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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

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:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented publication which meets basic scientific principles

Data source

Reference
Reference Type:
publication
Title:
A study on the mutagenic activity of styrene and styrene oxide
Author:
Vainio H et al
Year:
1976
Bibliographic source:
Scand. j. work environ. & health 3 (1976) 147-151
Report date:
1976

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
no positive controls
GLP compliance:
no
Remarks:
study performed before implementation of GLP
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
(epoxyethyl)benzene
EC Number:
202-476-7
EC Name:
(epoxyethyl)benzene
Cas Number:
96-09-3
Molecular formula:
C8H8O
IUPAC Name:
2-phenyloxirane

Method

Species / strain
Species / strain / cell type:
S. typhimurium, other: TA1535, TA1537, TA1538, TA100 and TA98
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
10 exp.-4 , 10 exp. -5, 10 exp. -6, 10 exp. -7 , 10 exp. –8 , 10 exp. –9, 0 mol / plate
Vehicle / solvent:
ethanol
Controls
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
no

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA1535, TA1537, TA1538, TA100 and TA98
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
not specified
Additional information on results:
strains TA 1537 and TA 98 were tested negative
Remarks on result:
other: strain/cell type: TA 1535, TA 1538, TA 100
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive

The test compound was positive in three of five strains and is therfore regarded positive in the bacterial reverse mutation assay
Executive summary:

In a reverse gene mutation assay in bacteria, strains TA1535, TA1537, TA1538, TA100 and TA98 ofS. typhimuriumwere exposed to Styrene Oxide dissolved in ethanol at concentrations of 10 exp-4, 10 exp. -5, 10 exp. -6, 10 exp. -7 , 10 exp. –8 , 10 exp. –9, 0 mol / plate in the presence and absence of mammalian metabolic activation (liver S9 mix from rats induced with Clophen) using the co-incubation method. 

Styrene Oxide was tested up to cytotoxic concentrations (10 exp-4 mol/plate). In strain TA 1535, a dose related increase to 357 (without metabolic activation) and 484 (with metabolic activation) revertants vs. 20 and 45 revertants in control was observed. In strain TA 100, a dose related increase to 1111 (without metabolic activation) and 1165 (with metabolic activation) revertants vs. 84 and 135 revertants in control was observed.  There was a concentration related positive response of induced mutant colonies over background.

This study is classified as acceptable. This study satisfies the requirement for Test Guideline  OPPTS 870.51001; OECD 471 for in vitro mutagenicity (bacterial reverse gene mutation) data. The lack of a positive control is acceptable as the test compound is clearly positive and thus demonstrates adequate sensitivity of the test system.