Substance fact sheet
The National Pollutant Inventory (NPI) provides information on the types and amounts of pollutants being emitted in the Australian community.
This page provides facts about aniline (benzenamine). It describes how you might be exposed to this substance, how exposure might effect you and the environment, common uses, comparative data about aniline (benzenamine) and its physical and chemical properties.
For more information about some of the terms used in this page, see the NPI glossary.
The National Pollutant Inventory (NPI) holds data for all sources of aniline (benzenamine) emissions in Australia.
Short-term exposure to the substance irritates the eyes, and may cause effects on the blood: methaemoglobinaemia, resulting in cyanosis, brain damage and kidney failure. It is potentially lethal to humans.
Long-term or repeated exposure may have effects on the liver, kidneys, blood and spleen: methemoglobanaemia (see short-term exposure). Aniline (benzenamine) is a probable carcinogen.
It does not remain in the body due to its breakdown and removal. Aniline is a possible reproductive hazard.
The substance can be absorbed into the body by inhalation of the vapour, through the skin and by ingestion.
Aniline can be formed from the breakdown of certain pollutants found in outdoor air, from the burning of plastics, or from burning tobacco. Airborne exposure to aniline may occur from breathing contaminated air, from smoking tobacco or proximity to someone who is smoking, or from being near industrial sources that use large quantities of aniline.
Occupational exposure to aniline could occur in industries that use aniline to make other chemicals.
Small amounts of aniline may be found in some foods, such as corn, grains, rhubarb, apples, beans, and rapeseed cake (animal feed). Aniline has also been found as a volatile component of black tea. Aniline has been detected in drinking water and has also been found in surface water.
See Sources for more information.
Worksafe Australia:
TWA: 2 ppm 7.6 mg/m<3 STEL: not given in Worksafe Australia.
Aniline and aniline oil:
Harmful : concentration cut-off level: 0.2 % weight/weight
Toxic: concentration cut-off level: 1 % weight/weight
Aniline salts:
Harmful : concentration cut-off level: 3 % weight/weight
Toxic: concentration cut-off level: 25 % weight/weight
The Australian NOHSC National Exposure Standards Database link is probably the most useful source of information.
Note that the emissions data in the NPI database is not directly comparable with these guidelines.
This substance may be hazardous to the environment; with special attention given to fish, crustaceans, and birds. Tests by the aniline industry show that aniline is highly toxic to aquatic life.
Aniline causes germination decrease, stunting, and size decreases (among other effects) on numerous agricultural crops.
Aniline acts to reduce the formation of photochemical smog.
Aniline is unlikely to exist in terrestrial environments in sufficient concentrations to cause serious acute or chronic effects to terrestrial organisms.
Aniline in solution adsorbs strongly to colloidal organic matter, which effectively increases its solubility and movement into ground water. It is also moderately adsorbed to organic material in the soil. It will slowly volatilise from soil and surface water (vapour pressure 0.67 mm Hg @ 25°C) and is subject to biodegradation. Although rapidly degraded in the atmosphere, aniline can be deposited in the soil by wet and dry deposition, and by adsorption on aerosol particles.
Air: Aniline degrades in the atmosphere primarily by reaction with photochemically produced hydroxyl radicals. The estimated half-life for aniline is 2 hours. The reaction products include nitrosamines, nitrobenzene, formic acid, nitrophenols, phenol, nitrosobenzene, and benzidine.
Soil: A number of microorganisms in soil can use aniline as a sole carbon and nitrogen source. Degradation of 44.2% of the incubated aniline to CO2 in 10 days and 12% in 20 days, respectively, by different isolated soil microorganisms has been demonstrated in the laboratory. Aniline bound to humic materials in the soil is subject to oxidation. Products apparently formed from oxidation include azobenzene, azoxybenzene, phenazine, formanilide, and acetanilide. Photodegradation of aniline on the soil surface is also thought to be an environmentally important removal process. The combination of these processes eventually results in the degradation of aniline to CO2. The half-life for the mineralisation of aniline to CO2 has been estimated at 4 days, utilising a model soil ecosystem. Information from studies done obtained under environmental conditions indicate that the half-life of aniline in the soil is less than one week
Water: Aniline in water is subject to biodegradation, photodegradation, and adsorption to sediment and humic materials. Low pH will increase the removal of aniline by adsorption; however, the adsorption to colloidal particles can extend the persistence of aniline in the aquatic environment. Although subject to oxidation when adsorbed to humic materials, aniline is resistant to hydrolysis. A half-life for aniline of 2.3 days has been reported in an industrial river. The presence of humic acids and various species of algae in the water can increase the photodegradation rates of aniline up to 50 fold.Biota: The bioconcentration factor in two species of fish has been estimated at less than 1. A bioconcentration factor of 3 has also been calculated for fish. Aniline is not expected to accumulate significantly in aquatic organisms; however, it is absorbed and metabolised by fish.
No national guidelines.
Aniline is used in rubber accelerators and anti-oxidants, dyes and intermediates, photographic chemicals, as isocyanates for urethane foams, in pharmaceuticals, explosives, petroleum refining; and in production of diphenylamine, phenolics, herbicides and fungicides. Aniline is also used in the manufacture of polyurethanes, rubber processing chemicals, pesticides, fibres, dyes and pigments, photographic chemicals, and pharmaceuticals.
Effluents from oil shale recovery and oil refiners, and from chemical and coal conversion plants.
Cigarette smoke. Agricultural uses of products containing or made from aniline.
It occurs naturally in some foods (for example, in corn, grains, beans, and tea), and in coal tars.
No mobile sources.
Aniline is predominantly used as a chemical intermediate for the dye, agricultural, polymer, and rubber industries. As such, there are few products directly containing aniline. Nevertheless, aniline is used as a solvent, and has been used as an antiknock compound for petrol.
Approximately 400 substances were considered for inclusion on the NPI reporting list. A ranking and total hazard score was given based on health and environmental hazards and human and environmental exposure to the substance.
Aniline (benzenamine) was ranked as 69 out of 400. The total hazard score taking into account both human health and environmental criteria is 4.2.
On a health hazard rating of 0 - 3 aniline (benzenamine) registers 2.0. A score of 3 represents a very high hazard to health, 2 represents a medium hazard and 1 is harmful to health.
On an environmental rating of 0 - 3 aniline (benzenamine) registers 2.2. A score of 3 represents a very high hazard to the environment and 0 a negligible hazard.
Factors taken into account to obtain this ranking and these scores include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the measure of its ability to remain active in the environment and whether it accumulates in living organisms. It does not take into account exposure to the substance. Environmental exposure is reflected in the NPI rank for this substance (see comparative data below). A substance that scores highly as an environmental hazard is oxides of nitrogen at 3.0 and one of the lower scores is carbon monoxide at 0.8. A substance that scores highly as a health hazard is arsenic at 2.3 and one of the lowest scores is ammonia at 1.0.
| Substance name | Aniline (benzenamine) |
| CASR number | 62-53-3 |
| Molecular formula | C6H7N |
| Synonyms | benzamine; aniline oil, phenylamine; aminobenzene; aniline oil; phenylamine; aminophen; kyanol; benzidam; blue oil; C.I. 76000; C.I. oxidation base 1; cyanol; krystallin; anyvim; arylamine |
| Physical properties: Aniline is a colourless to brown, oily liquid which darkens on exposure to air and light. It has a characteristic amine odour (detectable at 0.6 to 10 ppm ) and burning taste. Hygroscopic. Moderately soluble in water. Aniline is miscible with alcohol, benzene, chloroform, carbon tetrachloride, acetone, and most organic solvents. Melting Point (°C): -6.2 |
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| Chemical properties: Combustible. Darkens on exposure to air and light. The substance decomposes on heating at temperatures above 190 C, or on burning producing toxic and corrosive fumes (ammonia, nitrogen oxides, and carbon monoxide) and flammable vapours. The substance is a weak base. Reacts vigorously with strong oxidants, acids, acetic anhydride, chloromelamine monomers, beta-propiolactone, and epichlorohydrin causing fire and explosion hazard. Reacts with metals such as sodium, potassium, and calcium, producing flammable hydrogen gas. Attacks copper and its alloys. |
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There is more information that may be useful in understanding some of the issues surrounding the NPI.