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Diss Factsheets

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:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study according OECD/EU method.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
2,4-dichlorophenylacetic acid
EC Number:
243-248-7
EC Name:
2,4-dichlorophenylacetic acid
Cas Number:
19719-28-9
Molecular formula:
C8H6Cl2O2
IUPAC Name:
2,4-dichlorophenylacetic acid
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
Metabolic activation:
with and without
Metabolic activation system:
S9 mix of Aroclor 1294 induced rats.
Test concentrations with justification for top dose:
16, 50 160, 500, 1600, 5000 µg/plate
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
cumene hydroperoxide
mitomycin C
other: nitrofurantoin, 4-nitro-1,2-phenylene diamine, 2-aminoanthracene

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
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
Executive summary:

The Ames-test screening, employing doses of up to 5000 ug per plate, showed the test substance to produce bacteriotoxic effects, starting at 160 ug per plate.

Evaluation of individual dose groups, with respect to relevant assessment parameters (dose effect, reproducibility), revealed no biologically relevant variations from the respective negative controls.

In spite of the low doses used, positive controls increased the mutant counts to well over those of the negative controls, and thus demonstrated the system's high sensitivity.

Despite this sensitivity, no indications of mutagenic effects of the test substance could be found at assessable doses of up to 5000 ug per plate in any of the Salmonella typhimurium strains used.

Due to these screening-results the test substance has to be regarded as nonmutagenic.