white petroleum jelly in spoon with jar
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Petrolatum, or petroleum jelly, is a semisolid mixture derived from refining crude oil. Different grades of petrolatum differ in purity, largely based on the degree of refinement.

In accordance with U.S. Food and Drug Administration (FDA) regulations, petrolatum used in cosmetics, over-the-counter skin products and prescription ointments is highly refined and must meet strict purity standards set by the U.S. Pharmacopeia.

Pharmaceutical-grade petrolatum is a highly effective skin barrier, protectant and moisturizer that has been used for these purposes since the late 1800s. Petroleum jelly penetrates only the superficial layer of the skin and is not absorbed into the body. Purified petrolatum in skin care products is generally safe when used as directed, although a few precautions should be kept in mind.

Infection Risk With Deep Wounds

Over-the-counter petrolatum is commonly used to protect minor cuts, scrapes and burns as they heal. However, it should not be used for deep wounds. Because petroleum jelly forms a barrier at the skin surface, it might prevent normal drainage from a deep wound that could potentially increase the risk for a serious infection.

Additionally, petroleum jelly should not be used on a deep cut that has been closed with a dermal adhesive, commonly known as skin glue. Petrolatum breaks down skin glue, which could allow the wound to reopen.

Risks from Accidental Ingestion or Inhalation

Petroleum jelly and petrolatum-containing skin products are intended for external use only. The Illinois Poison Center notes that petrolatum is minimally toxic when ingested in small amounts but may cause soft stools or diarrhea.

Accidental inhalation of petroleum jelly poses a greater health risk as this may cause a condition called lipoid pneumonia, which can be serious and potentially life threatening.

Do not put petroleum jelly or petrolatum-containing products in your nose or mouth. In case of accidental ingestion or inhalation, contact your local poison control center immediately, especially if there was any coughing, choking or vomiting associated with the mishap.

Rare Skin Reactions

Petroleum jelly — especially white petrolatum — is generally considered nonirritating to the skin. However, petrolatum-containing skin products or ointments might cause a skin reaction due to other ingredients.

For example, petrolatum-based antibiotic ointments can cause an allergic skin reaction caused by the medications in product. A few cases of an allergic skin reaction to pure white petrolatum have been reported in the medical literature but this is extremely rare, as noted in a May 2004 "Journal of Dermatology" article.

A Word About PAHs

A quick internet search of petrolatum side effects will likely return some mentions of polycyclic aromatic hydrocarbons (PAHs). The Agency for Toxic Substances and Disease Registry states that these chemicals are found in crude oil, coal, coal tar pitch, creosote and roofing tar.

They are also found in the environment due to the incomplete burning of fossil fuels, wood, garbage, tobacco and charbroiled meat. Because PAHs persist in the environment, everyone has some exposure due to trace amounts in the air, water and some foods.

Exposure to high levels of PAHs has been linked to several cancers, including skin, lung, bladder, liver and certain digestive system cancers. There is also concern that PAH exposure might contribute to the development of breast cancer, although this has yet to be definitively determined.

Because crude oil contains PAHs and petrolatum is derived from it, some have questioned whether use of petroleum jelly skin products might pose a cancer risk.

There's no evidence to date that use of petrolatum skin products increases the risk for any type of cancer. This is largely explained by the fact that PAHs are completely or nearly completely removed during the purification processes used to produce these skin products.

To ensure that you're using high-quality petrolatum with the lowest possible level of impurities, chose products that list "white petrolatum USP" in the ingredients. The USP designation means the product meets U.S. Pharmacopeia purity standards.