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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non GLP, non-guideline, animal experimental study, published in peer reviewed literature, limitations in design and/or reporting but otherwise adequate for assessment.

Data source

Reference
Reference Type:
publication
Title:
The assay of acute vapour toxicity and the grading and interpretation of results on 96 chemical compounds
Author:
Carpenter CP, Smyth HF Jr and Pozzani UC
Year:
1949
Bibliographic source:
J. Ind. Hyg. Toxicol. Vol 32, p 343-346

Materials and methods

Test guideline
Qualifier:
no guideline available
Deviations:
yes
Remarks:
Older study, describes a grading system for acute inhalation exposures, based on concentration causing mortality. No clin obs or pathology reported.
Principles of method if other than guideline:
Exposures to known concentrations to evaluate relative toxicity independently of vapour pressure. Constant exposure time of 4 hours. Concentration varied increasing by a factor of 2 until the concentration killing 2, 3, or 4 of 6 rats within a 14-day observation period obtained.
GLP compliance:
no
Test type:
standard acute method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- No details reported

Test animals

Species:
rat
Strain:
Sherman
Sex:
not specified
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Own colony (Mellon Institute, University of Pittsburgh, Pennsylvania, USA
- Age at study initiation: no data
- Weight at study initiation: 100-150 g
- no further details reported

ENVIRONMENTAL CONDITIONS
- no data

IN-LIFE DATES:
- no data

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
not specified
Vehicle:
other: air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: All glass vessels
- The vapour concentration was prepared by delivering the fluid sample into an evaporator through which metered air was forced. The rate of flow of the dilution air was measured by a Fischer-Porter “Rotameter” covering a range of 0.5 to 30 liters/minute. The vapours were carried to the exposure chamber by the counter current of dilution air entering the bottom of the evaporator having passed through a desiccator.

TEST ATMOSPHERE
- No analytical checks were made on the concentration of the vapour prepared. The concentrations were based on empirical calculations. Observation of the flowmeter readings, Monodrum delivery and vaporizer performance was used to eliminate errors.
- Rationale for the selection of the starting concentration: The equipment utilized for the vapour exposures was not explosion-proof and concentrations were therefore kept below the lower explosive limit.
Analytical verification of test atmosphere concentrations:
no
Remarks:
The concentrations were based on empirical calculations.
Duration of exposure:
4 h
Concentrations:
4000 ppm
No. of animals per sex per dose:
6
Control animals:
no
Details on study design:
- During exposure: time of onset of clinical signs recorded
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: At termination
- Necropsy of survivors performed: yes, gross pathology and selected tissues for histopathology
- Other examinations performed: clinical signs
Statistics:
A grading system for acute (4 hour) inhalation exposures is based on the concentration causing mortality. Grades 1 - 5 indicate a slight hazard, grades 6 - 9 a moderate hazard, grades 10 -13 a definite hazard and grades 14 -19 a serious hazard.

Results and discussion

Effect levels
Sex:
not specified
Dose descriptor:
other: Degree of hazard: Moderate
Effect level:
4 000 ppm
Exp. duration:
4 h
Remarks on result:
other: 14084 mg/m3; (The conversion of ppm to mg/m3 is based on Rm of 86.09, 25 deg C, 1 atmosphere.) 2, 3 or 4/6 animals died post exposure

Applicant's summary and conclusion

Interpretation of results:
other: Defined as moderate by the authors in this older study
Remarks:
Criteria used for interpretation of results: other: Based on older 19-point grading system
Conclusions:
Exposure to vinyl acetate for 4 hours at 4000 ppm (range 2800 -5500 ppm) has a moderate degree of hazard.
Executive summary:

Exposures to known concentrations of vinyl acetate for 4 hours were used to evaluate its relative toxicity independently of vapour pressure and the concentration killing 2, 3, or 4 of 6 rats within a 14-day observation period was obtained. On this basis, vinyl acetate was considered to have a moderate degree of hazard with 4000 ppm killing up to 4/6 rats following 4 hours of exposure.