Volatile Organic Compounds and yes you should be at least aware of what they are. They are gases that are emitted from certain materials like paints and sealers that do pose a health risk if exposed for a certain length of time. They generally come from solvents that act as carriers for the actual material you are putting down such as an epoxy. The carrier flash dries off and leaves behind the epoxy. However, the epoxies we use are VOC free, 100% solids. You can work all day inside with 100% solids epoxies without a problem.