Isopropyl Myristate vs Petrolatum: which is worse?

What is Isopropyl Myristate?

Isopropyl myristate is a synthetic ester of isopropyl alcohol and myristic acid (from nutmeg or palm kernel oil). It is a dry, silky-feeling emollient that also acts as a penetration enhancer.

What is Petrolatum?

Petrolatum is a semi-solid mixture of hydrocarbons derived from petroleum refining. It forms an occlusive barrier on the skin surface, sealing in moisture and protecting against external irritants. It has been used in skincare since 1872.

Documented risks

Isopropyl Myristate: Isopropyl myristate is CIR-safe at cosmetic use concentrations. Like IPP, it has a notable comedogenicity rating (3–4/5) and may contribute to clogged pores in acne-prone users. Its penetration-enhancing properties mean that whatever active ingredients it accompanies are delivered more deeply into the skin — this is generally desirable but should be noted. No carcinogenic or endocrine-disrupting effects are documented.

Petrolatum: Fully refined white petrolatum (as used in cosmetics) is considered safe by the FDA and CIR, and is an FDA-approved OTC skin protectant. The EU restricts petrolatum unless full refining history is known due to concerns about polycyclic aromatic hydrocarbons (PAHs) in inadequately refined grades. Cosmetic-grade petrolatum in the US undergoes extensive refining that removes PAHs. It does not penetrate the skin, is non-comedogenic in pure form, and has no evidence of systemic toxicity or endocrine disruption at cosmetic use.