Silicic acid, aluminum sodium salt

Endpoint summary

Description of key information

Oral: In none of the studies in the test substance Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS) and structurally related Silicic acid, aluminum magnesium sodium salt (CAS 12040-43-6, SMAS) mortality was observed. In the only reliable study in the test substance two nanoforms of Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS) were tested at doses of 5000 mg/kg bw without mortality or gross pathological abnormalities. Therefore, no hazard was identified in the assessment of the test substance Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS).

 

Inhalation: Only one study in Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS) is available (all other studies are in read-across substances). In this study, according to the OECD TG 436, the acute lethal dose for inhalation route could not be determined for the tested nanoform of Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS), since no mortality or any toxic event could be registered at an actual dose level of 65.9 mg/m³. Thus, the test item showed an acute inhalation LC50 cut-off greater than 85.6 mg/m³. This was the only dose tested.

A much higher concentration was employed in a study with the read-across substance Silicic acid, aluminum magnesium sodium salt (CAS 12040-43-6, SMAS), here, a LC50 of > 5221 mg/l was assessed with no mortality observed.

 

Dermal: Only one study in Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS) is available (the others are in read-across substances). In this study, no mortality was observed up to 5000 mg/kg bw. The same result was attained in all other studies (in read-across substances): No mortality was observed up to the highest dose level.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

other: U.S. Fed. Hazardous Substance Act, Section 101.1 (f)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

Zeolex 23A & Zeolex 7

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

average body weight of 210 grams

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

Aqueous slurries (50% w/v) of each of the test materials were prepared for use in the acute oral toxicity evaluations.

Doses:

5 g/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

The procedure outlined in the Federal Hazardous Substances Act, Section 101.1 (f) (1) was followed. Groups of ten animals (5 male and 5 female) each were fasted approximately 18 hours but given water ad libitum prior to dosing. Each animal received 5 grams of assigned test material per kilogram of body weight (10 ml/kg) by gastric intubation. All animals were observed frequently for mortality and signs of toxicity during the 14-day observation period. Necropsies were performed on all surviving animals 14 days following dose administration.

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 5 000 mg/kg bw

Based on:

test mat.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

No deaths attributed to oral dosing with any of the test materials were recorded during the 14-day post-dosing observation period.

Clinical signs:

other: not specified

Gross pathology:

At autopsy of surviving animals, no grossly abnormal lesions were seen.

Interpretation of results:

GHS criteria not met

Conclusions:

None of the materials tested were orally toxic when administered to rats at a dose level of five grams per kilogram of body weight.

Executive summary:

The acute toxicity of Zeolex 23A and Zeolex 7 were studied in rats. No mortality occurred in these studies.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD0

Value:

>= 5 000 mg/kg bw

Quality of whole database:

reliablity 2

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

experimental phase (acute & sub-acute study): Jun. 5, 2018 - Apr. 17, 2019

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

not specified

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Specific details on test material used for the study:

Test item identification: Sodasil P95
Description: Amorphous silicate of sodium and aluminum
Formula/Chemical group: Nanosilicates
Chemical Abstract No.: 1344-00-9
EINECS No.: 215-684-8
Aspect: White powder
Storage condition: Room temperature

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Age (at treatment start): 10 weeks old
Body-weight range(at treatment start): 206.9 – 277.8 g (females) and 314.7 – 490.9 g (males)
Temperature: 20.0ºC – 24.0ºC (Mean 22.0ºC)
Humidity: 40.0% – 80.0% (Mean 60.0%)
Room air renovation cycles: 30
Photoperiod: 12 hours of light: 12 hours of darkness
Feeding: Irradiated certified laboratory dry diet RM1 (P) QC Reference 831193 (batch number 3077, Dietex SDS) was offered with unlimited supply.
Drinking: Autoclaved mineral water was offered ad libitum.

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

other: 0.05% BSA (CAS No. 9048-46-8), 30 μL of absolute alcohol and sterile water

Mass median aerodynamic diameter (MMAD):

ca. 392.8 nm

Geometric standard deviation (GSD):

14.8

Remark on MMAD/GSD:

Mass dispersion and particle sizes, as well as concentration in the inhalatory air were measured by ITENE, by using an optical particle sizer OPS-TSI 3330, at least in one occasion for each study. In parallel, samples of solutions for administration and from the air in the inhalation chamber were also collected and measured by using a nanosizer.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

theoretical (cut-off) dose: 85.6 mg/m³
actual dose: 65.9 mg/m³

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

After the acclimatization period of 5 days, a randomly selected animal was marked with a number at the base of the tail with a permanent marker in order to identify the animal.
The dose was prepared immediately before administration, different batches of 6-mL of a solution integrated by 0.05% BSA, 30 μL of absolute alcohol and sterile water (q.s.) to 6 mL and with Sodasil P95 at concentration of 2.567 mg/mL was used. It was not possible to assess higher concentrations or dose levels without affect dispersion and homogeneity feasible for inhalation. The solution is sonicated for 12 minutes at 31-36 mJ/m³ at 20% amplitude in an ultrasound bath.

The animals were exposed to the inhalation procedure at 0.1 mL/min of test item solution and at 3 L air/min for 4 hours (acute toxicity).
The animals were weighed and observed daily for the assessment of toxic effects for 14 days (acute toxicity). Throughout the study periods, food and water were also weighed regularly to monitor changes in food and water intake.
Clinical findings were checked daily by observing any toxic effects. They were graded and recorded according to a scale based on the basic animal welfare supervision protocol proposed by Morton and Griffiths.

Statistics:

For continuous data, a parametric analysis was performed to assess if variables follow a normal distribution and variances are homogeneous. If so, a one-way analysis of variance (ANOVA) followed by Dunnett’s test was performed. On the contrary, the Kruskal-Wallis ANOVA followed by the Mann-Whitney U-test was applied if Kolmogorov-Smirnov normality test was significant.
For organ weight data, parametric statistical comparison was done with absolute organ weights and those rated by the terminal body weight of each animal, unless non-parametric methods are applied when normality and variances homogeneity is not reached.

Sex:

male/female

Dose descriptor:

LC0

Effect level:

>= 65.9 mg/m³ air (analytical)

Exp. duration:

4 h

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Sex:

male/female

Dose descriptor:

LC50 cut-off

Effect level:

> 85.6 mg/m³ air

Exp. duration:

4 h

Mortality:

No mortality was observed in animals treated with Sodasil P95 at an actual dose level of 65.9 mg/m³.

Clinical signs:

bodyweight loss

Remarks:

Cf. below on body weight loss. No other clinical signs were observed.

Body weight:

Only a very weak and temporary decrease in female body weight could be seen for 2–3 days after inhalation, but this effect is commonly related to the exposure conditions. No effects could be seen on food and water intake.

Gross pathology:

No macroscopic alterations were observed in animals treated with Sodasil P95.

According to the OECD TG 436, the acute lethal dose for inhalation route could not be determined for Sodasil P95, since no mortality or any toxic event could be registered at a theoretical dose level of 85.6 mg/m³ (LC50 cut-off) and an actual one of 65.9 mg/m³. 

Conclusions:

According to the OECD TG 436, the acute lethal dose for inhalation route could not be determined for Sodasil P95, since no mortality or any toxic event could be registered at theoretical dose level of 85.6 mg/m³ (LC50 cut-off) and an actual one of 65.9 mg/m³. Therefore, the LC50 cut-off is greater than 85.6 mg/m³ and the LC0 at least 65.9 mg/m³.

Executive summary:

The aim of this study was to assess the acute and subchronic systemic toxicity following acute (4-hour exposure) and subacute inhalation (4-hour exposure daily for 5 days) of Sodasil P95 in Wistar rats. Only the acute experiment is documented here, the subacute one is found in chapter 7.5.2. No mortality was observed in both studies.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

> 85.6 mg/m³ air

Physical form:

inhalation: aerosol

Quality of whole database:

reliability: 1

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific asnd national standards, limited documentation, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

24-exposure, abraded and intact skin

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Specific details on test material used for the study:

Zeolex 23A

Species:

rabbit

Strain:

New Zealand White

Sex:

not specified

Vehicle:

water

Duration of exposure:

24 h

No. of animals per sex per dose:

4

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Dose descriptor:

LD0

Effect level:

>= 5 000 mg/kg bw

Mortality:

none: 0/16 (0/4 per each dose group)

Clinical signs:

other: no data

Gross pathology:

No pathological findings

Other findings:

Dermal reactions were limited to slight erythema and edema.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD0

Value:

>= 5 000 mg/kg bw

Quality of whole database:

reliabilty: 2

Justification for classification or non-classification

As no mortality was observed in any study, there is no need for classification.