imiprothrin (ISO); reaction mass of [2,5-dioxo-3-(prop-2-yn-1-yl)imidazolidin-1-yl]methyl (1R,3S)-2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropanecarboxylate and [2,5-dioxo-3-(prop-2-yn-1-yl)imidazolidin-1-yl]methyl (1R,3R)-2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropanecarboxylate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 23 - March 22, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

428-790-6

EC Name:

-

Cas Number:

72963-72-5

Molecular formula:

C17H22N2O4

IUPAC Name:

[2,5-dioxo-3-(prop-2-yn-1-yl)imidazolidin-1-yl]methyl (1R,3R)-2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropane-1-carboxylate; [2,5-dioxo-3-(prop-2-yn-1-yl)imidazolidin-1-yl]methyl (1R,3S)-2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropane-1-carboxylate

Test material form:

liquid: viscous

Details on test material:

Name: Imiprothrin
Appearance: viscous liquid
Colour: amber

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

other: corn oil

Mass median aerodynamic diameter (MMAD):

2.59 µm

Duration of exposure:

4 h

Concentrations:

The actual chamber and nominal chamber concentrations were 2.32 mg/l and 105.91 mg/l respectively.

No. of animals per sex per dose:

10 rats (5/sex)

Results and discussion

Preliminary study:

Initial pre-test trials indicated that the targeted chamber concentration could not be attained. The material proved too viscous to be aerosolized properly in its undiluted form. In an attempt to increase its concentration in the test atmosphere, the test substance was diluted to a 50% w/w solution in corn oil for trial numbers 1 through 3.

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

2.32 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality.

Clinical signs:

irregular respiration

Remarks:

All rats exhibited irregular respiration, tremors, abnormal gait, hunched posture, nasal discharge, ocular discharge and/or ano-genital staining. However all animals recovered by Day 10 and appeared actie and healthy for the 14-day observation period.

Body weight:

All animals gained body weight during the study.

Gross pathology:

No gross abnormalities were noted.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The single exposure acute inhalation LC50 of Imiprothrin TG is greater than 2.32 mg/l in male and female rats.
2.32 mg/l is the maximum concentration achievable of the substance in the air and niether mortality nor gross abnormalities were noted at that concentration.