ALUMINUM TRICHLORIDE

Aluminum trichloride
(Aluminum chloride, trichloroaluminum)
CAS 7446-70-0

AlCl₃

White crystalline solid
Sublimes at 181 °C
Reacts violently with water (90 g/100 mL)

Hydrogen chloride odor detectable when exposed to moist air

1 mmHg at 100 °C

LD₅₀ oral (rat) 3730 mg/kg

LD₅₀ skin (rabbit) >2 g/kg

TLV-TWA (ACGIH) 2 mg(Al)/m³

Highly corrosive solid that reacts with water to form hydrochloric acid.

Aluminum chloride is strongly irritating and highly corrosive to the skin, eyes, and mucous membranes owing to its reaction with water to form hydrochloric acid. It is slightly toxic by ingestion but can cause severe burns to the mouth and digestive tract until hydrolyzed in the stomach. Inhalation of aluminum trichloride dust, vapor, or its hydrolysis products can result in severe damage to the tissues of the respiratory tract and can lead to shortness of breath, wheezing, coughing, and headache; inhalation of large amounts may lead to respiratory tract spasms and pulmonary edema and can be fatal. Skin and eye contact with aluminum chloride can cause severe burns.

Aluminum chloride may cause allergic skin reactions. Long-term exposure can cause damage to lungs. In some animal tests, aluminum chloride has shown developmental and reproductive toxicity. Aluminum chloride has not been found to be carcinogenic in humans.

Aluminum chloride is not flammable but reacts violently with water, so fires involving this substance should be extinguished with carbon dioxide or dry chemicals. Toxic fumes (HCl and reaction products) can be released during fires.

Anhydrous aluminum chloride reacts violently with water to produce HCl and a great deal of heat. Aluminum chloride reacts violently on heating with nitrobenzene and may react violently or explosively with ethylene oxide, organic azides, organic perchlorates, and sodium borohydride. In the presence of moisture, this substance is highly corrosive to most metals.

Aluminum chloride should be handled in the laboratory using the "basic prudent practices" described in Chapter 5.C. In particular, work with this substance should be conducted in a fume hood, and impermeable gloves should be worn at all times when handling AlCl₃. Aluminum chloride should be stored in sealed containers under an inert atmosphere in a cool, dry place. Care should be taken in opening containers of this compound because of the possibility of the buildup of HCl vapor from hydrolysis with traces of moisture.

In the event of skin contact, immediately wash with soap and water and remove contaminated clothing. In case of eye contact, promptly wash with copious amounts of water for 15 min (lifting upper and lower lids occasionally) and obtain medical attention. If aluminum chloride is ingested, wash the mouth with water and seek immediate medical attention. If large amounts of this compound (or the HCl vapor generated from its contact with water) are inhaled, move the person to fresh air and seek medical attention at once.

In the event of a spill, sweep up the aluminum chloride (avoid raising dust) and collect in a bag while wearing appropriate protective clothing. Small spills may be collected and carefully hydrolyzed with a large excess of cold water, neutralized with base, and disposed of properly. Respiratory protection may be necessary in the event of a large spill or release in a confined area.

Small excess amounts of aluminum chloride and waste material containing this substance should be cautiously added to a large stirred excess of water, neutralized, and filtered. The insoluble solids should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines. The neutral aqueous solution should be flushed down a drain with plenty of water.

The information in this LCSS has been compiled by a committee of the National Research Council from literature sources and Material Safety Data Sheets and is believed to be accurate as of July 1994. This summary is intended for use by trained laboratory personnel in conjunction with the NRC report Prudent Practices in the Laboratory: Handling and Disposal of Chemicals. This LCSS presents a concise summary of safety information that should be adequate for most laboratory uses of the title substance, but in some cases it may be advisable to consult more comprehensive references. This information should not be used as a guide to the nonlaboratory use of this chemical.

Copyright 1995 National Academy of Sciences. All rights reserved.