Aluminum is the most abundant metallic element found in the Earth’s crust, representing nearly 9% of its mass. This naturally occurring element is widely utilized in modern society due to its valuable properties, including its lightweight nature, durability, and excellent thermal conductivity. Because of these characteristics, aluminum compounds are incorporated into a vast array of products designed for consumption, topical application, medical treatment, and household use.
Aluminum in Food Additives and Packaging
Aluminum compounds are intentionally added to various processed foods to serve specific technical functions. One of the most common applications is as a leavening agent, such as acidic sodium aluminum phosphate, which is found in many commercial baking powders, pancake mixes, and certain baked goods. These compounds facilitate the chemical reaction that produces carbon dioxide, causing the product to rise during cooking.
Other intentional uses include employing sodium aluminosilicate as an anti-caking agent, preventing clumping in powdered products like salt, non-dairy creamers, and certain instant drinks. Aluminum “lakes,” which are water-insoluble pigments formed by precipitating a food colorant with an aluminum salt, are also used to provide stable and brilliant coloring in various food products.
Beyond direct additives, aluminum can enter food through contact with packaging and cooking tools. Aluminum foil and beverage cans are widely used because the metal acts as an effective barrier against light, air, and moisture, which helps preserve the food and extend its shelf life. Small amounts of aluminum can transfer into food when acidic or salty items are stored or cooked in uncoated aluminum pots or foil.
Sources in Personal Care Products
Topical hygiene and cosmetic products represent a direct source of aluminum exposure through the skin. The most recognized application is in antiperspirants, which use aluminum salts, such as aluminum chlorohydrate or aluminum zirconium tetrachlorohydrex, as their active ingredient. These compounds work by dissolving in the moisture on the skin’s surface and forming a temporary plug of aluminum hydroxide polymer gel within the sweat ducts, thereby physically blocking the flow of sweat.
In cosmetics, aluminum compounds function in various ways to improve product texture, stability, and appearance. Aluminum powder and mineral compounds like alumina (aluminum oxide) are frequently used as pigments to impart a white color or to act as fillers and thickening agents. Certain colorant lakes, commonly found in products like lipsticks and eye shadows, contain aluminum to enhance color stability and dispersion.
Aluminum in Pharmaceutical and Medical Products
Aluminum compounds are administered for health purposes through both oral and injectable routes. In over-the-counter medications, aluminum hydroxide and aluminum phosphate are active ingredients in many antacid formulations. These compounds work by chemically reacting with and neutralizing excess stomach acid, providing relief from heartburn and indigestion.
Aluminum is also present in some buffered aspirin products, serving to protect the stomach lining from the aspirin’s acidity. For injectable products, aluminum salts are incorporated into certain vaccines, including those for Hepatitis A, Hepatitis B, and Diphtheria-Tetanus-acellular Pertussis (DTaP). Here, the aluminum acts as an adjuvant, enhancing the body’s immune response to the vaccine’s antigen, allowing for a more robust protective immunity.
Environmental and Household Exposure
Exposure to aluminum occurs constantly from the surrounding environment. Aluminum is naturally present in the air, soil, and water, as it is readily released into the environment through the natural weathering of rocks. People breathe in small amounts of aluminum particles that become airborne, particularly in dusty areas or near certain industrial sites.
Aluminum salts are utilized in the public water treatment process to help clarify drinking water by causing suspended particles to clump together. Although the levels in treated drinking water are generally low, this constitutes a continuous, minor source of exposure for the general population. Furthermore, everyday household items like aluminum foil and disposable aluminum containers contribute to the omnipresence of the metal in domestic settings.