Petrolatum (plain petroleum jelly)

What It Is

Petrolatum, also known as plain petroleum jelly, is a semi-solid mixture of hydrocarbons derived from petroleum. It was first discovered in the 19th century and has since become a staple in skincare and medical applications. It is colorless to pale yellow, odorless, and hydrophobic (repels water). Pharmaceutical-grade petrolatum is highly purified to remove impurities and carcinogenic residues, making it safe for medical and cosmetic use. Common brand names include Vaseline and Aquaphor (the latter often containing added ingredients).

How It Works

Petrolatum acts primarily as an occlusive barrier. When applied to the skin, it forms a protective, water-resistant film that prevents transepidermal water loss (TEWL) — the natural evaporation of moisture from the skin’s surface. This helps maintain hydration by trapping water in the stratum corneum (the outermost skin layer).

In wound care, petrolatum provides a moist healing environment, which supports faster tissue regeneration and reduces the risk of scabbing and infection. It also serves as a lubricant and protectant, minimizing friction and irritation in sensitive or healing skin.

Importantly, petrolatum itself is biologically inert, meaning it does not react with the skin or penetrate deeply; rather, it acts as a physical shield and moisture sealant.

Why It’s Important

Petrolatum plays a crucial role in both dermatology and general healthcare because of its broad protective and restorative properties. It is used to:

• Soothe and protect dry, cracked, or irritated skin, including lips, hands, and feet.
• Aid wound healing by maintaining moisture and preventing scab formation.
• Prevent diaper rash and irritation caused by friction or moisture.
• Act as a base or vehicle for topical medications and ointments, helping deliver active ingredients evenly across the skin.
• Protect minor cuts and burns by forming a barrier against contaminants and bacteria.

Because it is hypoallergenic and rarely causes sensitization, petrolatum is often recommended for individuals with eczema, psoriasis, and sensitive skin. It is recognized by organizations such as the U.S. Food and Drug Administration (FDA) and the American Academy of Dermatology as a safe and effective skin protectant.

Considerations

While petrolatum is generally safe and well tolerated, a few considerations apply:

• Purity matters: Only white petrolatum (fully refined, pharmaceutical-grade) should be used on the skin. Industrial or unrefined forms may contain harmful polycyclic aromatic hydrocarbons (PAHs).
• Not a moisturizer by itself: Petrolatum locks in existing moisture but doesn’t add hydration, so it’s best applied to slightly damp skin after bathing.
• Comedogenic potential: Although typically non-comedogenic, petrolatum may trap oils and debris if applied to uncleansed skin, leading to breakouts in acne-prone individuals.
• Environmental concerns: As a petroleum byproduct, its sustainability has been questioned; some people prefer plant-based occlusives such as shea butter or beeswax.
• Allergic reactions: Extremely rare, but possible in people sensitive to trace impurities or added fragrances in mixed formulations.

In summary, petrolatum is one of the most effective, affordable, and safe occlusive agents available, particularly valuable for protecting, healing, and maintaining the skin barrier when used appropriately.