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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The restrictions were that only four strains of bacteria were used.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1981
Report Date:
1981

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
insufficient range of strains to meet requirements of current guideline
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
other: Salmonella typhimurium TA98, 100, 1535, 1537
Metabolic activation:
with and without
Metabolic activation system:
Aroclor induced mouse and rat liver S9
Test concentrations with justification for top dose:
0.01, 0.04, 0.2, 1, 3,10 µl Dequest 2000/plate and 25 µl Dequest 2000 Dequest/plate for spot test. Expressed as ATMP: 0.0065, 0.026, 0.13, 0.65, 1.95, 6.5 µl/plate for plate incorporation; up to 9 µl for spot test
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: none given
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
water
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 and TA 100 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium nitrite
Remarks:
TA 1535 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA 1537 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
TA 98 and TA 100 with activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
TA 1535 and TA 1537 with activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation); as impregnation on paper disk


DURATION
- Preincubation period: none
- Exposure duration: 48 hours
- Expression time (cells in growth medium): 48 hours
- Fixation time (start of exposure up to fixation or harvest of cells): 48 hours

NUMBER OF REPLICATIONS: single applications (spot test), triplicate plates (plate incorporation)

DETERMINATION OF CYTOTOXICITY
- Method: other: reduction in microbial lawn

Evaluation criteria:
A positive response is indicated if three of more treatments are significantly greater than the solvent control with a significant dose-response.
Statistics:
Analysis of log10 revertants per plate used Bartlett's test for homogeneity of variance and comparison of treatments with controls used within-levels pooled variance and a one-sided t-test. Where values were found to be significant, a Grubb's test was applied and significance of dose-response was evaluated by a t-test.

Results and discussion

Test results
Key result
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:
cytotoxicity
Remarks:
1-3 µl/plate for plate incorporation
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
ADDITIONAL INFORMATION ON CYTOTOXICITY: In the main study toxicity was seen as follows: +S9; 10 µl, 3 µl (TA98, TA1535); 10 µl, 3 µl, 1µl (TA100, TA1537) -S9: 10 µl, 3 µl (all strains)

Any other information on results incl. tables

No increase in revertants in any strain/metabolic activation condition. Full details of results presented in report.  Positive and negative values acceptable.

Applicant's summary and conclusion

Conclusions:
Dequest 2000 (ATMP-H) showed a lack of mutagenic potential when tested in 4 strains of Salmonella in the absence and presence of rat and mouse liver S9 mix up to the toxicity limit (1-3 µl/plate). It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.