Background
The National Toxicology Program (NTP) announces its intent to review additional agents, substances, mixtures and exposure circumstances for possible listing in the Report on Carcinogens (RoC), Tenth Edition. This Report (previously known as the Annual Report on Carcinogens) is a Congressionally mandated listing of known human carcinogens and reasonably anticipated human carcinogens and its preparation is delegated to the National Toxicology Program by the Secretary, Department of Health and Human Services (DHHS). Section 301(b)(4) of the Public Health Service Act, as amended, provides that the Secretary, DHHS shall publish a report which contains a list of all substances (1) which either are known to be human carcinogens or may reasonably be anticipated to be human carcinogens, and (2) to which a significant number of persons residing in the United States (US) are exposed. The law also states that the reports should provide available information on the nature of exposures, the estimated number of persons exposed and the extent to which the implementation of Federal regulations decreases the risk to public health from exposure to these chemicals.
The scientific review of the nominated agents, substances, mixtures or exposure circumstances involves three separate scientific reviews: two Federal review groups and one non-government peer review body (a subcommittee of the NTP Board of Scientific Counselors) that meets in an open, public forum. Throughout the review process, multiple opportunities are provided for public input including at the Subcommittee meeting. In reviewing nominations for the RoC, all available data and public comments, which are relevant to application of the criteria for inclusion or removal of candidate agents, substances, mixtures or exposure circumstances or for a change in a candidate's classification, are evaluated. The criteria used in the review process are as follows:
Known To Be Human Carcinogens
There is sufficient evidence of carcinogenicity from studies in humans which indicates a causal relationship between exposure to the agent, substance or mixture and human cancer.
Reasonably Anticipated To Be Human Carcinogens
There is limited evidence of carcinogenicity from studies in humans which indicates that causal interpretation is credible but that alternative explanations such as chance, bias or confounding factors could not adequately be excluded; or
There is sufficient evidence of carcinogenicity from studies in experimental animals which indicates there is an increased incidence of malignant and/or a combination of malignant and benign tumors: (1) in multiple species, or at multiple tissue sites, or (2) by multiple routes of exposure, or (3) to an unusual degree with regard to incidence, site or type of tumor or at onset; or
There is less than sufficient evidence of carcinogenicity in humans or laboratory animals; However, the agent, substance or mixture belongs to a well defined, structurally-related class of substances whose members are listed in a previous Report on Carcinogens as either a known to be human carcinogen, or reasonably anticipated to be human carcinogen or there is convincing relevant information that the agent acts through mechanisms indicating it would likely cause cancer in humans.
Conclusions regarding carcinogenicity in humans or experimental animals are based on scientific judgment, with consideration given to all relevant information. Relevant information includes, but is not limited to dose response, route of exposure, chemical structure, metabolism, pharmacokinetics, sensitive subpopulations, genetic effects, or other data relating to mechanism of action or factors that may be unique to a given substance. For example, there may be substances for which there is evidence of carcinogenicity in laboratory animals but there are compelling data indicating that the agent acts through mechanisms which do not operate in humans and would therefore not reasonably be anticipated to cause cancer in humans.
A detailed description of the review procedures, including the steps in the formal review process, is available at http://ntp-server.niehs.nih.gov or can be obtained by contacting: Dr. C.W. Jameson, National Toxicology Program, Report on Carcinogens, MD EC-14, P.O. Box 12233, Research Triangle Park, NC 27709; phone: (919) 541-4096, fax: (919) 541-0144, email: jameson@niehs.nih.gov.
Public Comment Requested
The NTP is considering 11 agents, substances, mixtures and exposure circumstances for possible review in 2000, as either a new listing in or changing the current listing from reasonably anticipated to be a human carcinogen to the known to be a human carcinogen category in the Tenth Report. These nominations are provided in the following table with their Chemical Abstracts Services (CAS) Registry numbers (where available) and pending review action. The NTP solicits public input on these 11 nominations and asks for relevant information anyone may have concerning their carcinogenesis, as well as current production data, use patterns, or human exposure information. The NTP also invites interested parties to identify any scientific issues related to the listing of a specific nomination in the RoC that they feel should be addressed during the reviews. Comments concerning these nominations for listing in, changing the current listing in, or delisting from the Tenth Report on Carcinogens will be accepted through June 5, 2000. Individuals submitting public comments are asked to include relevant contact information (name, affiliation (if any), address, telephone, fax, and email). Comments or questions should be directed to Dr. C. W. Jameson at the address listed above.
Additional Nominations for Delisting or Listing Encouraged
The NTP solicits and encourages the broadest participation from interested individuals or parties in nominating agents, substances, or mixtures for listing in or delisting from the Tenth and future RoCs. Nominations should contain a rationale for listing or delisting. Appropriate background information and relevant data (e.g. Journal articles, NTP Technical Reports, IARC listings, exposure surveys, release inventories, etc.), which support a nomination, should be provided or referenced when possible. Contact information for the nominator should also be included (name, affiliation (if any), address, telephone, fax, and email). Nominations should be sent to Dr. Jameson's attention at the address given above.
Dated: March 27, 2000.
Kenneth Olden,
Director, National Toxicology Program.
Summary for Nominations To Be Reviewed in 2000 for Consideration of Listing In or Delisting From the Tenth Report on Carcinogens
[FR Doc. 00-8310 Filed 4-4-00; 8:45 am]
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