[National Research Council. Drinking Water & Health Volume 1. Washington, DC: National Academy Press, 1977. 781]**PEER REVIEWED**

... Both trichlorofluoromethane and dichlorofluoromethane admin as high acute inhalation dosages were expired unchanged by dogs and rabbits.
[The Chemical Society. Foreign Compound Metabolism in Mammals. Volume 4: A Review of the Literature Published during 1974 and 1975. London: The Chemical Society, 1977. 242]**PEER REVIEWED**

There is a significant accumulation of propellants in brain, liver and lung compared to blood levels, signifying a tissue distribution of fluorocarbons similar to that of chloroform. /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. 1203]**PEER REVIEWED**

Absorption of fluorocarbons is much lower after oral ingestion (35-48 times) than after inhalation. ... The lung generally have the highest fluorocarbon concn on autopsy. /Fluorocarbons/
[Ellenhorn, M.J. and D.G. Barceloux. Medical Toxicology - Diagnosis and Treatment of Human Poisoning. New York, NY: Elsevier Science Publishing Co., Inc. 1988. 884]**PEER REVIEWED**


Interactions:

IF INHALATION OCCURS, EPINEPHRINE OR OTHER SYMPATHOMIMETIC AMINES & ADRENERGIC ACTIVATORS SHOULD NOT BE ADMIN SINCE THEY WILL FURTHER SENSITIZE HEART TO DEVELOPMENT OF ARRHYTHMIAS. /FLUOROCARBONS/
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 3101]**PEER REVIEWED**

Adrenaline should not be admin, because of the possibility of inducing cardiac arrhythmias or arrest. /Flourocarbons/
[International Labour Office. Encyclopaedia of Occupational Health and Safety. 4th edition, Volumes 1-4 1998. Geneva, Switzerland: International Labour Office, 1998.,p. 104.185]**PEER REVIEWED**


Pharmacology:

Interactions:

IF INHALATION OCCURS, EPINEPHRINE OR OTHER SYMPATHOMIMETIC AMINES & ADRENERGIC ACTIVATORS SHOULD NOT BE ADMIN SINCE THEY WILL FURTHER SENSITIZE HEART TO DEVELOPMENT OF ARRHYTHMIAS. /FLUOROCARBONS/
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 3101]**PEER REVIEWED**

Adrenaline should not be admin, because of the possibility of inducing cardiac arrhythmias or arrest. /Flourocarbons/
[International Labour Office. Encyclopaedia of Occupational Health and Safety. 4th edition, Volumes 1-4 1998. Geneva, Switzerland: International Labour Office, 1998.,p. 104.185]**PEER REVIEWED**


Environmental Fate & Exposure:

Environmental Fate/Exposure Summary:

Dichlorofluoromethane's production and use may result in its release to the environment through various waste streams. Per 40CFR82, which implements the Montreal Protocol, dichlorofluoromethane will no longer be produced or imported in the United States after 2015, except for its use as a refrigerant in equipment manufactured before 1/1/2020; no production or importing after 1/1/2030 will be allowed. If released to air, a vapor pressure of 1.36X10+03 mm Hg at 25 deg C indicates dichlorofluoromethane will exist solely in the gas-phase in the ambient atmosphere. Gas-phase dichlorofluoromethane will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 1.5 years. If released to soil, dichlorofluoromethane is expected to have very high mobility based upon an estimated Koc of 35. Volatilization from moist soil surfaces will occur rapidly based upon an estimated Henry's Law constant of 1.08X10-02 atm-cu m/mole. Volatilization from dry soil surfaces will occur rapidly based upon a vapor pressure of 1.36X10+03. Complete aerobic biodegradation of dichlorofluoromethane in soil by methanotrophic bacteria in 5-19 days has been reported. Approximately 93% and 50% degradation of dichlorofluoromethane in anoxic sediment samples collected from freshwater and saltwater wetlands occurred within 27 and 43 days, respectively, at 20 degrees. If released into water, dichlorofluoromethane is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 1 and 97 hours, respectively. An estimated BCF of 35 suggests the potential for bioconcentration in aquatic organisms is low. A half-life of approximately 230 years for the neutral and alkaline hydrolysis reactions for dichlorofluoromethane indicates hydrolysis will not be an important fate process. (SRC)
**PEER REVIEWED**


Probable Routes of Human Exposure:

Inhalation, ingestion, eye and skin contact.
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 325]**PEER REVIEWED**

Occupational exposure to manufactured fluorocarbons occurs in the manufacture, use, servicing, and disposal of refrigeration units, solvent applications, and plastic foam blowing. Cylinder packers and shippers; occassional high exposure to tank truck and tank car fillers; maintenance operators; lab analysts. /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. 1195]**PEER REVIEWED**

NIOSH (NOES Survey 1981-1983) has statistically estimated that 12,182 workers (1,640 of these are female) are potentially exposed to dichlorofluoromethane in the US(1). Occupational exposure to dichlorofluoromethane may occur through inhalation of this compound at workplaces where dichlorofluoromethane is produced or used(SRC).
[(1) NIOSH; National Occupational Exposure Survey (NOES) (1983)]**PEER REVIEWED**

Personal air samples were collected from firefighters in Buffalo, NY while responding to 3 wood-frame building structure fires and one car fire; the range of dichlorofluoromethane detected in the breathing space varied from 0.67 to 12.1 ppm(1).
[(1) Brandt-Rauf PW et al; Br J Ind Med 45: 606-12 (1988)]**PEER REVIEWED**


Body Burden:

Dichlorofluoromethane was found in the expired air of 2 of 8 male volunteers; the amounts exhaled in these two subjects were 0.14 and 0.062 fg/hr(1). Dichlorofluoromethane was detected, but not quantified, in the expired air of a nonsmoking population of 62 males and females, suburban and urban residents(2). The percentage of subjects whose breath contained dichlorofluoromethane was not reported.
[(1) Conkle JP et al; Arch Environ Health 30: 290-5 (1975) (2) Krotoszynski BK, O'Neill HJ; J Environ Sci Health A17: 855-83 (1982)]**PEER REVIEWED**


Natural Pollution Sources:

Emissions of dichlorofluoromethane have been reported from volcanos(1).
[(1) Graedel TE; Chemical Compounds in the Atmosphere NY, NY: Academic Press (1978)]**PEER REVIEWED**


Artificial Pollution Sources:

... Dichlorofluoromethane (FC-21) ... appears as a contaminant of commercially available FC 22.
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 3096]**PEER REVIEWED**

Dichlorofluoromethane may be released to the environment during its production, transport, storage, and use as a refrigerant, solvent, propellant, and fire extinguishing agent(1,3). When used as a refrigerant, solvent, or aerosol propellant, dichlorofluoromethane will be eventually lost to the atmosphere unless it is captured and recycled(SRC). Per 40CFR82, which implements the Montreal Protocol, dichlorofluoromethane will no longer be produced or imported in the United States after 2015, except for its use as a refrigerant in equipment manufactured before 1/1/2020; no production or importing after 1/1/2030 will be allowed(4).
[(1) Hawley GG; Condensed Chem Dictionary 10th ed NY: Von Nostrand Reinhold (1981) (2) Graedel TE; Chemical Compounds in the Atmosphere, NY: Academic Press (1978) (3) Council on Environmental Quality; Fluorocarbons and the environment. June 1975 (1975) (4) Code of Federal Regulations; Significant New Alternatives Policy Program (SNAP). 40CFR82.170 (2000)]**PEER REVIEWED**


Environmental Fate:

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 35(SRC), determined from a measured log Kow of 1.55(2) and a regression-derived equation(3), indicates that dichlorofluoromethane is expected to have very high mobility in soil(SRC). Volatilization of dichlorofluoromethane from moist soil surfaces is expected to occur rapidly(SRC) given an estimated Henry's Law constant of 1.08X10-02 atm-cu m/mole(SRC), derived from its vapor pressure, 1.36X10+03 mm Hg(4), and water solubility, 1.88X10+04 mg/l(5).
[(1) Swann RL et al; Res Rev 85: 17-28 (1983) (2) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Heller SR, consult. ed., Washington, DC: Amer Chem Soc p. 3 (1995) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 4-9 (1990) (4) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals: Data Compilation Supplement 6 Design Institute for Physical Property Data American Institute of Chemical Engineers NY, NY: Hemisphere Publishing Corp (1989) (5) Horvath AL; Halogenated Hydrocarbons: Solubility-Miscibility With Water NY, NY: Marcel-Dekker, Inc p. 649 (1982)]**PEER REVIEWED**

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 35(SRC), determined from a measured log Kow of 1.55(2) and a regression-derived equation(3), indicates that dichlorofluoromethane is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 1.08X10-02 atm-cu m/mole derived from its vapor pressure, 1.36X10+03 mm Hg(4), and water solubility, 1.88X10+04 mg/l(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 1 and 97 hours, respectively(SRC). According to a classification scheme(6), from its log Kow of 1.55(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low. Rate constants for the neutral and alkaline hydrolysis reactions for dichlorofluoromethane are 2.1X10-10 and 5.4X10-09 L/mole-min, respectively(8); these rates correspond to a half-life of approximately 230 years(8).
[(1) Swann RL et al; Res Rev 85: 17-28 (1983) (2) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Heller SR, consult. ed., Washington, DC: Amer Chem Soc p. 3 (1995) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 4-9, 15-1 to 15-29 (1990) (4) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals: Data Compilation Supplement 6 Design Institute for Physical Property Data American Institute of Chemical Engineers NY, NY: Hemisphere Publishing Corp (1989) (5) Horvath AL; Halogenated Hydrocarbons: Solubility-Miscibility With Water NY, NY: Marcel-Dekker, Inc p. 649 (1982) (6) Franke C et al; Chemosphere 29: 1501-14 (1994) (7) Meylan WM et al; Environ Toxicol Chem 18: 664-72 (1999) (8) Jeffers PM, Wolfe NL; Environ Toxicol Chem 15: 1066-70 (1996)]**PEER REVIEWED**

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dichlorofluoromethane, which has a vapor pressure of 1.36X10+03 mm Hg at 25 deg C(2), is expected to exist solely in the gas-phase in the ambient atmosphere. Gas-phase dichlorofluoromethane is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 1.5 years(SRC), calculated from its rate constant of 3.03X10-014(3).
[(1) Bidleman TF; Environ Sci Technol 22: 361-367 (1988) (2) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals: Data Compilation Supplement 6 Design Institute for Physical Property Data American Institute of Chemical Engineers NY, NY: Hemisphere Publishing Corp (1989) (3) Atkinson R; J Phys Chem Ref Data. Monograph 1 p. 74 (1989)]**PEER REVIEWED**


Environmental Biodegradation:

AEROBIC: Complete degradation of dichlorofluoromethane, initially present at approximately 95 ppm, by methanotrophic bacteria occurred within approximately 19 days in soil samples collected from an agricultural field(1) when methane was added to the soil(1). In soil samples collected from a forest, complete degradation of dichlorofluoromethane, initially present at approximately 26 ppm, by methanotrophic bacteria occurred within approximately 5 days when methane was added to the soil(1).
[(1) Oremland RS et al; Appl Environ Microbiol 62: 1818-21 (1996)]**PEER REVIEWED**

ANAEROBIC: Approximately 93% of the dichlorofluoromethane added to anoxic sediment samples collected from a fresh water wetland was biodegraded within 27 days at 20 degrees C(1). Approximately 50% of the dichlorofluoromethane added to anoxic sediment samples collected from a salt water wetland was degraded in 43 days; however, approximately 26% degradation was also observed in the sterilized controls(1). Approximately 90% of dichlorofluoromethane was degraded in 24 hours (degradation rate of 0.3 umol/hour) by a mixed methanotrophic culture (ENV2041) suspended in a 3-(N-morpholino)-propanesulfonic acid solution at 20 degrees C with a pH of 7.4; degradation rates of 0.2 and 0.1 were observed using M. trichosporium (OB3b) and M. vaccae (JOB5), respectively(2).
[(1) Oremland RS et al; Appl Environ Microbiol 62: 1818-21 (1996) (2) Streger SH et al; Environ Sci Technol 33: 4477-82 (1999)]**PEER REVIEWED**


Environmental Abiotic Degradation:

The rate constant for the vapor-phase reaction of dichlorofluoromethane with photochemically-produced hydroxyl radicals is 3.03X10-014 cu cm/molecule-sec at 25 deg C(1). This corresponds to an atmospheric half-life of approximately 1.5 years at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(2). Utilizing a two-dimensional, tropospheric model that considers both vertical and latitudinal transport as well as reaction with atmospheric species, the half-life of dichlorofluoromethane in the troposphere is estimated to be 2.0 yr(3). As a result of its long half-life, the dichlorofluoromethane released to the atmosphere will accumulate in the atmosphere and disperse over a large area. About 5% of the dichlorofluoromethane is predicted to diffuse to the stratosphere(3) where it will be destroyed as a result of photodissociation and reaction with hydroxyl radicals and O(1D) atoms(3-6). In the process, free radicals are released which destroy the ozone layer. Rate constants for the neutral and alkaline hydrolysis reactions for dichlorofluoromethane are 2.1X10-10 and 5.4X10-09 L/mole-min; these rates correspond to a half-life of approximately 230 years(7).
[(1) Atkinson R; J Phys Chem Ref Data. Monograph 1 p. 74 (1989) (2) Meylan WM, Howard PH; Chemosphere 26: 2293-99 (1993) (3) Derwent RG, Eggleton AEJ; Atmos Environ 12: 1261-9 (1978) (4) Altschuler AP; Adv Environ Sci Technol 10: 181-219 (1979) (5) Davidson JA et al; J Chem Phys 69: 4277-9 (1978) (6) Hubrich C, Stahl F; J Photochem 12: 93-107 (1980) (7) Jeffers PM, Wolfe NL; Environ Toxicol Chem 15: 1066-70 (1996)]**PEER REVIEWED**


Environmental Bioconcentration:

An estimated BCF of 3 was calculated for dichlorofluoromethane(SRC), using a log Kow of 1.55(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low.
[(1) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Professional Reference Book. Heller, SR., consult. ed., Washington, DC: Amer Chem Soc. P. 3 (1995) (2) Meylan WM et al; Environ Toxicol Chem 18: 664-72 (1999) (3) Franke C et al; Chemosphere 29: 1501-14 (1994)]**PEER REVIEWED**


Soil Adsorption/Mobility:

Using a structure estimation method based on molecular connectivity indices(1), the Koc for dichlorofluoromethane can be estimated to be 35(SRC). According to a classification scheme(2), this estimated Koc value suggests that dichlorofluoromethane is expected to have very high mobility in soil.
[(1) Meylan WM et al; Environ Sci Technol 26: 1560-67 (1992) (2) Swann RL et al; Res Rev 85: 17-28 (1983)]**PEER REVIEWED**


Volatilization from Water/Soil:

The Henry's Law constant for dichlorofluoromethane is estimated as 1.08X10-02 atm-cu m/mole(SRC), derived from its vapor pressure, 1.36X10+03 mm Hg(1), and water solubility, 1.88x10+04 mg/l(2). Dichlorofluoromethane is a gas with moderate water solubility and would therefore be expected to volatilize rapidly from water. Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 1 hour(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 4 days(SRC). Dichlorofluoromethane's estimated Henry's Law constant(SRC) indicates that volatilization from moist soil surfaces will occur rapidly(SRC). Dichlorofluoromethane's vapor pressure indicates that volatilization from dry soil sources will also occur rapidly(SRC).
[(1) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals: Data Compilation Supplement 6 Design Institute for Physical Property Data American Institute of Chemical Engineers NY, NY: Hemisphere Publ Corp (1989) (2) Horvath AL; Halogenated Hydrocarbons: Solubility-Miscibility With Water NY, NY: Marcel-Dekker, Inc p. 649 (1982) (3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)]**PEER REVIEWED**


Environmental Water Concentrations:

DRINKING WATER: No dichlorofluoromethane was found in a survey of 1174 community wells and 617 private wells in Wisconsin, in which dichlorofluoromethane was one of the target compounds(1).
[(1) Krill RM, Sonzogni WC; J Amer Water Works Assoc 78: 70-5 (1986)]**PEER REVIEWED**

GROUNDWATER: Dichlorofluoromethane was detected in 2 of 4 off-site monitoring wells near a former plant that formulated non-lubricating automotive fluids concentrations of 3 and 0.5 ug/l(1).
[(1) USEPA; Superfund Record of Decision (EPA Region 5): U.S. Aviex, MI (First Remedial Action) p.5c USEPA/ROD/RO5-88/073 (1988)]**PEER REVIEWED**


Effluent Concentrations:

Dichlorofluoromethane was found in gases emanating from a simulated landfill(1). No quantitation was performed. The material in the simulated landfill consisted of municipal refuse and various loadings of municipal wastewater sludge. Dichlorofluoromethane was reported in landfill gas at a concentration of 93 mg/cu m(2). The site was a clay pit that received both municipal and industrial solid wastes, and liquid waste that were at the sampling point >15 mo. Dichlorofluoromethane was detected in municipal solid waste landfill gas at seven locations in the United Kingdom at concentrations ranging from 1-85 mg/cu m(3).
[(1) Vogt WE, Walsh JJ; pp. 1-17 in Proc. Air Pollut Control Assoc 78th Annual Meeting Vol 6 (1985) (2) Young P, Parker A; ASTM Spec Tech Publ 851 (Hazard Ind Waste Manage Test): 24-41 (1984) (3) Allen MR et al; Environ Sci Technol 31: 1054-61 (1997)]**PEER REVIEWED**


Atmospheric Concentrations:

RURAL/REMOTE: Based on air measurements made in the Red Sea and Indian Ocean, off the coast of Kenya, and at two locations in the Egyptian desert, the background concentration of dichlorofluoromethane ranges between 0 and 1 parts per trillion with excursions up to 5-7 parts per trillion(1). In the desert measurements, where samples were collected three times a day, no significant diurnal fluctuation was noted. Levels of dichlorofluoromethane measured at particularly clean sites in Tasmania, the South Pole and the Pacific Northwest averaged 0.08 parts per trillion(2). Levels at a site in southern England averaged 1.6 parts per trillion(2).
[(1) Crescentine G et al; Atmos Environ 20: 215-7 (1986) (2) Penkett SA et al; Nature 286: 793-5 (1980)]**PEER REVIEWED**


Other Environmental Concentrations:

The concentration of dichlorofluoromethane in six samples of municipal solid waste ranged from below detection (detection limit not provided) to 0.89 ppm(1).
[(1) Deipser A, Stegmann R; Waste Manage Res 12: 129-39 (1994)]**PEER REVIEWED**


Environmental Standards & Regulations:

TSCA Requirements:

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Dichloromonofluoromethane is included on this list.
[40 CFR 716.120 (7/1/2000)]**PEER REVIEWED**


Clean Water Act Requirements:

Toxic pollutant designated pursuant to section 307(a)(1) of the Clean Water Act and is subject to effluent limitations. /Halomethanes/
[40 CFR 401.15 (7/1/88)] **QC REVIEWED**


Chemical/Physical Properties:

Molecular Formula:

C-H-Cl2-F
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 1]**PEER REVIEWED**


Molecular Weight:

102.92
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 3-206]**PEER REVIEWED**


Color/Form:

Colorless heavy gas
[Sax, N.I. Dangerous Properties of Industrial Materials. Vol 1-3 7th ed. New York, NY: Van Nostrand Reinhold, 1989. 1154]**PEER REVIEWED**

Colorless gas ... [Note: A liquid below 48 degrees F. Shipped as a liquefied compressed gas].
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 100]**PEER REVIEWED**


Odor:

... Slight ether-like odor ...
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 100]**PEER REVIEWED**


Boiling Point:

8.9 deg C @ 760 mm Hg
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 3-206]**PEER REVIEWED**


Melting Point:

-135 deg C
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 3-206]**PEER REVIEWED**


Corrosivity:

Liquid Refrigerant 21 will attack some forms of plastics, rubber, and coatings
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**


Critical Temperature & Pressure:

Critical temperature: 451.58 K; critical pressure: 5.18 mPa
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 6-49]**PEER REVIEWED**


Density/Specific Gravity:

1.405 g/ml @ 9 deg C
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 3-206]**PEER REVIEWED**


Heat of Combustion:

-2.3117E+08 J/kmol
[Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.]**PEER REVIEWED**


Heat of Vaporization:

25.2 kJ/mol
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 6-103]**PEER REVIEWED**


Octanol/Water Partition Coefficient:

log Kow= 1.55
[Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995. 3]**PEER REVIEWED**


Solubilities:

Soluble in carbon tetrachloride
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 3-206]**PEER REVIEWED**

69 parts/100 parts acetic acid; 108 parts/100 parts dioxane
[Dean, J.A. Handbook of Organic Chemistry. New York, NY: McGraw-Hill Book Co., 1987.,p. 1-182]**PEER REVIEWED**

> 10% in ethyl alcohol; > 10% in ethyl ether;> 10% in chloroform
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 840]**PEER REVIEWED**

0.95% weight at 25 deg in water
[Riddick, J.A., W.B. Bunger, Sakano T.K. Techniques of Chemistry 4th ed., Volume II. Organic Solvents. New York, NY: John Wiley and Sons., 1985. 561]**PEER REVIEWED**

In water, 1.88X10+04 mg/l at 25 deg C
[Horvath AL; Halogenated Hydrocarbons. NY, NY: Marcel Dekker, Inc. p. 649 (1982)]**PEER REVIEWED**


Spectral Properties:

Index of refraction: 1.3724 @ 9 deg C/D
[Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 79th ed. Boca Raton, FL: CRC Press Inc., 1998-1999.,p. 3-206]**PEER REVIEWED**

IR: 1129 (Sadtler Research Laboratories Prism Collection)
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 840]**PEER REVIEWED**

NMR: 2429 (Sadtler Research Laboratories Spectral Collection)
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 840]**PEER REVIEWED**

MASS: 265 (Atlas of Mass Spectral Data, John Wiley & Sons, New York)
[Weast, R.C. and M.J. Astle. CRC Handbook of Data on Organic Compounds. Volumes I and II. Boca Raton, FL: CRC Press Inc. 1985.,p. V1 840]**PEER REVIEWED**


Surface Tension:

18 mN/m @ 25 deg C
[Riddick, J.A., W.B. Bunger, Sakano T.K. Techniques of Chemistry 4th ed., Volume II. Organic Solvents. New York, NY: John Wiley and Sons., 1985. 560]**PEER REVIEWED**


Vapor Density:

3.82 (Air= 1)
[Sax, N.I. Dangerous Properties of Industrial Materials. Vol 1-3 7th ed. New York, NY: Van Nostrand Reinhold, 1989. 1154]**PEER REVIEWED**


Vapor Pressure:

1360 mm Hg @ 25 deg C
[Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.]**PEER REVIEWED**


Viscosity:

0.313 cP @ 25 deg C (liq); 0.0114 cP @ 25 deg C, 101.3 kPa ... /gas/.
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. V10 862]**PEER REVIEWED**


Other Chemical/Physical Properties:

Dielectric constant: 5.34 @ 28 deg C (liq); 1.0070 @ 30 deg C, 50.65 kPa (vapor)
[Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. 10 862]**PEER REVIEWED**

Ionization potential: 12.39 eV
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 100]**PEER REVIEWED**

Enthalpy of formation @ 25 deg C: -68.10 kcal/mole (gas); Gibbs (free) energy of formation @ 25 deg C: -60.77 kcal/mole (gas); entropy @ 25 deg C: 70.04 cal/deg.mole (gas); heat capacity @ 25 deg C: 14.58 cal/deg.mole (gas)
[Dean, J.A. Handbook of Organic Chemistry. New York, NY: McGraw-Hill Book Co., 1987.,p. 5-14]**PEER REVIEWED**

Dipole moment: 1.3 debyes (gas)
[Dean, J.A. Handbook of Organic Chemistry. New York, NY: McGraw-Hill Book Co., 1987.,p. 4-55]**PEER REVIEWED**

Heat of formation = -2.8326X10+08 J/kmol; liquid molar volume = 0.073214 cu m/kmol
[Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.]**PEER REVIEWED**

Heat of vaporization = 5.79 Kcal/mol at 25 deg C; 6.01 kcal/mol at the boiling point
[Riddick, J.A., W.B. Bunger, Sakano T.K. Techniques of Chemistry 4th ed., Volume II. Organic Solvents. New York, NY: John Wiley and Sons., 1985. 560]**PEER REVIEWED**

Hydroxyl radical rate constant= 3.03X10-14 cu cm/mole-sec @ 25 deg C
[Atkinson R; J Phys Chem Ref Data Monograph 1 p.74 (1989)]**PEER REVIEWED**


Chemical Safety & Handling:

DOT Emergency Guidelines:

Fire or explosion: Some may burn, but none ignite readily. Containers may explode when heated. Ruptured cylinders may rocket.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-126]**PEER REVIEWED**

Health: Vapors may cause dizziness or asphyxiation without warning. Vapors from liquefied gas are initially heavier than air and spread along ground. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating, corrosive and/or toxic gases.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-126]**PEER REVIEWED**

Public safety: CALL Emergency Response Telephone Number . ... Isolate spill or leak area immediately for at least 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas. Ventilate closed spaces before entering.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-126]**PEER REVIEWED**

Protective clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-126]**PEER REVIEWED**

Evacuation: Large spill: Consider initial down wind evacuation for at least 500 meters (1/3 mile). Fire: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-126]**PEER REVIEWED**

Fire: Use extinguishing agent suitable for type of surrounding fire. Small fires: Dry chemical or CO2. Large fires: Water spray, fog or regular foam. Move containers from fire area if you can do it without risk. Damaged cylinders should be handled only by specialists. Fire involving tanks: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from the ends of tanks. Some of these materials, if spilled, may evaporate leaving a flammable residue.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-126]**PEER REVIEWED**

Spill or leak: Do not touch or walk through spilled material. Stop leak if you can do it without risk. Do not direct water at spill or source of leak. Use water spray to reduce vapors or divert vapor cloud drift. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Allow substance to evaporate. Ventilate the area.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-126]**PEER REVIEWED**

First aid: Move victim to fresh air. Call emergency medical care. Apply artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with liquefied gas, thaw frosted parts with lukewarm water. Keep victim warm and quiet. Ensure that medical personnel are aware of the material(s) involved, and take precautions to protect themselves.
[U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-126]**PEER REVIEWED**


Skin, Eye and Respiratory Irritations:

Refrigerant 21 vapor is respiratory irritant ...
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 1]**PEER REVIEWED**

On contact with liquid /dichlorofluoromethane/: frostbite
[International Labour Office. Encyclopaedia of Occupational Health and Safety. 4th edition, Volumes 1-4 1998. Geneva, Switzerland: International Labour Office, 1998.,p. 104.188]**PEER REVIEWED**


Fire Potential:

WEAKLY FLAMMABLE.
[Sunshine, I. (ed.). CRC Handbook of Analytical Toxicology. Cleveland: The Chemical Rubber Co., 1969. 622]**PEER REVIEWED**


Autoignition Temperature:

522 DEG C
[Sunshine, I. (ed.). CRC Handbook of Analytical Toxicology. Cleveland: The Chemical Rubber Co., 1969. 622]**PEER REVIEWED**


Fire Fighting Procedures:

If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 354]**PEER REVIEWED**


Hazardous Reactivities & Incompatibilities:

... ON CONTACT WITH ACIDS OR ACID FUMES THEY EMIT HIGHLY TOXIC FUMES. /FLUORIDES/
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 1660]**PEER REVIEWED**

/Incompatible with/ chemically active metals: sodium, potassium, calcium, powdered aluminum, zinc, magnesium.
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 325]**PEER REVIEWED**

Chemically-active metals such as sodium, potassium, calcium, powdered aluminum, zinc & magnesium; acid; acid fumes.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 100]**PEER REVIEWED**

/Dichlorofluoromethane/ will attack some forms of plastics, rubber, and coatings.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**


Hazardous Decomposition:

WHEN HEATED TO DECOMP IT EMITS VERY TOXIC FUMES OF /HYDROGEN CHLORIDE AND HYDROGEN FLUORIDE/.
[Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996. 1107]**PEER REVIEWED**

Toxic gases and vapors (such as hydrogen chloride, phosgene, and hydrogen fluoride) may be released when Refrigerant 21 decomposes.
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 2]**PEER REVIEWED**

All fluorocarbons will undergo thermal decomposition when exposed to flame or red-hot metal. Decomposition products of the chlorofluorocarbons will include hydroflouric & hydrochloric acid along with smaller amounts of phosgene & carbonyl fluoride. The last compound is very unstable to hydrolysis & quickly changes to hydrofluoric acid & carbon dioxide in the presence of moisture. /Fluorocarbons/
[International Labour Office. Encyclopaedia of Occupational Health and Safety. 4th edition, Volumes 1-4 1998. Geneva, Switzerland: International Labour Office, 1998.,p. 104.185]**PEER REVIEWED**

APPEARANCE OF TOXIC DECOMP PRODUCTS SERVES AS WARNING OF OCCURRENCE OF THERMAL DECOMP & DETECTION OF SHARP ACRID ODOR WARNS OF PRESENCE ... . /FLUOROCARBONS/
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 3101]**PEER REVIEWED**


Other Hazardous Reaction:

FLUOROCARBON VAPORS ARE FOUR TO FIVE TIMES HEAVIER THAN AIR. THUS HIGH CONCN TEND TO ACCUMULATE IN LOW-LYING AREAS, RESULTING IN HAZARD OF INHALATION OF CONCENTRATED VAPORS, WHICH MAY BE FATAL. ... THE HIGHEST EXPOSURE IN THE PLANT OCCURS WITH VENTING OF GASES FROM RETURNABLE CYLINDERS. /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. 1195]**PEER REVIEWED**


Immediately Dangerous to Life or Health:

5000 ppm
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 100]**PEER REVIEWED**


Protective Equipment & Clothing:

Employees should be provided with and required to use impervious clothing, gloves, face shields ... and other appropriate protective clothing necessary to prevent the skin from becoming wet with liquid Refrigerant 21. ... Employees should be provided with and required to use splash-proof safety goggles where liquid ... may contact the eyes.
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 2]**PEER REVIEWED**

... Individual breathing devices with independent air supply will minimize risk of inhalation. Lifelines should be worn when entering tanks or other confined spaces. /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. 1195]**PEER REVIEWED**

Wear appropriate personal protective clothing to prevent the skin from becoming frozen from contact with the liquid or from contact with vessels containing the liquid.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 101]**PEER REVIEWED**

Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 101]**PEER REVIEWED**

Recommendations for respirator selection. Max concn for use: 100 ppm. Respirator Class(es): Any supplied-air respirator.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 101]**PEER REVIEWED**

Recommendations for respirator selection. Max concn for use: 250 ppm. Respirator Class(es): Any supplied-air respirator operated in a continuous flow mode.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 101]**PEER REVIEWED**

Recommendations for respirator selection. Max concn for use: 500 ppm. Respirator Class(es): Any self-contained breathing apparatus with a full facepiece. Any supplied-air respirator with a full facepiece.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 101]**PEER REVIEWED**

Recommendations for respirator selection. Max concn for use: 5000 ppm. Respirator Class(es): Any supplied-air respirator operated in a pressure-demand or other positive-pressure mode.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 101]**PEER REVIEWED**

Recommendations for respirator selection. Condition: Emergency or planned entry into unknown concn or IDLH conditions: Respirator Class(es): Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive pressure mode. Any supplied-air respirator with a full facepiece and operated in pressure-demand or other positive pressure mode in combination with an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive pressure mode.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 101]**PEER REVIEWED**

Recommendations for respirator selection. Condition: Escape from suddenly occurring respiratory hazards: Respirator Class(es): Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister. Any appropriate escape-type, self-contained breathing apparatus.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 101]**PEER REVIEWED**


Preventive Measures:

SUFFICIENT EXHAUST & GENERAL VENTILATION SHOULD BE PROVIDED TO KEEP VAPOR CONCN BELOW RECOMMENDED LEVELS. /FLUOROCARBONS/
[International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983. 897]**PEER REVIEWED**

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.
**PEER REVIEWED**

Any clothing which becomes wet with liquid ... should be removed immediately and not reworn until the Refrigerant 21 has evaporated.
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 2]**PEER REVIEWED**

Filling areas should be monitored to ensure that the ambient CFC, HCFC, and HFC concentrations do not exceed prevailing work standards. /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. 1195]**PEER REVIEWED**

APPEARANCE OF TOXIC DECOMP PRODUCTS SERVES AS WARNING OF OCCURRENCE OF THERMAL DECOMP & DETECTION OF SHARP ACRID ODOR WARNS OF PRESENCE ... HALIDE LAMPS OR ELECTRONIC LEAK DETECTORS MAY ALSO BE USED. ADEQUATE VENTILATION ALSO AVOIDS PROBLEM OF TOXIC DECOMPOSITION PRODUCTS. /FLUOROCARBONS/
[Clayton, G. D. and F. E. Clayton (eds.). Patty's Industrial Hygiene and Toxicology: Volume 2A, 2B, 2C: Toxicology. 3rd ed. New York: John Wiley Sons, 1981-1982. 3101]**PEER REVIEWED**

Personnel protection: Keep upwind. Avoid breathing vapors. ... Do not handle broken packages unless wearing appropriate personal protective equipment.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 354]**PEER REVIEWED**

If material not on fire and not involved in fire: Attempt to stop leak if without personnel hazard.
[Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994. 354]**PEER REVIEWED**


Stability/Shelf Life:

/Condition/ contributing to instability: heat.
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 2]**PEER REVIEWED**


Shipment Methods and Regulations:

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./
[49 CFR 171.2 (7/1/2000)]**PEER REVIEWED**

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.
[IATA. Dangerous Goods Regulations. 41st Ed.Montreal, Canada and Geneva, Switzerland: International Air Transport Association, Dangerous Goods Regulations, 2000. 147]**PEER REVIEWED**

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.
[IMDG; International Maritime Dangerous Goods Code; International Maritime Organization p.2130 (1998)]**PEER REVIEWED**


Storage Conditions:

... MATERIALS MUST BE STORED IN PLACES THAT ARE COOL ... PROVIDE ADEQUATE VENTILATION ... FURTHER PRECAUTION IS TO LOCATE ... AREA ... AWAY FROM AREAS OF FIRE HAZARD ... .
[Sax, N.I. Dangerous Properties of Industrial Materials. 4th ed. New York: Van Nostrand Reinhold, 1975. 630]**PEER REVIEWED**


Cleanup Methods:

If Refrigerant 21 is spilled or leaked, the following steps should be taken: 1. Ventilate area of spill or leak. 2. If the gas is leaking, stop the flow. 3. If the liquid is spilled or leaked, allow to vaporize.
[Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) PublicationNo. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981. 3]**PEER REVIEWED**


Disposal Methods:

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.
**PEER REVIEWED**

Incineration, preferably after mixing with another combustible fuel. Care must be exercised to assure complete combustion to prevent the formation of phosgene. An acid scrubber is necessary to remove the halo acids produced.
[Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 325]**PEER REVIEWED**


Occupational Exposure Standards:

OSHA Standards:

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 1000 ppm (4200 mg/cu m).
[29 CFR 1910.1000 (7/1/2000)]**PEER REVIEWED**

Vacated 1989 OSHA PEL TWA 10 ppm (40 mg/cu m) is still enforced in some states.
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 362]**PEER REVIEWED**


Threshold Limit Values:

8 hr Time Weighted Avg (TWA) 10 ppm
[American Conference of Governmental Industrial Hygienists. TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH. 2000. 31]**PEER REVIEWED**

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed three times the TLV-TWA for no more than a total of 30 min during a work day, and under no circumstances should they exceed five times the TLV-TWA, provided that the TLV-TWA is not exceeded.
[American Conference of Governmental Industrial Hygienists. TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH. 2000. 6]**PEER REVIEWED**


NIOSH Recommendations:

Recommended Exposure Limit: 10 Hr Time-Weighted Avg: 10 ppm (40 mg/cu m).
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 100]**PEER REVIEWED**


Immediately Dangerous to Life or Health:

5000 ppm
[NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 100]**PEER REVIEWED**


Manufacturing/Use Information:

Major Uses:

Fully halogenated chlorofluorocarbons (CFCs) such as dichlorofluoromethane were scheduled for production phase-out in 1987 by the Montreal Protocol. Although originally scheduled for 50% production phase-out by the year 2000 in developed countries, the worsening ozone depletion has forced acceleration of the CFC phase-out.
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V21 (1997) 132]**PEER REVIEWED**

Dichlorofluoromethane /HCFC-21/ has much less usage than other chlorofluorocarbons, such as chlorodifluoromethane (HCFC-22) or dichlorotrifluoromethane (HCFC-123); however, it has had application as a refrigerant in the aerospace industry, as a solvent, as propellant gas, and as a heat exchange fluid in geothermal energy applications.
[American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I,II, III. Cincinnati, OH: ACGIH, 1991. 434]**PEER REVIEWED**


Methods of Manufacturing:

Reaction of chloroform and hydrogen fluoride
[Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997. 366]**PEER REVIEWED**

The most important commercial method for manufacturing /chlorofluoro carbons/ is the successive replacement of chlorine by fluorine using hydrogen fluoride ... CHCl2F /Freon 21/ is produced by reacting chloroform with HF
[Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present.,p. V11 507]**PEER REVIEWED**


General Manufacturing Information:

Per 40CFR82, which implements the Montreal Protocol, dichlorofluoromethane will no longer be produced or imported in the United States after 2015, except for its use as a refrigerant in equipment manufactured before 1/1/2020; no production or importing after 1/1/2030 will be allowed.
[Code of Federal Regulations; Significant New Alternatives Policy Program (SNAP). 40CFR82.170 (2000)]**PEER REVIEWED**

Chlorofluoroalkanes produced on an industrial scale are subject to stringent standards ... impurities must not exceed the following limits (vol%): acids, 0; moisture, <0.001; higher-boiling fractions, <0.05; other gases, 2 /Chlorofluoroalkanes/
[Gerhartz, W. (exec ed.). Ullmann's Encyclopedia of Industrial Chemistry. 5th ed.Vol A1: Deerfield Beach, FL: VCH Publishers, 1985 to Present.,p. VA11 358]**PEER REVIEWED**


Formulations/Preparations:

TECHNICAL GRADE
[Sax, N.I. and R.J. Lewis, Sr. (eds.). Hawley's Condensed Chemical Dictionary. 11th ed. New York: Van Nostrand Reinhold Co., 1987. 379]**PEER REVIEWED**


Consumption Patterns:

REFRIGERANTS, 39%; FOAM BLOWING AGENTS, 14%; SOLVENTS, 14%; FLUOROPOLYMERS, 14%; STERILANT GAS, 2%; AEROSOL PROPELLANTS, 2%; FOOD FREEZANT, 1%; OTHER, 8%; EXPORTS, 3% (1985) /FLUOROCARBONS/
[CHEMICAL PROFILE: FLUOROCARBON, 1986]**PEER REVIEWED**

Refrigeration/air conditioning, 43%; foam blowing agents, 20%; polymer precursors, 13%; solvent cleaning, 12%; aerosol propellants, 2%; medical equipment sterilization, 3%; other, 7% /Fluorocarbons/
[Chemical Profile: Fluorocarbons, 1992]**PEER REVIEWED**


Laboratory Methods:

Clinical Laboratory Methods:

FLUOROCARBON DETERMINATION IN BLOOD: GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE DETECTION. RECOVERY OF FLUOROCARBONS ADDED TO BLOOD RANGED FROM 85 TO 95%. MAJOR SOURCES OF ERROR ARE LOSS OF PURE FLUOROCARBON IN PREPARATION OF THE STANDARDS AND CHANGES IN CHROMATOGRAPHIC RESPONSE. /FLUOROCARBONS/
[Sunshine, Irving (ed.) Methodology for Analytical Toxicology. Cleveland: CRC Press, Inc., 1975. 175]**PEER REVIEWED**


Analytic Laboratory Methods:

NIOSH Method 2516: Analyte: dichlorofluoromethane; Matrix: air; Technique: gas chromatography, flame ionization detector; Desorption: 5 ml carbon disulfide, stand 30 min; Range: 1-35 mg/sample; Est limit of detection: 0.05 mg/sample; Precision (relative standard deviation): 0.024 @ 6-34 mg/sample; Interferences: none known
[U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health. NIOSH Manual of Analytical Methods. 4th ed.Methods A-Z & Supplements. Washington, DC: U.S. Government Printing Office, Aug 1994.]**PEER REVIEWED**

AOB Method VG-011-1. Halogenated and Aromatic Volatile Organic Compounds (VOCs) in Whole Gas Analyzed by Purge and Trap GC/ELCD/PID.
[USEPA; EMMI. EPA's Environmental Monitoring Methods Index. Version 1.1. PC# 4082. Rockville, MD: Government Institutes (1997)]**PEER REVIEWED**

AREAL Method IP-1A. Determination of Volatile Organic Compounds (VOCs) in Indoor Air Using Stainless Steel Canisters; Capillary GC/MS; detection limit = ppb (quantity not specified).
[USEPA/Atmospheric Research & Exposure Assessment Laboratory (AREAL); Compendium of Methods for the Determination of Air Pollutants in Indoor Air, Engineering Science, One Harrison Park, Suite 305, 401 Harrison Oaks Blvd, Cary, NC 27513 as cited in USEPA; EMMI. Environmental Monitoring Index Database Version 1.02 (1992) EPA/871-B-92-001 (NTIS Document No. PB92-503093)]**PEER REVIEWED**


Sampling Procedures:

NIOSH Method 2516: Analyte: dichlorofluoromethane; Matrix: air; Sampler: solid sorbent tubes (2 coconut shell charcoal tubes, 400 mg & 200 mg); Flow rate: 0.01-0.05 l/min; Vol: min 0.25 l @ 1000 ppm, max 3 l; Stability: greater than or equal to 7 days at 25 deg C
[U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health. NIOSH Manual of Analytical Methods. 4th ed.Methods A-Z & Supplements. Washington, DC: U.S. Government Printing Office, Aug 1994.]**PEER REVIEWED**


Special References:

Special Reports:


[WHO; Environmental Health Criteria 126: Partially Halogenated Chlorofluorocarbons (Methane Derivatives) (1991)]


Synonyms and Identifiers:

Synonyms:

F 21
**PEER REVIEWED**

ALGOFRENE TYPE 5
**PEER REVIEWED**

ARCTON 7
**PEER REVIEWED**

CFC-21
**PEER REVIEWED**

DICHLOROMONOFLUOROMETHANE
**PEER REVIEWED**

DWUCHLOROFLUOROMETAN (POLISH)
**PEER REVIEWED**

FC 21
**PEER REVIEWED**

FLUORODICHLOROMETHANE
**PEER REVIEWED**

FREON F 21
**PEER REVIEWED**

FREON 21
**PEER REVIEWED**

GENETRON 21
**PEER REVIEWED**

Halon 112
**PEER REVIEWED**

Methane, dichlorofluoro-
**PEER REVIEWED**

MONOFLUORODICHLOROMETHANE
**PEER REVIEWED**

R 21 (refrigerant)
**PEER REVIEWED**

Refrigerant 21
**PEER REVIEWED**


Formulations/Preparations:

TECHNICAL GRADE
[Sax, N.I. and R.J. Lewis, Sr. (eds.). Hawley's Condensed Chemical Dictionary. 11th ed. New York: Van Nostrand Reinhold Co., 1987. 379]**PEER REVIEWED**


Shipping Name/ Number DOT/UN/NA/IMO:

UN 1029; Dichloromonofluoromethane

IMO 2.2; Dichloromonofluoromethane


Standard Transportation Number:

49 045 74; Dichlorofluoromethane


RTECS Number:

NIOSH/PA8400000


Administrative Information:

Hazardous Substances Databank Number: 142

Last Revision Date: 20010809

Last Review Date: Reviewed by SRP on 1/20/2001

Update History:

Complete Update on 08/09/2001, 1 field added/edited/deleted.
Complete Update on 05/23/2001, 60 fields added/edited/deleted.
Field Update on 05/16/2001, 1 field added/edited/deleted.
Complete Update on 06/12/2000, 1 field added/edited/deleted.
Complete Update on 03/28/2000, 1 field added/edited/deleted.
Complete Update on 02/02/2000, 1 field added/edited/deleted.
Complete Update on 09/21/1999, 1 field added/edited/deleted.
Complete Update on 08/26/1999, 1 field added/edited/deleted.
Complete Update on 07/20/1999, 7 fields added/edited/deleted.
Complete Update on 01/20/1999, 1 field added/edited/deleted.
Complete Update on 11/12/1998, 1 field added/edited/deleted.
Complete Update on 06/02/1998, 1 field added/edited/deleted.
Complete Update on 10/17/1997, 1 field added/edited/deleted.
Complete Update on 07/28/1997, 1 field added/edited/deleted.
Complete Update on 03/27/1997, 2 fields added/edited/deleted.
Complete Update on 01/09/1997, 1 field added/edited/deleted.
Complete Update on 05/09/1996, 1 field added/edited/deleted.
Complete Update on 04/16/1996, 8 fields added/edited/deleted.
Field Update on 01/18/1996, 1 field added/edited/deleted.
Complete Update on 11/10/1995, 1 field added/edited/deleted.
Complete Update on 06/07/1995, 55 fields added/edited/deleted.
Field Update on 05/26/1995, 1 field added/edited/deleted.
Field Update on 05/17/1995, 2 fields added/edited/deleted.
Field Update on 01/18/1995, 1 field added/edited/deleted.
Field Update on 12/19/1994, 1 field added/edited/deleted.
Complete Update on 07/22/1994, 1 field added/edited/deleted.
Complete Update on 05/05/1994, 1 field added/edited/deleted.
Complete Update on 03/25/1994, 1 field added/edited/deleted.
Complete Update on 01/25/1994, 1 field added/edited/deleted.
Complete Update on 08/07/1993, 1 field added/edited/deleted.
Complete Update on 08/04/1993, 1 field added/edited/deleted.
Complete Update on 02/05/1993, 1 field added/edited/deleted.
Field update on 12/11/1992, 1 field added/edited/deleted.
Complete Update on 04/27/1992, 1 field added/edited/deleted.
Complete Update on 04/03/1992, 3 fields added/edited/deleted.
Field Update on 01/13/1992, 1 field added/edited/deleted.
Complete Update on 02/13/1991, 85 fields added/edited/deleted.
Field Update on 01/15/1990, 1 field added/edited/deleted.
Complete Update on 01/11/1990, 82 fields added/edited/deleted.
Complete Update on 04/24/1987