tert-butyl peracetate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1978-12-28 and 1979-02-07

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

tert-butyl peracetate

EC Number:

203-514-5

EC Name:

tert-butyl peracetate

Cas Number:

107-71-1

Molecular formula:

C6H12O3

IUPAC Name:

tert-butyl ethaneperoxoate

Test animals

Species:

rat

Strain:

other: Charles River CD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: male: 226 to 300 g
- Housing: group-housed during the quarantine period; housed individually in wire-mesh cages throughout the postexposure period
- Diet and water: Purina Laboratory Chow and water, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature and humidity: in accordance with standard outlined in the "Guide for the Care and Use of Laboratory Animals; DHEW No. (N.I.H. 74-23) 1974"

Administration / exposure

Route of administration:

other: inhalation: aerosols and vapors

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: FMI LAB pump
- Exposure chamber volume: 160 L cubical, stainless steel and glass chamber
- Method of holding animals in test chamber: individually
- Rate of air: 8 L/min
- pressure in air chamber: 10 psig
- Treatment of exhaust air: chamber exhaust was filtered with an activated charcoal filter and a Cambridge Absolute filter

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 aerosol dissemination to the rate of total chamber airflow.

Duration of exposure:

4 h

Concentrations:

calculated chamber conc. [mg/L]: 2.06, 4.85, 5.49, 6.34, 20.59

No. of animals per sex per dose:

5

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations for pharmacotoxic signs and mortality were made during and immediately following the 4-hour exposure period and twice daily thereafter for 14 days. Body weights were recorced prior to the 4-hour exposure and periodically thereafter.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Results and discussion

Preliminary study:

No preliminary study

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

6.1 mg/L air

Based on:

test mat.

95% CL:

> 5.65 - < 6.59

Exp. duration:

4 h

Mortality:

20.59 mg/L: all animals (5 males/5 females) died during the 14 day study period
6.34 mg/L: 7 animals (5 males/ 2 females) died during the 14 day study period
5.49 mg/L: 2 animals (1 male/ 1 female) died during the 14 day study period
4.85 mg/L: 1 male died during the 14 day study period

Clinical signs:

other: During exposure, salivation, nasal discharge, eye squint and dyspena were observed. At the high level, gasping and cloudy eyes were also observed.

Body weight:

20.59 mg/L: body weight loss was observed for 4 females on day 1 postexposure
6.34 mg/L: slight body weight loss was observed on day 1 postexposure
5.49 mg/L: slight body weight loss was observed, especially in the female rats
4.85 mg/L: a slight to moderate body weight loss was observed in all surviving rats
2.06 mg/L: no body weight effects were observed

Gross pathology:

Necropsy of the rats that died spontaneously revealed dark pink lungs (some wih red foci), red patchy lungs or clear fluid in the chest cavity. In addition, there were isolated cases of reddish urine in the bladder, hollow kidney, air-distened stomach and dark foci on the stomach mucosa. Necropsy of the animals sacrificed at the end of the observation periods revealed red patchy lungs in one rat, a brown hollow kidney in three rats and no gross lesions in 26 rats.

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The LC50 value was calculated to be 6.1 mg/L (vapors + aerosol) for the test material (75% active ingredient). Therefore, the acute LC50 value is expected to be 9.2 mg/L for the test material which contains 50% of the active ingr.

Executive summary:

The acute inhalation toxicity of t-butyl peracetate was studied in rats by exposing male and female rats for four hours to vapours and aerosols of the test material (75% t-buty peracetate in Shellsol 71). The five nominal exposure concentrations were 2.06, 4.85, 5.49, 6.34 and 20.59 mg/L, which resulted in 0, 1, 2, 7 and 10 deaths, respectively. The 4 -hour LC50 was calculated to be 6.1 mg/L (vapours + aerosol). Therefore, the acute LC50 value is expected to be 9.2 mg/L for the test material which contains 50% of the active ingr.