Comprehensive VOC Analysis Method for Architectural Coatings

By Lukas Brickweg, Audrey Guillermo, Dane Jones, Max Wills

Specific regulatory volatile organic compound (VOC) limits have been set for architectural coatings to ensure that emissions from these materials will decrease and air qual­ity will improve. As regulations have lowered limits of allowed VOCs, a significant prob­lem with enforceability of these regulations has developed since reliable methods for the analysis of these VOCs are not available.

Currently, the United States Environmental Protection Agency’s (U.S. EPA) Method 24 is used to test the VOC content of coatings. It is widely accepted that Method 24 is not reliable for the analysis of low VOC waterborne coatings. Method 24 is also not suit­able for determining the VOC content of solventborne coatings containing high levels of exempt compounds. In both cases, the reason for the unreliability of Method 24 results from its being an indirect method of measuring VOCs in these types of coatings.

Several other methods have been developed to deal with the problems of Method 24. However, none of these methods is applicable to all types of architectural coatings and none can deal with the specific problems mentioned. In addition, Method 24 cannot de­termine the level of hazardous air pollutants (HAPs) in coatings.

We have developed direct methods for determining the VOC content in architectural coatings based on direct injection, headspace analysis, and solid phase microextraction (SPME) using gas chromatography with both flame ionization and mass spectral detec­tion.

These methods are suitable for direct determination of VOCs for all waterborne ar­chitectural coatings, even those with very low VOC levels. The methods are also suitable for direct determination of HAPs and exempt compounds in solventborne coatings. These methods can be used with confidence to determine whether or not a given coating meets the appropriate regulatory VOC level.