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PROPOSAL:

Report on the Certification of VOC-Exempt Compounds as Clean Air Solvents

SYNOPSIS:

On July 11, 1997, the Board amended Rule 1122 - Solvent Degreasers, and also directed staff to investigate whether VOC-exempt chemicals should be certified as Clean Air Solvents (CAS) along with aqueous materials that meet the requirements of CAS. The CAS program was originally intended to promote the use of water-based cleaning materials that meet all future AQMD rule requirements and were environmentally benign. This report indicates that (i) VOC-exempt chemicals would be eligible for certification as CAS, and (ii) additional toxicity criteria may be needed for the CAS definition.

COMMITTEE:

Not Applicable

RECOMMENDED ACTION:

Receive and File

Barry R. Wallerstein, D.Env.
Acting Executive Officer

Background

Rule 1122 - Solvent Degreasers, was last amended in July 1997 to further reduce VOC emissions from the use of degreasers. In addition to other provisions, the rule provides incentives for the use of Clean Air Solvents (CAS), which are defined in Rule 102 - Definitions. The use of CAS is voluntary and not mandated under any AQMD rules. A CAS is a solvent containing no more than 50 gm/l of VOCs, no global warming or ozone depleting compounds, no hazardous air pollutants, and with low reactivity and low vapor pressure. The original staff intent was to certify aqueous solvents that met the above criteria, in order to encourage their use and provide assistance to the general consumer.

At the July 1997 public hearing, the Board received testimony asking for certification of VOC-exempt compounds as CAS, if they met all the established criteria mentioned earlier. Staff was accordingly directed to investigate this issue and report back to the Board with recommendations for further action.

Analyses

Staff has consulted with the public, vendors and suppliers of both aqueous and VOC-exempt solvents, and staff from responsible agencies such as the Department of Toxic Substance Control (DTSC), the California Air Resources Board (ARB), and the Office of Environmental Health Hazard Assessment (OEHHA). From an ozone reduction point of view, water (which constitutes 95% or more of the aqueous solvents) and VOC-exempt compounds behave in a similar manner, having negligible ozone-forming potential. Therefore, VOC-exempt compounds should be considered for CAS certification. However, it was not clear if the VOC-exempt chemicals were safe from a toxicity standpoint. Similar concerns can also be raised for the small amounts of other chemicals that may be present in aqueous solvents. The present screening criterion for toxicity for CAS is that it must not contain a compound listed as a hazardous air pollutant in the federal Clean Air Act. [ OEHHA has recommended that the present toxicity criteria for CAS Certification need to be expanded for protection of worker health.]

Staff will investigate the inclusion of additional toxicity criteria in order to ensure that the certified CAS do not produce other undesirable toxic impacts. However, staff would also like to maintain the momentum of the existing CAS certification program, which is providing assistance to both the supplier and the consumer, by keeping it as practical as possible. As requested by industry, staff will consult with the USEPA and affected parties for updating the criteria for excluding the global warming compounds, which is an ongoing process at USEPA.

Conclusions

VOC-exempt compounds have been determined to be eligible for certification as a CAS if they meet the substantive criteria of CAS. Staff also proposes to include additional toxicity criteria, such as the list of toxic compounds in AB 2588, in the definition of CAS in Rule 102 through a future rulemaking action.

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