Cyclohexanone, peroxide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Adequate details; non-GLP; no COA; no analytical data but test atmospher analyzed.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1977

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexanone, peroxide

EC Number:

235-527-7

EC Name:

Cyclohexanone, peroxide

Cas Number:

12262-58-7

Molecular formula:

Multi-constituent substance (equilibrium mixture of a number of cyclohexyl based organic peroxides, hydrogen peroxide, cyclohexanone and water)

IUPAC Name:

Peroxycyclohexanone

Constituent 2

Reference substance name:

12262-548-7

IUPAC Name:

12262-548-7

Constituent 3

Reference substance name:

Cyclonox LE

IUPAC Name:

Cyclonox LE

Test material form:

other: Colorless liquid

Details on test material:

21% cyclohexanone peroxides

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Young adult albino rats (SPF· reared, Wistar-derived) were used as the experimental animals. The weight of the males was 195-205 g, that of the females 135-145 g. The rats were obtained from the Central Institute for the Breeding of Laboratory Animals. TNO, Zeist, The Netherlands.

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Vehicle:

other: Filtered air

Details on inhalation exposure:

The exposure chamber used consisted of a horizontally placed-glass cylinder (0.90 x 0.15 m) with sampling ports on both ends and containing stainless steel wire screens for separately accommodating the experimental animals.

Analysis of cyclohexanone peroxides, was carried out according to a
method comprising absorption in xylene followed by spectrophoto-
metrical measurement.

The dynamic atmosphere was generated by passing a known amount of
filtered air (relative humidity c.~ 45%) from the compressed air line
through five glass evaporators (1.0 l/min/evaporator). Each evaporator
was laden with Chromosorb W-AW 60/80, saturrated with Cyclonox LE-50.
The temperature of the evaporators during the experiment was 22 deg C.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

The maximum attainable concentration of the peroxide vapours in the test atmosphere was 5.0 ppm.

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

One group of five males and five females was used. After exposure (4 hours), the animals were returned to their living cages and provided with stock diet and tap water ad libitum for an observation period of 14 days.

Statistics:

No applicable.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 ppm

Exp. duration:

4 h

Mortality:

There were no mortalities

Clinical signs:

other: During the first five minutes of exposure the rats were slightly restless. However, this symptom gradually disappeared and after a quarter of an hour all rats were quiet and asleep. This situation continued thoughout the remainder of the exposure period.

Body weight:

No data

Gross pathology:

No data

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

From the results of the present acute inhalation study it is concluded that the 4-hour LC50 of, Cyclonox LE-50 is higher than 5.0 ppm (>29 mg/m3). The study is not suitable for C&L. Only one concentraton was tested and the test atmosphere was based on the maximum attainable concentration by evaporation at 22 degrees celcius.

Executive summary:

The acute inhalation toxicity of Cyclonox LE-50 was studied by exposing rats for four hours to the vapour of this substance at the highest concentration attainable.

At 5.0 ppm; which is the highest peroxide concentration possible under the experimental conditions, no mortality or signs of intoxication were observed.