Appendix D - Dossier (PDF) - Tera

date: 20–JUL–2005
3. Environmental Fate and Pathways Substance ID: 71–43–2
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3.5 Biodegradation
Type: aerobic
Inoculum: activated sludge, domestic, non–adapted
Concentration: 17.37 mg/l related to Test substance
Degradation: 96.3 % after 28 day(s)
Result: readily biodegradable
Method: OECD Guide–line 301 F "Ready Biodegradability: Manometric
Respirometry Test"
Year: 2000
GLP: yes
Test substance: as prescribed by 1.1 – 1.4
Result: The average percent biodegradability of benzene was
determined to be 96.3 % (n=3) over a 28 day testing period (99
%, 103 % and 87 % in the single replicates).
The 10% biodegradation level was reached between days 3 and
4, and by day 5, biodegradation was 65.13% (n=3). At the end
of the10–day window a degradation of 93 %, 104 % and 86 % was
measured.
Blank controls showed cumulative background oxygen uptake of
16.87 mg/L over the 28 day test period, which satisfies the
OECD guidelines that background oxygen consumption in the
blanks not exceed 60 mg/L. Benzene was not inhibitory to the
test systems based on the results of the toxicity control
experiments.
Source: EXXON Biomedical Sciences East Millstone, NJ
German Rapporteur
Test condition: The aqueous aerobic biodegradability potential of benzene
was determined using the OECD (301F) manometric respirometry
test method. Biodegradability was determined by measuring
the oxygen consumption in a test medium with trace nutrients
and inoculated with activated sludge supernatant
(unacclimated). Benzene was evaluated at a mean
concentration of 17.37 mg/L (carried out in triplicate test
systems). The study was conducted at 22 °C ± 1 °C. The
positive control substance, sodium benzoate, was evaluated
in duplicates at a concentration of 30.29 mg/L. Duplicate
toxicity control test systems containing benzene and sodium
benzoate at the same concentrations as used alone.
Reliability: (1) valid without restriction
Flag: Risk Assessment
02–SEP–2003 (342)
Appendix D: Benzene SIDS Dossier
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