The Toxic Side of Vanity: Carcinogenic Substances Found in Creams, Shampoos and Straighteners

Formaldehyde is a toxic and carcinogenic substance used as a preservative in many beauty products, such as hair creams and straighteners. Even if it is not clearly indicated on the label, it can be present and absorbed through the skin or inhaled. Studies show that black and Latina women are more exposed to these products, which raises health and social justice concerns. Regulations are being proposed to protect consumers, but they are still limited.

Formaldehyde is a chemical widely used as a preservative in hygiene and beauty products, such as shampoos, creams and makeup. This compound can also be found on product labels under the names paraformaldehyde (polymeric formaldehyde), methylene glycol (formaldehyde equivalent) and quaternium-15 (PRF).

In addition to preventing the growth of fungi and bacteria, it can also help maintain the texture and effectiveness of products for longer.

Some products release formaldehyde gradually (called formaldehyde-releasing preservatives, or FRPs) to continue to protect against microorganisms. However, formaldehyde can be absorbed through the skin or inhaled while a person is using the product, and this poses a health risk.

Formaldehyde is considered highly toxic and is classified as a human carcinogen. Studies show that prolonged exposure to this chemical increases the risk of developing cancers in the nose, eyes, sinuses, and even blood cells.

In addition, formaldehyde and formaldehyde-releasing preservatives can cause contact allergies on the skin; it is estimated that about 8 in 100 people in the United States are sensitive to these preservatives, causing itching, redness, and irritation.

Despite the high risk, we still do not know exactly how many personal care products contain formaldehyde or PRFs. An analysis of 546 items found that 13% listed some PRF on the packaging, especially in hair and skin products.

Other studies have measured formaldehyde in products that didn’t even list the ingredient, raising concerns about hidden sources of contamination.

The use of hair straightening products has gained particular attention because many techniques release high doses of formaldehyde during the procedure. In 2011, occupational health agencies warned hair salons about the danger to stylists and clients, and the FDA (the US Food and Drug Administration) began investigating the safety of these straighteners in 2015.

In 2021, the FDA warned that a treatment known as “Brazilian Blowout” contained more formaldehyde than recommended. In 2023, the agency proposed rules to ban formaldehyde from hair straighteners, but those rules have not yet come into effect.

Some states have already taken tougher action: The European Union has banned formaldehyde as an ingredient in cosmetics since 2009 and requires packaging to display warnings if a product releases any formaldehyde.

In California and Washington, starting in 2025, formaldehyde and some formaldehyde-releasing preservatives will be banned from any cosmetics sold in the states. Other U.S. territories have also been passing laws to limit these preservatives.

In addition to health risks, the presence of formaldehyde in beauty products also raises social justice issues. Research shows that black and Latina women are more exposed to these chemicals, in part because they face discrimination against their hair and may feel pressured to use straighteners to fit into beauty standards.

Similarly, nail polish and other nail products, which are popular in these communities, can contain formaldehyde. Until now, little has been studied about exposure in skin care products, even though many Black and Latina women use lotions, creams, and soaps that can release formaldehyde.

To better understand this situation, researchers with the Taking Stock Study (TSS) analyzed the ingredient lists of more than 1,100 products used by 70 Black and Latina women in South Los Angeles.

Each participant recorded the products they used on a smartphone app, allowing them to get a detailed view of what comes into contact with their skin on a daily basis.

They then compared this data with the U.S. Environmental Protection Agency’s Chemical and Products Database (CPDat), a large database of information on ingredients in cosmetics and other consumer products.

Number of unique products in each subcategory used by TSS study participants. Dark gray bars indicate the number of products in each subcategory that listed formaldehyde (n = 1 product) or PRFs (n = 41 products) as ingredients. Product subcategories grouped by category (skin care, hair care, and cosmetics).

The study found that more than half of participants (53%) used at least one product that listed formaldehyde or a formaldehyde-releasing preservative on the packaging.

In contrast, only 4% of TSS products and 8% of products listed in the Chemical and Products Database had formaldehyde or PRFs explicitly listed.

Among the most common ingredients was DMDM ​​hydantoin, a formaldehyde-releasing preservative found in many lotions and cleansers. These results show that even when most products do not appear to contain formaldehyde, a significant number of people are exposed to it without knowing it.

Understanding where and how formaldehyde appears in everyday products is essential to protecting the health of the population, especially vulnerable groups such as Black and Latina women who face greater exposure and have less say in beauty research.

With this information, policymakers and regulatory agencies can create more effective rules to limit or ban formaldehyde and PRFs in cosmetics, ensuring safer products for everyone.

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Formaldehyde and Formaldehyde Releasing Preservatives in Personal Care Products Used by Black Women and Latinas

Robin E. Dodson, Elissia T. Franklin, Ami R. Zota, René LaPointe Jameson,  Janette Robinson Flint, Lariah Edwards, Emily B. Weaver, and Bhavna Shamasunder

Environmental Science & Technology Letters. 7 May 2025

DOI: 10.1021/acs.estlett.5c00242

Abstract:

Formaldehyde and formaldehyde releasing preservatives (FRPs) are used in personal care products (PCPs) to prevent microbial growth and extend the shelf life. Several countries and U.S. states have banned or restricted the use of these chemicals due to carcinogenicity and other health concerns. However, the prevalence of these chemicals in PCPs used by the public, particularly by Black women and Latinas, remains poorly documented. We examined the prevalence of formaldehyde and FRPs listed as ingredients on PCPs from the Taking Stock Study (TSS), a community-engaged study in which 70 Black women and Latinas in South Los Angeles logged their PCP use with a smartphone application. We contextualized our results using EPA’s Chemical and Products Database (CPDat), a public ingredient database. More than half of the TSS participants (53%) reported using at least one PCP with formaldehyde or FRPs despite only 4% of TSS PCPs and 8% of CPDat PCPs listing formaldehyde and/or FRPs as ingredients. We found formaldehyde and FRPs listed in frequently used products such as lotions and cleansers. The most common FRP was 1,3-dimethylol-5,5-dimethylhydantoin (DMDM) hydantoin. These results could inform the types of regulations needed to protect the U.S. population from adverse health risks due to formaldehyde exposure from PCP use.