3-Chloro-2-methylaniline

Aromatic amines (such as chloroanilines and toluidines) have been observed to undergo rapid and reversible covalent bonding with humic materials in aqueous solution; the initial bonding reaction is followed by a slower and much less reversible reaction believed to represent the addition of the amine to quinoidal structure followed by oxidation of the product to give an amino-substituted quinone; these processes represent pathways by which aromatic amines may be converted to latent forms in the biosphere(1). In the absence of covalent bonding, a Koc value of approximately 235 can be estimated from 3-chloro-2-methylphenylamine's estimated log Kow of 2.58(2) using an appropriate regression-derived equation(3,SRC); this Koc value suggests medium soil mobility(4).

Based upon an estimated log Kow of 2.58(1), the BCF for 3-chloro-2-methylphenylamine can be estimated to be 54 from a recommended regression-derived equation(2,SRC). A fish BCF of approximately 50 was measured using the Japanese MITI procedure for bioaccumulation(3). The estimated and measured BCF values suggest that bioconcentration in aquatic organisms is not important environmentally(SRC).

The Henry's Law constant for 3-chloro-2-methylphenylamine can be estimated to be 1.56X10-6 atm-cu m/mole using a structure estimation method(1,SRC). This value of Henry's Law constant indicates slow volatilization from water(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep flowing 1 m/sec with a wind velocity of 3 m/sec) can be estimated to be about 28 days(2,SRC). Volatilization half-life from a model environmental pond can be estimated to be about 434 days(3,SRC).

The rate constant for the vapor-phase reaction of 3-chloro-2-methylphenylamine with photochemically produced hydroxyl radicals has been estimated to be 1.2X10-10 cu cm/molecule-sec at 25 °C which corresponds to an atmospheric half-life of about 3.2 hrs at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1,SRC). Aromatic amines and halogens are generally resistant to aqueous environmental hydrolysis(2); therefore, 3-chloro-2-methylphenylamine is not expected to hydrolyze in water(SRC). As a class, aromatic amines react relatively rapidly in sunlit natural water via reaction with photochemically produced hydroxyl radicals and peroxy radicals(3); typical half-lives for hydroxyl radical and peroxy radical reaction are on the order of 19-30 sunlight hours(3); however, rate data specific to 3-chloro-2-methylphenylamine were not located(SRC).

Aqueous solutions of chloroanilines, similar in structure to 3-chloro-2-methylphenylamine, have been observed to undergo direct photolysis in sunlight with half-lives ranging from a few hours to a few days(1-3); therefore, 3-chloro-2-methylphenylamine may experience some direct photolysis when exposed to sunlight(SRC).

3-Chloro-2-methylphenylamine could be released to the environment in wastewater emissions from azo dye manufacturing sites using it as an intermediate. If released to the atmosphere, 3-chloro-2-methylphenylamine is expected to degrade rapidly (estimated half-life of 3.2 hr) by reaction with photochemically produced hydroxyl radicals. If released to soil, 3-chloro-2-methylphenylamine may undergo a covalent chemical bonding with humic materials which can result in its chemical alteration to a latent form and prevent leaching. In the absence of covalent bonding, moderate leaching may be possible. If released to water, covalent bonding with humic materials in the water column and sediments may result in partitioning from the water column to sediments. By analogy to similar aromatic amines, 3-chloro-2-methylphenylamine in the water column may be susceptible to photooxidation (via hydroxyl and peroxy radicals) and direct photolysis. Insufficient data are available to assess the relative importance of biodegradation of 3-chloro-2-methylphenylamine in soil or water. Occupational exposure occurs primarily through dermal contact, although exposure through inhalation can also occur. (SRC)