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CHEMINFO Record Number: 193
CCOHS Chemical Name: Aluminum phosphate, tribasic

Aluminium phosphate, tribasic
Aluminophosphoric acid
Aluminum acid phosphate
Aluminum monophosphate
Aluminum orthophosphate
Aluminum phosphate
Phosphoric acid, aluminum salt
Aluminum phosphate (non-specific name)

CAS Registry Number: 7784-30-7
RTECS Number(s): TB6450000
Chemical Family: Phosphoric acid salt / inorganic phosphate salt / inorganic aluminum compound / aluminum salt
Molecular Formula: Al-O4-P
Structural Formula: Al(PO4)


Appearance and Odour:
White, very hard, crystalline material (16,17). Probably odourless.

Odour Threshold:
Probably odourless.

Warning Properties:
NONE - aluminum phosphate is probably odourless and nonirritating.

There are several different forms of aluminum phosphate. The properties and hazards of the different forms can vary considerably. This record applies only to the tribasic form.

Uses and Occurrences:
This material is not widely used in industry. It is mainly used as a refractory material and as an abrasive.(18) It is also used as a catalyst in the ammonolysis of isopropyl alcohol.(19)


White, very hard, crystalline material; probably odourless. Will not burn. Can decompose at high temperatures forming toxic phosphorus oxides and/or phosphine. Essentially non-toxic following short term exposure.


Effects of Short-Term (Acute) Exposure

There are no reports of effects following short-term inhalation of tribasic aluminum phosphate dust. In general, high concentrations of dust may cause coughing and mild, temporary irritation.

Skin Contact:
Tribasic aluminum phosphate dust is probably not irritating to the skin, based on animal information for related insoluble salts. There is no human or animal information available for tribasic aluminum phosphate.
It has generally been considered that aluminum is very poorly absorbed through the skin.(1) An unconfirmed animal toxicity value indicates that toxic effects would not be expected following short-term skin contact with tribasic aluminum phosphate.

Eye Contact:
Tribasic aluminum phosphate dust is probably not irritating to the eye, except as a "foreign object". Some tearing, blinking and mild temporary pain may occur as the solid material is rinsed from the eye by tears.

Aluminum is a normal component of the human diet and the normal daily intake of various aluminum compounds is significant. In adults, daily aluminum intake has been estimated at about 9 to 14 mg (2) in one reference and 1 to 100 mg (mean 5 mg) (3) in another. It can be much higher (1000 mg or more (4)) in individuals taking antacids containing aluminum hydroxide. An unconfirmed animal toxicity value indicates that oral toxicity is low. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

Nervous System:
A link between exposure to aluminum or aluminum compounds and Alzheimer's disease or other neurological diseases has been suggested. This link was suggested because of severe neurological effects which have been observed in patients receiving dialysis treatment (with dialysis fluids containing aluminum); effects seen in animals exposed to aluminum using non-occupational routes of exposure; case reports of neurological effects in individual workers; and findings of elevated aluminum levels in the brains of patients with neurological diseases. At present, whether or not this association is a true effect is controversial and findings are inconsistent. Based on the available information, including studies of occupationally-exposed employees, recent reviewers have concluded that the evidence is inadequate to establish a link between occupational exposure to aluminum and specific effects on the nervous system or Alzheimer's disease, in normal, healthy workers.(1-3,5-7) One reviewer has concluded that there is a likely connection between long-term occupational exposure to aluminum and a specific effect, impaired co-ordination, but not other toxic effects on the nervous system or Alzheimer's disease.(8)

INGESTION: Ingestion of large amounts of aluminum salts over a prolonged period may cause phosphate deficiency, based on animal and human information.(9) Prolonged ingestion of very large amounts (several grams/day) may result in osteomalacia (softening and bending of the bones).(10) There are no reports of these effects from occupational exposures to tribasic aluminum phosphate.


There is no animal or human information available for tribasic aluminum phosphate. Negative results have been obtained for other aluminum salts in animal studies.(11)

The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.

The American Conference of Governmental Industrial Hygienists (ACGIH) has no listing for this chemical.

ACGIH has proposed a carcinogenicity designation of A4 (not classifiable as a human carcinogen) (aluminum metal and insoluble compounds).

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
There is no human or animal information available.

Reproductive Toxicity:
There is no human or animal information available.

There is no information available.

Toxicologically Synergistic Materials:
There is no information available.

Potential for Accumulation:
Aluminum is absorbed only to a limited degree from either the gastrointestinal tract or the lungs, and is rapidly excreted in the urine. A certain amount of tissue uptake does occur and animal experiments have shown that it can accumulate in bone.(12) The degree of absorption of aluminum following ingestion has been shown to depend on the chemical form of the metal as well as the presence of other dietary constituents such as citrate, ascorbate and lactate.(13) Water solubility has not been found to be a good indicator of the degree of aluminum absorption for different aluminum compounds.(14)


If symptoms are experienced, remove source of contamination or have victim move to fresh air. Obtain medical advice immediately.

Skin Contact:
If irritation occurs, remove contaminated clothing, shoes and leather goods (e.g. watchbands, belts). Gently blot or brush away excess chemical quickly. Wash gently and thoroughly with water and non-abrasive soap. If irritation persists, obtain medical advice immediately.

Eye Contact:
Do not allow victim to rub eye(s). Let the eye(s) water naturally for a few minutes. Have victim look right and left, and then up and down. If particle/dust does not dislodge, flush with lukewarm, gently flowing water for 5 minutes or until particle/dust is removed, while holding the eyelid(s) open. If irritation persists, obtain medical attention. DO NOT attempt to manually remove anything stuck to the eye(s).

If irritation or discomfort occur, obtain medical advice immediately.

First Aid Comments:
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.


Flash Point:
Not combustible (does not burn)

Lower Flammable (Explosive) Limit (LFL/LEL):
Not applicable

Upper Flammable (Explosive) Limit (UFL/UEL):
Not applicable

Autoignition (Ignition) Temperature:
Not applicable

Sensitivity to Mechanical Impact:
Not sensitive. Stable material.

Sensitivity to Static Charge:
Not applicable. Not combustible.

Combustion and Thermal Decomposition Products:
Aluminum oxide and toxic fumes of phosphorus oxides and/or phosphine.(16)

Fire Hazard Summary:
Aluminum phosphate does not burn or support combustion. Heating aluminum phosphate to high temperatures may produce toxic phosphorus oxides and/or phosphine. Well-sealed containers may rupture violently when exposed to fire or excessive heat for sufficient time.

Extinguishing Media:
Does not burn. Use fire extinguishing agents suitable for materials which are burning.

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance. Approach fire from upwind to avoid hazardous vapours and toxic decomposition products.
Closed containers may rupture violently when exposed to the heat of the fire. If possible, isolate materials not yet involved in the fire, and move containers from the fire area if this can be done without risk, and protect personnel. Otherwise, fire-exposed containers or tanks should be cooled by application of water spray. Application should begin as soon as possible and should concentrate on any unwetted portions of the container. Take care not to get water inside container. Apply water from the side and from a safe distance until well after the fire is out. For a massive fire, consider using unmanned hose holders or monitor nozzles. In any case, stay away from the ends of tanks involved in the fire.
The decomposition products of aluminum phosphate are hazardous to health. Do not enter without wearing specialized protective equipment suitable for the situation. Firefighter's normal protective clothing (Bunker Gear) will not provide adequate protection. Chemical resistant clothing (e.g. chemical splash suit) and positive pressure self-contained breathing apparatus (MSHA/NIOSH approved or equivalent) may be necessary.


NFPA - Comments:
NFPA has no listing for this chemical in Codes 49 or 325.


Molecular Weight: 121.95

Conversion Factor:
Not applicable

Physical State: Solid
Melting Point: Greater 1500 deg C (2732 deg F) (20)
Boiling Point: Not applicable.
Relative Density (Specific Gravity): 2.56 at 23 deg C (water = 1) (17)
Solubility in Water: Insoluble (18,20)
Solubility in Other Liquids: Soluble in ethanol (20); very slightly soluble in hydrochloric acid and nitric acid; practically insoluble in acetic acid.(17)
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available.
pH Value: Not applicable
Vapour Density: Not applicable
Vapour Pressure: Probably practically zero.
Saturation Vapour Concentration: Not applicable
Evaporation Rate: Probably zero
Critical Temperature: Not applicable


Normally stable. Heating aluminum phosphate to high temperatures may produce toxic phosphorus oxides and/or phosphine.(16)

Hazardous Polymerization:
Does not occur.

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.

This material is generally unreactive.(18)
STRONG ACIDS (e.g sulfuric acid) - may slowly dissolve this material and react violently.
STRONG BASES (eg. sodium hydroxide) - may react violently.(16)

Hazardous Decomposition Products:
None reported

Conditions to Avoid:
High temperatures.

Corrosivity to Metals:
Insufficient information


LD50 (oral, rat): 1000 - 4640 mg/kg (at 1000 mg/kg 0/4 rats died; at 4640 mg/kg 4/4 rats died) (50% solution) (21)

LD50 (dermal, rabbit): Greater than 4640 mg/kg (0/2 rabbits died) (50% solution)(21)


Selected Bibliography:
(1) Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological profile for aluminum. TP-91/01. US Department of Health and Human Services, July 1992
(2) Industrial Disease Standards Panel. Interim Report to the Workers' Compensation Board on Aluminum. IDSP report of findings No. 9. Toronto, Ontario, May 1992
(3) Bertholf, R.L., et al. Aluminum. In: Handbook on toxicity of inorganic compounds. Edited by H.G. Seiler. Marcel Dekker, 1988. p. 56-64
(4) Kilburn, K.H. Pulmonary and neurologic effects of aluminum. In: Environmental and occupational medicine. Edited by W.N. Rom. Little, Brown and Company, 1992. p. 465-473
(5) Wennberg, A. Neurotoxic effects of selected metals. Scandinavian Journal of Work, Environment and Health. Vol. 20, Special Issue (1994). p. 65-71.
(6) Martyn, C.N. The epidemiology of Alzheimer's disease in relation to aluminium. In: Aluminium in biology and medicine. Ciba Foundation Symposium 169. John Wiley and Sons, 1992. p. 69-86.
(7) Sjogren, B., et al. Aluminium. Arbete och Halsa. Criteria documents from the Nordic Expert Group 1992. Edited by B. Beije, et al. No. 1 (1993)
(8) Doll, R. Review: Alzheimer's disease and environmental aluminium. Age and Aging. Vol. 22, no. 2 (Mar. 1993). p. 138-153
(9) Krueger, G.L., et al. The health effects of aluminum compounds in mammals. Critical Reviews in Toxicology. Vol. 13, issue 1 (1984). p. 1-24
(10) Elinder, C.-G., et al. Aluminum. In: Handbook on the toxicology of metals. 2nd ed. Vol. II: Specific metals. Edited by L. Friberg, et al. Elsevier, 1986. p. 2-25
(11) Leonard, A., et al. Mutagenicity, carcinogenicity and teratogenicity of aluminium. Mutation Research. Vol. 196, no. 3 (Nov. 1988). p. 247-257
(12) Beliles, R.P. The metals. In: Patty's industrial hygiene and toxicology. Edited by G.D. Clayton, et al. 4th ed. Vol. II. Toxicology. Part C. John Wiley and Sons, Inc., 1994. p. 1880-1900
(13) Domingo, J.L. Reproductive and developmental toxicity of aluminum: a review. Neurotoxicology and Teratology. Vol. 17, no. 4 (1995). p. 515-521
(14) Yokel, R.A. Benefit vs. risk of oral aluminum forms: antacid and phosphate binding vs. absorption. Drug and Chemical Toxicology. Vol. 12, nos. 3 and 4 (1989). p. 277-286
(15) RTECS record for phosphoric acid, aluminum salt (1:1). Last updated: 9701
(16) The Sigma-Aldrich library of chemical safety data. Ed. II. Vol. 1. Sigma-Aldrich Corporation, 1988. p. 115C
(17) Budavari, S, ed. The Merck index: an encyclopedia of chemicals, drugs, and biologicals. 12th ed. Merck and Col, Inc., 1996. p. 63
(18) Gard, D.R. Phosphoric acid and phosphates. In: Kirk-Othmer encyclopedia of chemical technology. 4th ed. Vol. 18. John Wiley and Sons, 1996. p. 694
(19) Unruh, J.D., et al. Propyl alcohols: isopropyl alcohol. In: Kirk-Othmer encyclopedia of chemical technology. 4th ed. Vol. 20. John Wiley and Sons, 1996. p. 221-222
(20) Weast, R.C., ed. Handbook of chemistry and physics. 66th ed. CRC Press, 1985-1986. p. B-69
(21) Initial submission: Toxicology lab report T-1680 regarding toxicity studies including tripotassium phosphate and other chemicals with cover letter dated 10-27-92. Rhone- Poulenc Inc. (submitting organiziation), Stauffer Chemical Co. (contractor). NTIS OTS0571153.
(22) International Programme on Chemical Safety (IPCS). Aluminum. Environmental Health Criteria 194. World Health Organization, 1997

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.

Review/Preparation Date: 1997-10-29

Revision Indicators:
Bibliography 2005-01-18
TLV proposed changes 2007-04-12
TLV definitions 2007-04-12
Carcinogenicity 2007-04-12
WHMIS detailed classification 2007-04-12

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