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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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:
August to September 1996
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

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

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:
17-Hydroxy-1 alpha,2 alpha-methylene-4,6-pregnadiene-3,20-dione
EC Number:
606-682-1
Cas Number:
2098-65-9
Molecular formula:
C22 H28 O3
IUPAC Name:
17-Hydroxy-1 alpha,2 alpha-methylene-4,6-pregnadiene-3,20-dione

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:
1,2-Methylen-4,6-dien: six concentrations from 0.1 to 5.0 mg/plate
9-Acridinamine, hydrochloride: 100 µg/plate
2-Aminoanthracene: 2.0 µg/plate
2-Nitrofluorene: 10 µg/plate
Benzo[a]pyrene: 2.5 µg and 5.0 µg/plate
Sodium azide: 5 µg/plate
Cyclophosphamide: 400 µg/plate



Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 9-Acridinamine, hydrochloride; 2-Aminoanthracene; 2-Nitrofluorene; Benzo[a]pyrene; Sodium azide; Cyclophosphamide

Results and discussion

Test results
Key result
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
growth inhibition was observed with S9 mix from 2.5 mg/plate and without S9 mix from 1.0 mg/plate onwards
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

There were precipitates in the agar starting at 1.0 mg/plate in all tested strains in absence and presence of S9 mix.

Applicant's summary and conclusion

Executive summary:

1,2 -Methylen-4,6 -dien was examined for mutagenic activity up to 5000 µg/plate in the five histidine-dependent Salmonella typhimurium strains TA 1535, TA 100, TA 1537, TA 1538 and TA 98 with and without metabolic activation.


A cytotoxic effect was seen at from 2.5 mg/plate onwards with S9 mix and from 1.0 mg/plate onwards without S9 mix, adjustment of the tested concentrations to low purity of test item (> 67%) was therefore irrelevant.


There was no evidence for a mutagenic activity of 1,2 -Methylen-4,6 -dien, when tested up to the precipitating and cytotoxic dose levels and the maximum recommended dose level of 5 mg/plate in the absence and presence of S9 mix.