Registration Dossier

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: This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labelling and/or risk assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
Qualifier:
according to
Guideline:
EPA OPPTS 870.1300 (Acute inhalation toxicity)
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
Qualifier:
according to
Guideline:
other: EEC Methods for the Determination of Toxicity Method B.2 Directive 92/69/EEC
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
Qualifier:
according to
Guideline:
other: MAFF Japan Agricultural Chemicals Regulation Laws 2-1-3 Notification 12-Nousan-8147 and Notification 13 Seisan 1739
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Purity: 28 wt%

Test animals

Species:
rat
Strain:
other: Crl:CD(SD)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: Approximately 8 weeks
- Weight at study initiation: 248 - 265 g (males), 182 - 234 g (females)
- Fasting period before study: No
- Housing: Except during exposure, animals were housed individually in solid bottom caging with bedding and nestlets as enrichment.
- Diet (e.g. ad libitum): Ad libitum except during exposure
- Water (e.g. ad libitum): Ad libitum except during exposure
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-26ºC
- Humidity (%): 30-70%
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): Approximate 12-hour light/dark cycle.

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
nose only
Vehicle:
air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The exposure chamber was constructed of glass (cylindrical). A polycarbonate baffle at the chamber inlet promoted uniform chamber distribution of the test atmosphere.
- Exposure chamber volume: 34L
- Method of holding animals in test chamber: During exposure, animals were individually restrained in perforated stainless steel cylinders with conical nose pieces. The restrainers were inserted into a polymethylmethacrylate faceplate attached to the exposure chamber so that the nose of each animal extended into the exposure chamber. On the day before the exposure, animals were placed in restrainers once for approximately 15 minutes to acclimate the animals to the restrainers.
- Source and rate of air: Chamber airflow was 14 L/min which provided at least 25 air changes per hour
- Method of conditioning air: Chamber oxygen concentration was 21%.
- System of generating particulates/aerosols: Chamber atmosphere was generated by aerosolization of the test substance in air with a nebulizer. The test substance was placed in a 500 mL Erlenmeyer flask (on a stir-plate with a mixing bar) and metered into the nebulizer with a console drive pump equipped with a piston. High-pressure air, metered into the nebulizer by a mass flow controller, carried the resulting atmosphere into the exposure chamber. The mass flow controller and the syringe infusion pump were controlled and monitored by an automated data system. Chamber concentrations of test substance were controlled by varying the test substance feed rate to the nebulizer.
- Method of particle size determination: Two samples to determine particle size distribution (mass median aerodynamic diameter, geometric standard deviation, and percent particles less than 1, 3, and 10 μm diameter) were taken during the exposure with a cyclone preseparator/cascade impactor and air sampler.
- Treatment of exhaust air: The test atmosphere was exhausted through a dry-ice cold trap followed by a charcoal/HEPA filter cartridge prior to discharge into the fume hood.
- Temperature, humidity, pressure in air chamber: 21°C, 81 – 87%%, pressure not reported. Relative humidity in the exposure chamber was outside the targeted parameters due to the test substance containing 36% water. The chamber environmental conditions were considered adequate for the conduct of the study, and the relative humidity values that were above the targeted maximum of 70% do not adversely affect the results or interpretation of this study.

TEST ATMOSPHERE
- Brief description of analytical method used: The atmospheric concentration of the test substance in the test chamber was determined by gravimetric analysis at approximately 30-minute intervals. Known volumes of chamber atmosphere were drawn from the sampling port through a 25 mm filter cassette containing a pre-weighed glass fibre (Type A/E) filter. The filters were weighed on a microbalance. The filter weights were automatically transferred to an automated data system, which calculated the chamber concentrations based on the difference between pre- and post-sampling filter weights divided by the volume of chamber atmosphere sampled. Gravimetric sample start- and stop-times for each sample were controlled and recorded by an automated data system. Upon completion of the exposures, sample results were transferred to a reporting and analysis system, which collated sample calculations. Because the test substance contained water and glycol solvent mixture, the gravimetric filters were placed in a desiccator overnight and weighed again the following day to determine the chamber concentration of the non-volatile ingredients in the exposure atmosphere.

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: Two samples to determine particle size distribution (mass median aerodynamic diameter, geometric standard deviation, and percent particles less than 1, 3, and 10 μm diameter) were taken during the exposure with a cyclone preseparator/cascade impactor and constant flow air sampler.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The MMAD (GSD) was 3.2 μm (2.3) and 3.2 μm (2.2).
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
Rats were exposed to a total atmospheric aerosol concentration of 5.6 ± 0.90 mg/L test substance (mean ± standard deviation) which contained 2.6 ± 0.31 mg/L non-volatile components (determined by wet and dry gravimetric filter weights, respectively).
No. of animals per sex per dose:
One group of 5 males and 5 females
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days following exposures.
- Frequency of observations: Since the animals were restrained in nose-only exposure tubes and due to the dense atmosphere resulting from the high concentration of the test substance observations for clinical signs of toxicity could not be conducted during the exposure; however, animals were observed for mortality during the exposure. Animals were observed for mortality and clinical signs of toxicity immediately after they were removed from the restrainers following exposure. During the 14-day recovery period, all rats were observed each day for mortality and were observed for clinical signs of toxicity on test days 0, 1, 2, 3, 7, and 14.
- Frequency of weighing: Rats were weighed on test days 0, 1, 2, 3, 7, and 14.
- Necropsy of survivors performed: Yes, gross pathology.

Results and discussion

Effect levelsopen allclose all
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.6 mg/L air
Based on:
other: total atmospheric concentration
Exp. duration:
4 h
Remarks on result:
other: gravimetric measurement
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 2.6 mg/L air
Based on:
other: non-volatile components
Exp. duration:
4 h
Remarks on result:
other: gravimetric measurement
Mortality:
No animals died.
Clinical signs:
One male demonstrated laboured breathing when the animals were removed from exposure chamber. All animals had their facial skin/fur stained with test article and this same clinical sign was also observed in 4/5 males and 4/5 females on the day after exposure (day 1). Stains of test substance on facial skin/fur are commonly observed following acute nose only exposures and therefore are not considered to be adverse.
Body weight:
The male who had laboured breathing after exposure lost 16% body weight on day 1 while the rest of the animals lost ≤ 9% body weight. All animals gained weight during the rest of the 14-day recovery period.
Gross pathology:
No gross lesions were present in the rats at necropsy.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: other: Official Journal of the European Communities (EEC Directive 93/21)
Conclusions:
The study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability).
4-hr LC50 (rats) >5.6 mg/L total atmospheric concentration and >2.6 mg/L non-volatile components
Executive summary:

One group of 5 male and 5 female rats was exposed nose-only for 4 hours to a total atmospheric aerosol concentration of 5.6 ± 0.90 mg/L test substance (mean ± standard deviation) which contained 2.6 ± 0.31 mg/L non-volatile components (determined by wet and dry gravimetric filter weights, respectively).The aerosol size was determined twice for the atmosphere and the mass median aerodynamic diameter (MMAD) measured 3.2 μm (2.3) and 3.2 μm (2.2) [MMAD (GSD), geometric standard deviation]. All animals survived the 5.6 mg/L exposure and subsequent recovery period. One male had laboured breathing during clinical observation after animals were removed from exposure chamber. The male who had laboured breathing after exposure lost 16% body weight (BW) on day 1 while the rest of the animals lost ≤9% BW. All animals gained weight and did not show any test substance-related clinical signs on day 2 or during the rest of the 14-day recovery period. There were no gross findings for all animals at the scheduled necropsy. Under the conditions of this study, the 4-hour inhalation LC50 for the test substance in male and female rats was >5.6 mg/L total atmospheric concentration and >2.6 mg/L non-volatile components.