Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
06 September 2011 to 06 December 2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EPA OPPTS 870.1300 (Acute inhalation toxicity)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 8684-90, Experimental

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: BIOAGRl's (DF) rearing house
- Age at study initiation: 10 weeks
- Weight at study initiation: 305-347 grams
- Fasting period before study: no
- Housing: 41x34x20 cm polypropylene cages with autoclaved wood shavings and stainless steel mesh lids containing five rats of same sex per cage on the experimental phase were used
- Diet (e.g. ad libitum): Pelleted and autoclaved commercial diet for rats
- Water (e.g. ad libitum): Filtered potable water
- Acclimation period: 14 days prior to exposure

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.2 to 21.8°C
- Humidity (%): 37.9 to 69.8%
- Air changes (per hr): 10 to 20 air changes in the room per hour
- Photoperiod (hrs dark / hrs light): 12 hours dark and 12 hours light

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
nose only
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The chamber used was a Jaeger Inhalation Chamber, Mark II with a collision nebulizer integrated system
- Exposure chamber volume: 667 ml/min/animal
- Method of holding animals in test chamber: Rats were exposed to the aerosolized test item in plexiglass nose-only tubes applying a direct-flow exposure principle.
- Source and rate of air: The source of air used came from an air compressor
- Method of conditioning air: The compressed air was treated with a filter absolute model F - 771 K03 Trox and filter of activated carbon F - 760 Trox;
- System of generating particulates/aerosols: collision nebulizer integrated system
- Method of particle size determination: Two equally time-spaced air samples were taken from the vicinity of the breathing zone using an air sampling pump previously calibrated to a 0.500 L/min flow rate, to collect the aerosol in a Seven Stage Cascade Impactor (ln-Tox, Albuquerque, New Mexico, U.S.A.) for five minutes. Before and after sampling, the stages were weighed
- Treatment of exhaust air:
- Temperature, humidity, pressure in air chamber: The study animals were maintained at a temperature from 22.3 to 23.8°C and a relative humidity from 51 to 59%. Temperature and relative humidity were recorded four times during the exposure. The equipment used to measure temperature and humidity was a digital thermo-hygrometer TFA;

TEST ATMOSPHERE
- Brief description of analytical method used: Rats were exposed to the aerosolized test item in plexiglass nose-only tubes applying a direct-flow exposure principle.
- Samples taken from breathing zone: yes/no

VEHICLE
- Composition of vehicle (if applicable):
- Concentration of test material in vehicle (if applicable):
- Justification of choice of vehicle:
- Lot/batch no. (if required):
- Purity:

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution:
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration:
Duration of exposure:
4 h
No. of animals per sex per dose:
five/sex/cage
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Aerodynamic particle-size distribution: Before and after sampling, the stages were weighed
- Mortality: yes
- Necropsy of survivors performed: yes. All exposed rats were necropsied and subsequently incinerated. The presence or absence of any macroscopic finding observed on gross necropsy was recorded systematically and individually
- Clinical examinations: Following exposure, two clinical observations were made during the first 24 hours and then daily during a fourteen­ day observation period
Statistics:
Not applicable

Results and discussion

Preliminary study:
Preliminary test without animals was conducted to define the appropriate conditions to reach a test atmosphere with adequate particle-size.
Effect levels
Key result
Sex:
male/female
Dose descriptor:
LC50
Effect level:
>= 15.246 mg/L air (nominal)
Based on:
test mat.
Exp. duration:
4 h
Mortality:
No compound-related deaths were observed during this study.
Clinical signs:
The compound-related clinical signs observed in this study were: piloerection, slight apathy, kyphosis, slight dyspnea, tremors, epistaxis and chromodacryorrhea. These were acute systemic signs that started on days 0 and 1 and reverted on days 1 to 3 of the observation period.
Body weight:
The mean body weight increased for both sexes in all post-exposure weighings, except in the first post-exposure weighing. All animals exceeded their initial body weight at the end of the observation period of 14 days.
Gross pathology:
No compound-related macroscopic findings were observed during this study.
Other findings:
Histopathology
It was not considered necessary due to the reversibility of the clinical signs and to the absence of compound-related macroscopic findings.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The combined (males and females) median lethal concentration in a 4-hour nose-only exposure period (4-h LC50) to the test substance aerosol inhaled by Wistar Hannover rats was greater than 15.246 mg/L.