NCSAB Practices and Policies

Practices and Policies of the Department of Environment and Natural Resources:
Policies Concerning the Secretary's Science Advisory Board on Toxic Air Pollutants (NCSAB)


This document outlines the standard operating procedures for DENR staff interacting with the Secretary's Science Advisory Board on Toxic Air Pollutants (NCSAB). The DENR Secretary established the NCSAB upon the recommendation of the North Carolina Academy of Sciences. The NCSAB was created to provide technical expertise to DENR and the Division of Air Quality in the areas of toxicology and risk assessment. NCSAB duties also include issuing recommendations for acceptable ambient air concentrations for chemicals that carry the potential for causing adverse health effects as a result of industrial emissions in North Carolina. These recommendations are finalized by the NCSAB and forwarded to DENR, which undertakes to establish acceptable ambient air level guidelines (AALs) for these agents. The Toxics Protection Branch of the Division of Air Quality sets the final agenda for the NCSAB, and accepts NCSAB recommendations for review on behalf of DENR.

NCSAB Meetings
NCSAB meetings are held bimonthly at predetermined locations. The NCSAB Liaison is responsible for organizing the time and location of the meeting and disseminating the meeting agendas to interested parties in a timely manner. The NCSAB review process is an open forum. NCSAB frequently invites guest speakers to present toxicological and/or epidemiological information relevant to issues at hand. Industry and citizen groups may also request to provide information or make scientific presentations; these stakeholders must submit a request to the NCSAB Liaison. An attempt will be made to accommodate a request, so that information and/or a presentation can be made as efficiently as the schedule permits. Any material that is intended for NCSAB consideration should be provided to the NCSAB Liaison at least one week before that meeting date.

Deliberations involving a particular chemical usually require several months. This gives the NCSAB ample time to adequately consider the relevant literature and provides multiple opportunities for arranged presentations. Following deliberation, the NCSAB develops a recommendation, including a "range of risks" for the compound being reviewed. NCSAB recommendations are part of a narrative (see model outline below) prepared by the NCSAB Liaison and approved by NCSAB members. The narrative is not an in-depth examination of the toxicology of the compound. Rather, it is a document that is intended to discuss the NCSAB recommendation, with adequate explanation of all safety factors used, points of uncertainty or disagreement, a discussion on alternate recommendations and the resulting risks to the public health, and a mathematical representation of the final risk assessment methodology.

The NCSAB and DENR then publish the recommendation to its website and notify stakeholders to review and submit written comments on the recommendation for a 30-day period following publication. Recommendations received within the comment period are reviewed by the NCSAB and the recommendation is then revised and finalized, then forwarded to DENR.

The NCSAB issues ambient air concentration recommendations for toxic air pollutants but does not issue recommended averaging times. The Toxics Protection Branch of the Division of Air Quality is responsible for recommending appropriate averaging times based on the guidelines found in the 1986 North Carolina Academy of Sciences report entitled, "Report and Recommendations of the Air Toxics Panel of the North Carolina Academy of Sciences."

All NCSAB meetings are recorded in their entirety and minutes of each meeting are compiled. Meeting minutes that have been approved by the NCSAB are posted on the NCSAB website here. By clicking on the calendar year menu, the meeting minutes for that year can be selected and viewed.

NCSAB summary narratives will be provided to the Air Quality Committee and the Environmental Management Commission when the Division of Air Quality forwards a proposal for rule making based on an NCSAB recommendation.

NCSAB considers only toxicology and epidemiology in its risk assessment considerations. The Planning and Technical Services sections of the Division of Air Quality provide input to the Air Quality Committee (AQC) and the Environmental Management Commission (EMC) on economic and other technical issues. These economic and technical feasibility assessments must be provided in a timely manner to the AQC and EMC to allow informed risk management decisions on their part.

Attachment 1: NCSAB Model Narrative Outline
Summary: Overview of NCSAB consideration
  • Reason for consideration: see Selection and Prioritization document
  • NC Air Toxics background for agent in question (if applicable)
  • Short summary of NCSAB deliberation and decision process
  • Basis for decision and final conclusion
  • Final recommendation

Data Assessment: Toxicological, epidemiological review processes

  • Short (one paragraph) synopsis of all known adverse effects
  • Non-finalized endpoint(s) of consideration
    • Short summary of effect
    • Review of literature considered
    • "Chicken scratch" risk assessment outcome
  • Finalized endpoint(s) of consideration
    • More detailed summary of effect
    • Review of literature
    • Greater detail on study used for final risk assessment
    • Risk assessment calculation
    • Justification for uncertainty factors used
    • Finalized recommendation

Conclusion: Narrative of NCSAB risk assessment deliberation process

  • Agent and health effect of principal importance
  • Outside party involvement (if applicable)
  • NCSAB conclusion and recommendation
    • Degree of confidence and areas of contention or disagreement
    • "Range of Risks"
    • Alternate values, approaches used and associated risks
    • Comparison
    • Illustration of other states' AAL values and EPA reference concentration value
    • "Non-traditional" risk assessment approaches used by NCSAB (if applicable)

Averaging Time: DENR recommended averaging time based on NCAS guidelines

Bibliography: Listing of relevant scientific literature and presentations considered by NCSAB