PAINT -The U.S. Environmental Protection Agency (EPA) has determined that certain volatile organic compounds (VOC) have been determined to have negligible photochemical reactivity (40 CFR 51.100(s)). As such, these compounds do not have to be counted toward the VOC content of coatings products. Several widely used exempt VOCs include, but are not limited to, acetone, methyl acetate, t-butyl acetate (TBAC), dimethyl carbonate, 2-amino-2-methyl-1-propanol (AMP), and parachlorobenzotrifluoride (PCBTF).
While EPA has exempted these compounds, various states and California Air Districts have to go through a rulemaking to adopt these exemptions (many have a direct reference to the EPA exemption, so the compounds are automatically exempted in many State when EPA exempts). California's South Coast Air Quality Management District (SCAQMD), Bay Area AQMD, San Diego AQMD, and Sacramento AQMD have not exempted several of these compounds, and recent regulatory activities in these air districts will likely lead to the removal of several exemptions and further restrictions.
The following provides a brief update on several exempt VOC compounds of interest.
T-Butyl Acetate (TBAC)
TBAC is exempt in all states, except for the four California air districts mentioned above. SCAQMD is expected to delete the exemptions for TBAC for Industrial Maintenance and certain Auto Refinish Coatings later in 2018.
Dimethyl carbonate and AMP
These two compounds are exempt — or will be soon regarding AMP — in all states except the four California air districts mentioned above.
PCBTF
PCBTF is exempt in all states and all California air districts. However, based on a recent National Toxicity Program study, SCAQMD will likely petition the State of California to review the health effects of PCBTF (which may lead to further restrictions including Proposition 65), which will likely lead to changes to South Coast's PCBTF exemption soon. Given the extensive use of PCTBF in the coatings industry, these changes could be very problematic.
ACA tracks VOC exemptions across the United States. ACA will host a member webinar later in 2018, providing an update on exempt VOC compounds under regulations across the country.