2-Butanone, peroxide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1979-05-09 to 1979-06-14

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

old study report, non GLP and non Guideline study, but well documented. For justification of read across please refer to section 13.

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)

Deviations:

no

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 4-methylpentane-2,2-diyl dihydroperoxide, dioxybis-4-methylpentane-2,2-diyl dihydroperoxide and methylisobutylketon

EC Number:

942-932-9

Cas Number:

37206-20-5

Molecular formula:

Reaction mass of C6H14O4 and C12H26O6 and C6H12O

IUPAC Name:

Reaction mass of 4-methylpentane-2,2-diyl dihydroperoxide, dioxybis-4-methylpentane-2,2-diyl dihydroperoxide and methylisobutylketon

additive 1

Reference substance name:

Diisobutyl phthalate

EC Number:

201-553-2

EC Name:

Diisobutyl phthalate

Cas Number:

84-69-5

Molecular formula:

C16H22O4

IUPAC Name:

diisobutyl phthalate

Test material form:

liquid

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Central Institute for the Breeding of Laboratory Animals TNO, Zeist, The Netherlands
- Weight at study initiation: males: 180 g, females: 135 g
- Fasting period before study: none
- Housing: 5 animals per cage, stainless steel cages
- Diet: ad libitum the Institute's stock diet for rats
- Water: ad libitum unfluoridated water

ENVIRONMENTAL CONDITIONS
- Temperature: 21 ± 1 °C
- Humidity (%): 50 - 60

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: stainless steel exposure chamber
- Exposure chamber volume: 1.5 m3
- Source and rate of air: total airflow of 1.6 m3/h
- System of generating particulates/aerosols: nebulizer provided with a baffle to remove large rdroplets from the mist produced
- Method of particle size determination: particle size determinations and counts were carried out in samples taken from the atmosphere in the chamber with a Cascade Impactor

TEST ATMOSPHERE
- Brief description of analytical method used: analysis of the test atmosphere was performed gravimetrically, samples were takne by passing a measured quantity of the test atmosphere through a Cambridge glassfibre filter at intervals of about 1.5 h
- Samples taken from breathing zone: yes
- Particle size distribution: maximum diameter 6.7 µm, 80 % of the mist consisted of droplets with a diameter of 1.7-3.3 µm

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

2.56, 1.77, 1.55, 1.38, 1.30 g/m3 (measured)

No. of animals per sex per dose:

5

Control animals:

no

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1 500 mg/m³ air

Based on:

test mat.

95% CL:

> 1 400 - < 1 610

Exp. duration:

4 h

Mortality:

All animals of the highest dose group died until day 4 as well as 2 males and all females of the 1.77 g/m3 dose group, 3 males and 4 females of the 1.55 g/m3 dose group, 2 males and 2 females of the 1.38 g/m3 dose group and 2 males of the lowest (1.3 g/m3) dose group.

Clinical signs:

other: Restlessness during the first half an hour was observed. During exposure, animals kept their eyes closed and some had wet noses. After exposure mouth breathing was observed in the higher doses.

Body weight:

Animals lost weight during the first week of observation period. Surviving animals gained weight during the second week.

Gross pathology:

no data

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Based on the LC 50 value of 1.5 g/m3 (1.5 mg/L) the read across-substance has to be classified for acute toxicity after inhalation into category 4.

Executive summary:

The acute inhalation toxicity of the read across-substance (60 % in Di-isobutyl phthalate) was tested on 50 male and 50 female Wistar rats. The animals were individually exposed to the aerosol at concentrations of 2.56, 1.77, 1.55, 1.38 and 1.30 g/m3 (5 males anf 5 females per doese group) for 4 hours. The animals were observed for a period of 14 days afterwards. All animals of the highest dose group died until day 4 as well as 2 males and all females of the 1.77 g/m3 dose group, 3 males and 4 females of the 1.55 g/m3 dose group, 2 males and 2 females of the 1.38 g/m3 dose group and 2 males of the lowest (1.3 g/m3) dose group. Restlessness during the first half an hour of exposure was observed. During exposure, animals kept their eyes closed and some had wet noses. After exposure mouth breathing was observed in the higher doses. A weight loss was observed during the first week of the observation period, but the surviving animals gained weight again in the second week. An LC 50 value of 1.5 mg/L was detemined.