Silicic acid, aluminum magnesium sodium salt

Respiratory sensitisation

Administrative data

Endpoint:

respiratory sensitisation: in vivo

Type of information:

other: reference link

Adequacy of study:

other information

Cross-reference

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Deviations:

not specified

GLP compliance:

yes

Remarks:

Hungarian GLP Regulations: 9/2001

Test type:

standard acute method

Limit test:

yes

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

Species:

rat

Strain:

other: CRL (WI) BR of Wistar origin

Sex:

male/female

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.

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

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:

yes

Remarks:

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

Concentrations:

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:

5

Control animals:

no

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

Statistics:

Dose group: 5 mg/L: No animal died during the study.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.221 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

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.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

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.