Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

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:
no data available
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP toxicity study conducted under the US National Toxicology Program (NTP). Tested with 5 strains of salmonella, TA100, TA 98, TA 1535, TA 97 and TA102.
Cross-reference
Reason / purpose:
reference to same study

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Salmonella Mutagenicity Tests: V. Results from the Testing of 311 Chemicals
Author:
Zeiger, E., Anderson, B., Haworth, S., Lawlor, T. & Mortelmans, K.
Year:
1992
Bibliographic source:
Environmental and Molecular Mutagenesis Volume 19, Supplement 21:2 - 141.
Reference Type:
publication
Title:
Unnamed
Year:
2000

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name/CAS number of test material (as cited in study report): gallium arsenide/ 1303-00-0
- Physical state: solid
- vendor: Johnson Mattey
- Analytical purity: (vendors purity: 99.99%, analyzed purity at Midwest Research Institute, Kansas, City, MO: 99%)
No further details are given.

Method

Target gene:
not applicable
Species / strainopen allclose all
Species / strain:
S. typhimurium TA 102
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9-mix (metabolic activation enzymes and cofactors from Aroclor 1254-induced male Sprague-Dawley rat or Syrian hamster)
Species / strain:
S. typhimurium TA 100
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Species / strain:
S. typhimurium TA 1535
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Species / strain:
S. typhimurium TA 97
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Species / strain:
S. typhimurium TA 98
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Test concentrations with justification for top dose:
0.0, 10, 33, 100, 333, 1000, 1666, 3333 and 10000 µg/plate
Vehicle:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: no data
Controlsopen allclose all
Negative controls:
no
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
with metabolic activation; all strains
Negative controls:
no
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
without metabolic activation; strains TA 1535 and TA 100
Negative controls:
no
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
without metabolic activation; strain TA 97
Negative controls:
no
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 4-nitro-o-phenylenediamine
Remarks:
without metabolic activation; strain TA98
Negative controls:
no
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
mitomycin C
Remarks:
without metabolic activation; strain TA102
Details on test system and conditions:
Cultures were grown overnight at 37°C in defined minimal medium supplemented with biotin (0.8 µg/mL) and histidine (40 µg/mL). The phenotypes of the strains were analysed at the time of their use in mutagenicity assay.

METHOD OF APPLICATION: in agar; preincubation;

DURATION
- Preincubation period: 20 minutes at 37°C
- Exposure duration: 48 hours at 37°C

NUMBER OF REPLICATIONS: 3

EVALUATION: Histidine-independent (his+) colonies arising on the plates were counted. Plates were machine counted unless precipitate was present which interfered with the count.

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth:
A toxicity assay was run initially to determine the appropriate dose range for the mutagenicity assay. The toxicity assay was performed using TA 100 . Toxic concentrations were defined as those that produced a decrease in the number of his+ colonies, or a clearing in the density of the background lawn, or both.
The test substance was initially tested in the preincubation test at half-log dose intervals up to a dose that elicited toxicity. If the test substance was not toxic, it was tested to a maximum dose of 10 mg/plate or up to the dose defined by its solubility. At least five doses were tested in triplicate, and repeat experiments were performed at least one week following the initial trial.
Evaluation criteria:
A chemical was judged mutagenic (+) or weakly mutagenic (+W) if it produced a reproducible, dose-related response over the solvent control, under a single metabolic activation condition, in replicate trials.
A chemical was judged questionable (?) if the results of individual trials were not reproducible, if increases in his+ revertants did not meet the criteria for a “+W” response, or if only single doses produced increases in hisf revertants in repeat trials.
Chemicals were judged nonmutagenic (-) if they did not meet the criteria for a mutagenic or questionable response.
Statistics:
not mandatory for this test system

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 97
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
not examined
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
not examined
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
not examined
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
not examined
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
not examined
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Additional information on results:
No further details are reported.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

According to the study, gallium arsenide gave a non-mutagenic response.
Executive summary:

The purpose of the study was to present the results and data from the testing of gallium arsenide for its ability to induce mutations in tester strains of Salmonella typhimurium.The test substance was suspended in DMSO and tested at following concentrations in the preincubation method in the presence and absence of metabolic activation: 0.0, 10, 33, 100, 333, 1000, 1666, 3333 and 10000 µg/plate.

Toxicity was determined with TA 97, TA 98, TA 100, TA 102 and TA 1535. Concurrent solvent and positive controls were run with each trial.

According to the results, gallium arsenide is not mutagenic in the Ames test.