Mineral Oil in Cosmetics — Is Paraffinum Liquidum Safe?

What is mineral oil in cosmetics?

Mineral oil, listed on INCI labels as Paraffinum Liquidum, is one of the most hotly debated cosmetic ingredients. It is derived from the refining of crude oil and has been used in cosmetics for more than 100 years. Despite this long track record, plenty of myths have grown up around it — some wildly negative, others uncritically positive.

In practice, the mineral oil used in cosmetics goes through a multi-stage purification process that makes the final product significantly different from raw crude oil. It is worth understanding this distinction before drawing any conclusions about its safety.

Purity requirements in the European Union

One of the key aspects of mineral oil safety is its purity. The European Union enforces strict standards for the refining of mineral oils used in cosmetics. Under Regulation (EC) No 1223/2009 on cosmetic products, mineral oils must meet specific purity criteria.

Cosmetic- and pharmaceutical-grade mineral oil (USP/Ph.Eur.) undergoes a refining process that removes potentially harmful polycyclic aromatic hydrocarbons (MOAH). It is precisely the unrefined or poorly refined mineral oils that were classified by the IARC as possibly carcinogenic — not the ones used in cosmetics.

If you want to check which ingredients your cosmetic contains, use our ingredient search.

The mineral oil comedogenicity myth

One of the most common accusations levelled at mineral oil is the belief that it clogs pores and causes acne. Where did this myth come from?

Research into the comedogenicity of mineral oil produces mixed results. Early tests carried out on rabbit ears (the Mills method from the 1970s) suggested high comedogenicity, but later studies on human skin did not confirm these findings to the same degree.

Refined cosmetic mineral oil has molecules that are too large to penetrate pores. On the comedogenicity scale (0–5), pure Paraffinum Liquidum is usually rated at 0–1, indicating very low risk. By comparison, coconut oil — perceived as "natural" — scores a 4.

Of course, individual skin reactions can vary. Anyone prone to acne should monitor their skin after using any new product, regardless of whether it contains natural or synthetic ingredients.

Occlusive properties — a benefit or a drawback?

Mineral oil is one of the most effective occlusive ingredients — it forms a barrier on the skin that reduces transepidermal water loss (TEWL) by as much as 98%. By comparison, other popular occlusive ingredients cut TEWL by 20–30%.

This property is at once its greatest strength and the source of controversy:

• Advantages: excellent protection for dry, damaged or irritated skin; helps rebuild the hydrolipid barrier; protects against external aggressors
• Potential drawbacks: a heavy feel on the skin; may not be suitable for oily or combination skin; does not deliver active nourishing ingredients to the skin

It is worth remembering that occlusion in itself is not a bad thing — it is a natural function of a healthy skin barrier. The problem arises when occlusion is the only thing a product does, while the skin also needs hydration and active ingredients.

Mineral oil versus natural ingredients — a comparison

In the "natural vs. synthetic" debate, mineral oil often loses out to plant oils in consumers' eyes. It is worth looking at this objectively, though:

• Stability: mineral oil does not go rancid or oxidise, unlike many plant oils
• Allergenicity: mineral oil rarely triggers allergic reactions because it contains no plant proteins
• Active action: plant oils deliver vitamins, antioxidants and fatty acids that mineral oil lacks
• Environmental impact: the production of mineral oil is tied to the petrochemical industry, which raises legitimate environmental concerns

For more on how to assess controversial ingredients, read our guide to parabens — another ingredient that stirs up similar emotions.

Who might mineral oil be good for?

Mineral oil works especially well for people with:

• Very dry, flaky skin
• Atopic dermatitis (eczema) — it is one of the emollients most frequently recommended by dermatologists
• A damaged skin barrier after procedures
• Sensitive skin prone to allergies to plant-based ingredients

When to avoid mineral oil?

Mineral oil may not be the best choice if:

• You have oily or acne-prone skin and are looking for a lightweight formula
• You prefer cosmetics with the smallest possible environmental footprint
• Your skin needs active hydration rather than just occlusion
• You expect added benefits such as antioxidant action

Summary

Cosmetic-grade mineral oil is a safe and well-studied ingredient, though not necessarily the best choice for every skin type. Concerns about carcinogenicity relate to unrefined industrial forms, not to the Paraffinum Liquidum used in cosmetics. The comedogenicity myth is not borne out by studies on human skin.

As always, the most important thing is an informed approach: check the full ingredient database and choose products suited to your skin's needs, rather than being guided solely by marketing — whether it is "natural" or "scientific".