Methyl acetoacetate

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:

other: Study meets generally accepted scientific standards, is well documented and acceptable for assessment.

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)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Methyl acetoacetate

EC Number:

203-299-8

EC Name:

Methyl acetoacetate

Cas Number:

105-45-3

Molecular formula:

C5H8O3

IUPAC Name:

methyl 3-oxobutanoate

Details on test material:

- Name of test material (as cited in study report): Acetessigsaeuremethylester (methyl acetoacetate);
- Physical state: transparent liquid
- Analytical purity: ca. 98 %

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPF-Zucht, Firma WIGA, Sulzfeld, Germany
- Age at study initiation: no data
- Mean weight at study initiation: males: 183 g and females: 193 g
- Fasting period before study: no data
- Housing: no data
- Diet (e.g. ad libitum): Herilan MRH; H. Eggersmann KG, Rinteln, Germany, ad libitum after treatment
- Water (e.g. ad libitum): tap water, ad libitum, after treatment
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- no data

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

clean air

Remarks:

none

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
The test substance was converted into vapour by passing through a vaporiser at 120°C. For this purpose, a constant amount of test substance was conducted through the vaporiser by means of a continuous infusion pump (UNITA I, B. BRAUN, Melsungen). The test substance vapour was mixed to fresh air which was conducted through an inhalation chamber with a capacity of ca. 180 liters.

TEST ATMOSPHERE
- An analytical monitoring of the test substance was performed by means of GC. For this purpose, a series of air/vapour samples of 5 liters of the vapour-air mixture was collected from the inhalation chamber, close to the animals. The tested nominal concentration of 8.6 mg/l corresponded to a measured concentration ranging between 6.36 and 6.86 mg/l. Thus, a mean analytical dose of 6.6 mg/l was issued for the test.

TREATMENT
- After ca. 20 min. pre air flow, animals were put in the inhalation chamber through a positing system.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Gas chromatography. The analytical monitoring of a series of air/vapour samples collected from the inhalation chamber showed that the nominal concentration of 8.6 mg/l corresponded to a measured mean analytical dose of 6.6 mg/l.

Duration of exposure:

4 h

Concentrations:

analytically detected: 6.6 mg/l; nominal dose: 8.6 mg/l

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Weighing was done at the beginnibg of the study, on day 7 and 14. Observation was several times at the day of exposure and presumably daily exception of weekends and holidays afterwards.
- Necropsy of survivors performed: yes, at the end of the observation period, the animals were sacrificed and subjected to necropsy.
- Other examinations performed: clinical signs of toxicity

Statistics:

No statistics were performed.

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 6.6 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: No mortality

Effect levels 2

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 26.4 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

1 h

Remarks on result:

other: conversion according to Haber rule (C x t = k)

Mortality:

All rats survived.

Clinical signs:

other: Piloerection was reported for all rats.

Body weight:

No noticeable differences in body weight gain were seen between control and treated rats.

Gross pathology:

Necropsy revealed no abnormalities.

Other findings:

No other findings.