A new study of sunscreens, baby lotions, shampoos, soaps, and other everyday products found that nearly all contained chemicals not disclosed on their labels. Most contained at least one unlabeled chemical with known or suspected health hazards, and one in four contained a chemical that contradicted claims on the package, including "phthalate-free" products that contained phthalates.
"We found undisclosed harmful chemicals in products claiming to be free of them," said Jenna Hua, PhD, MPH, senior author of the study and founder of the Million Marker Research Institute. "That means someone can carefully read ingredient lists, choose 'clean' products, and still end up exposed to the very chemicals they were trying to avoid. The label can't protect you when it doesn't show what's really in the bottle."
The researchers tested 113 personal care and cleaning products across 12 categories. On average, each product contained 51 detected chemicals, more than three times the average of 16 ingredients listed on the label. Overall, 98% of products contained at least one unlabeled chemical, and 85% contained at least one unlabeled chemical with known or suspected health hazards. The specific brands and items will be revealed in an upcoming report.
These undisclosed chemicals included endocrine-disrupting compounds such as phthalates and parabens, fragrance chemicals, silicone contaminants, and butylated hydroxytoluene (BHT). Previous research has linked some of these chemicals to infertility, miscarriage, breast cancer, obesity, diabetes, allergies, and other health problems. Others are classified as potential carcinogens, endocrine disruptors, reproductive or developmental toxicants, or skin sensitizers.
Undisclosed harmful chemicals were found across product categories, price points, company sizes, and marketing claims. Products advertised as "natural," "non-toxic," or "organic" frequently contained undisclosed chemicals linked to health harm.
More than one-quarter of the products contained chemicals that contradicted claims made on labels or company websites. Researchers found synthetic chemicals in some products marketed as "100% natural," as well as fragrance, phthalates, parabens, silicones, or oxybenzone in products claiming to be specifically free of those substances. Some products labeled "hypoallergenic" contained known allergens or sensitizers.
The researchers note that this does not necessarily mean manufacturers intentionally added these chemicals. Contaminants can enter products through raw materials, processing equipment, chemical reactions, storage or packaging. Changes in suppliers may also alter a product's chemical composition without a corresponding change to its label.
The study used nontargeted analysis, an advanced laboratory method that can screen for thousands of chemicals without relying on a predefined list of substances. Researchers detected 3,141 chemical signals and identified 303 compounds with confirmed, probable, or tentative confidence.
Most product safety ratings and certifications programs rely heavily on disclosed ingredient lists. According to the authors, that approach can miss contaminants, impurities, breakdown products, and chemicals introduced during manufacturing or packaging. The researchers recommend making nontargeted analysis of finished, packaged products a standard part of product safety and quality control, alongside existing checks such as stability, microbial, and preservative testing.
The authors also argue that current U.S. oversight remains too dependent on ingredient disclosure and manufacturer reporting. Although the 2022 Modernization of Cosmetics Regulation Act expanded the U.S. Food and Drug Administration's authority over cosmetics, routine testing of finished products for undisclosed chemical contaminants is still generally not required.
"People shouldn't need a chemistry lab to know what they're bringing into their homes or putting on their skin," Hua said. "The next generation of product safety must look beyond the label and test what is actually there."
