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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
June - August 1997
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report date:
1997

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
1997
Deviations:
no
Remarks:
according to current version (2020) no bacteria strain included to detect cross-linking mutagens
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
5,6 beta-Epoxy-7 beta-hydroxy-15 beta,16 beta-methylene-3 beta-pivaloyloxy-5 beta-androstan-17-one
EC Number:
617-351-6
Cas Number:
82544-13-6
Molecular formula:
C25 H36 O5
IUPAC Name:
5,6 beta-Epoxy-7 beta-hydroxy-15 beta,16 beta-methylene-3 beta-pivaloyloxy-5 beta-androstan-17-one

Method

Target gene:
Histidine gene locus
Species / strain
Species / strain / cell type:
other: S. typhimurium TA 1535, TA 100, TA 1537, TA 1538, TA 98
Metabolic activation:
with and without
Metabolic activation system:
liver S9-mix from Aroclor 1254 -treated rats
Test concentrations with justification for top dose:
Methylenepoxidpivalat: six concentrations from 0.1 to 5 mg/plate
Sodium azide: 5 µg/plate (TA 1535 and TA 100)
2-Nitrofluorene: 10 µg/plate (TA 1538 and TA 98)
9-Acridinamine: 100 µg/plate (TA 1537)
Benzo[a]pyrene: 2.5 µg/plate (TA 100 and TA 98)
Cyclophosphamide: 400 µg/plate (TA 1535)
2-Aminoanthracene: 2 µg/plate
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: Sodium azide (TA 1535 and TA 100), 2-Nitrofluorene (TA 1538 and TA 98), 9-Acridinamine (TA 1537), Benzo[a]pyrene (TA 100 and TA 98), Cyclophosphamide (TA 1535), 2-Aminoanthracene

Results and discussion

Test results
Key result
Species / strain:
other: Salmonella typhimurium strains TA 1535, TA 100, TA 1537, TA 1538, TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
growth inhibition and precipitates in the agar were observed in all strains starting at 2.5 mg/plate with and without S9 mix
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Executive summary:

Methylenepoxidpivalat was tested in the Salmonella/microsome test for point-mutagenic effects in doses up to 5000 µg/plate on the five histidine-auxotrophic Salmonella typhimurium LT2 strains TA 1535, TA 100, TA 1537, TA 1538 and TA 98.

A cytotoxic effect was seen in all strains at doses of 2.5 mg/plate and above with and without metabolic activation. Precipitates in the agar were also detectable starting at 2.5 mg/plate in all strains.

There was no evidence for a mutagenic activity of Methylenepoxidpivalat, when tested up to the highest recommended dose level of 5.0 mg/plate in the absence and presence of S9 mix.