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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:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Remarks:
DATA QUALITY: Study was conducted in accordance with a recognized scientific procedure for determining the acute inhalation toxicity of a test substance, following GLP regulations. The study meets national and international scientific standards and provides sufficient information to support the conclusions regarding the acute inhalation toxicity of Ethyl Methacrylate.

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Ethyl Methacrylate; 2-propionic acid, 2-methyl-, ethyl ester; 99.1% purity

Test animals

Species:
rat
Strain:
other: Crl: CD BR
Sex:
male/female
Details on test animals and environmental conditions:
Young adult male and female Crl:CD BR rats, 8 weeks old,  weighing 240-351 grams (males) and 152-221 grams (females); housed singly  or in pairs by sex. Food and water available ad libitum, except during  exposure.

Administration / exposure

Route of administration:
inhalation
Type of inhalation exposure:
nose only
Vehicle:
other: unchanged (no vehicle)
Analytical verification of test atmosphere concentrations:
yes
Remarks:
see comment below
Duration of exposure:
4 h
Concentrations:
12.2, 40.4, 48.4 and  57 mg/L
No. of animals per sex per dose:
5 males and 5 females per dose group. 
Control animals:
not specified
Details on study design:
Four groups of five male and five female rats were exposed  nose-only for 4 hours to several concentrations of the test material in  air. The chamber airflow was 25 L/min, the chamber temperature was 23-30  degrees C, and the relative humidity was 31-44%, with 21 percent oxygen.  Test concentrations were generated by 
vaporizing the test material in air  using a heated J-tube. Filtered high pressure air fed through the J-tube mixed with the test substance and was metered into the 29 L glass  exposure chamber. Concentrations were varied by varying the rate of test  substance introduced into the J-tube.  Each group of rats was observed for 
mortality and  clinical signs during exposure and daily throughout the 14 days  post-dosing.  Animals were  weighed daily throughout the study. No  necropsy was conducted.

Analytical verification of test atmosphere concentrations: Atmospheric concentrations were  monitored at 30 min intervals during exposure, by gravimetric analysis  and GC. The chamber vapor concentration was 
determined by comparing the GC response of the test material with calibration standards.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
55 mg/L air
Based on:
test mat.
Exp. duration:
4 h
Mortality:
 Deaths occurred at 48 mg/L and higher; 1/5 males and 0/5 females at 48  mg/L; and 4/5 males and 2/5 females at  57/L. No deaths occurred at the  other doses.
Clinical signs:
other: Rats exposed to 57 mg/L experienced nasal discharge,  gasping, irregular respiration, lethargy, lung noise, and moderate weight  loss. At 48 mg/L, rats demonstrated oral, nasal and ocular discharge,  gasping, irregular respiration lethargy, lung noise, hu
Body weight:
sporadic weight loss returned to normal by the end of  the study.

Applicant's summary and conclusion

Conclusions:
In a valid guideline study acute (4 hr) inhalation LC50 in rats was 55 mg/L.
Executive summary:

In a valid guideline study acute (4 hr) inhalation LC50 in rats was 55 mg/L.