1-phenylethyl hydroperoxide

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

January 1979 to 29 December 1980

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: The test material contained components other than 1-phenylethyl hydroperoxide, therefore observed effects cannot be attributed to either 1-phenylethyl hydroperoxide or other components (ethyl benzene or other volatile componetnts).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

not applicable

Principles of method if other than guideline:

The study followed the methodologies as in Ames et al., 1975 and is equivalent to the OECD TG 471 (adopted in July 1997).

Ames, B.N., McCann, J. and Yamasaki, E. (1975). Methods for Detecting Carcinogens and Mutagens with the Salmonella/Mammalian-Microsome Mutagenicity Test. Mutation Res., 31, 347-364.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1-phenylethyl hydroperoxide

EC Number:

221-341-3

EC Name:

1-phenylethyl hydroperoxide

Cas Number:

3071-32-7

Molecular formula:

C8H10O2

IUPAC Name:

1-phenylethane-1-peroxol

Details on test material:

- Name of test material (as cited in study report): EBHP plant stream samle (33.9% of ethyl benzene hydroperoxide (EBHP) in ethyl benzene).

- Analytical purity: 33.9%

- Composition of test material, percentage of components: ethylbenzene hydroperoxide plant stream 33.9%, acetophenone 2.95%, phenyl ethyl alcohol 2.40%, benzaldehyde 0.04%, phenol 0.23%, sodium 0.5% and acids (titration) 0.001% Meq/G.

- Purity test date: 28 June 1978.

- Lot/batch No.: 78/12484

- Stability : For at least 4 hours (in DMSO)

Method

Target gene:

Histidine operon (his) for Salmonella.
Tryptophan operon (trp) for E.Coli.

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium, other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Species / strain 2

Species / strain / cell type:

E. coli, other: E. coli WP2 and E. coli WP2 uvr A

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

rat liver microsomal activation system

Test concentrations with justification for top dose:

0.0678, 0.678, 6.78, 67.8 and 678 µg of EBHP (final amounts of 0.2, 2, 20, 200 and 2000 µg of EBHP plant stream per plate) with or without S9.

Vehicle / solvent:

ethyl benzene (33.9% of ethyl benzene hydroperoxide (EBHP) in ethyl benzene)

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

(concurrent untreated control)

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

for S. typhimurium with or without S9

Migrated to IUCLID6: 20 µg

Controls 2

Untreated negative controls:

yes

Remarks:

(concurrent untreated control)

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: neutral red, 20 µg

Remarks:

for S. typhimurium with or without S9

Controls 3

Untreated negative controls:

yes

Remarks:

(concurrent untreated control)

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

for E. coli with or without S9

Migrated to IUCLID6: 20 µg

Controls 4

Untreated negative controls:

yes

Remarks:

(concurrent untreated control)

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

for E. coli with or without S9

Migrated to IUCLID6: 20 µg

Results and discussion

Test results

Test results 1

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100 and E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not applicable

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not applicable

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 3

Species / strain:

E. coli WP2

Metabolic activation:

without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not applicable

Untreated negative controls validity:

not applicable

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

See attachment tables for results.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive without metabolic activation In E. coli WP2

Application of the EBHP plant stream sample up to 2000 µg per plate did not consistently increase the reverse gene mutation rate of E. coli WP2 uvrA,
S. typhimurium TA 1535, TA 1537, TA 1538, TA 98, and TA I00 in vitro in the presence or absence of a rat liver S9 fmaction, but did result in an increase in the reverse mutation frequency in E. coli WP2 in the absence of the rat liver S9 fraction. Therefore the EBHP is considered to be a a weak
microbial mutagen in E. coli WP2 in the absence of S9 under the conditions of this test.

Executive summary:

The mutagenic activity of an EBHP plant stream sample was investigated in agar layer cultures of Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100, Escherichia coli WP2 and WP2 uvr both with and without the incorporation of a rat liver microsomal activation system.

Application of the EBHP plant stream sample up to 2000 µg per plate did not consistently increase the reverse gene mutation rate of E. coli WP2 uvrA,

S. typhimurium TA 1535, TA 1537, TA 1538, TA 98, and TA I00 in vitro in the presence or absence of a rat liver S9 fraction, but did result in an increase in the reverse mutation frequency in E. coli WP2 in the absence of the rat liver S9 fraction.

 

The results with the EBHP plant stream sample indicate that it is a weak microbial mutagen in E. coli WP2 in the absence of S9.

The test material contains only 33.9% of 1-phenylethyl hydroperoxide. There were not enough information to identify observed effects attributed to the substance, therefore a reliability of 3 is assigned.