Over a dozen aerosol dry shampoos made by Unilever have been recalled because they may have "elevated levels" of benzene.

Benzene is a naturally occurring chemical that can cause cancer when it is in high concentrations for a long time.

The consumer goods giant's dry shampoo recall last week was the most recent one related to benzene levels in several aerosol products, including some deodorants and sunscreen.

The Washington Post interviewed aerosol and cosmetics specialists about the recall and the health concerns of chronic benzene exposure. They stated the following:

The source of the benzene, according to Unilever, was the propellant in dry shampoo's aerosol cans, and the company stated it is collaborating with suppliers to find a solution.

Butane, a petroleum product, is a typical propellant in aerosol cans, according to Chris Cappa, an environmental engineering professor at the University of California at Davis.

If the process of refining butane "isn't very good," you can get gas that has other parts of the crude oil, like benzene, in it.

"That gas is where, most likely, this benzene is coming from," Cappa said.

Dry shampoos, according to Minneapolis-based cosmetic chemist Marisa Plescia, are "very basic" solutions that use a combination of powdered starches, silica, and scent to absorb oil from your hair.

No business knowingly includes benzene in its goods. It is pollution, according to Plescia. 

Unilever voluntarily recalls aerosol dry shampoos made before October 2021 and sold in the U.S. under Bed Head, Dove, Nexxus, Suave, Rockaholic, and TRESemme.

In a statement, the company said that it had not heard of any "adverse events" related to the recalled products and that an "independent health hazard evaluation" had found that daily exposure to the benzene in those products is not likely to hurt anyone's health.

"Unilever U.S. is recalling these products out of an abundance of caution," the statement said. "Consumers should stop using the affected aerosol dry shampoo products."

There are refunds available from the company for the products listed here.

READ NEXT: Johnson & Johnson Recalling Neutrogena and Aveeno Sunscreens Over Benzene Traces 

What Is Benzene?

Per the U.S. Centers for Disease Control and Prevention, benzene is in gasoline and cigarette smoke. Benzene is one of the most common compounds made in the U.S.

People can be exposed to the chemical by breathing it in, touching oil products, eating or drinking tainted food or drinks, or touching surfaces that have been contaminated.

According to CBS News, after an internal examination discovered slightly higher levels of benzene in some samples, Unilever voluntarily recalled two Suave 24-hour protection aerosol antiperspirants in late March.

This year, four more companies recalled their products after benzene was found in samples. Last year, there were more than half a dozen recalls for the same reason.

Procter & Gamble Issued Dry Shampoo Recall, Too

Following testing that indicated the presence of benzene, Procter & Gamble announced the voluntary recall of many dry shampoos and dry conditioners from several of its brands.

According to a statement from P&G, the known carcinogen was found in more than 30 aerosol sprays from Pantene, Herbal Essences, Aussie, Waterless, Old Spice, and Hair Food.

However, "the levels detected in our testing would not be expected to cause adverse health consequences," the company said.

The company said no one has complained about bad things because of the benzene in its dry shampoos and conditioners. They only recall the products to be safe.

READ MORE: California Teacher Arrested for Hiding a Missing Teenager in Her Home for 2 Years 

This article is owned by Latin Post.

Written by: Bert Hoover

WATCH: Unilever issues dry shampoo recall over cancer risk - From CBS Evening News