Styrene
Avoid
Volatile Organic Compound; Monomer; Fragrance-related Chemical
Also Known As
Ethenylbenzene; Vinylbenzene; Phenylethene
CAS Number
100-42-5
What It Does
Primarily used as an industrial monomer in polymers and plastics; may occur as a residual monomer or contaminant rather than an intentional skincare ingredient.
Why Oh Daisey Rates It This Way
Styrene has significant inhalation and occupational toxicity concerns and is classified by IARC as probably carcinogenic to humans (Group 2A). Residual exposure should be minimized in cosmetic-related materials.
Evidence Level
Strong
Sources
- https://pubchem.ncbi.nlm.nih.gov/compound/Styrene ; https://monographs.iarc.who.int/wp-content/uploads/2018/06/mono121-01.pdf