Aniline

62-53-3

Aniline is used in the manufacture of polyurethanes (MDI),
rubber processing, chemicals, pesticides, fibers, dyes and
pigments, hydroquinone, pharmarceuticals etc (Chemical 
Profile 1985).

Characteristic.

Hedonic tone: pungent.

Human odour perception: non perception: 0.34 mg/m3
                            perception: 0.37 mg/m3
Human reflex response: adverse response: 0.07 mg/m3
Animal chronic exposure: adverse effect: 0.05 mg/m3
(Stern 1968).

93.14

Using a measured Henry's law constant of 1.2x10-4 atmxm3/mole
the estimated half-life for evaporation of aniline from a model
river 1 m deep with a 1 m/sec current and a 3 m/sec wind is
12 days (Yoshida et al. 1983) (Lyman et al. 1982).

When an environmental test system containing soil, plants,
simulated photoperiods, rain and wind was dosed with 14C
labeled aniline and left for 30 days, 24% of the radioactivity
was found in the air compartment, of which 5% was identified
as CO2 (Figge et al. 1983).

The OECD generic aquatic-terrestrial environment 14% of applied
aniline partitioned to the air phase (Yoshida et al. 1983).

Aniline has a pKa value of 4.596 and therefore exists partially
as a cation. 
Therefore the soil adsorption is not only a
funcition of percent organic carbon but also the pH of the soil
increasing with the percentage organic carbon and decreasing
with pH. 
Additionally adsorption is correlated with the clay
content of the soil. 
For 14 soils the soil/water partition
coefficient (Kd) averaged 0.074 and the Koc value averaged
1.86 (Moreale & Bladel 1976).

The Koc values in two silt loams were 130 and 410 with the
higher value occurring in the more acidic soil, and averaged
25.5 in seven agricultural soils (Pillai et al. 1982).

Anilines Koc to colloidal organic carbon from ground water is a
relatively high 3900 and this effectively increases aniline
solubility and leaching into ground water (Means et al. 1982).

The adsorption constant for adsorption to H-montmorillonite (pH
8.35) and Na-montmorillonite (pH 6.8) is 1300 and 130 (Bailey 
et al. 1968).

Aromatic amines including aniline are known to form covalent
bonds with humic materials, adding to quinone-like structure
followed by slow oxidation (Parris 1980).

In a generic aquatic-terrestrial environment, 0.26% was
distributed in soil and 1.23% in sediment. 
The sediment-water
distribution constants ranged from approx 3 to 900, which is
higher than predicted and possibly reflects a component of
chemical binding (Yoshida et al. 1983).

Aniline has a strong UV adsorption band at 285 nm which extends
above 290 nm and is therefore a candidate for direct photolysis
by sunlight (Howard 1989).

Aniline is oxidized on exposure to sunlight in air, forming
products such as hydrazobenzene, 4-aminodiphenylamine,
2-aminodiphenylamine, benzidine and azobenzene (Zechner et al 
1976) (Zepp et al. 1981).

In the atmosphere aniline inhibits the conversion of NO to NO2
and photochemical smog formation (Gitchell et al. 1975) 
(NIOSH 1983).

The half-life for direct photolysis of aniline inthe atmosphere
has been estimated to be 2.1 days based on a measured reaction
rate constant of 0.32 day-1 (Mill & Davenport 1986).

The half-life for aniline vapor reacting with photochemically
generated hydroxyl radicals in the atmosphere has been
estimated  to be 3.3 hr, based on a measured reaction rate
constant of 1.17x10-10 cm3-molecule/mole at 25 °C and assuming
an avg hydroxyl radical concn of 5x10+5 molecules/cm3
(Atkinson et al. 1987).

When aniline in water is irradiated in July sunlight, 19.3%
degradation occurred in 5 hours; however the rate decreased
with increasing concentration (Kondo 1978).

One investigators report only 0.7% oxidant formation after 4 hr
exposure to sunlight, and a half-life of 0.2 hr during exposure
to light >290 nm in the laboratory (Draper & Crosby 1983) 
(Kotzias et al. 1982).

Humic acid photosensitize the reaction of aniline in water. 
The
half-life in distilled water was 1 week, whereas it was 4-8 hr
in Georgia's May sunshine in the near-surface black water from
the Aucilla River (Zepp et al. 1981).

The presence of various species of algae can increase the
photodegradation rates by factors of 4-50 over that in
distilled water (Zepp & Schlotzhauer 1983).

When aniline is adsorbed on silica gel 46.5% mineralitazion
occurs in 17 hr upon irradiation with light >290 nm (Freitag 
1982).

In the presence of nitrite ions, photolytic products formed are
mutagenic using the Ames assay (Suzuki et al. 1983).

Aniline is degraded by many common species of bacteria and
fungi in soil and acetanilide, 2-hydroxyacetanilide,
4-hydroxyaniline and catechol are reported metabolites
(Howard 1989).

The rate of degradation in four soils reached a maximum value
after one week and declined to a low value after 2 week. 
After
10 weeks 16-26% of the aniline was mineralized (Suess et al 
1978).

In an oligotrophic lake water sample 75-99% mineralization of
aniline occurred in 21 days and 40-60% of the aniline degraded
in 1 day in river water and seawater when incubated at 30 °C
(Subba-Rao 1982) (Kondo 1978).

Degradation occurred in Nile River water after 3-day lag
(El-Dib & Aly 1976).

The half-life in the Rhine River was 2.30 days as determined by
concentration reduction between sampling points (Zoeteman 
1980).

Biodegradation removed 56% of anions in a week and was the most
significant removal process for aniline in water from a
eutrophic pond, with a substantial portion being mineralized to
CO2 within this 1-week period (Brown & Laboureur 1983).

Decomposition period by a soil microflora: 4 days 
(Verschueren 1983).

Degradation of aniline is frequently 90-100% in laboratory
tests utilizing activated sludge or sewage seed lasting from 3
to 28 days with acclimation not always being required
(Howard 1989).

It is completely degraded by asoil incolum in 4 days and by
bacteria in river mud in 20 days (Calamari et al. 1980).

Amendation of the pond with sewage sludge greatly increased the
rate of degradation. 
The major pathway of biodegradation
involved oxidative deamination to catechol, which was further
metabolized to CO2 whereas minor pathways involved reversible
acylation to form acetanilide and anilide (Lyons et al 1984).

In <1 year 39% of aniline in Rhine River water was removed by
bank filtration, which would involve both biodegradation and
adsorption (Zoeteman et al. 1980).

Although aniline is amenable to degradation in anaerobic
reactors, only 19% degradation was reported in 53 days,
including a 28-day lag with a sewage inocolum forming
acetanilide and 2-methylquinoline as products and no
degradation occurred in an anaerobic reactor in 110 days with a
2 to 10 day retention time using an inoculum maintained on
acetate (Howard 1989).

Aniline was completely degraded in 7 days using composting
(Howard 1989).

The log BCF aniline in two species of fish are 0.78 and <1.0,
which demostrates that aniline does not bioconcentrate in fish
(Ly & Metcalt 1975) (Freitag 1982).

Man: severe toxic effects: 80 ppm, 60 min
symptoms of illness: 20 ppm
unsatisfactory: > 10 ppm
(Verschueren 1983).

Mutagenicity in the Salmonella test: neg., < 0.005 revertant
colonies/nmol; < 70 revertant colonies at 1 mg/plate 
(McCann et al. 1975).

Amphibian: lethality and teratogenicity to early embryonic
stages of South African clawed frog, Xenopus laevis:
                            day
conc. mg/l       1           2          3          4
                A/S   %     A/S   %    A/S   %    A/S    %
0               0/50  0     0/50  0    0/50  0    0/50   0
10              0/50  0     0/47  0    4/36  11   4/36   11
50              1/50  2     3/48  6    3/48  6    3/48   6
                (A/S = abnormals/survivors)
(Dumont et al. 1979).

Mexican axoloth (3 - 4 weeks after hatching):48 hr LC50:440 mg/l
Clawed toad (3 - 4 weeks after hatching): 48 hr LC50: 560 mg/l
(Slooff & Baerselman 1980).

Tanytarsus dissimilis: LC59, 2 days, > 219 mg/l 
(Holcombe et al. 1987).

Bacteria: Escherichia coli: no effect at 1 g/l 
(Bringmann & Kühn 1976).

Toxicity threshold (cell multiplication inhibition test):
bacteria: Pseudomonas putida: 130 mg/l
(Bringmann & Kühn 1980).

Degradation by Aerobacter: 500 mg/l at 30 °C:
                parent: 100 % ring disruption in 54 hours
                mutant: 100 % ring disruption in 12 hours
                (Verschueren 1983).

Inhibition of photosynthesis of a fresh water non-axenic
uni-algal culture of Selenastrum capricornutum:
at   10 mg/l: 90 % carbon-14 fixation (vs controls)
at  100 mg/l: 34 % carbon-14 fixation (vs controls)
at 1000 mg/l: 3 % carbon-14 fixation (vs controls)
(Verschueren 1983).

Aquatic community; 4 days, 1 - 300 mg/l; stress effect
(observed physiological tension in animals or plants)
(Yount & Shannon 1987).

EC50, 24hr, 190 mg/l, rpd, Tetrahymena pyriformis 
(Yoshioka et al. 1985).

Protozoa: ciliate (Tetrahymena pyriformis): 24 hr LC100: e/l 
(Schultz et al. 1978).

Algae: Scenedesmus: toxic: 10 mg/l
crocystis aeruginosa: inhibition of cell
ultiplication starts at 0.16 mg/l; LD50 20 ppm
(Bringmann & Kühn 1976, Verschueren 1983).

Arthropoda: Daphnia: toxic: 0.4 mg/l 
(Bringmann & Kühn 1980).

Toxicity threshold (cell multiplication inhibition test):
green algae (Scenedesmus quadricauda): 8.3 mg/l
protozoa (Entosiphon sulcatum): 24 mg/l
protozoa (Uronema parduczi): 91 mg/l
(Bringmann & Kühn 1980).

Aplexa hypnorum; LC50, 4 days, > 219 mg/l 
(Holcombe et al. 1987).

LC50, 48hr, 450 mg/l, Tubificidae
LC50, 48hr, 175 mg/l, Chironomus gr. thummi
LC50, 48hr, 760 mg/l, Erpobdella octoculata
LC50, 48hr, 800 mg/l, Lymnaea stagnalis
LC50, 48hr, 155 mg/l, Dugesia cf. lugubris
LC50, 48hr, 406 mg/l, Hydra oligactis
LC50, 48hr, 150 mg/l, Corixa punctata
LC50, 48hr, 235 mg/l, Ischura elegans
LC50, 48hr, 64 mg/l, Nemoura cinerea
LC50, 48hr, 220 mg/l, Cloeon dipterum
(Slooff 1983)