Hidden health threat: Undeclared chemicals found in shampoos, creams and soaps

Nearly all personal care and household products tested in a new study contained chemicals that were not listed on their labels. In some cases, the compounds directly contradicted manufacturers’ claims, such as statements that products were free of phthalates or parabens.

The findings, published in the journal Environment & Health, raise questions about how effectively current product safety assessments detect chemicals that are not disclosed to consumers.

Researchers tested 113 products across 12 categories, including sunscreens, baby lotions, shampoos, soaps and household cleaning products. On average, they detected 51 chemicals per product, while labels listed only about 16 ingredients.

At least one undeclared chemical was detected in 98% of the products tested. In 85% of the products, these substances included compounds that could potentially pose health risks.

The chemicals identified included phthalates and parabens, which can interfere with the endocrine system, as well as fragrance-related compounds, silicone contaminants and butylated hydroxytoluene (BHT).

Some of these substances have previously been associated with reproductive health problems, allergies, obesity and other health concerns.

The presence of undeclared chemicals did not appear to depend on the product’s price, the size of the manufacturer or its marketing claims. They were also found in products promoted as “natural,” “non-toxic” or “organic.”

Another finding was particularly notable: more than one-quarter of the products contained substances that contradicted claims made on their packaging or manufacturers’ websites.

For example, some products labelled “100% natural” contained synthetic compounds. Products advertised as free of certain chemicals contained fragrances, phthalates, parabens, silicones or oxybenzone. Some products labelled “hypoallergenic” contained known allergens or substances capable of causing sensitisation.

The researchers stress, however, that detecting these chemicals does not necessarily mean manufacturers deliberately added them to the products.

Compounds can enter products through raw materials, manufacturing equipment, chemical reactions, storage or contact with packaging. Changes in suppliers can also alter a product’s chemical composition without prompting a corresponding change to its label.

To identify hidden substances, the scientists used untargeted chemical analysis. Unlike conventional testing, which searches for a predetermined list of chemicals, this approach can screen for thousands of different compounds simultaneously.

Overall, the researchers detected 3,141 chemical signals and identified 303 compounds with varying degrees of confidence.

The authors argue that current product safety assessment systems rely too heavily on information disclosed by manufacturers. Such an approach may fail to detect contaminants, impurities, degradation products and compounds that emerge during manufacturing or through interactions with packaging.

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