BOARD MEETING DATE: January 9, 2004
AGENDA NO. 10

Notification of Recent State-Approved Health Risk Values for New Source Review

SYNOPSIS:

In August 2003, the state Office of Environmental Health Hazard Assessment (OEHHA) finalized chronic risk values for fluorides, including hydrogen fluoride. Rule 1401(e)(2) and (e)(3) require an analysis and report to the Board before new and updated risk factors, respectively, are used for air toxics new source review. In addition, Rule 1402(j)(4) requires an analysis of the potential impacts on sources subject to Rule 1402 prior to use of new or updated risk factors for facility-wide health risk assessments. Under normal circumstances staff would be able to comply with these rule requirements. However, in finalizing the risk values, the state has not yet completed a multi-pathway assessment. Without this assessment, staff cannot complete the required impact analysis. Staff recommends postponing the Rule 1401 amendment and Rule 1402 analysis until 150 days after OEHHA has finalized the multi-pathway assessment.

COMMITTEE:

Not Applicable

RECOMMENDED ACTION:

Approve staff’s recommendation to postpone amending Rule 1401 and analyzing Rule 1402 until 150 days after OEHHA has finalized the multi-pathway assessment; facilities use of the OEHHA-approved risk factors for fluorides under Rule 1402 shall be postponed until 90 days after the Rule 1402 analysis is submitted to the Board.

Barry R. Wallerstein, D.Env.
Executive Officer

Background

Rule 1401 – New Source Review of Toxic Air Contaminants establishes permitting requirements for new, relocated and modified sources that emit one or more of the toxic air contaminants (TACs) listed in the rule.

The Office of Environmental Health Hazard Assessment (OEHHA) establishes risk values for TACs. The Scientific Review Panel (SRP) reviews and approves the methodologies used to develop these risk values, thereby finalizing these values for use by state and local agencies in assessing risk from exposures to TACs. This approval is considered final action by the state.

Rule 1401(e)(2) and (e)(3) requires an analysis and report to the Board before new and updated risk factors, respectively, are used for new source review. This includes a requirement for the AQMD to bring proposed amendments to the rule to update the list of TACs within 150 days of final action by OEHHA. Rule 1402– Control of Toxic Air Contaminants from Existing Sources, requires a report to the Governing Board within 150 days of final action by OEHHA on the potential impacts of the changes before new or updated risk factors are used for risk assessments in Rule 1402.

Rule 1401 and 1402 Impact Assessment

On June 20, 2003, the SRP approved the chronic reference exposure level (REL) risk values for fluorides, including hydrogen fluoride. The final technical support documents were subsequently released by OEHHA on August 15, 2003. However, OEHHA’s analysis did not include a multi-pathway assessment as it has in the past. Consequently an impact assessment cannot be completed as required by Rules 1401 and 1402.

The multi-pathway analysis is needed to complete both the impact assessment and the analysis required for permitting purposes. OEHHA is currently working to complete the multi-pathway assessment; once finished, it will go through a public comment process. The multi-pathway factor is especially important for fluorides as there are two routes (oral and inhalation) of exposure associated with them. The additional (oral) route of exposure has a compounding effect on the potential risk associated with the inhalation of emissions.

Conclusion

At this time staff is unable to evaluate whether any additional facilities would be subject to either Rule 1401 or 1402. In addition, the actual permit evaluation cannot proceed. On this basis, staff recommends postponing the Rule 1401 amendment and Rule 1402 analysis until 150 days after OEHHA has finalized the multi-pathway assessment.

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