Chlorimuron ethyl

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

ethyl 2-({[(4-chloro-6-methoxypyrimidin-2-yl)carbamoyl]amino}sulfonyl)benzoate

EC Number:

618-690-2

Cas Number:

90982-32-4

Molecular formula:

C15H15ClN4O6S

IUPAC Name:

ethyl 2-({[(4-chloro-6-methoxypyrimidin-2-yl)carbamoyl]amino}sulfonyl)benzoate

Test material form:

solid

Details on test material:

- Purity: 99.2%
- Impurities: Not reported

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

albino

Sex:

male/female

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

3 µm

Geometric standard deviation (GSD):

2.15

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Concentrations:

Gravimetric chamber concentration: 5.18 ± 0.24 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.18 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

4-h LC50 (Rat): >5.18 mg/L air (highest concentration tested)

Executive summary:

An acute inhalation toxicity test was conducted with rats to determine the potential for test substance to produce toxicity from a single exposure via the inhalation (nose-only exposure) route according to the guidelines OECD 403 and EPA OPPTS 870.1300.

After establishing the desired generation procedures during pre-test trials, 10 healthy Sprague-Dawley derived, albino rats (5/sex) were exposed to the test atmosphere for 4 hours. Chamber concentration and particle size distributions of the test substance were determined periodically during the exposure period. The animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once daily for 14 days following exposure. Body weights were recorded prior to exposure and again on Days 1, 3, 7 and 14 (termination). Necropsies were performed on all animals at terminal sacrifice.

All animals survived exposure to the test atmosphere. The gravimetric chamber concentration was 5.18 ± 0.24 mg/L. Based on graphic analysis of the particle size distribution as measured with an Andersen Cascade Impactor, the mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) of the 5.18 mg/L atmosphere was 3.0 μm ± 2.15 (MMAD ± GSD).

Immediately following exposure and throughout the 14-day observation period, all animals appeared active and healthy. There were no clinical signs of toxicity or abnormal behavior observed in this study. Although all rats lost body weight one day following exposure, all animals gained weight over the entire observation period. No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day recovery period.

Under the conditions of this study, the single 4-hour inhalation medial lethal concentration (LC50) for the test substance is greater than 5.18 mg/L in male and female rats.