Polyisobutene

Polyisobutene (PIB) is a synthetic hydrocarbon polymer derived from isobutylene. It is widely used in cosmetics, food packaging adhesives, and leather conditioners as a film-forming and waterproofing agent. At the concentrations found in leather care products (typically 50–70%), it forms a flexible, breathable barrier on the leather surface that resists water penetration without creating a greasy film. Polyisobutene is not classified as hazardous under GHS/OSHA HazCom. It has no skin sensitization, irritation, or inhalation hazard classification. It does not biodegrade readily, making it an environmentally persistent ingredient, but its low aquatic toxicity and non-volatile nature limit environmental exposure risk in leave-on applications.