Cyclohexanone, peroxide

Endpoint summary

Description of key information

The oral LD50 is 1.08 ml per kg body weight which corresponds to 1242 mg/kg bw (the density is 1.15). From the results of an 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 fro C&L. Only one concentraton was tested and the test atmsphere was based on the maximum attainable concentration by evaporation at 22 degrees celcius. There is no acute dermal toxicity study. According to REACH Annex VIII column II acute studies do not need to be conducted when 'the substance is classified as skin corrosion'

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Limited details; no COA; non-GLP. Needs test article id statement

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not specified

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Young adult albino rats (Wistar-derived) from the Institute's colony were used. The body weights of males varied from 247 to 345 g, those of females from 146 to 249 g. The rats were housed in groups of five in screen-bottomed stainless steel cages in a well-ventilated room, maintained at 23-25 degs C. Before dosing the rats were fasted overnight.

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on oral exposure:

After some preliminary observations, the test material was given by gavage as a 10 % (v/v) dilution in propylene glycol to groups of five males and five females in single doses of 6.94, 8.33, 10.0 or 12.0 ml per kg body weight. After treatment the rats received stock diet and tap water ad
libitum. They were observed for signs of intoxication during a 14-day period, after which autopsies were carried out on the survivors.

Doses:

0.96, 0.83, 1.00, 1.2 ml/kg test material

No. of animals per sex per dose:

5

Control animals:

no

Statistics:

The LD50 was calculated according to the method of Weil (Biometrics 8 (l952) 249-263).

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1.08 mL/kg bw

Based on:

test mat.

95% CL:

>= 1.02 - <= 1.15

Mortality:

See table.

Clinical signs:

other: Within a few hours after dosing the rats showed sluggishness and humpback behaviour. Unconsciousness was frequently observed and preceded death. Deaths occurred between 7 and 23 hours after treatment. Thereafter, the survivors recovered gradually and look

Gross pathology:

Macroscopic examination of the survivors revealed no treatment-related gross alterations.

The density is 1.15.

The LD50 was calculated to be 1.08 ml per kg body weight which corresponds to 1242 mg/kg bw.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

From the mortality figures the LD50 was calculated to be 1.08 ml per kg body weight with 1.02 and 1.15 as the 95 % confidence limits.

Executive summary:

The acute LD50 was determined following the oral gavage administration of the test substance to groups of five males and five females in single doses of 6.94, 8.33, 10.0 or 12.0 ml per kg body weight. Animals were observed for 14 days following administration for clinical signs of toxicity and mortality. The LD50 was calculated to be 1.08 ml per kg body weight with 1.02 and 1.15 as the 95 % confidence limits.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 242 mg/kg bw

Quality of whole database:

K2 study

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

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.

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

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.

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.

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

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.

Reference 2

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is classified as corrosive to the skin

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

K2 study

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is classified as corrosive to the skin

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on an oral LD50 of 1242 mg/kg bw the substance is classified in Acute Tox. 4 as harmful if swallowed.

The acute inhalation study is not suitable for C&L and there is no acute dermal study.