Notice of Intent to List Chemicals by the Labor Code Mechanism: Chloral, chloral hydrate, 1,1,1,2-tetrachloroethane, and trichloroacetic acid

The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) intends to list the chemicals identified in the table below as known to the State to cause cancer under the Safe Drinking Water and Toxic Enforcement Act of 1986.  The Act, commonly known as Proposition 65, is codified in Health and Safety Code section 25249.5 et seq.  This action is being taken pursuant to the Labor Code mechanism contained in Health and Safety Code section 25249.8(a).








IARC (2012);
Guha et al. (2012)

Chloral hydrate



IARC (2012);
Guha et al. (2012)




IARC (2012);
Guha et al. (2012)

Trichloroacetic acid



IARC (2012);
Guha et al. (2012)

Background on listing by the Labor Code mechanism: Health and Safety Code section 25249.8(a) incorporates California Labor Code Sections 6382(b)(1) and 6382(d) into Proposition 65.  The law requires that certain substances identified by the International Agency for Research on Cancer (IARC) be listed as known to cause cancer under Proposition 65.  Labor Code section 6382(b)(1) refers to substances identified as human or animal carcinogens by IARC.  Labor Code section 6382(d) refers to chemicals that are within the scope of the federal Hazard Communications Standard.  The Federal Hazard Communications Standard relies on chemical designations made by IARC.  An explanation of the carcinogenicity classifications used by IARC, and the Monographs development and peer review by the international Working Groups of scientific experts convened by IARC, may be found at the following URL:

As the lead agency for the implementation of Proposition 65, OEHHA evaluates whether chemical listing is required by Proposition 65.

OEHHA’s determination: Chloral, chloral hydrate, 1,1,1,2-tetrachloroethane, and trichloroacetic acid each meet the requirements for listing as known to the state to cause cancer for purposes of Proposition 65.

IARC has published on its website a list entitled “Agents classified by the IARC Monographs, Volume 1-106" (IARC, 2012).  IARC concludes that chloral and chloral hydrate are each classified in Group 2A (the agent is “probably carcinogenic to humans”) and1,1,1,2-tetrachloroethane andtrichloroacetic acidare each classified in Group 2B (the agent is “possibly carcinogenic to humans”).  IARC concludes that there is “sufficient evidence of carcinogenicity in experimental animals” for chloral, chloral hydrate, 1,1,1,2-tetrachloroethane andtrichloroacetic acid (Guha et al., 2012). Therefore, these substances meet the requirements of both Labor Code sections 6382(b)(1) and (d).

Opportunity for comment: OEHHA is providing this opportunity to comment as to whether the chemicals identified above meet the requirements for listing as causing cancer specified in Health and Safety Code section 25249.8(a).  Because these are ministerial listings, comments should be limited to whether IARC has identified the specific chemical or substance as a known or potential human or animal carcinogen.  Under this listing mechanism, OEHHA cannot consider scientific arguments concerning the weight or quality of the evidence considered by IARC when it identified these chemicals and will not respond to such comments if they are submitted.

OEHHA must receive comments by 5:00 p.m. on Monday, August 26, 2013.  We encourage you to submit comments in electronic form, rather than in paper form. Comments transmitted by e-mail should be addressed to, and should include “NOIL” and the chemical name in the subject line.  Comments submitted in paper form may be mailed, faxed, or delivered in person to the address below.  A public workshop will be held only upon request.  Such request must be made in writing within 10 days from the publication of this notice to the Proposition 65 Office of OEHHA via email at or to the attention of the Proposition 65 Office at the address listed below:

Mailing Address: Sam Delson
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-19B
Sacramento, California 95812-4010
Fax: (916) 323-2265
Street Address: 1001 I Street
Sacramento, California 95814

Any public comments received will be posted after the close of the comment period.  If you have any questions, please contact Sam Delson at or at (916) 445-6900. 

Footnotes and References

Guha N, Loomis D, Grosse Y, Lauby-Secretan B, El Ghissassi F, Bouvard V, Benbrahim-Tallaa L, Baan R, Mattock H, Straif on behalf of the International Agency for Research on Cancer Monograph Working Group. (2012). Carcinogenicity of trichloroethylene, tetrachloroethylene, some other chlorinated solvents, and their metabolites.  The Lancet Oncology. Published online October 26, 2012, doi:10.1016/S1470-2045(12)70485-0. [URL:]

International Agency for Research on Cancer (IARC, 2012). Agents Classified by the IARC Monographs, Volumes 1-106. Available at URL:  [Accessed June 4, 2013].