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Engineering | Safe Engineering

Chloroform, Dichloromethane, and Other Halogenated Organic Compounds

Chloroform is a common solvent, starting with NMR samples in sophomore-level chemistry. Why should I worry?

Chloroform, dichloromethane, and many other halogenated organic compounds readily pass through nitrile gloves. This means that the disposable gloves most people wear every day in laboratories provide no protection from chloroform and dichloromethane, and small splashes can result in exposure. Exposure must be avoided because these chemicals are known or suspected carcinogens and teratogens.

The interaction of some halogenated organics with different glove polymers is shown below on glove manufacturer’s chemical compatibility charts.

This table is an excerpt of chlorinated compounds from the Ansell 8th Edition Chemical Resistance Guide for gloves. Excerpted chemicals are carbon tetrachloride, chlorobenzene, chloroform, 1-chloronaphthalene, 2-chlorotoluene, 4-chlorotoluene, 1,2-dichloroethane (ethylene dichloride or EDC), epichlorohydrin, methylene chloride (dichloromethane or DCM), perchloroethylene (PERC), trichloroethylene (TCE), and vinyl chloride gas. PVA (polyvinyl alcohol) gloves have permeation breakthrough times of 360 minutes or more for carbon tetrachloride, chlorobenzene, chloroform, 1-chloronaphthalene, 1,2-dichloroethane (ethylene dichloride or EDC), epichlorohydrin, methylene chloride (dichloromethane or DCM), perchloroethylene (PERC), and trichloroethylene (TCE). Laminate Film

Excerpt of chlorinated compounds from the Ansell 8th Edition Chemical Resistance Guide: https://beta-static.fishersci.com/content/dam/fishersci/en_US/documents/programs/scientific/brochures-and-catalogs/guides/ansell-chemical-resistance.pdf

Required Documents

Chloroform Standard Operating Procedure (SOP)

Dichloromethane Standard Operating Procedure (SOP)

Carbon Tetrachloride Standard Operating Procedure (SOP)

Working with Thick Gloves Guide

Carcinogen Use Area Signage (contact Amanda.L.Hoyt@asu.edu or Rita.Bottesch@asu.edu for laminated signs)

Other Resources

Halogenated Organic Compounds – NOAA

OSHA-Regulated Carcinogens (the “OSHA Thirteen”) – OSHA

This table is an excerpt of chlorinated compounds from the Ansell 8th Edition Chemical Resistance Guide for gloves. Excerpted chemicals are carbon tetrachloride, chlorobenzene, chloroform, 1-chloronaphthalene, 2-chlorotoluene, 4-chlorotoluene, 1,2-dichloroethane (ethylene dichloride or EDC), epichlorohydrin, methylene chloride (dichloromethane or DCM), perchloroethylene (PERC), trichloroethylene (TCE), and vinyl chloride gas. PVA (polyvinyl alcohol) gloves have permeation breakthrough times of 360 minutes or more for carbon tetrachloride, chlorobenzene, chloroform, 1-chloronaphthalene, 1,2-dichloroethane (ethylene dichloride or EDC), epichlorohydrin, methylene chloride (dichloromethane or DCM), perchloroethylene (PERC), and trichloroethylene (TCE). Laminate Film

Excerpt from the 2016 Ansell Chemical Glove Resistance Guide: https://cdn.mscdirect.com/global/media/pdf/search/ansell/ansell-chemical-glove-resistance-guide.pdf

Polyvinyl alcohol (PVA) gloves provide good protection, but their thickness can make some lab techniques difficult. The “Working with Thick Gloves” guide illustrates how to incorporate PVA gloves into chemical handling while maintaining manual dexterity.

Ensure a written SOP is in place, and appropriate engineering controls & PPE (including compatible gloves) are available, before using any of the following halogenated organic compounds:

  • 1-chloronaphthalene (CAS# 90-13-1)
  • 2-chlorotoluene (CAS# 95-49-8)
  • 4-chlorotoluene (CAS# 106-43-4)
  • 1,2-dibromo-3-chloropropane (CAS# 96-12-8)
  • 3,3′-dichlorobenzidine (CAS# 91-94-1)
  • 1,2-dichloroethane, also called ethylene dichloride or EDC (CAS# 107-06-2)
  • benzoyl chloride (CAS# 98-88-4)
  • bis-chloromethyl ether (CAS# 542-88-1)
  • carbon tetrachloride (CAS# 56-23-5)
  • chlorobenzene (CAS# 108-90-7)
  • chloroform (CAS# 67-66-3)
  • dichloromethane, also called methylene chloride (CAS# 75-09-2)
  • epichlorohydrin (CAS# 106-89-8)
  • methyl chloromethyl ether (CAS# 107-30-2)
  • perchloroethylene, also called PERC (CAS# 127-18-4)
  • trichloroethylene (CAS# 79-01-6)
  • vinyl chloride (CAS# 75-01-4)

Dichloromethane is included with the following chlorinated compounds among the OSHA-regulated carcinogens.

dichloromethane or methylene chloride methyl chloromethyl ether 3,3′-dichlorobenzidene (and its salts)
bis-chloromethyl ether vinyl chloride 1,2-dibromo-3-chloropropane

In addition to the SOP, appropriate engineering controls, and PPE, OSHA-regulated carcinogens also require signage on every door or entry to the area of the lab where the chemical(s) will be stored and used. The signage must include the following wording:

DANGER
(CHEMICAL IDENTIFICATION)
MAY CAUSE CANCER
AUTHORIZED PERSONNEL ONLY

This is a photo of three styles of placards used at ASU to mark areas where carcinogens or the carcinogen dichloromethane are stored and used. Sign 1 text: CAUTION Select Carcinogens! Designated Area. Use by Authorized Personnel Only. Sign 2 text: CAUTION This is a designated area for use of Particularly Hazardous Material including select carcinogens Only authorized workers wearing appropriate protective clothing and equipment shall be admitted Sign 3 text: DANGER Methylene Chloride Cancer Hazard Harmful if swallowed. Causes skin, eye, and respiratory tract irritation. May affect the central nervous system. Physical and health hazard information is available on the Material Safety Data Sheet