OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

February 2, 1994

Angela M. Mack
Product Safety Information Coordinator
25 East Algonquin Road
Des Plaines, Illinois 60017-2000

Dear Ms. Mack:

Thank you for your letter of October 5 concerning the requirements under the Occupational Safety and Health Administration's (OSHA) Hazard Communication Standard (HCS), 29 CFR 1910.1200. Specifically, you inquired about section 1910.1200(d)(4)(ii) regarding hazard determination for carcinogenic compounds, in particular cobalt phthalocyanine sulfonate compounds.

Your question has been addressed in OSHA's compliance directive, Inspection Procedures for the Hazard Communication Standard (CPL 2-2.38C). This directive states the following: "For purposes of compliance with the MSDS and labeling requirements, the IARC monograph's summary evaluation for the chemical can generally be relied upon but it may be necessary to review the actual evaluations. In some cases, a group of compounds may be listed in the summary as carcinogenic but closer examination of the appropriate monograph will reveal that IARC had data to support the carcinogenicity of only certain compounds. Those compounds are the only ones covered by the HCS."

Under the Hazard Communication Standard chemical manufacturers have the responsibility to "identify and consider" all available scientific evidence for the chemicals they produce or import to determine if they are hazardous. In general, if an IARC monograph does not address a specific chemical or group of chemicals, the results of the monograph would not apply. However, it is your duty as the chemical manufacturer to evaluate all other scientific evidence and available studies to determine if any other evidence exists that may indicate a carcinogenic health hazard is associated with exposure to the cobalt phthalocyanine sulfonate compounds. The fact that your product was not addressed in the IARC monograph does not relieve you of the mandate to look elsewhere for other statistically significant evidence that carcinogenic or other health effects may result from employee exposure to cobalt phthalocyanine sulfonate compounds.

We hope this information is helpful. If you have any further questions please contact us at (202) 219-8036.


Ruth McCully, Director
Office of Health Compliance Assistance

October 7, 1993

U.S. Department of Labor
Occupational Safety and Health Administration
200 Constitution Avenue, N.W.
Washington, DC 20210

Attention: Jennifer Silk
Re: OSHA Hazard Communication Standard

Dear Ms. Silk:

We would like to obtain clarification of the OSHA Hazard Communication Standard, particularly Section 1910.1200(d)(4)(ii) regarding hazard determination for carcinogenic compounds. The standard states:

(4) Chemical manufacturers, importers and employers evaluating chemicals shall treat the following sources as establishing that a chemical is a carcinogen or potential carcinogen for hazard communication purposes:

(ii) International Agency for Research on Cancer (IARC) Monographs.

Our concern is the applicability of this requirement given the following circumstances:

We have a group of products that contain cobalt phthalocyanine sulfonate compounds. The 52 Volume of the IARC Monograph series includes an evaluation of cobalt and cobalt compounds. The Monograph states at page 363 that agents considered in it include (a) metallic cobalt, (b) cobalt alloys, and (c) cobalt compounds. It specifically then says: "Organic cobalt-containing agents (e.g. vitamin b(12)) are not covered comprehensively in the monograph." This infers that IARC was treating organic cobalt-containing compounds differently than inorganic cobalt-containing compounds, and was excluding such compounds from the general evaluation of cobalt and cobalt compounds.

This differentiation is further shown in the data present in the Monograph. Of the nine specific chemicals evaluated by IARC, two of them show sufficient animal evidence for carcinogenicity (cobalt metal powder and cobalt [II] oxide); three showed limited evidence and the remainder showed insufficient evidence. Notably, the two organic cobalt-containing compounds, cobalt acetate and cobalt naphthenate, showed insufficient evidence of carcinogenicity in experimental animals. Though the overall evaluation on page 450 of the Monograph states that cobalt and cobalt-compounds are possibly carcinogenic to humans (Group 2B), the specific evaluations on page 449 of the Monograph say: "There is inadequate evidence for the carcinogenicity of ... cobalt naphthenate and cobalt [III] acetate in experimental animals."

Based on our evaluation of the information presented in the IARC Monograph, there is no evidence to show that organic cobalt-containing compounds present a potential carcinogenic risk. Our products contain cobalt phthalocyanine sulfonate compounds, which were not specifically analyzed in the IARC Monograph. Nevertheless, cobalt phthalocyanine sulfonate is an organic cobalt-containing compound like cobalt naphthenate and cobalt [III] acetate, which were examined in the IARC Monograph.

In terms of the OSHA Hazard Communication Standard, can our hazard evaluation be based on the specific information presented within the IARC Monograph, or are we bound by the overall evaluation of cobalt and cobalt compounds. In other words, must we state that products, which contain cobalt phthalocyanine, are considered by IARC to be possibly carcinogenic to humans (Group 2B), when specific information in the IARC Monograph says that there is inadequate evidence for the carcinogenicity of organic cobalt-containing compounds.

Your advice on this question will be greatly appreciated.

Very truly yours,

Angela M. Mack
Product Safety Information Coordinator