2-phenoxyethyl isobutyrate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 July 1979 to 07 September 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: A non-GLP study performed in accordance with generally accepted scientific principles with incomplete reporting and methodological deficiencies which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Four to five week old white mice were dosed with 3 dose levels using graded volumes of the test material via gavage. Animals were observed for up to 7 days after exposure. All animals dying were autopsied and those surviving until termination were sacrificed and examined post mortem after 7 days.

GLP compliance:

no

Test type:

other: Oral intubation at 3 dose levels

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-phenoxyethyl isobutyrate

EC Number:

203-127-1

EC Name:

2-phenoxyethyl isobutyrate

Cas Number:

103-60-6

Molecular formula:

C12H16O3

IUPAC Name:

2-phenoxyethyl 2-methylpropanoate

Test material form:

other: liquid (undefined)

Details on test material:

- Name of test material (as cited in study report): Phenoxyethyl-Iso-Butyrate
- Physical state: Clear Colourless Liquid
- pH: 5.00
- Specific gravity: 1.03

Test animals

Species:

mouse

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 4-5 weeks.
- Fasting period before study: 4 hours.
- Housing: animals were placed in individual cages.
- Diet: commercial pelleted diet ad libitum.
- Water: ad libitum.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

The animals were placed in individual cages, fasted for four hours and then the animals were individually weighed and inbtubated with the appropriate volumes of the test material. Each animal on one dose level received the same amount per kg body weight.

Doses:

2, 5 and 10 mL/kg bw.

No. of animals per sex per dose:

One male and one female were dosed with 2 and 10 mL/kg bw of the test material.
Three males and three females were dosed with 5 mL/kg bw of the test material.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days.
- Frequency of weighing: Animals were weighed prior to dosing, and then again prior to sacrifice.
- Necropsy of survivors performed: yes.

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 - < 5 mL/kg bw

Based on:

act. ingr.

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 060 - 5 150 mg/kg bw

Based on:

act. ingr.

Mortality:

Mortalities can be seen in Table 1.

Clinical signs:

other: Mice dosed at all three dose levels were drowsy, showing signs of stress, and exhibiting laboured breathing within 30 minutes. Within 1 hour after treatment mice were also hypothermic. Within 2 hours of treatment the mice dosed at 10 mL/kg were comatose a

Gross pathology:

Autopsy of the animals that died revealed distension of the stomach due to the presence of orange/yellow fluid. The stomach and intestines were very pale and the ileum was irritated and haemorrhaging present in some animals. These mice also exhibited pale livers and kidneys. The surviving females appeared normal at autopsy.

Any other information on results incl. tables

Table 1. Mortalities

Dose Level ml/kg bw	No. of Dead Mice/No. of Animals Treated
10.0	2/2
5.0	4/6
2.0	1/2

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the test the approximate LD50 of the test material was determined to be between 2.0 and 5.0 mL/kg bodyweight.

Executive summary:

The acute oral toxicity of the test material was determined by gavage in 4-5 week old white mice at 3 dose levels using graded volumes of the test material, 10.0, 5.0 and 2.0 mL/kg bw. Animals were observed for up to 7 days after exposure. All animals dying were autopsied and those surviving until termination were sacrifices and examined post mortem after 7 days. Two mice were dosed at the high and low dose levels and six for the middle dose level. Equal numbers of males and females were used.

During the study both mice dosed with 10 mL/kg, four of the six mice dosed with 5 mL/kg and the one male mouse dosed at 2 mL/kg died within 18-24 hours of treatment. Mice dosed at all three dose levels were drowsy, showing signs of stress, and exhibiting laboured breathing within 30 minutes. Within 1 hour of treatment mice were hypothermic. Within 2 hours of treatment the mice dosed at 10 mL/kg were comatose and those animals dosed at 2 and 5 mL/kg were semi-comatose. The surviving female mice recovered within 48 hours following treatment. Autopsy of the animals that died revealed distension of the stomach due to the presence of orange/yellow fluid. The stomach and intestines were very pale and the ileum was irritated and haemorrhaging present in some animals. These mice also exhibited pale livers and kidneys. The surviving females were normal in appearance at autopsy.

The dose level was converted from mL/kg bw to mg/kg bw, for classification, based on the specific gravity of the test material reported in this study.

Under the conditions of the study the approximate LD50 of the test material was determined to be between 2060 and 5015 mg/kg bw.