Also known as: phenoxyethanol, ethylene glycol monophenyl ether
2-Phenoxyethanol
Sourced from FDA-approved package inserts (DailyMed). Last verified: 2026-07-07.
What It Is & Why It's in Vaccines
2-Phenoxyethanol is a glycol ether used as a preservative and antimicrobial agent in some vaccines, cosmetics, and pharmaceuticals. It is the preservative used in inactivated polio vaccine (IPV) and some combination vaccines.
Preservative — prevents bacterial and fungal contamination in multi-dose vials. 2-Phenoxyethanol is used as an alternative to thimerosal in some products, particularly IPV and DTaP-IPV combination vaccines.
Dose-in-Context
Per-Dose Quantity
≤5 mg per dose (varies by product). FDA maximum: 0.5% w/v for parenteral products.
Reference Comparison
2-Phenoxyethanol is widely used as a preservative in cosmetics and personal care products at concentrations of 0.5–1%. Cosmetic products containing 2-phenoxyethanol are applied topically in gram quantities — orders of magnitude more than a vaccine dose. The Cosmetic Ingredient Review (CIR) Expert Panel has determined 2-phenoxyethanol is safe for topical use at ≤1%.
Source: Cosmetic Ingredient Review. Safety Assessment of Phenoxyethanol. 2020.
Route-of-Administration Note
Injected route. The toxicological profile of 2-phenoxyethanol is based primarily on oral and topical studies. Parenteral safety data at low single doses in humans is limited to the established safety record of IPV and combination vaccines over decades of use.
Documented Adverse Effects
2-Phenoxyethanol is a recognized contact allergen with repeated topical exposure (cosmetics). Localized injection-site reactions have not been specifically attributed to 2-phenoxyethanol in the vaccine context, though it is difficult to isolate single-ingredient effects in multicomponent vaccines.
Case reports of contact urticaria and allergic contact dermatitis to 2-phenoxyethanol in cosmetics exist. The relevance to parenteral vaccine administration is uncertain. Anaphylaxis to parenteral 2-phenoxyethanol has not been documented as a distinct clinical entity.
Vaccines Containing 2-Phenoxyethanol
DTaP/Tdap — Daptacel (Sanofi Pasteur)
Polio (IPV) — IPOL (Sanofi Pasteur)
Inactivated whole-virus; no aluminum adjuvant.
ⓘ Methodology Disclaimer: Ingredient lists are sourced from official FDA-approved package inserts for the specific branded products named on each vaccine page. Formulations can change between manufacturing lots and over time — always verify against the current package insert before making a clinical decision. The presence of a substance in a vaccine does not by itself indicate harm; toxicology is dose-, route-, and context-dependent. Comparisons to reference exposure levels are provided with their sources where available, and are approximate — see the cited source for full methodology.