According to the NY Times , Unilever has recalled a number of spray-on dry shampoo products manufactured before October 2021, sold in the US, because they are suspected to contain benzene – a carcinogen. According to Unilever, the propellant in the aerosol of dry shampoo could be the source of benzene. The recall is voluntary, prudent, and precautionary. Unilever in the US claims it has not received any complaints from customers about health issues.

Benzene is classified as a human carcinogen. Users can be exposed to this substance through inhalation, orally, and through the skin, leading to leukemia, blood cancers, bone marrow cancers, and several forms of blood disorders that can be life-threatening. Benzene can also harm a woman’s reproductive organs.
Benzene is commonly used in many industrial products such as nylon and plastics. It is also released into the air through cigarette smoke and gaseous coal, oil, and gasoline. Inhaling benzene in the air is inevitable every day. However, long-term exposure to high levels of chemicals can damage cells, reduce red blood cell counts, and wreak havoc on the immune system.
Because benzene is suspected in spray products, to prevent the risk of inhalation of this substance, you may prefer to use powdered shampoos. Besides, you should also note the following when using dry shampoos in general.
Dry shampoo cannot replace regular shampoo
Each dry shampoo can have a different formula, but in general, they work on the principle of absorbing excess oil from the scalp and hair roots, so that the hair looks cleaner, less greasy, more bouncy. Trichology expert Anabel Kingsley says dry shampoo is not harmful to hair, but can delay people from cleaning their scalp in the usual way.

“Dry shampoos should not be used regularly because in fact, they do not clean excess oil, dirt, sweat accumulated on the hair and scalp. Not cleaning the scalp properly regularly can cause many problems such as itching, flaking, dandruff, hair loss,” the expert said.
Dr. Neil Sadick also said that using too much dry shampoo can cause the accumulation of chemicals in this type of product on the scalp and hair follicles, causing itching and hair loss for a long time.
Frequency of use
Most doctors and experts agree that dry shampoo should not be used for more than two days in a row. Expert Anabel Kingsley suggests using dry shampoo 1-2 times in between regular hair washes. When washing your hair with water, you also need to clean it more thoroughly to be able to completely remove the impurities stuck on the scalp and hair, including those in dry shampoo that are still left on the hair. “You should wash twice as often as usual, that is, wash your shampoo twice, then rinse your hair and incubate your hair as usual,” Anabel said.
Dermatologist Lindsey Zubritsky advises, “I would definitely recommend washing your hair with water the next day (after the day of dry shampoo). People with oily scalps that don’t want to have to wash their hair every day may find it easier to wash their hair with water the next day (after dry shampoo day). Dry shampoos can be used more often than people with dry, sensitive skin but it’s best not to use them for more than two days in a row.The risk of overusing dry shampoo can lead to clogging of hair follicles. Over time, they can cause inflammation, acne or dandruff. I recommend avoiding this product if you are experiencing symptoms such as dandruff, scalp psoriasis, hair loss.”

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