1-phenylethyl hydroperoxide

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

(Exposure) 7 September to 8 December 1978

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:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The subchronic effects of ethylbenzene hydroperoxide (EBHP) plant stream, which contained 34% of the substance, was tested in rats for 12-week of exposure period. The test methodology referred the following methodologies;

Armitage, P. (1971) Statistical Methods in Medical Research, Oxford, Blackwell Scientific Publications.

Browning, E. (1975) Toxicology and Metabolism of Industrial Solvents. Amsterdam, Elsevier Publishing Company.

Dunnett, C. W. (1964) New tables for multiple comparisons with a control. Biometrics. 20, 482-491.

GLP compliance:

not specified

Limit test:

no

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): simulated ethylbenzene hydroperoxide (EBHP) plant stream.

- 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)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Vehicle:

air

Remarks on MMAD:

MMAD / GSD: No data.

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

12 weeks.

Frequency of treatment:

6 h/day, 5 days/week.

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
3.6 ppm (v/v)
Basis:
analytical conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
7.4 ppm (v/v)
Basis:
analytical conc.

No. of animals per sex per dose:

18 animals per sex per dose group and control.

Control animals:

yes, concurrent vehicle

Results and discussion

Effect levels

Dose descriptor:

NOAEL

Basis for effect level:

other: The study design did not allow to derive the substance specific NOAEL.

Remarks on result:

not determinable

Remarks:

no NOAEL identified

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

It is most likely that the toxic effects of exposure to the test material atmosphere are due to the volatile components or 1-phenylethyl hydroperoxide in the test material other than ethyl benzene. There may be a trend of dose-dependent effects based on the concentration of 1-phenylethyl in the test material, however there were no enough information given on the report to identify this matter. Therefore no substance-specific NOAEL is derived.

Executive summary:

Rats were exposed to ethylbenzene (EB) or simulated ethylbenzene hydroperoxide (EBHP) plant stream atmospheres 6 hr/day, 5 days/week for 12 weeks.

Exposure to a simulated EBHP plant stream atmosphere containing 50 ppm EB resulted in decreased body weight gain in both males and females, increased red cells, haemoglobin and neutrophils in males and increased heart and

kidney weights (adjusted for terminal body weight) in males.

Exposure to a simulated EBHP plant stream atmosphere containing 100 ppm EB resulted in decreased body weight gain in females and minor histopathological changes in males.

It is suggested that the toxic effects of simulated EBBP plant stream exposure are due to the release of volatile materials other than EB during the generation of the experimental atmospheres. Such conditions would not prevail under the normal industrial situation where exposure would be more equivalent to a simple EB exposure because of the relatively high volatility of EB. Exposure to 100 ppm EB has been shown to be without effect.

It is most likely that the toxic effects of exposure to the test material atmosphere are due to the volatile components or 1-phenylethyl hydroperoxide in the test material other than ethyl benzene. There may be a trend of dose-dependent effects based on the concentration of 1-phenylethyl in the test material, however there were no enough information given on the report to identify this matter. Therefore no substance-specific NOAEL is derived.

The test material contains only 34% of 1-phenylethyl hydroperoxide. There were not enough information to identify observed effects attributed to the substance, therefore a reliability of 3 is assigned.