Method 24
Determination of Volatile Matter Content, Water Content, Density, Volume Solids, and Weight Solids of Surface Coatings
40 CFR Part 60, Appendix A-7
From the method — regulatory text
Sections 1.0 and 2.0 of Method 24—Determination of Volatile Matter Content, Water Content, Density, Volume Solids, and Weight Solids of Surface Coatings, as published at 40 CFR Part 60, Appendix A-7. Retrieved 10/07/2026. The full method is on the eCFR.
1.0 Scope and Application
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Volatile organic compounds Water | No CAS Number assigned 7732-18-5 |
1.2 Applicability. This method is applicable for the determination of volatile matter content, water content, density, volume solids, and weight solids of paint, varnish, lacquer, or other related surface coatings.
1.3 Precision and Bias. Intra-and inter-laboratory analytical precision statements are presented in section 13.1. No bias has been identified.
2.0 Summary of Method
2.1 Standard methods are used to determine the volatile matter content, water content, density, volume solids, and weight solids of paint, varnish, lacquer, or other related surface coatings.
EssentialRegs notes
Our plain-English reading of Method 24. Not the method text.
What it measures
The volatile organic compound (VOC) content of a surface coating, together with the coating's water content, density, volume solids and weight solids.
How it works
A sample of the coating is analyzed in a laboratory. The method determines the total volatile matter, the water, and the density, and from these it works out how much of the volatile matter is organic compound. Results are expressed as mass of VOC per volume of coating, with water and exempt compounds treated as the rule specifies, or per volume of solids, which can be compared with a coating VOC content limit.
Equipment
Laboratory equipment and the standard test procedures from ASTM International that the method names, such as an analytical balance and a drying oven. There is no stack sampling train.
When a rule cites it
Coating VOC content limits and recordkeeping, where a regulated source applies paints, primers or other surface coatings and must show that each coating meets the limit. It is the reference method for checking a coating's VOC content.
Notes for compliance staff
Method 24 tests the coating as supplied, not the emissions from a stack. Method 24A is the corresponding method for printing inks and related coatings.
Cited by
Provisions in the corpus whose text cites Method 24. Subscribers land on the provision in the regulation reader; visitors see a preview of it (the GP05 sample opens in full).
Regulation 6
Regulation 26
The sections marked as regulatory text above are reproduced from the CFR. Everything under ‘EssentialRegs notes’ is our reference copy, not the method. The method as published in the CFR controls.