Unilever United States has announced a recall of 19 dry shampoo aerosol products manufactured before October 2021, according to a statement released by the US Food and Drug Administration. These include Dove, Suave and TRESemmé dry shampoos.

After conducting an internal investigation, the company identified the propellant used in its aerosol cans as the source of the high benzene levels.

"Unilever has been working with its fuel suppliers to resolve this issue," the company said, adding that US retailers had been notified to remove the 19 recalled products from their shelves.

But Unilever said an independent health risk assessment found that daily exposure to benzene in its recalled dry shampoo products "is not expected to cause adverse health effects".

What is benzene? According to the Centers for Disease Control and Prevention, benzene is a chemical that can occur naturally in the environment—such as in diesel or gasoline—

and can be used to make plastics, lubricants, dyes, and detergents. Indoor and outdoor air also contains low levels of benzene from tobacco smoke, motor vehicle exhaust, industrial emissions, and/or household paint.

The main effect of long-term benzene exposure is on the blood, which can lead to a drop in the number of red blood cells—or anemia—after a year or more of exposure to high levels of benzene. 

The Department of Health and Human Services (DHHS) has found that benzene can also cause blood-related cancers such as leukemia.

The FDA has outlined steps for consumers to take if they come into contact with one of the 19 recalled dry shampoos. 

Anyone with recalled products is encouraged to either throw them away or return the items to where they were purchased. 

Those who have experienced adverse reactions or quality problems with any of the recalled products can file a report through the FDA website.