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Administrative data

acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guidelineopen allclose all
according to guideline
EPA OPPTS 870.1300 (Acute inhalation toxicity)
equivalent or similar to guideline
OECD Guideline 403 (Acute Inhalation Toxicity)
not specified
equivalent or similar to guideline
EU Method B.2 (Acute Toxicity (Inhalation))
not specified
GLP compliance:
Hungarian GLP Regulations: 9/2001
Test type:
standard acute method
Limit test:

Test material

Constituent 1
Chemical structure
Reference substance name:
Silicic acid, aluminum magnesium sodium salt
EC Number:
EC Name:
Silicic acid, aluminum magnesium sodium salt
Cas Number:
Molecular formula:
aluminium(3+) magnesium(2+) sodium tris(oxosilanebis(olate))
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
Test item: Silic acid Aluminium Magnesium Sodium salt
Batch No.: 1107274003
Appearance: White powder
Composition: Silic acid Aluminium Magnesium Sodium salt
CAS No.: 12040-43-6
Einecs No.: 234-919-5
Molecular formula: not stated
Purity: > 99 %
Date of production: July 2011
Expiry date: November 2018
Store: at room temperature 20 ± 5°C, dry

Test animals

other: CRL (WI) BR of Wistar origin
Details on test animals or test system and environmental conditions:
Source: Toxi-Coop Zrt. 1103 Budapest, Cserkesz u. 90.
Hygienic level: SPF at arrival and kept in good conventional environment during the study.
Age of animals: Young adult rats, 8-12 weeks old
Body weight range at treatment: Male: 307-363 g Female: 192-206 g
Number of animals: 5 male and 5 female (nulliparous and non pregnant animals) rats
Number of animals/group: 5 animals/ sex
Acclimatisation time: 21 days
Acclimatisation to the
test apparatus: 20 days

Environmental conditions
Illumination: Artificial light, from 6 a.m. to 6 p.m.
Temperature: 22 ± 3 °C
Relative humidity: 30 - 70 %
Ventilation: 8-12 air exchanges/hour by central air-condition system.
Environmental conditions were maintained by an air-condition system. Temperature and relative humidity were verified and recorded daily during the study.

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
nose only
not specified
Details on inhalation exposure:
A group of ten animals (five males and five females) was exposed to an atmosphere of the test item for a single, continuous four-hour period, generated according to the system and flow rates determined during the technical trials. The four-hour exposure period did not start until theoretical chamber concentration equilibration had been reached. Twice during treatment the aerosol generator was re-filled and the exposure system was cleaned from deposited dust of the test item. These periods were not taken into account in calculation of the average test item concentration and the duration of exposure was expanded accordingly by 54 minutes.
The actual concentration was monitored by the Aerosol Light Scattering Photometer that is part of the exposure system. The test item input rate was adjusted according to the actual readings.

The characteristics of the test atmosphere were as follows:
Mean Mass Median Aerodynamic Diameter (MMAD) (μm): 3.57
Geometric Standard Deviation: 2.93
Inhalable Fraction (% < 4μm): 54.3
Analytical verification of test atmosphere concentrations:
The actual test item concentration was measured gravimetrically at regular intervals during exposure by pulling a volume of 5 L of test atmosphere from the exposure chamber through glass fibre filters Fiberfilm T60A20 (Pallflex Product Corp.).
Duration of exposure:
4 h
Remarks on duration:
followed by a fourteen day observation period
Mean Achieved Concentration (mg/L): 5.221
Relative Standard Deviation (%): 12.0
Nominal Concentration (mg/L): 24.3
No. of animals per sex per dose:
Control animals:
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:twice daily for morbidity and/or mortality, all animals were observed for clinical signs at 1st, 2nd and 3rd hours during exposure, as soon as practicable following removal from restraint, one hour after exposure and subsequently once daily for fourteen days.
Body Weight: Individual bodyweights were recorded on the day of exposure Day 0 (prior to exposure) and Days 1, 3, 7 and 14.
- Necropsy of survivors performed: yes, at the end of the fourteen day observation period, the animals were euthanized by exsanguination under anaesthesia (intra-peritoneal injection of Euthasol® 40%) and gross necropsies were performed. These included a detailed examination of the abdominal and thoracic cavities with special attention given to the respiratory tract for macroscopic signs of irritancy or local toxicity.
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other: see above
Dose group: 5 mg/L: No animal died during the study.

Results and discussion

Effect levels
Key result
Dose descriptor:
Effect level:
> 5.221 mg/L air
Based on:
test mat.
Exp. duration:
4 h
In the male and female animals no test item related effects during the inhalation exposure and observation period were found.
Body weight:
In both genders body weight loss was observable on the day of inhalation exposure. In both sexes a compensation of body weight loss was found from third day of observation period.
On basis of body weight and body weight gain data, there was no notable test item effect observable in the exposed animals.

Applicant's summary and conclusion

Interpretation of results:
not classified
Migrated information Criteria used for interpretation of results: EU
Under the experimental conditions of this study, no deaths occurred in a group of ten rats exposed to a mean atmospheric concentration of 5.221 mg/L for four hours. The acute inhalation median lethal concentration (4h LC50) of test item Silic acid Aluminium Magnesium Sodium salt, in Wistar Crl:(WI) BR rats, was therefore considered to be higher than 5.221 mg/L.