Synonyms: Difluorodichloromethane; Fluorocarbon 12; Freon® 12; Genetron® 12; Halon® 122; Propellant 12; Refrigerant 12
Chemical Abstracts Service (CAS) Registry Number: 75-71-8
NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: PA8200000
Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 1028 126
NIOSH Pocket Guide to Chemical Hazards, Dichlorodifluoromethane: chemical description, physical properties, potentially hazardous incompatibilities, and more
OSHA Permissible Exposure Limit (PEL):
General Industry: 29 CFR 1910.1000 Table Z-1 - 1000 ppm, 4950 mg/m3 TWA
Construction Industry: 29 CFR 1926.55 Appendix A - 1000 ppm, 4950 mg/m3 TWA
Maritime: 29 CFR 1915.1000 Table Z-Shipyards - 1000 ppm, 4950 mg/m3 TWA
American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 1000 ppm, 4950 mg/m3 TWA ; Appendix A4 - Not Classifiable as a Human Carcinogen
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 1000 ppm, 4950 mg/m3 TWA
NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 15,000 ppm
Potential Symptoms: Dizziness, drowsiness, confusion; tremor, unconsciousness, asphyxia, cardiac arrhythmias, cardiac arrest; frostbite (from liquid)
Health Effects: Narcosis (HE8); Asphyxiant (HE17)
Affected Organs: Cardiovascular system, peripheral nervous system
- Dichlorodifluoromethane, when at least 99.97% pure, is approved by the FDA as a direct-contact freezing agent for foods (21 CFR 173.355). It is now banned by the EPA, however, due to environmental concerns about stratospheric ozone depletion.
- Dichlorodifluoromethane has not been manufactured in the U.S. since 1995, although it was detected at least twice in at least one drinking water source in California during the period, 2002-2004.
- EPA's oral reference dose (daily oral exposure likely to be without an appreciable risk of deleterious effects during a lifetime) of dichlorodifluoromethane is 0.2 mg/kg/day.
Date Last Revised: 11/17/2005
Primary Laboratory Sampling/Analytical Method (SLC1):
- sampling media: Two Charcoal Tubes in series (first tube 400/200 mg second 100/50 mg sections, both 20/40 mesh)
analytical solvent: Methylene Chloride
maximum volume: 4 Liters
maximum flow rate: 0.05 L/min
current analytical method: Gas Chromatography; GC/FID
method reference: NIOSH Analytical Method (NIOSH 1018 [23 KB PDF, 4 pages])
method classification: Fully Validated
note: Refrigerate samples after collection and during shipment to the laboratory.
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