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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
Study period:
10 Apr - 11 May 1989
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP -Guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
only 4 strains tested
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
yes
Remarks:
only 4 strains tested
Qualifier:
according to
Guideline:
other: EPA, Title40, F, 1986, The salmonella typhimurium reverse mutation assay
Deviations:
yes
Remarks:
only 4 strains tested
GLP compliance:
yes
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): Sulfurylchloride
- CAS No.: 7791-25-5
- Molecular formula: ClSO2Cl
- Molecular weight: 134.96
- Substance type:
- Physical state: liquid (at room temperature)
- Colour: yellowish
- Analytical purity: according to specification
- Lot/batch No.: 29.08.88
- Expiration date of the lot/batch: Auguts 29, 1989
- Stability under test conditions: stable for at least 4 hours in ethyleneglycoldimethylether
- Storage condition of test material: moisture protected

Method

Target gene:
TA 1537: his C 3076; rfa-; uvrB-;
TA 98: his D 3052; rfa-; uvrB-; R-factor
TA 1535: his G46; rfa-; uvrB-;
TA 100: his G46; rfa-; uvrB-; R-factor
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell type (if applicable):
- Type and identity of media: Nutrient medium: Difco Nutrient Broth (NaCl added)
- Selective agar: 2.0% Vogel-Bonner-Glucose-Minimal-Agar
- Periodically checked for membrane permeability, ampicillin resistence and spontaneous mutation rates
Additional strain / cell type characteristics:
other: the strains are derived from S.typhimurium strain LT2
Metabolic activation:
with and without
Metabolic activation system:
S9 mix
Test concentrations with justification for top dose:
experiment I and II: 10, 33.3, 100, 333.3 and 1000 µg/plate
experiment IIa: 10, 100, 333.3, 1000 and 5000 µg/plate
experiment IIb: 100, 333.3, 666.6, 1000 and 3333.3 µg/plate (only strains TA 98 and TA 100 without S9 mix)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: on the day of exp. sulfurylchloride was dissolved in ethyleneglycoldimethylether
- Justification for choice of solvent/vehicle: solubility properties and its relative non-toxicity for the bacteria
Controls
Untreated negative controls:
yes
Remarks:
untreated
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium azide (NaN3), 4-nitro-o-phenylene-diamine (4-NOPD), 2-aminoanthracene (2-AA)
Remarks:
without S9 mix: TA 1535 and TA 100: NaN3; TA 1537 and TA 98: 4-NOPD; with S9 mix: all strains: 2-AA
Details on test system and experimental conditions:
METHOD OF APPLICATION: plate incorporation test

DURATION
After solidification the plates were incubated upside down for 72 hours at 37 °C in the dark.

NUMBER OF REPLICATIONS: 3

DETERMINATION OF TOXICITY
- Method: relative total growth (reduced spontaneous revertants, reduced background growth)
Evaluation criteria:
The test substance is considered as mutagen if in strain TA 100 the number of reversions is at least twice higher and in strains TA 1535, TA 1537 and TA 98 it is at least three times higher as compared to the spontaneous reversion rate. Also, a dose-dependent increase in the number of revertants is regarded as an indication of possibly existing mutagenic potential.
Statistics:
no appropriate statistical method is available (at the time of experiment)

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 100
Metabolic activation:
without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
other: >= 3333 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium, other: TA 98, TA 1535, TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: >= 3333 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: >= 3333 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Distinct toxic effects, evidenced by a reduction in the number of spontaneous revertants, occured in the following test groups at 5000 µg/plate: TA 1535 (exp. IIa), TA 1537 (exp. IIa), TA98 (exp. IIa, without S9 mix), TA 100 (exp. IIa), and at 3333.3 µg/plate in TA 98 (exp. IIb), and TA 100 (exp. IIb).
Remarks on result:
other: strain/cell type: Salmonella typhimurium TA 100
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Significant and reproducible dose-dependent increase up to the highest investigated concentration only in TA 100
without S9-mix.
Negative in TA 98, TA 1535 and TA 1537 with and without metabolic activation.

Precipitation concentration: 5000 µg/plate

Applicant's summary and conclusion

Executive summary:
In one study sulfuryl chloride induced a significant and reproducible dose-dependent increase in the number of revertants in Salmonella typhimurium TA 100 in the absence of metabolic activation, while no mutagenicity was reported in this strain in the presence of metabolic activation and in tester strains TA 98, TA 1535, and TA 1537 both with and without metabolic activation (concentrations up to 5000 μg/plate, and including cytotoxic exposures) (Bayer AG, 1989). In the second study Salmonella typhimurium TA 100 was tested negative with and without metabolic activation (concentrations up to 4000 μg/plate; 4000 μg/plate were slightly cytotoxic) (Bayer AG, 1993).