What is Benzene?
Benzene is a colourless and flammable liquid with a sweet smell. It is made from crude oil and is used as a solvent in many industries, including the cosmetics industry.
The International Agency for Research on Cancer (IARC) classifies various compounds based on their association with cancer. Benzene has been classified by IARC as "carcinogenic to humans" and has been linked to leukemia and other cancers, which is why its presence in shampoo is a cause for concern.2
In 1963, Italy banned benzene as a solvent, recognizing its ill-effects on human health.3
The IARC is far from alone in its conclusion either. When the sunscreen recall occurred, the Canadian Dermatology Association4 released a statement that included a few key points:
- "Currently there are no benzene concentration limits in sunscreen."
- "There is likely no safe level of benzene and the CDA will be monitoring closely for recommendations."
- "There is no direct data on systemic absorption of benzene from applying sunscreen with this contaminant."
- "Long-term (a year or more) exposure to benzene causes neurological symptoms and affects the bone marrow causing aplastic anemia, granulocytopenia, lymphocytopenia, and/or thrombocytopenia."
Where Does Benzene Come From?
Benzene can enter the environment through emissions from factories and automobiles. It can also be found in cigarette smoke. Once benzene is in the air, it can be absorbed by plants and water. This means that traces of benzene can be found in fruits, vegetables, and fish. Benzene can also enter the body through the skin, which is why it's important to be aware of the products you're using on your skin and hair.
In the case of this international news story, the recalled dry shampoos were all aerosol spray types and benzene was detected in the propellent.
How Can I Avoid Benzene?
The best way to avoid exposure to benzene is to limit your exposure to product fumes, secondhand smoke, and traffic fumes because of how quickly it evaporates. The chemical itself is denser than air, meaning it sinks down to our level relative to the atmosphere.
When choosing a shampoo, look for products that are labelled "benzene-free."
Herbatint is one example of a brand that does not use benzene or other harmful compounds like ammonia, parabens, or alcohol in its products. Founded in Italy by herbalist Michele Albergo in 1970, the company was one of the first to use only plant-based extracts for colour.
The company itself is also B Corp Certified and in 2017, took the necessary steps to become a Benefit Corporation, each year releasing an impact report to assess its impact on the shared environment.5 They also joined forces with 30 other B Corps to form the B Corp Beauty Coalition to share in both social and environmental best practices.
Benzene is a carcinogen that can be found in some shampoos. While exposure to benzene seems unavoidable in today's world, there are steps you can take to minimize your exposure. Choose benzene-free products whenever possible and limit your exposure to secondhand smoke as well as product and traffic fumes
By taking these precautions, you can help keep yourself healthy and safe.
1. Conte, Santina, et al. "Benzene, a Known Human Carcinogen, Detected in Suncare Products." Journal of Cutaneous Medicine and Surgery 25.6 (2021): 650-651.
2. International Agency for Research on Cancer. IARC monographs on benzene, volume 120. Lyon, France: IARC; 2018 Available from: https://monographs.iarc.who.int/wp-content/uploads/2018/06/mono100F-24.pdf.
3. Belingheri, Michael, et al. "Benzene and leukemia: from scientific evidence to regulations. A historical example." La Medicina del Lavoro 110.3 (2019): 234.
4. Canadian Dermatology Association. "Sunscreens: Benzene Exposure Risk." Practice Point. Communique to CDA Members. (2021)
5. Oomen-Lochtefeld, Zulia. Sustainable Transitions for Large Enterprises: A case study of B Corporations. MS thesis. 2022.