o-TOLUIDINE CAS N°: 95-53-4 - UNEP Chemicals

OECD SIDS o-TOLUIDINE
With adapted activated sludge from an industrial sewage treatment plant a test on inherent
biodegradation was conducted. The procedure followed the OECD guideline 302 B. After 11 days
(4 days adaptation) 96 % of the initial concentration were removed (Wellens, 1990). Under
anaerobic conditions o-toluidine could not be removed after a period of 10 months in an aquifer
slurry (Kuhn and Suflita, 1989) and after 150 days in a landfill environment (Kromann and
Christensen, 1998). Both tests were not performed according to current standard methods and
represent only special conditions.
The key data of the biodegradation studies are listed in Table 6.
Table 6 Tests on biodegradation of o-toluidine (IUCLID 3.5)
Inoculum Procedure Result Reference
Activated sludge,
non-adapted
Activated sludge,
domestic, nonadapted
Activated sludge,
domestic, nonadapted
Activated sludge,
domestic, adapted
Activated sludge,
industrial
Anaerobic aquifer
slurry
MITI (comparable to
OECD TG 301 C)
65 % after 28 d MITI, 1992
OECD TG 301 A 88 - 90 % after 28 d
OECD TG 301 E > 90 % (5 results)
67 % (1 result)
after 28 d
OECD TG 302 B 98 % after 5 d Pitter, 1976
Brown and Laboureur, 1983
Brown and Laboureur, 1983
OECD TG 302 B 96 % after 11 d Wellens, 1990
Test medium: aquifer
slurries
Initial concentration:
ca. 0.2 mM
Anaerobic landfill Group of organic
chemicals in a landfill
environment in situ
and in a laboratory
leachate reactor
2.2.6 Bioaccumulation
0 % removal over a
10 months period
0 % removal over a
150 days (o-toluidine
formed as degradation
product)
Kuhn and Suflita, 1989
Kromann and
Christensen, 1998
The available experimental bioconcentration factors (BCF) for o-toluidine indicate no significant
potential for bioaccumulation in Pacific oysters (Crassostrea gigas) or Common bay mussels
(Mytilus edulis). Oysters and mussels were exposed to 5 mg/l of o-toluidine in seawater for 24
hours, at 15 °C and pH 7.9. o-Toluidine carbon was 14 C-ring-labelled, 3 replicates were conducted.
The steady state of the body burden was reached after 2 - 4 hours of exposure for the oysters and
4 hours for the mussels (Knezovich and Crosby, 1985). See results on Table 7. Concerning the
bioaccumulation potential of o-toluidine in fish no measured values are available.
Taking into account the octanol-water partition coefficient, a bioconcentration factor (BCF) can be
calculated with the BCFWIN Program (v. 2.15). Using log Kow = 1.40, the calculated BCF was 2.4
(Bayer AG, 2003).
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