2-Naphthylamine

Chemical properties

2-Naphthylamine is a white to red crystals with a faint, aromatic odor. Darkens in air to a reddish-purple color.

Physical properties

White crystals becomes purplish-red on exposure to air. Odor threshold concentrations ranged from 1.4 to 1.9 mg/m³ (quoted, Keith and Walters, 1992).

The Uses of 2-Naphthylamine

2-Naphthylamine was widely used in themanufacture of dyes and in rubber. Currently, its use is curtailed because of thehealth hazard.

The Uses of 2-Naphthylamine

It is listed as a known human carcinogen. Used in manufacturing of dyes, as antioxidant in rubber

The Uses of 2-Naphthylamine

An amine compound used for research purposes

Definition

ChEBI: 2-naphthylamine is a naphthylamine carrying the amino group at position 2. It has a role as a carcinogenic agent.

Production Methods

2-Naphthylamine was previously produced in substantial amounts for nearly 50 years but is no longer produced commercially. It is now used exclusively for research, and only rarely. It was formerly used in the manufacture of dyestuffs and as an antioxidant in the rubber industry.
Prior to termination of its domestic production and use in the dye and rubber industries, an estimated 1000 U.S. workers were possibly exposed to 2-naphthylamine by inhalation and dermal routes. Currently, laboratory technicians and scientists who use the compound for research purposes may constitute the group with the greatest risk of potential exposure.

Synthesis Reference(s)

Journal of the American Chemical Society, 75, p. 2014, 1953 DOI: 10.1021/ja01104a525
Synthesis, p. 830, 1980 DOI: 10.1055/s-1980-29225

General Description

A white to reddish colored solid in the form of flakes. Slightly soluble in hot water and denser than water. Toxic by ingestion, inhalation and skin absorption. Used to make dyes and agricultural chemicals.

Air & Water Reactions

2-Naphthylamine darkens in air to a reddish-purple color (oxidizes). Slightly soluble in hot water and denser than water. Napthyl amines can be slowly hydrolyzed, releasing NH3 as a byproduct [N.L. Drake, Org. React. 1, (1942), 105].

Reactivity Profile

2-Naphthylamine is a weak base. 2-Naphthylamine is incompatible with strong oxidizing agents and strong acids. 2-Naphthylamine is also incompatible with nitrous acid. 2-Naphthylamine reduces warm ammoniacal silver nitrate.

Hazard

Toxic by ingestion, inhalation, skin absorption; a confirmed carcinogen. Causes bladder cancer.

Health Hazard

2-Naphthylamine poses a severe health haz ard because of its carcinogenicity. Admin istration of this compound by all routesresulted in cancers in various tissues in testanimals. It caused tumors in the kidney, blad der, liver, lungs, skin, and blood tissues.There is sufficient evidence that this com pound causes bladder cancer in humans aftera latent period of several years.The toxicity of 2-naphthylamine is lowto moderate. However, high doses can pro duce severe acute toxic effects. The routesof exposures are ingestion, skin contact, andinhalation of its dusts or vapors. The acutetoxic symptoms are similar to those produced by 1-naphthylamine: hemorrhagic cystitis or methemoglobinemia (causing hypoxiaor inadequate supply of oxygen to tissues),respiratory distress, and hematuria (blood inurine).LD50 value, oral (rats): 727 mg/kg.

Fire Hazard

Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.

Safety Profile

Confirmed human carcinogen with experimental neoplastigenic and tumorigenic data. Long and continued exposure to even small amounts may produce tumors and cancers of the bladder. Poison by intraperitoneal route. Moderately toxic by ingestion. Experimental reproductive effects. Human mutation data reported. A very toxic chemical in any of its physical forms, such as flake, lump, dust, liquid, or vapor. It can be absorbed into the body through the lungs, the gastrointestinal tract, or the skin. Combustible when exposed to heat or flame. At elevated temperatures it evolves a vapor that is flammable and explosive. Incompatible with nitrous acid. When heated to decomposition it emits toxic fumes of NOx.

Toxicology

2-Naphthylamine is a human carcinogen that leads predominately to formation of tumors in the epithelium of the bladder. The conclusive epidemiological studies on humans are backed up by a wealth of animal data. However, although a proven carcinogen in mouse, hamster, dog, and monkey, 2-naphthylamine exhibits little, if any, carcinogenicity in rat or rabbit. Several metabolic pathways have been identified, but the main one involves N-hydroxylation followed by rearrangement to 2-amino-1- hydroxynaphthalene. Only the former is a proven animal carcinogen.

Potential Exposure

2-Naphthylamine is presently used only for research purposes. It is present as an impurity in α-naphthylamine. It is as an intermediate in the preparation of other compounds. 2-Naphthylamine was widely used in the manufacture of dyestuffs; as an antioxidant for rubber; and in rubber coated cables.

Carcinogenicity

2-Naphthylamine is known to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in humans.

Environmental Fate

Photolytic. Low et al. (1991) reported that the photooxidation of aqueous primary amine solutions by UV light in the presence of titanium dioxide resulted in the formation of ammonium and nitrate ions.
Chemical/Physical. Kanno et al. (1982) studied the aqueous reaction of 2-naphthylamine and other substituted aromatic hydrocarbons (aniline, toluidine, 1-naphthylamine, phenol, cresol, pyrocatechol, resorcinol, hydroquinone, and 1-naphthol) with hypochlorous acid in the presence of ammonium ion. They reported that the aromatic ring was not chlorinated as expected but was cleaved by chloramine forming cyanogen chloride. At lower pHs, the amount of cyanogen chloride formed increased (Kanno et al., 1982).
2-Naphthylamine will not hydrolyze because it does not contain a hydrolyzable functional group (Kollig, 1993).
At influent concentrations of 10, 1.0, 0.1, and 0.01 mg/L, the GAC adsorption capacities were 300, 150, 75, and 37 mg/g, respectively (Dobbs and Cohen, 1980).

Shipping

UN1650 β-Naphthylamine, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Purification Methods

Sublime the amine at 180o in a stream of nitrogen. Crystallise it from hot water (charcoal) or *benzene. Dry it under vacuum in a drying pistol. The styphnate has m 194-195o (from EtOH). [Beilstein 12 H 1265, 12 III 2989, 12 IV 3122.] CARCINOGEN.

Incompatibilities

A weak base. Dust may form explosive mixture with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Incompatible with nitrous acid.

Waste Disposal

Controlled incineration whereby oxides of nitrogen are removed from the effluent gas by scrubber, catalyst, or thermal device. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal.