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Risk Assessment

Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens


In 1983, the National Academy of Sciences (NAS)/National Research Council (NRC) published its report entitled Risk Assessment in the Federal Government: Managing the Process. In that report, the NRC recommended that Federal regulatory agencies establish "inference guidelines" to promote consistency and technical quality in risk assessments and to ensure that the risk assessment process was maintained as a scientific effort separate from risk management. EPA responded to this recommendation by publishing a set of risk assessment guidelines in 1986, including the Guidelines for Carcinogen Risk Assessment (51 FR 33992, September 24, 1986).

EPA began revising the 1986 cancer guidelines in light of significant advances in our understanding of the processes of carcinogenesis and the modes of actions of disease at the cellular level. Revising the cancer guidelines is in keeping with EPA's original intent when it issued the first set of final risk assessment guidelines in 1986. The risk assessment guidelines were meant to be dynamic, flexible documents that would evolve to reflect the current state of the science and risk assessment practices. In keeping with this, EPA undertook an effort to revise the cancer guidelines as described below in the History and Chronology section.


  • Mar 2003 EPA released the Draft Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens for public comment. At this time, the SAB reviewed the Draft Supplemental Guidance.
  • Mar 2004 EPA received SAB comments on the Supplemental Guidance.
  • 2004/05 In response to an SAB recommendation, EPA extended the analysis supporting the Supplemental Guidance. The National Institute of Environmental Health Sciences (NIEHS) journal, Environmental Health Perspectives, peer reviewed this analysis and accepted it for publication. A separate peer review of this analysis was also conducted.
  • Mar 2005 EPA published the final Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens.

Next Steps

The Supplemental Guidance serve as EPA's recommendation to Agency risk assessors preparing cancer risk assessments. As EPA prepares cancer assessments under the Integrated Risk Information System (IRIS) program, as well as in other EPA programs, the Agency intends to begin to use the Guidelines and Supplemental Guidance. EPA also intends to consider the Guidelines and Supplemental Guidance along with other selection factors when EPA selects agents for reassessment in annual IRIS agendas.


U.S. EPA. Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens. U.S. Environmental Protection Agency, Washington, DC, EPA/630/R-03/003F, 2005.

Document Details and Links

The Cancer Guidelines explicitly call for consideration of possible sensitive sub-populations and/or life-stages (such as childhood). The consideration of childhood risks in the final Cancer Guidelines has been augmented by the development of the document entitled Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens EPA/630/R-03/003F. 

EPA cancer risk assessments may be conducted differently than envisioned in this Supplemental Guidance for many reasons including:

  • New information
  • New scientific understanding
  • Different science policy judgment

The practice of risk assessment with respect to accounting for early-life exposures to toxicants continues to develop, and specific components of this Supplemental Guidance may become outdated or may otherwise require modification in individual settings. It is EPA’s intent to use, to the extent practicable and consistent with Agency statutes and regulations, the best available science in its risk assessments and regulatory actions and this Supplemental Guidance is not intended to provide any substantive or procedural obstacle in achieving that goal.

Therefore, the Supplemental Guidance has no binding effect on EPA or on any regulated entity. Where EPA does use the approaches in the Supplemental Guidance in developing risk assessments, it will be because EPA has decided in the context of that risk assessment that the approaches from the Supplemental Guidance are suitable and appropriate. This judgment will be tested through peer review, and the risk assessment will be modified to use different approaches if appropriate.

This Supplemental Guidance is intended for guidance only. It does not establish any substantive “rules” under the Administrative Procedure Act or any other law and has no binding effect on EPA or any regulated entity, but instead represents a non-binding statement of policy.

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