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Request for Information: Announcement of Carcinogen and Recommended Exposure Limit (REL) Policy Assessment

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National Institute for Occupational Safety and Health (NIOSH) of the Centers for Disease Control and Prevention (CDC), Department of Health and Human Services (HHS).


Notice of public comment period.


The National Institute for Occupational Safety and Health (NIOSH) of the Centers for Disease Control and Prevention (CDC) intends to review its approach to classifying carcinogens and establishing recommended exposure limits (RELs) for occupational exposures to hazards associated with cancer. As part of this effort, NIOSH is requesting initial input on these issues (including answers to the 5 questions in the following section), to be submitted to the NIOSH Docket number 240, for a comment period lasting through September 22, 2011. This information will be taken under consideration and used to inform NIOSH efforts to assess and document its carcinogen policy and REL policy regarding occupational hazards associated with cancer. NIOSH has also created a new NIOSH Cancer and REL Policy Web Topic Page [see​niosh/​topics/​cancer/​policy.html] to provide additional details about this effort and progress updates.

Public Comment Period: Comments must be received by September 22, 2011.


Written comments, identified by docket number NIOSH-240, may be submitted by any of the following methods:

  • Mail: NIOSH Docket Office, Robert A. Taft Laboratories, MS-C34, 4676 Columbia Parkway, Cincinnati, Ohio 45226.
  • Facsimile: (513) 533-8285.
  • E-mail:

All information received in response to this notice will be available for public examination and copying at the NIOSH Docket Office, 4676 Columbia Parkway, Room 111, Cincinnati, Ohio 45226. A complete electronic docket containing all comments submitted will be available on the NIOSH Web page at​niosh/​docket, and comments will be available in writing by request. NIOSH includes all comments received without change in the docket, including any personal information provided. All electronic comments should be formatted as Microsoft Word. Please make reference to docket number NIOSH-240.


NIOSH is announcing a Request for Information on key issues identified and associated with the NIOSH Carcinogen and REL policies. Special emphasis will be placed on consideration of technical and scientific issues with the current NIOSH Cancer and REL Policies that require further examination including the following:

(1) Should there explicitly be a carcinogen policy as opposed to a broader policy on toxicant identification and classification (e.g. carcinogens, reproductive hazards, neurotoxic agents)?

(2) What evidence should form the basis for determining that substances are carcinogens? How should these criteria correspond to nomenclature and categorizations (e.g., known, reasonably anticipated, etc.)?

(3) Should 1 in 1,000 working lifetime risk (for persons occupationally exposed) be the target level for a recommended exposure limit (REL) for carcinogens or should lower targets be considered?

(4) In establishing NIOSH RELs, how should the phrase “to the extent feasible” (defined in the 1995 NIOSH Recommended Exposure Limit Policy) be interpreted and applied?

(5) In the absence of data, what uncertainties or assumptions are Start Printed Page 52665appropriate for use in the development of RELs? What is the utility of a standard ”action level” (i.e., an exposure limit set below the REL typically used to trigger risk management actions) and how should it be set? How should NIOSH address worker exposure to complex mixtures?

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NIOSH and stakeholders have expressed concerns recently about limitations in the NIOSH Carcinogen Policy, prompting NIOSH to initiate a review of the carcinogen policy in 2010. A major limitation in the policy is the use of the term “Potential Occupational Carcinogen” which dates to the 1980 OSHA hazard classification for carcinogens outlined in 29 CFR 1990.103 and is defined as “* * * any substance, or combination or mixture of substances, which causes an increased incidence of benign and/or malignant neoplasms, or a substantial decrease in the latency period between exposure and onset of neoplasms in humans or in one or more experimental mammalian species as the result of any oral, respiratory or dermal exposure, or any other exposure which results in the induction of tumors at a site other than the site of administration. This definition also includes any substance which is metabolized into one or more potential occupational carcinogens by mammals.” A major limitation of this definition is that the policy allows for only one cancer category, which is “potential occupational carcinogen.” The adjective “potential” conveys uncertainty that is not warranted with many carcinogens such as asbestos, benzene, and others. This policy does not allow for classification on the basis of the magnitude and sufficiency of the scientific evidence. In contrast, other organizations, such as the International Agency for Research on Cancer (IARC) and the National Toxicology Program (NTP) allow for a more differential classification.

The revision of the NIOSH Carcinogen Policy also coincides with the international realization that there is a need for more efficient and quicker means of classifying chemicals. Qualitative and semi-quantitative approaches such as hazard banding are increasingly being investigated as a means of addressing the vast numbers of unregulated chemicals. NIOSH has been in collaboration with various organizations to consider utilizing hazard banding approaches to control chemicals. This will also be reflected in the review of the carcinogen and RELs policies.

This Federal Register notice serves to provide stakeholders and the public an opportunity for input on the revision of the NIOSH Carcinogen and REL Policies. It is anticipated that NIOSH will develop a report on the revised NIOSH Carcinogen and REL Policies to be made available in the Spring of 2012. Additional information regarding NIOSH plans to assess and revise the Carcinogen and REL Policy can be found in the April 2011 NIOSH e-news at​niosh/​enews/​enewsV8N12.html and on the NIOSH Cancer and REL Policy Web Topic Page [see​niosh/​topics/​cancer/​policy.html].

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T.J. Lentz, telephone (513) 533-8260, or Faye Rice, telephone (513) 533-8335, NIOSH, MS-C32, Robert A. Taft Laboratories, 4676 Columbia Parkway, Cincinnati, Ohio 45226.

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Dated: August 12, 2011.

John Howard,

Director, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention.

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[FR Doc. 2011-21405 Filed 8-22-11; 8:45 am]