Aluminum Chlorohydrate (ACH) is a widely used metallic salt and the active ingredient in many antiperspirants. Its safety is often debated, particularly concerning whether the aluminum component can be absorbed into the body and contribute to long-term health effects. This article examines the function of ACH, the public health concerns, the scientific evidence on absorption, and the conclusions drawn by global regulatory bodies.
Function and Use in Personal Care Products
Aluminum Chlorohydrate belongs to a class of aluminum salts used specifically in antiperspirants. These products are distinct from deodorants, which primarily mask or neutralize odor. ACH is an active drug ingredient that physically reduces wetness by interfering with the body’s natural sweating process.
When applied, ACH dissolves in the sweat duct’s moisture. The resulting aluminum ions and a mucopolysaccharide mixture create a temporary, gel-like plug within the duct opening. This obstruction reduces the amount of sweat released to the skin’s surface, controlling wetness for a period of time. Antiperspirants may contain ACH at concentrations up to 25% for non-aerosol products, adhering to regulatory guidelines.
The Primary Health Concerns
Public concern centers on two primary, unproven hypotheses related to systemic aluminum exposure. The first involves a potential link to breast cancer, theorized because the application site is near breast tissue and lymph nodes. Proponents suggest that absorbed aluminum compounds might mimic estrogen or cause genotoxic effects.
The second major concern relates to neurological health, specifically the potential for ACH to contribute to Alzheimer’s disease. This idea originated from older studies that found elevated aluminum levels in the brains of some Alzheimer’s patients. The fear is that aluminum absorbed from antiperspirants could accumulate in the central nervous system, contributing to neurodegenerative changes.
Scientific Evidence on Absorption and Systemic Effects
Scientific research has investigated the extent to which aluminum from antiperspirants is absorbed through the skin. Studies using the radioisotope aluminum-26 have demonstrated that dermal absorption is extremely low, particularly through intact skin. One study found that only about 0.012% of the applied aluminum was absorbed from a single application.
More recent research indicates the absorbed fraction is even lower, estimated at approximately 0.00052% of the applied dose. The amount of aluminum absorbed from a single use of ACH is negligible compared to the daily intake from dietary sources, which is the largest contributor to the body’s aluminum burden. Even when applied to damaged skin, the systemic exposure from antiperspirants is considered minimal.
Epidemiological studies examining antiperspirant use and breast cancer have not established a causal link. Although some laboratory studies suggest aluminum might interfere with estrogen receptors in breast cancer cells, large-scale population studies lack consistent evidence of increased risk. Furthermore, comprehensive reviews of the aluminum-Alzheimer’s connection find the evidence mixed and inconclusive. There is no consistent data associating aluminum exposure from any source, including antiperspirants, with the risk of Alzheimer’s disease.
Regulatory Oversight and Official Health Guidance
Aluminum Chlorohydrate is recognized as safe for use in antiperspirants at permitted concentrations by major regulatory and health organizations worldwide. The U.S. Food and Drug Administration (FDA) regulates antiperspirants as over-the-counter (OTC) drug products, and ACH is an approved active ingredient with concentration limits up to 25%.
Organizations like the American Cancer Society and the European Union’s Scientific Committee on Consumer Safety (SCCS) have also evaluated the data. They maintain there is no established link between aluminum-containing antiperspirants and breast cancer or neurological disorders. Regulatory bodies base their conclusions on the consensus that dermal absorption of aluminum from these products is minimal, making the contribution to the body’s total aluminum load insignificant under normal use conditions.