N-(1,3-Dimethylbutyl)-N

OECD SIDS
N-(1,3-DIMETHYLBUTYL)-N´-PHENYL-1,4-PHENYLENEDIAMINE
5. TOXICITY ID: 793-24-8
DATE: 11.05.2005
incubation period of ca. 19 hrs. TS was evaluated for cytotoxicity at doses
of 0.16, 0.5, 1.6, 5, 16.6, 50, 166.6, 500, 1666 and 5000 µg/ml with and
without S-9 activation. The cell survival frequencies were used to estimate
the 5 dose levels of TS which were expected to yield ca. 10-100 % cell
survival.
All mutation assays were performed using duplicate cultures for each TS
dose level as well as positive (ethyl methanesulfonate without S-9 and
dimethylnitrosamine with S-9) and negative controls (DMSO). The TS was
evaluated at doses of 0.05-0.6 µg/ml without S-9 and at doses of 10-55
µg/ml with S-9. Following treatment, relative cell survival was determined
for each culture. After growth for a period of 7 days to allow expression of
the mutant phenotype, 1,000,000 cells from each culture were plated in
medium containing thioguanine to select for mutant cells. The mutant
frequency (expressed as TG/r mutants/1,000,000 clonable cells) was
calculated by dividing the total number of mutant clones by the number of
cells plated, corrected for the cloning efficiency (average of 3 plates) of the
cells at the time of mutant selection. A substance is considered positive if it
exhibits a dose-dependent increase in mutation induction, with at least one
dose resulting in a mutant frequency of >= 50 TG/r mutants per 1,000,000
clonable cells.
The plates for the 55 µg/ml dose level with S-9 mix were contaminated at
the time of selection staining and could not be evaluated. There were no
dose-dependent increases in the mutant frequencies of the cultures treated
with the TS with and without activation. The positive control chemicals led
to the expected increases in mutatant frequency.
Reliability : (1) valid without restriction
Comparable to guideline study
Flag : Critical study for SIDS endpoint
04.06.2004 (82)
Type : Unscheduled DNA synthesis
System of testing : primary rat hepatocytes
Test concentration : 0.3, 1.0, 3.0, 10.0, 33.0, 100.0, 333.0,1000, 3333, 10000 µg/well
Cycotoxic concentr. : >= 3333 µg/well
Metabolic activation : without
Result : negative
Method : other
Year : 1984
GLP : yes
Test substance : other TS: in study protocol adressed as "Flexzone 7F" (no data on
chemical identity or purity)
Method : autoradiographic method of Williams
Remark : The positive control chemical (2-acetamidofluorene) led to the expected
increase in grain counts.
Test condition : Isolation of adult rat hepatocytes was done according to a modification of
the method of Williams, Cancer Lett. 4, 69-75, 1978. The liver of a male
Fischer 344 rat was perfused, excised and combed yielding 1.79 million
cells per ml WME culture medium with an 83 % cell viability.
500,000 cells were seeded in triplicate culture and treated with 20 µl of TS
in DMSO at doses of 0.3-10,000 µg/well for 18-20 hrs. In addition, a DMSO
group, an untreated control (WME culture medium only) and a positive
control (2-acetamidofluorene) were evaluated concurrently. The highest
dose of TS scored in the DNA Repair Test was 1000 µg/well due to
excessive cytotoxicity at the 3333 and 10,000 µg/well levels.
Unscheduled DNA repair synthesis was quantified by a net nuclear
increase of black silver grains for 20 cells/slide. This value was determined
by taking a nuclear count and subtracting the highest of three adjacent
cytoplasmic counts. Three slides at each dose point were evaluated for a
total of 60 cells/dose.
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