Appendix D - Dossier (PDF) - Tera

date: 20–JUL–2005
5. Toxicity Substance ID: 71–43–2
______________________________________________________________________________
Blood was obtained from healthy adult men. Benzene was
dissolved in serum–free culture medium. Cells were
suspended in the serum–free culture medium containing
benzene and the metabolic activation system (S9 mix derived
from rat liver) and incubated for 2 hours. The flask was
agitated to ensure even distribution of active metabolites
among the cells. After incubation, the cells were washed,
resuspended in the same medium and incubated further. SCEs
were analysed.
Source: BP Chemicals Ltd LONDON
Test substance: Laboratory reagent grade; purity not specified.
13–DEC–1996 (793)
Type: Sister chromatid exchange assay
System of testing: human peripheral lymphocytes
Concentration: 10, 100, 500, 600 µg/ml
Metabolic activation: with and without
Result: negative
Method: OECD Guide–line 479
Year: 1986
GLP: no data
Test substance: other TS
Remark: Benzene was dissolved in dimethylsulphoxide and added to the
cultures for 48 hours. Diepoxybutane was used as the
positive control and untreated cells acted as the negative
control. Colcemid was added at the end of the treatment
period and preparations made to assess SCE. In the studies
using metabolic activation, cells were exposed to S9 derived
from Aroclor–induced rat liver, at the same time as exposure
to the highest benzene concentration tested in the study
without activation. After 1 hour exposure, cells were
washed and reincubated in complete medium for 24 hours.
Colcemid was added and preparations made to assess SCE.
Cyclophosphamide was used as the positive control in the
presence of S9.
Benzene was tested at 10, 100, 500 and 600 µg/ml in the
absence of S9 and at 600 µg/ml in its presence. No increase
in SCE rate was noted in any of the benzene treated
cultures. Similar negative results, in the absence of
activation have been reported by Gerner–Smidt P. & Friedrich
U. Mutation Res. 58, 313–316, 1978; Morimoto K. & Wolff S.
Cancer Res. 40, 1189–1193, 1980.
Source: BP Chemicals Ltd LONDON
Test substance: Laboratory reagent grade; 99% pure.
13–DEC–1996 (849)
Appendix D: Benzene SIDS Dossier
– 405/957 –