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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
Study period:
14 June 2017 to 06 August 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Title:
Unnamed
Year:
2017
Report date:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)
Qualifier:
according to guideline
Guideline:
JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Castor oil, hydrogenated, ethoxylated
EC Number:
500-147-5
EC Name:
Castor oil, hydrogenated, ethoxylated
Cas Number:
61788-85-0
Molecular formula:
C57H110O9 (C2H4O)n where n = 1-6.5
IUPAC Name:
Castor oil, hydrogenated, ethoxylated
Test material form:
solid
Remarks:
pasty wax

Method

Target gene:
histidine/tryptophan
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Details on mammalian cell type (if applicable):
CELLS USED
- Source of cells: University of California, Berkeley, on culture discs, on 04 August 1995, • British Industrial Biological Research Association, on a nutrient agar plate, on 17 August 1987.
- Methods for maintenance in cell culture if applicable: stored at -196 °C in a Statebourne liquid nitrogen freezer, model SXR 34

Metabolic activation:
with and without
Metabolic activation system:
phenobarbital/beta-naphthaflavone induced rat liver S9 (Lot No. PB/NF S9 30 June 2017 )
Test concentrations with justification for top dose:
Test 1 (plate incorporation): 1.5, 5, 15, 50, 150, 500, 1500 and 5000 µg/plate
Test 2 (pre-incubation): 15, 50, 150, 500, 1500 and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: acetone
- Justification for choice of solvent/vehicle: substance is insoluble in water and DMSO, completely soluble in acetone at 100 mg/L
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
acetone (in pre-incubation test 0.05 mL in final test solution)
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
N-ethyl-N-nitro-N-nitrosoguanidine
benzo(a)pyrene
other: 2-Aminoanthracene
Details on test system and experimental conditions:
METHOD OF APPLICATION: exp 1 plate incorporation; exp 2 preincubation

DURATION
- Preincubation period: 30 min at 37 ± 3 °C
- Exposure duration: 48 h at 37 ± 3 °C

NUMBER OF REPLICATIONS: 3/concentration

DETERMINATION OF CYTOTOXICITY
- Method: visible reduction in the growth of the bacterial background lawn
Evaluation criteria:
a substance is considered positive when:
1. A dose-related increase in mutant frequency over the dose range tested (De Serres and Shelby, 1979).
2. A reproducible increase at one or more concentrations.
3. Biological relevance against in-house historical control ranges.
4. Statistical analysis of data as determined by UKEMS (Mahon et al., 1989).
5. Fold increase greater than two times the concurrent solvent control for any tester strain (especially if accompanied by an out-of-historical range response (Cariello and Piegorsch, 1996)).
Statistics:
Dunnetts Regression Analysis

Results and discussion

Test results
Key result
Species / strain:
other: TA1535, TA1537, TA98, TA100 and WP2uvrA
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: at 1500 and 5000 ug/plate a slight film of the substance was seen (not preventing scoring)

Applicant's summary and conclusion

Conclusions:
Based on the findings in this test the substance is considered non-mutagenic in bacteria
Executive summary:

In an Ames test the substance was tested in Salmonella typhimurium strains TA1535, TA1537, TA98, TA100 and E. coli strain WP2uvrA in presence and absence of metabolic activation. No increase in mutant frequency was reported in any of the strains tested both in presence and absence of metabolic activation. The substance is considered to be non-mutagenic under the conditions of this test.