Acrylonitrile

107-13-1

Solvent. 
The major use of acrylonitrile is in the production 
of acrylic and modacrylic fibres by copolymerization with 
methylacrylate, methylmethacrylate, vinylacetate, 
vinylchloride, or vinylidenechloride. 
Other major uses include 
the manufacture of acrylonitrile-butadiene-styrene (ABS) and 
styrene-acrylonitrile (SAN) resins. 
Acrylonitrile is also used 
as a fumigant.

Colourless liquid.

Characteristic.

Quality: onion, garlic.

Hedonic tone: pungent

Threshold Odour Concentration: recognition: 3.72 -51.0 mg/m3
                                            1.7 - 23 ppm
Population Identification Threshold (50 %): 21.4 ppm
Population Identification Threshold (100 %): 21.4 ppm
average: 18.6 ppm
number of panellists: 16
41.9 mg/m3 = 19 ppm
45 mg/m3 = 20.4 ppm
detection: 3.4 mg/m3
recognition: 47 mg/m3 (Verschueren 1983).

Practically odorless or with a very slight odor of peach 
kernels (HSDB 2001).

53.06

Relative volatility (nBuAc=1) = 6.33

The overall transfer coefficient for acrylonitrile relative to 
oxygen is 0.59. 
Coupled with the reaeration rates for oxygen in 
typical bodies of water, one can estimate that the 
volatilization half-life of acrylonitrile in a typical pond, 
river and lake are 6, 1.1 and 4.8 days, respectively. 

Acrylonitrile is highly volatile and not strongly adsorped to 
soil and will therefore volatilize rapidly from soil and other 
surfaces. 
The Henry's Law constant for acrylonitrile estimated 
from the structure is 1.38X10-4 atm-cm3/mole. 
Using this 
Henry's Law constant, the volatilization half-life from a model 
river flowing i m/sec with a 3 m/sec wind and 1 m depth in 6.8 
hours (HSDB 2001).

The Koc for acrylonitrile calculated from the water solubility 
is 9 indicating that adsorption to soil will be insignificant 
(HSDB 2001).

Photooxidation by ultraviolet light in aqueous medium at 50 °C:
24.2 % degradation to CO2 after 24 hours (Verschueren 1983).

Acrylonitrile does not absorb light >290 nm and is therefore
not susceptible to direct photolysis (Grasselli & Ritchey 1975).

Acrylonitrile reacts with photochemically produced hydroxyl
radicals with a reaction half-life of 3.5 days (assuming 12 hr
of sunlight) (Edney et al. 1983).

Reaction with ozone is not fast enough to be a significant
sink (Harris et al. 1981)

In a smog chamber, the formation of ozone is significant with
the time to maximum ozone formation averaging 5.3 times faster
than propane in five experiments and 5.3%/hr of acrylonitrile
disappeared (Dimitriades & Joshi 1977) (Sickles et al. 1980).

For a first-order reaction, this is equivalent to a half-life of
13 hr. 
Formaldehyde and PAN-type compounds are formed
(Spicer et al. 1985).

Photooxidation half-life in air:
8.25d - 13.4hr, based upon measured rate constant for reaction
with hydroxyl radical in air (Howard 1991).

The photolysis of acrylonitrile vapor at 213.9 nm was shown to
proceed via two molecular elimination pathways, one yielding
acetylene and hydrogen cyanide and the other yielding
cyanoacetylene and hydrogen. 
The quantum yields for the two
processes were determined to be 0.50 and 0.31, respectively. 
In
the presence of such photosensitizers as xanthene,
triphenylene, bentzophenone, acetophenone, fluorenone and
dibromoanthracene, the major product of photolysis of
acrylonitrile in solution was shown to be
1,2-dicyanocyclobutane. 
Teh dicyanocyclobutane is not very
stable, however and it is unlikely that the reaction will
proceed in the gas phase (HSDB 2001).

It has showed that the reaction of acrylonitrile with hydroxyl
radicals was independent of temperature in the range studied
but showed a small increase with increasing pressure (Risk
Assessment 1998).

Photooxidation by ultra violet light in aqueous medium (50 C):
24.2 % degradation to CO2 after 24 hours (Verschueren 1983).

Acrylonitrile (10 ppm) was stable at pH 4 to 10 for 23 days
indicating that hydrolysis is negligible under these
conditions (Going et al. 1979).

First-order hydrolysis half-life: 1.06X10 7 hr (1210yr)
(t1/2 at pH 7.0) Based upon measured acid and base
catalyzed hydrolysis rate constants (Howard 1991).

Acid rate constant (M(H+)-hr)-1: 4.2X10-2 M-1 hr-1
(t1/2 = 1.65X10 6 hr (188 years) at pH 5.0) Based upon measured 
acid and base catalyzed hydrolysis rate constants (Howard 
1991).

Base rate constant (M(OH-)-hr)-1: 6.1X10-1 M-1 hr-1
(t1/2=1.14X10 5 hr (13 years) at pH 9.0) Based upon measured 
acid and base catalyzed hydrolysis rate constants (Howard 
1991).

In studies using activated sludge inocula >95% degradation, 70%
of theoretical BOD removal was reported after 21 days
acclimation in a screening study; 30% of theoretical BOD
removal was reported after 10 days in a treatment plant; and
>99% degradation, 30% of theoretical BOD removal was reported
in a bench-scale continuous flow reactor (Stover & Kincannon
1983) (Howard 1989).

It has reported 0 and 38% of theoretical BOD removal after 5
and 20 days, respectively, and complete degradation in 7 days
in screening studies with sewage seed (Young et al. 1968)
(Tabak et al. 1981).

Acrylonitrile completely degraded in Missisippi river water in 6
days (Going et al. 1979).

Aerobic half-life:
23d - 30hr, scientific judgement based upon river die-away
testa data (Howard 1991).

Under anaerobic conditions acrylonitrile was poorly degraded in
a reactor with a 2 - 10 day retention time, with only 17%
utilization being reported after 110 days acclimation (Chou 
1979).

Anaerobic half-life:
92d - 5d, scientific judgement based upon estimated aqueous
aerobic biodegradation half-life (Howard 1991).

Aerobic biodegradation of acrylonitrile was evaluated in soil 
samples at concentrations between 10 and 1000 ppm. 
In a Londo 
soil, complete degradation occurred in less than 2 days fot 
concentrations uo to 100 ppm. 
Acrylamide and acrylic acid were 
observed as transient intermediates of the degradation process. 

The slowness of the degradation process at higher 
concentrations was probably due to inhibitory effects of the 
initial acrylonitrile (HAZARDTEXT 2001).

Biodegradation:
41-74% by BOD
period: 14d
substance: 30 mg/l
sludge: 100 mg/l
(MITI 1992)

The biodegradation of acrylonitrile is reported to occur
readily at concentrations less than 20 mg/l during anaerobic
digestion processes operated in multicipal sewage treatment
facilities. 
Is has been observed that a Pseudomonas-containing
sludge used for the treatment of industrial acrylonitrile
wastes, could degrade up to 35 % of the pollutant at
concentration levels of 500 mg/l (HSDB 2001).

Microbial activity can reduce initial concn. of 10, 25 and 50
ppm. 
The two lower concentrations supporting mixed microbes and
the higher concn favoring fungi (HSDB 2001).

150 mg/l of acrylonitrile can be utilized by saprophytic
microorganisms. 
At concn above 50 ppm acrylonitrile may inhibit
bacterial nitrification, affecting activated sludge processes
(HSDB 2001).

  Method          Experimental details         Result
OECD 301 D    2 mg/l acrylonitrile, effluent   0% degr. 28 d
              from laboratory waste water
              treatment plant
OECD 301 C    100 mg/l acrylonitrile and       14.7% degr. 28 d
              30 mg/l suspended solids
OECD 302 C    30 mg/l acrylonitrile and       41-74% degr. 28 d
              100 mg/l suspended solids
(Risk Assessment 1998).

Biodegradation by mutant microorganisms  (Verschueren 1983)
- 500 mg/l at 20 C disruption:
  mutant 100 % in 4 hours

Impact on biodegradation processes: BOD test is not influenced
up to 1 g/l (Verschueren 1983).

At 100 mg/l no inhibition of NH3 oxidation by Nitrosomonas sp
(Verschueren 1983).

The whole body bioconcentration factor for a bluegill exposed
to acrylonitrile for 28 days, or until equilibrium was obtained
in a flowing water system, was 48 (Barraws et al. 1978).

The bioconcentration factor estimated from the water solubility
is 1 (Kenaga 1980).

Rat inhalation: slight transitory effect: 129 ppm
Rat inhalation: fatal: 636 ppm, 4 hours
Rabbit inhalation: slight transitory effect: 97 ppm
Rabbit inhalation: fatal: 258 ppm
Cat inhalation: sometimes fatal: 152 ppm
Guinea pig inhalation: slight transitory effect: 267 ppm
Dog inhalation: very slight effects: 29 ppm
Dog inhalation: 3/4: 110 ppm
Rats: ingestion: 35 ppm (4 mg/kg body weight /day): mild signs
of toxicity (decreased water and food consumption, decreased
body weight).

100 ppm (10 mg/kg body weight /day) during 12
months: stomach papillomas (1 of 20 rats); central nervous
system tumors (6 of 20 rats).

Zymbal gland carcinoma (2 of 20 rats).

Rats: inhalation: 80 ppm (6 hr/day, 5 days/week, 1 year): 3 of
26 rats; central nervous system tumors.

(Verschueren 1983).

Pseudomonas putida: inhibition of cell multiplication starts at
53 mg/l (Verschueren 1983).