A new study has found that more than half of the beauty and personal-care products used by Black and Latina women in Los Angeles contain formaldehyde or formaldehyde-releasing chemicals, highlighting a worrying connection between daily grooming habits and exposure to cancer-causing substances. Published on May 8, 2025 in Environmental Science & Technology Letters, the study has reignited calls from health experts and advocacy groups for tighter regulation of cosmetic ingredients and greater transparency for consumers—concerns that resonate far beyond the United States, including in Thailand’s rapidly growing beauty industry.
Thai society has long embraced beauty and personal-care routines, reflected in both traditional herbal treatments and a thriving modern cosmetics market. The findings of this US-based study signal an urgent need for consumers and regulators in Thailand to examine potential hazards lurking in widely used soaps, shampoos, lotions, and cosmetics. The global cosmetics industry is interconnected, with many imported and locally manufactured products sharing similar formulations, ingredients, and regulatory gaps.
The newly published research centered on 64 Black and Latina women in Los Angeles, who were asked to photograph the ingredient lists of all personal-care products they used at home over one week. Researchers discovered that 53% of participants regularly applied products containing formaldehyde or so-called “formaldehyde-releasing preservatives”—a group of chemicals known for their ability to slowly release formaldehyde over time. These substances are widely acknowledged as carcinogens, meaning they can cause cancer in humans according to decades of research reviewed by agencies such as the World Health Organization’s International Agency for Research on Cancer (IARC) and the US National Toxicology Program (NTP).
The suite of items used by study participants included soap, lotion, shampoo, conditioner, skin lightening products, eyeliner, eyelash glue, and other cosmetics—illustrating how pervasive these chemicals are in everyday grooming. On average, participants used 17 different products each day, with some reporting as many as 43. “It’s really concerning that we are intentionally putting chemicals that release a carcinogen into our products that we apply to ourselves every day,” cautioned the study’s lead author, associate director of research at Silent Spring Institute, a US-based nonprofit investigating environmental causes of breast cancer (NPR).
Formaldehyde and its chemical derivatives play a crucial role as preservatives, inhibiting the growth of microbes and extending the shelf life of beauty products. Yet the health cost can be severe. Beyond their link to cancer—breast, uterine, and ovarian cancers in particular—formaldehyde-releasing ingredients may also trigger skin rashes and respiratory problems. The danger is heightened by the fact that such chemicals are often camouflaged on ingredient lists under unfamiliar names, such as DMDM hydantoin, making it next to impossible for the typical consumer to spot a potential risk.
The scientific community has long warned about such hazards. More than a decade ago, the US government’s National Toxicology Program classified formaldehyde as a human carcinogen. The European Union banned its use as a cosmetic ingredient in 2009 and mandates clear warnings when any formaldehyde-releasing preservatives are present in amounts above a tiny threshold (European Commission). Despite these precedents, proposed regulations to ban formaldehyde in American hair straighteners, for example, remain unimplemented, with the US Food and Drug Administration’s promised action still pending.
According to the co-author and executive director of Black Women for Wellness, the study shows that “We shouldn’t have to be chemists to figure out what kinds of products will make us sick.” This sentiment is echoed by the director of the University of California, San Francisco’s Program on Reproductive Health and the Environment, who noted the influence of social and economic pressure, particularly among Black women, to conform to Eurocentric beauty standards—pressures that fuel frequent product use and increase cumulative chemical exposure.
“In Thailand, the desire for lighter skin and straight hair, driven by societal beauty ideals and media representation, has similarly fueled demand for products that sometimes contain hazardous chemicals,” contextualized a toxicologist from a leading Thai university. Notably, the Thai Food and Drug Administration has periodically issued consumer alerts regarding unregistered cosmetics and personal-care products found to contain mercury, hydroquinone, and other restricted substances (Thai FDA). However, ingredients such as formaldehyde and formaldehyde-releasing agents have historically received less attention in the national regulatory conversation.
The US study’s methodology—which involved real-time documentation of product use across a typical week—also revealed a startling diversity and intensity of exposure. One participant reported using three separate formaldehyde-containing products, including a leave-in conditioner, a rinse-off conditioner, and a body wash, while another washed her hands twice daily with formaldehyde-laden soap. Across the sample, women averaged 17 products per day, underscoring the cumulative risks involved.
This phenomenon extends to Thailand’s own context, where the routine use of multiple beautification products—influenced by advertising, peer behavior, and societal expectations—creates overlapping exposures, especially among urban women and salon workers. A recent market report noted that Thai women are often targeted by international brands promoting similar formulations seen in Western markets (Euromonitor).
History underscores the slow pace of regulatory change. It took the European Union several years of public advocacy and scientific review before banning formaldehyde outright, and similar health-protective policies remain incomplete in many other countries, including the US and most of Southeast Asia. Some US states like California and Washington have recently enacted regulations limiting formaldehyde in cosmetics, a policy trend that some health advocates urge Thailand’s Ministry of Public Health to study closely.
What complicates oversight is the disguised nature of risk: cosmetic ingredient lists do not always clearly label formaldehyde, instead using technical terms such as DMDM hydantoin, imidazolidinyl urea, and quaternium-15. These compounds slowly release formaldehyde after manufacture, sustaining product freshness but exposing users to incremental toxic buildup. Health professionals warn that even legislation focused on banning ‘formaldehyde’ specifically can leave loopholes if formaldehyde-releasing preservatives are not equally regulated.
Thailand’s beauty industry, estimated to be worth over $6 billion in 2023, is a key contributor to the country’s economy and employs hundreds of thousands, from factory workers to salon staff to influencers and retail clerks. The relative lack of robust domestic regulation on cosmetic preservatives creates a situation where both salon workers and customers may unknowingly encounter health risks every day. “Salon employees are vulnerable, especially those working with hair-straightening and nail products, which are often imported and may not be fully compliant with local safety standards,” observed a senior officer with Thailand’s Consumer Protection Board.
A 2022 investigation published by the Thai Environmental Health Association found that up to 12% of randomly sampled personal-care products collected from Bangkok markets contained potentially hazardous preservatives, some of which are prohibited or tightly restricted in Europe but allowed in Thailand in certain concentrations (TEHA Journal). The lack of public knowledge about ingredient nomenclature further limits consumer ability to make safe choices.
Consumer advocates and several Thai dermatologists urge policymakers to strengthen enforcement of existing rules, require clearer ingredient labeling in Thai, and consider harmonizing domestic safety standards with those implemented in the European Union. “Shopping for beauty should not be a high-risk activity, whether you are in Los Angeles, Bangkok, or anywhere else,” argued a Bangkok-based representative of a leading non-profit focusing on women’s health.
Globally, breast, uterine, and ovarian cancers remain among the top causes of cancer deaths for women; in Thailand, breast cancer is the most common cancer in women, with over 14,000 new cases reported every year according to the National Cancer Institute of Thailand (NCI Thailand). While causes are complex and include genetic, lifestyle, and environmental factors, repeated exposure to known carcinogens in personal-care products may contribute to cumulative cancer risk.
Looking forward, what is needed is stronger regulatory action, more public education, and industry reform. The researchers and outside experts quoted in the US study agree that “government oversight and regulation of cosmetics and other personal-care products” should be a top priority. For Thai consumers, practical steps include checking ingredient lists for known formaldehyde-releasing chemicals, avoiding overuse of products with unclear or foreign-language labeling, and seeking out brands with transparent safety certifications.
For Thai authorities, policymakers, and industry leaders, the lesson is clear: implement and enforce comprehensive bans on formaldehyde and its releasing agents in all cosmetics; mandate clear Thai-language ingredient labeling; support ongoing monitoring and enforcement; and invest in local research to identify the prevalence of hazardous ingredients in domestic markets. For end users, especially salon staff and frequent cosmetic users, the advice is to stay informed, regularly consult trusted health resources, and favor reputable brands with demonstrated adherence to international safety standards.
As this new research makes clear, the pursuit of beauty should never come at the expense of health. Whether in the US, Europe, or Thailand, truly safe personal care requires a coordinated effort between science, industry, regulators, and—crucially—an empowered public that demands and deserves full transparency.
Sources:
NPR – Cancer-causing chemicals are in many beauty products women use, a study finds
Environmental Science & Technology Letters – Associated Research Publication
World Health Organization – IARC Monographs on Formaldehyde
Food and Drug Administration Thailand – Cosmetics Regulation
National Cancer Institute of Thailand – Annual Cancer Statistics