Benzene, a known human carcinogen, has been detected in some aerosol hairspray and other personal care products, prompting public concern. This chemical is not listed as an active ingredient, nor is it intentionally added to the product formulation. Independent laboratory testing revealed trace amounts of benzene present as an unexpected contaminant in certain batches of aerosol sprays, including dry shampoos and hairsprays. Since there is no universally agreed-upon safe level of exposure to this chemical, this contamination issue has led to numerous voluntary product recalls by manufacturers.
Why Benzene Appeared in Hairspray
The introduction of benzene into aerosol hair products is primarily a consequence of the manufacturing and purification process of the propellant gases. Aerosol sprays rely on liquefied petroleum gases, such as butane, isobutane, and propane, which are derived from crude oil and natural gas. These raw materials naturally contain varying amounts of benzene.
Benzene is a volatile organic compound that remains as a trace impurity if the refinement process for these hydrocarbon propellants is not rigorous enough. Manufacturers have confirmed that the aerosol propellant was the source of contamination, which is why aerosol sprays are consistently identified as a high-risk category for benzene contamination.
Understanding the Health Risks
Benzene is classified as a human carcinogen, meaning it has the capacity to cause cancer. The primary concern is its effect on the bone marrow, the soft tissue inside bones where new blood cells are produced. Long-term exposure, even at low levels, can decrease blood cell formation, potentially leading to disorders such as aplastic anemia.
The most serious health risk associated with cumulative exposure is an increased risk of developing blood cancers, notably leukemia. Exposure occurs through inhalation, which is highly relevant for aerosol products used in enclosed spaces, and through skin absorption. While the risk from low levels in cosmetics is very low for a single use, the danger lies in chronic, cumulative exposure over many years.
Identifying and Avoiding Contaminated Products
Consumers concerned about potential exposure should check for public recalls of specific products and lot numbers. Many manufacturers have voluntarily recalled affected batches following findings from independent testing laboratories submitted to the Food and Drug Administration (FDA).
Although the FDA has not set a specific benzene limit for cosmetics, its guidance for drug products recommends that benzene should not exceed two parts per million (2 ppm). Manufacturers are implementing stricter quality control measures for raw materials, especially propellant suppliers, or switching to alternative ingredients. Consumers can monitor the FDA’s website or consult third-party testing databases that track contaminated products.