tert-butyl 2-ethylperoxyhexanoate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Report date:

1978

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

May 1981

Deviations:

yes

Remarks:

only limited data about analytics

Principles of method if other than guideline:

NA

GLP compliance:

no

Test type:

other: standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

tert-butyl 2-ethylperoxyhexanoate

EC Number:

221-110-7

EC Name:

tert-butyl 2-ethylperoxyhexanoate

Cas Number:

3006-82-4

Molecular formula:

C12H24O3

IUPAC Name:

tert-butyl 2-ethylhexaneperoxoate

Test material form:

liquid

Test animals

Species:

rat

Strain:

other: Charles River CD

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Weight: male 216 to 300 g; females 200 to 299 g
- Housing: wire-mesh cages
- Diet and water (e.g. ad libitum): Purina Laboratory Chow and water (ad libitum)
- Acclimation period: 4 hour

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

- Exposure apparatus: FMI LAB pump
- Exposure chamber volume: 160-liter cubical
- Rate of air: 8 L/min
- Pressure in air chamber: 10 psig

Analytical verification of test atmosphere concentrations:

no

Remarks:

The individual concentrations of the compound in the chamber atmosphere were calculated from the ratio of the rate of liquid dissemination to the rate of total chamber airflow.

Duration of exposure:

4 h

Concentrations:

"metered" conc.: 9.2, 20.8, 46.5 and 103.4 mg/L

No. of animals per sex per dose:

5 animals per sex per dose (total: 20 animals)

Control animals:

not specified

Details on study design:

95 % confidence limits

Results and discussion

Preliminary study:

No preliminary study

Effect levels

Effect levels 1

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

42.2 mg/L air

95% CL:

28.4 - 62.9

Exp. duration:

4 h

Effect levels 2

Key result

Sex:

female

Dose descriptor:

LC50

Effect level:

42.2 mg/L air

95% CL:

25.2 - 70.7

Exp. duration:

4 h

Effect levels 3

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

42.2 mg/L air

95% CL:

30.8 - 58

Exp. duration:

4 h

Mortality:

All animals (5 male, 5 females) died during the 14 day study period at the chamber concentration of 103.4 mg/L.
Further animals (6 animals) died at the chamber concentrations of 20.8 (1 female) and 46.5 mg/L (2 females, 3 male).

Clinical signs:

other: Exposure concentration (103.4 mg/L): By 30 minutes of exposure, a nasal discharge was observed in all rats. Slight dyspnoea was observed in 4 rats by 3 hours of exposure and in all rats by 4 hours of exposure. Redness was observed in the ears and the paws

Body weight:

Exposure concentration (103.4 mg/L): A slight body weight loss was observed for day 1 postexposure.
Exposure concentration (46.5 mg/L): A slight body weight loss was observed for day 1 postexposure. This condition persisted for 7 days in the surviving rats.
Exposure concentration (20.8 mg/L): A slight body weight loss was observed in all rats for day 1 postexposure.
Exposure concentration (9.2 mg/L): A slight body weight loss was observed for day 1 postexposure which persisted for 5 days for 3 male rats and 14 days for 1 female rat.

Gross pathology:

Exposure concentration (103.4 mg/L): Necropsy of the rats revealed red patches in the lungs.
Exposure concentration (46.5 mg/L): Necropsy of the rats which died revealed pink lungs with dark red patches.
Exposure concentration (20.8 mg/L): Necropsy of the 1 female rat revealed 2 large red patches on the left lung.

Other findings:

NA

Any other information on results incl. tables

No remarks

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LC50 was calculated to be 42.2 mg/L with 95% confidence limits of 30.8 and 58.0 mg/L.

Executive summary:

Four groups of male and female rats were exposed to the aerosol and vapour atmospheres of tert.-Butylperoxy- 2-ethylhexanoat. The four "metered" concentrations were 103.4, 46.5, 20.8 and 9.2 mg/L, respectively. During the 4 -hour exposures, nasal discharge and slight dyspnoea were observed in all groups of rats. Redness of ears and paws developed shortly after exposure in all rats exposed to 103.4 and 46.5 mg/L. Death occurred in all groups on 1 or 2 days postexposure at concentrations above 9.2 mg/L.

The LC50 was calculated to be 42.2 mg/L with 95% confidence limits of 30.8 and 58.0 mg/L.

Necropsy of the rats that died during the observation period revealed red patches in the lungs.