Registration Dossier

Administrative data

acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 05 to 19 Jun 2014
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study run to a method comparable with current guidelines and to GLP

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 403 (Acute Inhalation Toxicity)
GLP compliance:
Test type:
standard acute method
Limit test:

Test material

Constituent 1
Chemical structure
Reference substance name:
EC Number:
Cas Number:
Molecular formula:
Test material form:
solid: particulate/powder
migrated information: powder
Details on test material:
- Analytical purity: 98%
- Lot/batch No.: CPo84700201-022901

Test animals

Details on test animals or test system and environmental conditions:
- Source: Charles Rivers Deutschland, Sulzfeld, Germany
- Age at study initiation: Approximately 12 weeks old
- Weight at study initiation: body weight did not exceed +/- 20% of the sex mean
- Fasting period before study: no
- Housing: labelled Makrolon cages
- Diet (e.g. ad libitum): pelleted rodent diet
- Water (e.g. ad libitum): tap water
- Acclimation period: At least 5 days before start of treatment

- Temperature (°C): 18 - 24
- Humidity (%): 40 - 70
- Air changes (per hr): at least 10 air changes/hour
- Photoperiod (hrs dark / hrs light): 12-hour light / 12-hour dark cycle

IN-LIFE DATES: From 05 to 19 June 2014

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
nose only
Details on inhalation exposure:
- Exposure apparatus: The design of the exposure chamber is based on the flow past nose-only inhalation chamber. The chamber consisted of three animal sections with eight animal ports each. Each animal port had its own atmosphere inlet and exhuast outlet. The animals were placed in restraining tubes and connected to the animal ports. The number of animal sections and numver of open inlets were adapted to the air flow in such a way that at each animal port the theoretical air flow was at least 1 L/min, which ensures an adequate oxygen supply to the animals. The main inlet of the test atmosphere was located at the top section and the main outlet was located at the bottom section. The direction of the flow of the test atmosphere guaranteed a freshly generated atmosphere for each individual animal.
- System of generating particulates/aerosols: The test substance was fed to a stream of dried pressurized air by means of a accurate dust feeder and a micronizing jet mill. The aerosol was passed through two cyclones, in order to allow larger particles to settle, and subsequently entered the exposure chamber.
- Method of particle size determination: The paricle size distribution was characterized twice during the each exposure period. The samples were drawn from the test atmosphere through a tube mounted in one of the free animal ports of the middle section of the exposure chamber. The samples were collected with an 8 stage Marple personal cascade impactor containing fiber glass filters and a fiber glass back-up filter. Amounts of test substance collected were measured gravimetrically. Subsequently the Mass Median Aerodynamic Diameter and the Geometric Standard Deviation were determined.
- Temperature, humidity, pressure in air chamber: The temperature of the atmosphere during the exposure was between 19.6 and 20.2 °C and relative humidity was between 36 and 38%.

- Brief description of analytical method used: The nominal concentration was calculated by dividing the amount of test substance used by the volume of pressurized air entering the exposure chamber used for exposure of the animals. Due to the small volumn of the exposure chamber the equilibrium time was negligible. The volumn of air was calculated from the averaged air flow and the exposure time. The acutual concentration was determined twenty two times during the exposure period. Samples were drawn from the test atmosphere through a tube mounted in one of the free animal ports of the middle section of the exposure chamber. Samples were drawn through a glass fiber filter. The collected amount of the test substance in the air sample was measured gravimetrically. Sample volumes were measured by means of a dry gas meter. Subsequently the time-weighted mean concentration with the standard deviation was calculated.

- Composition of vehicle (if applicable): dried pressurized air
- Concentration of test material in vehicle (if applicable): 5 mg/L
Analytical verification of test atmosphere concentrations:
Duration of exposure:
4 h
5 mg/L
No. of animals per sex per dose:
5 animals
Control animals:
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality: twice daily.
Clinical signs: During exposure: 3 times for mortality, behavioural signs of distress and effects on respiration. After exposure: on day 1, one and three hours after exposure and once daily thereafter until day 15.
Body weight: days 1 (pre-administration), 2, 4, 8 and 15.
- Necropsy of survivors performed: yes, all animals were sacrificed at the end of the observation period by an intraperitoneal injection with Euthasol. All animals assigned to the study were subjected to necropsy and descriptions of all internal macroscopic abnormalities were recorded. Paticular attention was given to any changes in the respiratory tract.
- Other examinations performed: no.
No statistical analysis was performed.

Results and discussion

Effect levels
Dose descriptor:
Effect level:
> 5 mg/L air
Based on:
test mat.
Exp. duration:
4 h
No mortality occurred.
Clinical signs:
other: During exposure, no clinical signs were seen. After exposure, all animals showed hunched posture between days 1 and 5.
Body weight:
Reduced body weight gain and body weight loss was noted for the animals up to Day 8. All animals regained weight during the second week, except for one female that did not gain weight.
Gross pathology:
No abnormalities were found at macroscopic post mortem examination of the animals.

Applicant's summary and conclusion

Interpretation of results:
not classified
Migrated information Criteria used for interpretation of results: EU
The inhalatory LC 50, 4 h value of the test substance in Wistar rats was established to exceed 5 mg/L.