home edit2 whole TSD November 2002 PDF format - OEHHA

ACRYLONITRILE
CAS No: 107-13-1
I. PHYSICAL AND CHEMICAL PROPERTIES (From HSDB, 1994)
Molecular weight 53.06
Boiling point
77.3°C
Melting point
-82°C
Vapor pressure 100 mm Hg at 23°C
Air concentration conversion 1 ppm = 2.2 mg/m 3
II.
HEALTH ASSESSMENT VALUES
Unit Risk Factor: 2.9 E-4 (µg/m 3 ) -1
Slope Factor: 1.0 E+0 (mg/kg-day) -1
[Human respiratory tract cancer incidence data (O’Berg, 1980), relative risk model (US EPA,
1983), reevaluated by CDHS/RCHAS (1988).]
III.
CARCINOGENIC EFFECTS
Human Studies
Cancer incidence and mortality in a cohort of 1345 male workers exposed to acrylonitrile at a E.I. du
Pont de Nemours and Co., Inc. textile plant in Camden SC was studied by O’Berg (1980). The study
cohort was identified as having had potential exposure to acrylonitrile in the period between plant
startup in 1950 and 1966. The 1966 cutoff date allowed for a 10-year follow-up through the end of
1976. Worker exposure levels were assessed qualitatively by the author and a committee of six
DuPont employees with long-term experience in the acrylonitrile exposure area; plant environmental
monitoring data was not available for the 1950-1966 period. High, moderate and low exposure
categories were established. The U.S. Environmental Protection Agency (US EPA) (1983) noted that
DuPont representatives agreed that 5, 10 and 20 ppm might be used to represent the low medium and
high exposure classification levels. Expected numbers of cancer cases and deaths were calculated from
both DuPont corporate data and from the 1969-1971 National Cancer Institute survey data set.
However, the author only listed the results of cancer incidence and mortality calculations using the
DuPont “control” data set as the source of the expected numbers of cancer cases and mortality; US
EPA (1983) stated that the presentation of results based on this control cohort only would ignore the
possible effects of other chemicals on the company control cohort. Exposed workers demonstrated 25
cases of all types of cancer, with 20.5 expected. Of these cases, 8 were lung cancer versus 4.4
expected. For workers employed during plant startup (1950-1952) and exposed for at least 6 months,
8 cases of lung cancer were noted vs. 2.6 expected (p < 0.01). Most of this excess occurred during
the latest followup period (1970-1976) (6 cases of lung cancer vs. 1.5 expected, p < 0.01). Total
cancer cases in this period were also significantly increased (17 observed, 5.6 expected, p < 0.01).
39