Methyl 2-[(1,5-dihydro-3-methyl-5-oxo-1-phenyl-4H-pyrazol-4-ylidene)ethylidene]-1,3,3-trimethylindoline-5-carboxylate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

fixed concentration procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methyl 2-[(1,5-dihydro-3-methyl-5-oxo-1-phenyl-4H-pyrazol-4-ylidene)ethylidene]-1,3,3-trimethylindoline-5-carboxylate

EC Number:

227-217-5

EC Name:

Methyl 2-[(1,5-dihydro-3-methyl-5-oxo-1-phenyl-4H-pyrazol-4-ylidene)ethylidene]-1,3,3-trimethylindoline-5-carboxylate

Cas Number:

5718-26-3

Molecular formula:

C25H25N3O3

IUPAC Name:

methyl 1,3,3-trimethyl-2-[2-(3-methyl-5-oxo-1-phenyl-1,5-dihydro-4H-pyrazol-4-ylidene)ethylidene]indoline-5-carboxylate

Constituent 2

Reference substance name:

4-[(1,5-dihydro-3-methyl-5-oxo-1-phenyl-4H-pyrazol-4-ylidene)methyl]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one

EC Number:

225-184-1

EC Name:

4-[(1,5-dihydro-3-methyl-5-oxo-1-phenyl-4H-pyrazol-4-ylidene)methyl]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one

Cas Number:

4702-90-3

Molecular formula:

C21H18N4O2

IUPAC Name:

4,4'-methylylidenebis(5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one)

Test material form:

solid

Details on test material:

Macrolex Orange R, Batch CHA 001

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Three male and three female rats were simultaneously exposed under nose-only conditions for 4 h. This procedure is in compliance with the limit test described in OECD Test Guideline No. 403 and OECD GD#39 (2009).

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

3.7 µm

Geometric standard deviation (GSD):

2.14

Remark on MMAD/GSD:

Primary goal of the limit test is to generate an aerosol with a MMAD between 1-4 µm at 2000 mg/m³. Aerosol testing at greater than 2000 mg/m³ should only be attempted if a respirable particle size is achievable. Consequently animals were exposed to 2441 mg/m³ of an aerosol with a MMAD of 3.70 µm. Higher concentrations have been tested in pretest without animals and resulted in MMAD >4 µm.

Details on inhalation exposure:

Gravimetric analysis of filter samples and the real-time monitoring of the aerosol test atmosphere from the breathing zone area indicated that the exposure conditions were temporally stable over the 4-h exposure period.

Analysis of the aerosol particle-size distribution from the breathing zone samples demonstrates that the aerosol generated was in the respirable range. Repeated measurements made during one exposure demonstrated temporally stable particle-size distributions. The total gravimetric concentration recovered by the cascade impactor was similar to that concentration found by filter analyses. From this finding it can be concluded that interstage wall losses occurring within the low-pressure critical orifice cascade impactor or potential anisokinetic sampling errors appear to be negligible.

Temperature values in the inhalation chamber were in the range suggested by the testing guidelines. Humidity values were lower than suggested by the test guidelines due to the use of dry pressurized air for particle dispersion. This deviation from the guideline had no apparent negative impact on the outcome of study.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

2441 mg/m³

No. of animals per sex per dose:

3 males and 3 females

Control animals:

yes

Details on study design:

A study on the acute inhalation toxicity of Macrolex Orange R (henceforward referred to as test item) on rats has been conducted in accordance with OECD Test Guideline no. 403 (2009). Test procedures were adapted so as to comply also with the Method B.2 of the Annex to Regulation (EC) No 440/2008, and especially OECD Guidance Document no. 39 (2009). One group of rats was nose-only exposed to the solid aerosol of the test item at 2441 mg/m³. This procedure is in accordance with the limit test of the OECD Test Guideline no. 403 (2009). Primary goal of the limit test is to generate an aerosol with a MMAD between 1-4 µm at 2000 mg/m³. Aerosol testing at greater than 2000 mg/m³ should only be attempted if a respirable particle size is achievable. Consequently animals were exposed to 2441 mg/m³ of an aerosol with a MMAD of 3.70 µm. Higher concentrations have been tested in pretest without animals and resulted in MMAD >4 µm. Rats exposed to dry conditioned air only under otherwise identical circumstances served as controls.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC0

Effect level:

2 441 mg/m³ air (analytical)

Based on:

act. ingr.

Exp. duration:

4 h

Mortality:

no

Clinical signs:

other: During the clinical observation test item-dependent orange discoloration was seen on nose and muzzle as well as on the head and forelegs. No findings were seen at the functional observation battery.

Body weight:

No toxicological relevant test item-related changes in incremental body weight gain were observed.

Gross pathology:

No gross-pathological findings were observed

Other findings:

Significantly decreased body temperatures were found in animals exposed to 2441 mg/m³ test item when compared to the control animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Executive summary:

A study on the acute inhalation toxicity of Macrolex Orange R (henceforward referred to as test item) on rats has been conducted in accordance with OECD Test Guideline no. 403 (2009). Test procedures were adapted so as to comply also with the Method B.2 of the Annex to Regulation (EC) No 440/2008, and especially OECD Guidance Document no. 39 (2009). One group of rats was nose-only exposed to the solid aerosol of the test item at 2441 mg/m³. This procedure is in accordance with the limit test of the OECD Test Guideline no. 403 (2009). Primary goal of the limit test is to generate an aerosol with a MMAD between 1-4 µm at 2000 mg/m³. Aerosol testing at greater than 2000 mg/m³ should only be attempted if a respirable particle size is achievable. Consequently animals were exposed to 2441 mg/m³ of an aerosol with a MMAD of 3.70 µm. Higher concentrations have been tested in pretest without animals and resulted in MMAD >4 µm. Rats exposed to dry conditioned air only under otherwise identical circumstances served as controls. The results can be summarized as follows:

LC50 inhalation (aerosol, 4 h)

LC50: >2441 mg/m³ test item

The respirability of the aerosol was adequate and in compliance with the test guidelines [the mass median aerodynamic diameter (MMAD) was 3.70 µm, the geometric standard deviation (GSD) was 2.14]. Rats exposed to the test item did not show clinical signs at 2441 mg/m³. During the clinical observation test item-dependent orange discoloration was seen on nose and muzzle as well as on the head and forelegs. No findings were seen at the functional observation battery. No toxicological relevant test item-related changes in incremental body weight gain were observed. Significantly decreased body temperatures were found in animals exposed to 2441 mg/m³ test item when compared to the control animals. Mortality did not occur at 2441 mg/m³. No gross-pathological findings were observed at necropsy in animals exposed to 2441 mg/m³ Macrolex Orange R.