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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:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Method in accordance with OECD Guideline, GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Principles of method if other than guideline:
other: 10 animals (m/f)/dose group (strain: Crl:CD BR); MAA aerosol/vapor (aerosol mass median diameter: 10, 6.5, 5.5, 7.2 um); observation period: 13-14 days
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
2-propenoic acid, 2-methyl (methacrylic acid (MAA), Glacial Methacrylic acid
Lot 5-031342
Haskell No H-19762
purity: 98.5 %
clear liquid

Test animals

Species:
rat
Strain:
other: Crl:CD BR
Sex:
male/female

Administration / exposure

Route of administration:
inhalation
Type of inhalation exposure:
nose only
Vehicle:
air
Details on inhalation exposure:
aerosol/vapor atmosphere
Analytical verification of test atmosphere concentrations:
yes
Remarks:
aerosol: gravimetric; vapor: gas chromatography
Duration of exposure:
4 h
Concentrations:
4.3, 5.9, 7.3, 8.2 mg/L
No. of animals per sex per dose:
5
Control animals:
yes
Details on study design:
Rats observed for 13-14 days and body weights collected.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
7.1 mg/L air
Based on:
other: mixed exposure vapour/aerosol
Exp. duration:
4 h
Remarks on result:
other: saturated vapour approx 3.4-3.7 mg/L
Mortality:
Deaths occured at 5.9 mg/L or greater
Clinical signs:
other: In the 8.2 mg/l group all rats died during exposure. In the 7.3 mg/l group, two female rats died during exposure. One male rat was found dead on test day 2 and one male rat was found dead on test day 7. Following exposure, typical clinical observations we
Other findings:
Mortality is clearly associated with exposure to aerosol. Exposure to (saturated) vapour was +/- the same at all concentration levels (3.4-3.7 mg/L). Exposure to vapour alone was not associated with mortality, while exposure to aerosol increased ( 0.9-4.7 mg/L) in parallel to an increase in mortality.

Any other information on results incl. tables

SUMMARY OF MAA CHAMBER CONCENTRATIONS AND ASSOCIATED RAT MORTALITY

TOTAL ATMOSPHERIC

CONCENTRATION (mg/L)

 

AEROSOL/VAPOR

CONCENTRATION

RATIO *

VAPOR

CONCENTRATION

AEROSOL

CONCENTRATION

MORTALITY

(# DEATHS/# EXPOSED)

MEAN

N

 

MEAN  ST.DEV.

MEAN  ST.DEV.

MALES

FEMALES

4.3

8

21 / 79

3.4 +/- 0.17

0.91 +/- 0.26

0 / 5

0 / 5

5.9

9

37 / 63

3.7 +/- 0.24

2.2 +/- 0.94

0 / 5

1 / 5

7.3

8

50 / 50

3.7 +/- 0.27

3.6 +/- 0.41

2 / 5

2 / 5

8.2

9

57 / 43

3.6 +/- 0.20

4.7 +/- 1.8

5 / 5

5 / 5

* Aerosol/vapor ratios were calculated using the mean aerosol and vapor concentrations for each exposure.

Aerosol mass median diameters were 10, 6.5, 5.5, or 7.2 um for concentrations of 4.3, 5.9, 7.3, 8.2 mg/L, respectively.

Applicant's summary and conclusion

Interpretation of results:
Toxicity Category IV
Remarks:
Migrated information for aerosol according to 1272/2008/EC Criteria used for interpretation of results: EU
Conclusions:
Using a valid experimental method, the 4 hour LC50 of MAA to male and female rats was 7.1 mg/L (1983 ppm; vapour/aerosol mix).

Mortality is clearly associated with exposure to aerosol. Exposure to (saturated) vapour was +/- the same at all concentration levels (3.4-3.7 mg/L). Exposure to vapour alone was not associated with mortality, while exposure to aerosol increased ( 0.9-4.7 mg/L) in parallel to an increase in mortality.
Executive summary:

Rats (5m/5f) were exposed to a vapour/aerosol mix at four doses between 4.3 and 8.2 mg/L (1201 - 2291 ppm).

Mortality is clearly associated with exposure to aerosol. Exposure to (saturated) vapour was +/- the same at all concentration levels (3.4-3.7 mg/L). Exposure to vapour alone was not associated with mortality, while exposure to aerosol increased ( 0.9-4.7 mg/L) in parallel to an increase in mortality.

Using a valid experimental method, the 4 hour LC50 of MAA to male and female rats was 7.1 mg/L air (vapour/aerosol mix).