Toxicity Profiles

RAGs A Format for Aluminum - CAS Number 7429905

Aluminum is a silver-white flexible metal with a vast number of uses. It makes up about 8% of the earth's crust. The aluminum content of seawater ranges from 3 to 2400 ppb. Aluminum metal is used as a structural material in the construction, automotive, and aircraft industries, in the production of metal alloys, and in the electrical industry in power lines, insulated cables and wiring. Other uses of aluminum metal include cooking utensils, decorations, fencing, highway signs, cans, food packaging, foil, and dental crowns and dentures. Aluminum powder is used in paints and fireworks, and natural aluminum minerals are used in water purification, sugar refining, and in the brewing and paper industries. Aluminum borate is used in the production of glass and ceramics, and aluminum chloride is used to make rubber, lubricants, wood preservatives, and cosmetics. Aluminum chlorohydrate is the active ingredient in antiperspirants and deodorants, while aluminum hydroxide is used as a pharmaceutical to lower plasma phosphorus levels of patients with kidney failure. Until recently, aluminum has existed in forms not available to humans and most other species. However, acid rain has increased the availability of aluminum to biological systems and has resulted in destructive effects on fish and plant species. It is unknown if humans are susceptible to this increased bioavailability. It is poorly absorbed and efficiently eliminated; however, when absorption does occur, aluminum is distributed mainly in bone, liver, testes, kidneys, and brain. Aluminum may be involved in Alzheimer's disease (dialysis dementia) and in Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Syndromes of Guam. Aluminum content of brain, muscle, and bone increases in Alzheimer's patients. Neurofibrillary tangles are found in patients suffering from aluminum encephalopathy and Alzheimer's disease. Symptoms of "dialysis dementia" include speech disorders, dementia, convulsions, and myoclonus. Neurological effects have also been observed in rats orally exposed to aluminum compounds.

The respiratory system appears to be the primary target following inhalation exposure to aluminum. Alveolar proteinosis has been observed in guinea pigs, rats, and hamsters exposed to aluminum powders. Rats and guinea pigs exposed to aluminum chlorohydrate exhibited an increase in alveolar macrophages, increased relative lung weight, and multifocal granulomatous pneumonia. Male rats exposed to aluminum (as aluminum chloride) via gavage for 6 months exhibited decreased spermatozoa counts and sperm motility, and testicular histological and histochemical changes. Male rats exposed to drinking water containing aluminum (as aluminum potassium sulfate) for a lifetime exhibited increases in unspecified malignant and nonmalignant tumors and similarly exposed female mice exhibited an increased incidence of leukemia. Rats and guinea pigs exposed via inhalation to aluminum chlorohydrate developed lung granulomas while granulomatous foci developed in similarly exposed male hamsters.

Aluminum has been placed in the EPA weight-of-evidence classification D, not classifiable as to human carcinogenicity.

Noncarcinogenic Health Effects

  • The Oral Chronic Reference Dose is 1.00E+00 (mg/kg-day).
  • The Oral Chronic Reference Dose has a modifying factor of 1.
  • The Oral Chronic Reference Dose has an uncertainty factor of 100.
  • The Oral Chronic Reference Dose is based on the Donald et. al. study from 1989.
  • The Oral Chronic Reference Dose study critical effect is minimal neurotoxicity in offspring.
  • The Oral Chronic Reference Dose is based on mouse study.
  • The overall confidence in the Oral Chronic Reference Dose is low.

  • The Inhalation Chronic Reference Concentration is 5.00E-03 (mg/m3).
  • The Inhalation Chronic Reference Concentration has a modifying factor of 1.
  • The Inhalation Chronic Reference Concentration has an uncertainty factor of 300.
  • The Inhalation Chronic Reference Concentration is based on the Hosovski et. al. study from 1990.
  • The Inhalation Chronic Reference Concentration study critical effects are psychomotor and cognitive impairment.
  • The Inhalation Chronic Reference Concentration is based on human study.
  • The overall confidence in the Inhalation Chronic Reference Concentration is low to medium.
  • The Inhalation Chronic Reference Dose (converted from the RfC) is 1.43E-03 (mg/kg-day).

  • The Dermal Chronic Reference Dose is 1.00E-01 (mg/kg-day).
  • The Dermal Chronic Reference Dose is based on a gastrointestinal absorption factor of 0.10.