It’s known to be found in cigarette smoke and petrol fumes. It has an industrial application, used to manufacture plastics, resins, synthetic fibres, detergents and pesticides. And it’s produced naturally by fires.

But it’s also finding its way into dry shampoos, hand sanitisers, body sprays, deodorant, bottled water and, ironically, because it’s a known carcinogen, even in sunscreen.

Dry shampoos, used as a quick fix between hair washes, absorb dirt, oil and grease of your scalp without washing it.

Depending on the amount, route and length of exposure, compounded by age and other medical risk factors, benzene is creeping into consumer products — some at levels the Food and Drug Administration (FDA) has characterised as “life-threatening”. 

Why worry?

Aerosol consumer products use propellants that are derived from fossil fuels, and while product labels will never stipulate “benzene” — as manufacturers would not willingly add benzene to products as an ingredient — contamination is a growing concern.

This taint is likely due to the presence of inactive petroleum-derived ingredients such as propane, isopropane, butane or polyacrylic acid. The benzene could also come from ethanol produced without adequate purity control.

On 18 October, Unilever issued a major recall of 19 popular dry shampoo aerosol products in the US and Canada after detecting elevated levels of benzene, citing an “abundance of caution”.

The products included popular brands such as Dove, Bed Head and TRESemmé. 

It’s not the first time elevated levels of benzene have been found in these products: on 17 December last year, Procter & Gamble issued a voluntary product recall of dry conditioner and dry shampoo sprays from Pantene, Aussie, Herbal Essences, and Waterless produced in the US, due to the presence of benzene.

In a statement, Procter & Gamble said, “we began a review of our total portfolio of aerosol products. While benzene is not an ingredient in any of our products, our review showed that unexpected levels of benzene came from the propellant that sprays the product out of the can. We detected benzene in aerosol dry shampoo spray products and aerosol dry conditioner spray products. Nothing is more important to us than the safety of the consumers who use our products and the quality of the products we ship.

“No other products from Pantene, Aussie, Herbal Essences, Hair Food, and Waterless are in the scope of this recall and such other products may continue to be used as intended, including those aerosol dry shampoo spray products with production code ranges different from those specifically communicated. The vast majority of our products are not part of this recall, including mousses, hairsprays, liquid shampoos, liquid conditioners, styling products, treatments, and unaffected aerosol dry shampoo sprays.”

Now, an independent laboratory in the US, known for its consumer activism, tested and detected high levels of benzene in several brands and batches of dry shampoo products — some with levels of up to 170 times the FDA limit.

The analysis of 148 batches of dry shampoo spray from 34 companies found that 70% contained quantifiable levels of benzene, and 11 samples tested by Valisure showed above 10 times the FDA limit.

Valisure has called for the contaminated batches be recalled and that the FDA better define limits for benzene contamination in cosmetics and other regulated products.

Exposure to benzene, which is classified as a human carcinogen, can occur through inhalation, ingestion or skin contact.

The International Agency for Research on Cancer, a WHO agency, says benzene exposure causes acute myeloid leukaemia. It has also been linked to acute lymphocytic leukaemia, chronic lymphocytic leukaemia, multiple myeloma and non-Hodgkin’s lymphoma.

‘Does not affect SA market’ (or does it?)

Last month, Unilever told Business Maverick that the recall in North America did not affect the South African market.

“Unilever US and Canada voluntarily recalled select lot codes of dry shampoo produced prior to October 2021 out of an abundance of caution, after an internal investigation identified elevated levels of benzene. An independent health hazard evaluation concluded that levels of benzene detected do not pose a health risk. If consumers have any questions, they can visit www.UnileverRecall.com for more information.”

Weeks later though, Valisure announced it had found levels of benzene exceeding FDA requirements in a number of mainstream brands, including Redken, Paul Mitchell, Batiste and Sebastian — some of which are only manufactured in the US and therefore affect South African consumers.

Not Your Mother’s dry shampoo — widely sold in South Africa — was one of the worst offenders, with a benzene concentration of up to 340 ppm. 

Valisure has now filed a citizen petition with the FDA, requesting not only a recall of the contaminated dry shampoo products, but also for the authority to redefine and clarify benzene limits in cosmetics and other regulated products.

“The detection of high levels of benzene in dry shampoos should be cause for significant concern, since these products are more than likely used indoors where benzene may linger and be inhaled for prolonged periods of time,” said David Light, CEO of Valisure. 

“Unfortunately, it’s not so surprising that we continue to see benzene in consumer products, especially in aerosol consumer products,” he told MedPage Today. 

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In South Africa, research and development chemist Jaqueline Kachidza expressed alarm about the fact that benzene was found at such astonishing levels. 

“A hundred and seventy times above the limit is not a little bit, but quite a lot, considering it’s lethal. You know, when students are working with solvents in a laboratory, they have to work under extraction. When I was an undergraduate student, I was not allowed to work with it for three consecutive days — I had to take a break. No matter the level of exposure, it’s not okay.”

Propellants are an effective delivery tool to release active ingredients in small doses, but will always be a risk with petroleum byproducts.

Redken manufacturer L’Oreal South Africa said it is aware of the recent Valisure study but its dry shampoos are not sold in SA. “The health of our consumers and the safety of our products have always been our highest priority. As a result, each of our products goes through extensive testing and a thorough safety review. We work closely with our aerosol propellant manufacturers to ensure they meet our highest quality standards.  We are confident in the safety of our products including our dry shampoos.” BM/DM

This story has been updated to reflect Redken’s comments