| Use | DYE INT, PHARMACEUTICALS, AGRICULTURAL CHEMICALS
CHEM INT FOR DYES, EG, VAT RED 32
CHEM INT FOR AZOIC COUPLING AGENTS 5 & 10
CHEM INT FOR UREA HERBICIDES, EG, MONURON
CHEM INT FOR PIGMENTS, EG, PIGMENT GREEN 10
Reacts with anhydrous hydrogen chloride and phosgene at 70-75 deg C in dioxane to produce
p-chlorophenyl isocyanate, an intermediate used for the production of urea herbicides.
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| Environmental Fate | The average concn of chemicals, 4-chloroaniline, hexachlorobenzene, &
pentachloronitrobenzene, dosed in small experimental ponds in Southern Germany during the
application period (4-6 wk) was about 50 ug/l. Residues were determined in water, sediment, &
flora & fauna species up to 166 wk later. Decrease of all chemicals in water phase follows
exponential functions & can be correlated to some extent with the physicochemical properties
such as volatility & vapor pressure. The residual behavior of the model compounds followed a
similar pattern resulting in high initial concentrations in biota & a slow buildup & subsequent
decline of concentrations in sediment. Radioactivity could be found in some fauna species &
sediment 3 yr after application. Anisols & azo compounds were found to be conversion products
of pentachloronitrobenzene & 4-chloroaniline.
Three short-term lab test systems were used to determine volatilization rates, mineralization
rates, & conversion rates of 14 (14)C-labeled chemicals one of which was p-chloroaniline. In
order to compare data obtained with the environmental behavior of the respective chemicals, data
from an outdoor experimental setup which had been shown to give residue data within the range
limits of field conditions were used. Volatilization rates, mineralization rates, & conversion rates
obtained in the lab were correlated to those found under outdoor conditions. The predicted values
for total field residues were comparable to those found experimentally, with the exception of
di(2-ethylhexyl)phthalate & p-chloroaniline.
(14)C labeled 4-chloroaniline was applied to soil in lysimeter, corresponding to 1.25 ppm to a
depth of 10 cm, & barley was sown. After 20 wk, a total of 32.8% of the radiocarbon applied was
recovered, in soil 32.4%, in plants 0.3% & in leaching water 0.1%. Radioactivity in soil consisted
of 30.8% unextractable residues & 1.6% sol conversion products; that in plants consisted of
0.24% unextractable residues & 0.03% sol metabolites (% of applied (14)C). In the 2nd & 3rd yr
after the application potatoes & carrots, respectively, were grown; total recoveries were 32.0% &
31.2% respectively. The soluble radioactive fractions in soil & plants of the first 2 yr contained
4-chloroformanilide, 4-chloroacetanilide, 4-chloronitrobenzene, 4-chloronitrosobenzene,
4,4'-dichloroazoxybenzene, and 4,4'-dichloroazobenzene. The radioactive substances
unextractable in soil and those in leaching water were partially hydrolyzable and gave
4-chloroaniline.
TERRESTRIAL FATE: If released on soil, p-chloroaniline will bind tightly to soil although in
the first few hours after a spill, a small amount will volatilize. The p-chloroaniline will undergo
both biological and chemical transformation. Mineralization occurs most rapidly in the early
weeks of incubation with as much as 7.5% degradation to CO2 occurring in 6 weeks and 17%
occuring in 16 weeks. Most (70-90%) of the p-chloroaniline is transformed into inextractable
residues and there is no significant leaching out either vertically or horizontally into surrounding
layers of soil. A three year field test in which (14)C labeled p-chloroaniline was applied to
60X60X60 cm box cultivated with barley and later with potatoes and carrots under outdoor
conditions resulted in approximately 30% of the applied radioactivity being retained at the
application site in the upper layer of soil after the first year and 67% being lost to the
atmosphere . Uptake by plants, migration into deeper soil layers or into leaching water was
low . From previous experiments, it is known that the bulk of the atmospheric loss is not
volatilized 4-chloroaniline or conversion products, but rather CO2 resulting from
mineralization . The situation after the second and third year did not alter appreciably . No
free unchanged 4-chloroaniline could be detected in either soil or plants . Conversion products
isolated under these environmental conditions included 4-chloroformanilide, 4-chloroacetanilide,
4-chloronitrobenzene, 4-chloronitrosobenzene, and the condensation products
4,4'-dichloroazoxybenzene and 4,4'-dichloroazobenzene . It is hypothecized that phenolic and
hydroxylamine metabolites were not identified although they were found in laboratory
experiments because of their chemical instability . In summary, it is clear that free
4-chloroaniline is not presistent in soil; it is subject to various acylation and oxidation reactions
and finally to total biodegradation and incorporation into soil and plant constituents(1,SRC).
AQUATIC FATE: If released into water, p-chloroaniline will volatilize (half-life 6.4 hrs in a
typical river), photooxidize in surface layers (half-life 0.4 hr), biodegrade (half-life several days in
well acclimated water), and chemically bind to clays and humus in sediment and particulate matter
in the water column. When (14)C labeled p-chloroaniline was added to an experimental pond, the
(14)C label disappeared from the water phase in two phases with half-lives of about 3 and 11
days, respectively . It was assumed that the initial loss results from volatilization. After a day, a
thin brown film of decomposition products was formed. The reduced loss rate after the first few
days is probably a result of lower volatility of the decomposition products . In estuarine water,
photolysis was also an important process, but no biodegradation occurred in 3 days . The
half-life estimated by sampling at points along the Rhine River in the Netherlands is 0.3 to 3
days .
ATMOSPHERIC FATE: If released into air, p-chloroaniline will degrade by reacting with
photochemically produced hydroxyl radicals (half-life 4.6 hr) and possibly also by photolysis in the
vapor phase or while adsorbed on airborne particulate matter. The rates for vapor phase
photolysis are not available. A highly soluble chemical, p-chloroaniline will probably be scavenged
by rain.
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| Drinking Water Impact | DRINKING WATER: Germany (treated Rhine water source) 7 parts per trillion, annual
average . The Netherlands; maximum from bank-filtered Rhine water 1 ppb, including
m-isomer .
SURFACE WATER: Not detected in Lakes Ontario (1 location), Erie (2 locations), Michigan (5
locations), and Superior (1 location). Rhine River (Germany) - 80 ppt, yearly average . Rhine
River and two tributaries (The Netherlands) 130-220 ppt, average; 240-740 ppt maximum with
96-100% frequency of detection . Meuse River (The Netherlands) 20-30 ppt, average, 80-120
ppt maximum, 44-50% frequency of detection . While detected in Rhine Delta water, not found
in surface waters from agricultural areas in the Netherlands .
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