(NEXSTAR) – An independent laboratory is petitioning the Food and Drug Administration to pull several acne products from shelves after it says tests found dangerously high levels of benzene, a carcinogen known to cause cancer.

Valisure found in its tests that benzene can form in treatments that contain benzoyl peroxide. In some products, benzene was detected at levels over 800 times higher than the concentration “conditionally restricted” by the FDA.

In the past, shampoo products, deodorants and sunscreens have all been recalled over the presence of benzene.

“Exposure to benzene can occur by inhalation, orally, and through the skin and it can result in cancers, including leukemia and blood cancer of the bone marrow and blood disorders which can be life-threatening,” according to the U.S. Food and Drug Administration.

Valisure found that benzene even leaked out of product packages in some cases, presenting an inhalation risk.

In one test, Valisure said it left a Proactiv product in a hot car (158 degrees) for almost 17 hours, CNN reports. The lab said it found benzene levels in the cabin of the vehicle at roughly 1,270 the Environmental Protection Agency’s “calculated threshold for increased cancer risk by long-term inhalation exposure to benzene.”

The lab tested dozens of products with brands including Estee Lauder’s Clinique, Clearasil, Target’s Up & Up, and Walmart’s Equate beauty line.

Valisure’s tests on dozens of prescription and over-the-counter benzoyl peroxide products suggest that currently formulated BPO medications are fundamentally unstable and can generate unacceptably high levels of benzene when handled or stored at higher temperatures that the products may be exposed to during handling by consumers. Benzene can be produced in the product itself and potentially escape into the surrounding air. Therefore, Valisure is requesting an investigation and market withdrawal of BPO-containing products.

Valisure

Other products that use salicylic acid or adapalene did not appear to have the same problem.

Reckitt, the manufacturer of popular Clearasil acne products, told Reuters that Valisure’s findings reflect “unrealistic scenarios rather than real-world conditions,” adding that the treatments were safe “when used and stored as directed on their labels.”