Cocamide diethanolamine (cocamide DEA) is a chemically-modified form of coconut oil, sometimes used as a thickener or foaming agent in a number of products. It has also been listed by the state of California as a known carcinogen, meaning manufacturers are required to include a warning on the label. But recent tests found 98 shampoos, soaps, and other personal care products, that contain the chemical but don’t have any warning.

In 2012, California added cocamide DEA to its list of known carcinogens [PDF] after tests by the International Agency for Research on Cancer found “sufficient evidence in experimental animals for the carcinogenicity” of the chemical [PDF].

As such, any products sold in California that contain cocamide DEA are required by law to include the following message on the label: “Warning: This product contains cocamide DEA, a substance known to the state of California to cause cancer.”

To see whether manufacturers were complying with this requirement, the Center for Environmental Health went out and purchased products online and at retailers in the San Francisco Bay area. CEH then had these products tested to see whether they contained cocamide DEA. Nearly 100 items sold at retailers like Walgreens, Rite Aid, Sears, Target, Sephora, Safeway, Kohl’s, Trader Joe’s, Bloomingdales, Saks Fifth Avenue, Babies R Us, and many others were found to contain the chemical without any clear and reasonable warning to the consumer, says CEH. (See below for entire list of products).

Believing these companies to be in violation of California state law, CEH has sent out legal letters advising each party of the alleged violations. Furthermore, CEH is filing a lawsuit [PDF] today in the California Superior Court in Alameda County against four companies: Walgreens, Lake Consumer Products, Ultimark, and Todd Christopher International (aka Vogue International). CEH had previously notified these defendants of the alleged violations, but the law requires a 60-day time period before a lawsuit could be filed.

The lawsuit alleges the defendants “knowingly and intentionally expose individuals in California to chemicals known to the State to cause cancer without providing clear and reasonable warnings to individuals prior to their exposure.” It seeks penalties of $2,500 per day for each violation, along with a request for a permanent injunction against selling products in California without including the proper warning.

Here is the full list of products the CEH claims contain cocamide DEA:

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