Client had a building with a chemical odor after old flooring removal and new carpet installation. TO-15 air testing in the space showed heavy hydrocarbon vapors. Client sent in samples of installed and uninstalled carpet for chamber testing, the carpet that had been installed emitted the same heavy hydrocarbon vapors. Client then sent in samples of two types of mastic remover used for chamber testing. The products were applied to cardboard substrates and tested. One of the products showed the same heavy hydrocarbon, indicating the mastic remover as the source of the odor.