tert-Butylbenzene

tert-Butylbenzene (CAS 98-06-6) is a single-ring aromatic hydrocarbon — a benzene ring with a branched four-carbon substituent — present at 1–3% in heavy-aromatic-naphtha solvent cuts. It is an identified constituent of the C9–C15 heavy aromatic hydrocarbons fraction (CAS 64742-94-5) and is broken out separately on the SDS because it appears on California's Safer Consumer Products Candidate Chemicals List. The bioaccumulation potential (log Kow 4.11) and persistence place it in the "of-concern" tier for aquatic and soil environments. As a VOC it contributes to ground-level ozone formation. At 1–3% in a consumer aerosol it is not the dominant health driver, but it stacks with naphthalene, the heavy-aromatic fraction, and the petroleum distillate to push the mixture into multiple GHS classifications simultaneously. For users: a marker ingredient indicating the product is a true solvent-naphtha-based formula rather than a milder modified-petroleum cleaner. Not a single-ingredient action item by itself.