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Chemical Sampling Information (CSI)
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General Description

Synonyms: Trichloromethane

OSHA IMIS Code Number: 0670

Chemical Abstracts Service (CAS) Registry Number: 67-66-3

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: FS9100000

Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 1888 151

NIOSH Pocket Guide to Chemical Hazards, Chloroform: chemical description, physical properties, potentially hazardous incompatibilities, and more

Exposure Limits

OSHA Permissible Exposure Limit (PEL):

General Industry: 29 CFR 1910.1000 Table Z-1 - 50 ppm, 240 mg/m3 Ceiling

Construction Industry: 29 CFR 1926.55 Appendix A - 50 ppm, 240 mg/m3 Ceiling

Maritime: 29 CFR 1915.1000 Table Z-Shipyards - 50 ppm, 240 mg/m3 TWA

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 10 ppm, 49mg/m3 TWA; Appendix A3 - Confirmed Animal Carcinogen with Unknown Relevance to Humans

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 2 ppm, 9.78mg/m3 STEL (60 Minutes); Appendix A - NIOSH Potential Occupational Carcinogens

Health Factors

Carcinogenic Classification:

Environmental Protection Agency (EPA): Group B2, probable human carcinogen

National Toxicology Program (NTP): Group 2, reasonably anticipated to be a human carcinogen [153 KB PDF, 3 pages]

International Agency for Research on Cancer (IARC): Group 2B, possibly carcinogenic to humans [236 KB PDF, 52 pages]

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 500 ppm

Potential Symptoms: Dizziness, mental dullness, irritability, confusion, distorted perceptions; loss of appetite, nausea; headaches; fatigue; anesthesia; hepatomegaly, hepatitis, jaundice; eye irritation (tearing, conjunctivitis, permanent eye damage), skin irritation (drying, cracking, redness, dermatitis, pain); [potential occupational carcinogen] INGES ACUTE: abdominal pain, vomiting

Health Effects: Cumulative liver and kidney damage (HE3); Known animal and suspected human carcinogen (HE2); Narcosis (HE8)

Affected Organs: Liver, kidneys, heart, eyes, skin, CNS


  1. The odor threshold of chloroform (85 ppm) is greater than its PEL.
  2. Metabolized to the toxic reactive metabolite, phosgene, by the CYP2E1 and CYP2A6 isozymes of cytochrome P450, with a higher affinity for CYP2E1, an enzyme induced in the liver by chronic ethanol consumption.

Date Last Revised: 01/05/2004

Literature Basis:

  • NIOSH Pocket Guide to Chemical Hazards: Chloroform.
  • International Chemical Safety Cards (WHO/IPCS/ILO): Chloroform.
  • EPA Air Toxics Website: Chloroform. U.S. Environmental Protection Agency Technology Transfer Network.
  • Gemma, S., Vittozzi, L. and Testai, E.: Metabolism of chloroform in the human liver and identification of the competent P450s. Drug Metab. Dispos. 31(3): 266-274, 2003.
  • Pohanish, R.P. (editor): Chloroform. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 568-571.
Monitoring Methods used by OSHA

Laboratory Sampling/Analytical Method:

  • sampling media: Charcoal Tube (100/50 mg sections, 20/40 mesh)
    analytical solvent: Carbon disulfide
    alternative solvent: (99:1) Carbon disulfide/Dimethylformamide
    maximum volume: 10 Liters   
    maximum flow rate: 0.2 L/min (TWA)
    maximum volume: 15 Liters   
    maximum flow rate:
    0.2 L/min (Ceiling)
    current analytical method: Gas Chromatography; GC/FID
    method reference: OSHA Manual of Analytical Methods (OSHA 5)
    method classification: Fully Validated

On-Site Sampling Techniques/Methods:

  • device: Detector Tube
    manufacturer: AUER/MSA
    model/type: Trichloroethane-5, MSA P/N 487343, AUER P/N 5086-834
    sampling information: follow manufacturer's instructions
    upper measurement limit: 100 ppm
    detection limit: approximately 8 ppm
    overall uncertainty: unknown
    method reference: on-site air secondary (manufacturer)

  • device: Detector Tube
    manufacturer: Dräger
    model/type: Chloroform 2/a, order no. 67 28861
    sampling information: 10 strokes
    upper measurement limit: 10 ppm
    detection limit: approximately 1 ppm
    overall uncertainty: approximately 33%
    method reference: on-site air secondary (manufacturer)
  • device: Detector Tube
    manufacturer: Gastec
    model/type: 137L
    sampling information: 3 or 5 strokes
    upper measurement limit: 27 ppm
    detection limit: 0.1 ppm
    overall uncertainty: 16% for 0.5 to 2 ppm, 8% for 2 to 10 ppm
    method reference: on-site air secondary (manufacturer)
  • device: Detector Tube
    manufacturer: Matheson-Kitagawa
    model/type: 8014-152S
    sampling information: 2 or 4 strokes
    upper measurement limit: 500 ppm
    detection limit: approximately 20 ppm
    overall uncertainty: unknown
    method reference: on-site air secondary (manufacturer)

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