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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:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Study period:
From 25 August 1996 to 30 September 1996
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP Guideline study with acceptable restrictions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Neither E.coli WP2 strains nor S. typhimurium TA102 were used.
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
yes
Remarks:
Neither E.coli WP2 strains nor S. typhimurium TA102 were used.
GLP compliance:
yes (incl. certificate)
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): Lauryl polyglycol ether
- Ethoxylation degree: 2
- Analytical purity: No data
- Physical state: Clear colourless liquid
- Lot/batch No.: 962190
- Storage condition of test material: Ambient <25ºC, shielded from light

Method

Target gene:
His-operon
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
not applicable
Species / strain / cell type:
S. typhimurium TA 1538
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S9 liver microsomal fraction
Test concentrations with justification for top dose:
without metabolic activation: 0, 1.5, 5, 15, 50, 150 and 500 µg/plate
with metabolic activation: 0, 5, 15, 50, 150, 500, 1500 and 5000 µg/plate
Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: N-ethyl-N'-nitrosoguanidine (3-5 µg/plate), 9-aminoacridine (80 µg/plate), 4-Nitro-o-phenylenediamine (5 µg/plate), 4-nitroquinoline-N-oxide (0.2 µg/plate), 2-aminoanthracene (0.5-2 µg/plate)
Details on test system and experimental conditions:
METHOD OF APPLICATION:
A known aliquot (0.5 mL) of S9-mix and 2 mL of molten, trace histidine supplemented media were overlaid onto a sterile Vogel-Bonner Minimal agar plate in order to assess the sterility of the S9-mix.

Incubation and Assessment of Plates: all of the plates were incubated at 37 ºC for approximately 48 h and the frequency of revertant colonies assessed using a Domino colony counter.

NUMBER OF REPLICATIONS: Triplicate

DETERMINATION OF CYTOTOXICITY
- Method: The cytotoxicity was rated as follows:
S= sparse background lawn
V= very thin background lawn
T= toxic
NT= not tested at this dose level
Evaluation criteria:
The test item was considered positive if:
There is a dose related increase in the number of revertants or a biologically relevant increase for at least one test concentration.

Results and discussion

Test results
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Number of Revertants (Number of Colonies per plate)
Base-pair Substitution Type Frameshift Type
TA100 TA1535 TA1538 TA98 TA1537
147 33 29 29 9
124    (133) 32    (34) 21  (25) 40   (31) 7   (10)
129 36 24 33 13
2225 (22)b19
Number of Revertants (Number of Colonies per plate)
Base-pair Substitution Type Frameshift Type
TA100 TA1535 TA1538 TA98 TA1537
88 15 9 23 7
93    (88) 19    (16) 7   (9) 22   (22) 8   (9)
84 15 10 21 12

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The test material was found to be non-mutagenic.
Executive summary:

Salmonella typhimurium strains TA1535, TA1537, TA1538, TA98 and TA100 were treated with the test material using the Ames plate incorporation method in triplicates, both with and without the addition of a rat liver homogenate metabolising system (10% liver S9 in standard co-factors). The dose range was determined in a preliminary toxicity assay and ranged between 1.5 and 5000 µg/plate in the first experiment. The vehicle (dimethyl sulphoxide) control plates produced counts of revertant colonies within the normal range. All the positive control chemicals used in the test induced marked increases in the frequency of revertant colonies, both with and without the metabolising system. The test material caused a visible reduction in the growth of the bacterial lawn to all of the strains of salmonella tested. The sensitivity of the bacterial strains to the toxicity of the test material varied between strains and between exposures with or without S9 -mix. The first incidence of toxicity was recorded at 150µg/plate. The test material was, therefore, tested up to its toxic limit. The test material was considered to be NON-MUTAGENIC under the conditions of this test.