Hydrogenated Polyisobutene
Also known as Hydrogenated Polyisobutene, HPIB, Panalane H-300E, Panalane L-14E
“CIR Expert Panel says: safe as used in cosmetics.”
Hydrogenated Polyisobutene is a fully synthetic hydrocarbon emollient produced by hydrogenation of polyisobutene polymer, saturating residual double bonds to yield a highly stable, non-reactive oil used as a petroleum-jelly alternative in face products and lip cosmetics. The CIR Expert Panel conducted a full safety assessment (IJT 2008, PMID 19101833) and confirmed safety at cosmetic use concentrations: the ingredient is not a dermal irritant, not a sensitizer, not an ocular irritant, and not phototoxic or photoallergenic. Clinical patch testing with products containing up to 4% Hydrogenated Polyisobutene showed no reactions beyond slight erythema. Lifetime exposure studies in rats and dogs showed no carcinogenic or tumor-promoting effects. Very limited systemic absorption is expected due to the large polymer molecular weight and low water solubility. The CIR re-affirmed safety in 2020 (IJT 39(S2):59-90). The EU Annex II prohibited substances list was verified and Hydrogenated Polyisobutene does not appear, confirming it is a general-inventory ingredient with no EU refining-history conditions analogous to Petrolatum Entry 904 — the fully-synthetic nature means no PAH carcinogenicity concerns apply.
Effective occlusive emollient with silky, non-greasy skin feel; widely used as a petroleum-jelly alternative in face and lip products
Not a dermal irritant or sensitizer: extensive clinical testing shows excellent tolerability (CIR 2008)
Not phototoxic or photoallergenic — suitable for leave-on sun-exposed formulations
Fully synthetic — no refining-history conditions or PAH contamination risk unlike petrolatum
High stability: hydrogenation eliminates residual double bonds, resulting in an oxidation-resistant, shelf-stable emollient
Not listed in EU Annex II — clean general-inventory status in EU, no conditional restrictions
- · Very high concentrations (up to 95% in lipsticks) may contribute to occlusive feel; well tolerated in clinical studies at these levels
- · Non-biodegradable synthetic polymer — environmental persistence concern (not a safety concern for human use)
CIR Quick Reference Table (October 2024) — HYDROGENATED POLYISOBUTENE row: Finding=S, Citation=IJT 27 (Suppl. 4):83-106, 2008; IJT 39(S2)…
“Hydrogenated Polyisobutene S IJT 27 (Suppl. 4):83-106, 2008;IJT 39(S2):59-90,2020”— QRT-Update-100824_0.pdf, p. 129