Silicic acid, sodium salt

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

19 Oct 2004 - 16 Dec 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Meets national standard methods; GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

GLP compliance:

yes

Remarks:

Product Safety Laboratories

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, potassium salt

EC Number:

215-199-1

EC Name:

Silicic acid, potassium salt

Cas Number:

1312-76-1

Molecular formula:

K2O x (SiO2)n with Molar Ratio (MR) (SiO2/K2O): 0.5 – 5 (with exception of MR = 1)

IUPAC Name:

Potassium hydroxy(oxo)silanolate

Details on test material:

- Name of test material (as cited in study report): AgSil TM 25 Potassium silicate solution
- Physical state: claer to hazy white, thick liquid
- Composition of test material, percentage of components: 70% water, 30% silicic acid, potassium salt, potassium silicate
- Lot/batch No.: C052804K1
- Stability under test conditions: stable for the duration of testing
- Storage condition of test material: at room temperature
- Other: ratio: 2.47; specific gravity: 1.231 g/mL

Test animals

Species:

rat

Strain:

other: Sprague-Dawley derived albino

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Ace Animals, Inc., Boyertown
- Age at study initiation: 8 - 9 weeks
- Weight at study initiation: 255 - 285 g (males) and 180 - 205 g (females)
- Housing: singly in stainless steeel cages
- Diet (e.g. ad libitum): Purina Rodent Chow #5012
- Water (e.g. ad libitum): tap wter
- Acclimation period: 9 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 22
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 21 Oct To: 4 Nov 2004

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: filtered air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: whole body plexiglas chamber
- Exposure chamber volume: 150 L
- Method of holding animals in test chamber: cages
- Source and rate of air: air compressor, total airflow 45.7 L per minute
- System of generating particulates/aerosols: The test atmosphere was generated using a 1/4 inch JCO atomizer, FC3 fluid cap and 70SS air cap. Compressed air was supplied. The test substance was metered to tthe atomization nozzle through size 14 tygon tubing using a peristaltic pump.
- Method of particle size determination: eight stage Andersen cascade impactor
- Temperature, humidity, pressure in air chamber:


TEST ATMOSPHERE
- Brief description of analytical method used: Gravimetric samples were collected with filter papers which were wighed before and after collection to determine the mass collected. This value was devided by the total vlume of air sampled to determine the chamber concentration. Sample airflows were measured using a Mass Flowmeter.
- Samples taken from breathing zone: yes


TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: 9 µM: 4%, 5.8 µm: 8.3%, 4.7 µm: 11.1%, 3.3 µm: 12%, 2.1 µm: 32%, 1.1 µm: 22.6%, 0.7 µm: 7.4%, 0.4 µm: 2.6%
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 2.7 µm/1.96

Analytical verification of test atmosphere concentrations:

yes

Remarks:

see above

Duration of exposure:

4.4 h

Concentrations:

2.06 ± 0.19 mg/L

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: in chamber animal observations and at least daily following exposure; body weights were recorded prior to exposure and again on days 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other:

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.06 mg/L air (analytical)

Exp. duration:

4 h

Any other information on results incl. tables

During exposure, animals showed hunched posture and hypoactivity. All animals recovered from the above clinical signs upon removal from the exposure chamber and appeared healthy and active over the 14 -day observation period. All animals survived exposure to the test atmosphere and gained body weight over the 14 -day period. No gross abnormalities were noted for any of the animals at terminal necropsy.