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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions (only 4 strains tested, only summarized data shown)

Data source

Reference
Reference Type:
publication
Title:
Salmonella mutagenicity test results for 250 chemicals.
Author:
Haworth, S. et al.
Year:
1983
Bibliographic source:
Environ. Mutagen. Supplement 1, 3-142

Materials and methods

Principles of method if other than guideline:
Method: other: pre-incubation modification of the Ames test acc. to Yahagi, T. et al. (1975), Cancer Lett. 1, 91-96
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): nitrobenzene, American Cyanamid
- Analytical purity: > 99.9%
- Lot/batch No.: 9071

Method

Species / strain
Species / strain / cell type:
other: S. typhimurium TA1535, TA1537, TA100, and TA98
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
liver S-9 was prepared from male Sprague-Dawley rats and Syrian hamsters that were induced with Aroclor 1254
Test concentrations with justification for top dose:
10, 33, 100, 333 and 1000 ug/plate
Vehicle / solvent:
DMSO was used as a solvent.
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Remarks:
choline chloride, glycerol, glycine, mannitol and sodium phosphate
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene (all strains ± S9), 4-nitro-o-phenylenediamine (TA98 -S9), sodium azide (TA100/Ta1535-S9), 9-aminoacridine (TA1537-S9)
Details on test system and experimental conditions:
METHOD OF APPLICATION: preincubation


DURATION
- Preincubation period: 20 min at 37 °C
- Fixation time (start of exposure up to fixation or harvest of cells): 48 h at 37 °C


NUMBER OF REPLICATIONS: three plates


DETERMINATION OF CYTOTOXICITY
- Method: other: In dose setting expriments, the test chemical was checked for toxicity to TA100 up to a concentration of 10 mg/plate or the limit of solubility, both in the presence and absence of S9 mix. Indications of toxicity were viability in complete medium and reduced numbers of revertant colonies per plate and/or thinning or absence of the bacterial lawn
Evaluation criteria:
A positive response was indicated by a reproducible, dose-related increase, whether it be twofold over background or not. Questionable or inconclusive were low-level responses that were not reproducible or results that did not show a definite trend. It also included tests in which an elevated revertant colony yield occured at only a single dose level.

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: Concentrations were chosen so that the high dose exhibited some degree of toxicity (see dose setting experiments).
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative