High levels of the carcinogen benzene have been found in some acne products, including Estee Lauder’s Clinique, Target’s Up&Up and Reckitt Benckiser’s Clearasil, independent US lab Valisure claims.

Valisure, based in New Haven, Connecticut, appealed to the US Food and Drug Administration, asking the regulator to recall the products, conduct an investigation and revise the guidelines it has issued.

Estee Lauder’s stock fell about 2% after the announcement. Benzene was also found in Proactiv, PanOxyl, Walgreens acne soap and Walmart’s Equate Beauty cream, among others.

Target, Estee Lauder, Walmart and Reckitt did not respond to Reuters’ request for comment. The FDA has yet to respond to Valisure’s request.

According to the lab, benzene could form “at unacceptably high levels” in both prescription and over-the-counter acne treatment products.

This substance has already been detected in many consumer products, such as sunscreens, hand sanitizers and dry shampoo. Many companies, including Procter & Gamble and Johnson & Johnson recalled their products.

But the detection of benzene in acne products “differs significantly” from the other cases, the lab says. “The benzene found in sunscreen and other consumer products were impurities that came from contaminated ingredients. However, the benzene in benzoate peroxide formulations comes from the benzoate peroxide itself,” said Valisure co-founder and president David Light.

Valisure’s tests showed that some products could form more than 800 times the concentration limit of benzene set by the FDA.

High levels of benzene were not only found in acne products but also in the air around the packaging, which may indicate that the carcinogen may be leaking from some packaging, posing a risk of inhalation, Valisure said.