EXECUTIVE SUMMARY AQ-2013-006 DEFINITIONS.PDF

Executive Summary
Of The Report to the Board of Supervisors
Prepared by the Maricopa County Air Quality Department
Board Hearing Date: September 25, 2013
Case #/Title: AQ-2013-006-Definition Of “Non-Precursor Organic Compound”
Agenda Item:
Supervisor Districts: All Districts
The Maricopa County Air Quality Department complied with all statutory and county policies throughout this
rulemaking process. Per the Enhanced Regulatory Outreach Program Policy: “In addition to the required staff report, an
executive summary of the report including an overview of stakeholder input and staff responses will be provided to the Board
of Supervisors at least one week prior to any Board of Supervisors’ public hearing.”
Overview Of The Report To The Board Of Supervisors: Periodically the U.S. Environmental Protection Agency
(EPA) updates the definition of a volatile organic compound (VOC). Included in the EPA definition of a VOC is a list of
compounds that are not considered to be a contributing factor to the formation of ground level ozone (40 CFR 51.100(s)(1)).
Maricopa County defines VOC identical to the EPA definition of a VOC as found in 40 CFR 51.100(s). Maricopa County
separately defines the compounds the EPA has “…determined to have negligible photochemical reactivity…” as “non-
precursor organic compounds.”
Twenty-two (22) rules in the Maricopa County Air Pollution Control Regulations include either a definition of
“VOC” or a definition of “non-precursor organic compound” or include both definitions. In the Maricopa County Air
Pollution Control Regulations, Rule 100 (General Provisions and Definitions), the department is proposing to delete the list
of non-precursor organic compounds. The department is proposing to relocate the list of EPA-recognized “non-precursor
organic compounds” into Maricopa County Air Pollution Control Regulations, Appendix G (Incorporated Materials).
Appendix G is routinely revised during the incorporation by reference rulemaking, thus providing a means to expeditiously
update any revisions to the EPA definition of VOC. For the remaining twenty-one (21) rules, the department is proposing to
delete the definitions of “non-precursor organic compound” and “VOC.” This will provide a consistent definition of VOC
and “non-precursor organic compounds” throughout the Maricopa County Air Pollution Control Regulations, thus
eliminating the current confusion between the definitions found in Rule 100 and the definitions found in each of these rules.
In addition, this will make Maricopa County regulations consistent with other jurisdictions and allow businesses to use a
wider range of materials leveling the playing field for companies within Maricopa County with those operating in other
jurisdictions. Citizens will benefit due to the reduction in ground-level ozone formation by the expected increase in the use of
non-precursor organic compounds. The proposed rule revisions should not have any negative economic, consumer or public
impact in Maricopa County.
Overview Of Stakeholder Input And Staff Responses: During the rulemaking process, the department received
comments from the following stakeholders: The American Coating Association (ACA) and Lyondell Chemical Company.
The City of Phoenix submitted a comment requesting a copy of the department’s stakeholder presentation.
The American Coatings Association (ACA) stated that it “…supports Maricopa County directly referencing the
most recent update to EPA definition of VOC - however we suggest referencing both 40 CFR 51.100(s)(1) and 40 CFR
51.100 (s)(5) since (s)(5) exempts TBAc which is a very important exempt compound for the coatings industry.”
In addition, the department received an e-mail with an attached letter from the ACA stating: “The American
Coatings Association (ACA) supports Lyondell’s comments and requests that the Maricopa County Air Quality Department
amend the proposed definition of non-precursor organic compounds as follows. The coatings industry is under constant
pressure to reformulate products to lower VOC content. As a result, there is a critical and urgent need for safe, effective and
affordable exempt solvents, and coating formulators need all available tools TBAC to formulate both lower VOC and
reactivity coatings. TBAC is very useful for coatings formulation…This will not change the department’s definition in any
way, but it will clarify the VOC exempt status of TBAC in Appendix G. Any future changes to the reporting requirement of
TBAC will be more readily made in Appendix G and would not require reopening Rule 100.”
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The Lyondell Chemical Company stated: “Your list of non-photochemically reactive compounds in Appendix G
does not include Tert-butyl acetate, also known as TBAC, which was exempted in 2004. It is listed in 40 CFR 51.100 (s)(5).
Please add TBAC to your list of exempt compounds in Appendix G. Thank you.”
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