Aluminum oxide, also known as alumina, is a common and naturally occurring material that forms when aluminum reacts with oxygen in air. Alumina occurs in a variety of forms in nature and is used in the production of aluminum. Alumina has a wide range of practical uses in the medical, automotive, electrical, household consumer, and food industries and it is generally considered to be an inert, non-toxic substance with limited potential for adverse health effects following exposure.
Aluminum compounds such as alumina are commonly found in food, water, air, and soil. It has been estimated that the average adult consumes approximately 7 – 9 mg of aluminum compounds per day in food. For example, alumina is widely used in the production of ceramics, as a component in antacids, as a component of toothpaste, food additives, sunscreen, auto polish, and as a filler for certain cosmetic products.
The particle size of a compound is important in determining the potential for adverse health effects. Particle sizes of 2.5 micrometers or less are of greatest concern, as they can reach deep into the lungs. Based on sampling conducted by Century, the alumina used by Century in particle form has an average size of approximately 70-100 micrometers. As such, the alumina material released is generally too large to be inhaled into the lungs, and therefore does not pose a significant potential for inhalation health risks.
The Department of Health and Environmental Control (DHEC) has been conducting air monitoring for particulate matter in the nearby community where alumina dust has been reported. Levels of particulate matter in the community have been reported below National Ambient Air Quality Standards (NAAQS) established by the United States Environmental Protection Agency (USEPA) for particulate matter in ambient air. These standards provide public health protection, including protecting the health of sensitive populations such as asthmatics, children, and elderly.
Like all airborne dusts, alumina can cause irritation of the eyes and upper respiratory tract. Some of the released alumina dust may have been deposited on outdoor surfaces. A person may be exposed to alumina dust by ingesting small amounts of the dust that has settled on surfaces. This may happen when a person puts their hands on a surface with dust on it and brings their hand to their mouth (hand-to-mouth contact) while eating, smoking, etc. This does not represent a significant exposure that would result in adverse health effects as alumina in this form is inert and non-toxic. Alumina is an insoluble material, and it is poorly absorbed through the skin; therefore dermal contact does not represent a significant exposure route for absorption into the body. Furthermore, contact sensitivity with alumina dust is rare. Irritation of the skin and eyes is possible as the texture of alumina dust can be abrasive to the skin like sand.
Settled alumina dust may be deposited on surfaces that people or animals may contact. As alumina dust in this form is non-toxic and poorly absorbed through the skin, good hygiene practices such as washing the skin with a mild detergent or hand soap can safely remove the material from the skin.
Fruits and vegetables that may have alumina dust on them can still be safely consumed, as aluminum oxide is a naturally occurring compound normally present in many foods and is an intentional additive that the United States Food & Drug Administration (FDA) has designated as a generally recognized as safe (GRAS) food substance. Simply washing any potentially affected fruits or vegetables will remove any residual alumina dust.
Settled dust may be deposited on surfaces that children or animals may contact. Dust residues on surfaces will diminish in the presence of rain, moisture, or cleaning. If skin contact is made, the skin can be washed with a mild detergent or hand soap rinsed with water.
The information on alumina has been compiled by CTEH, a science-based environmental consulting firm dedicated to helping companies, governments, and communities prepare for, respond to, and recover from threats to their environment and people. Their more than 25 years of experience enables them to manage complex situations efficiently. CTEH has a team of professional level scientists, including PhD toxicologists, certified industrial hygienists, and safety professionals, that are active in conducting field work and help address toxicology and human health risk assessment issues related to chemicals in the environment.