Disodium hexafluorosilicate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14d

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Disodium hexafluorosilicate

EC Number:

240-934-8

EC Name:

Disodium hexafluorosilicate

Cas Number:

16893-85-9

Molecular formula:

F6Si.2Na

IUPAC Name:

disodium hexafluorosilicate

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH
- Age at study initiation: About 9 weeks
- Housing: Single caging in Makrolon cages type III
- Diet (e.g. ad libitum): Ssniff R/M-H maintenance diet
- Water (e.g. ad libitum): Tap water or acidified water to pH 3 with HCl, from Makrolon-bottles or from a watering system, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 °C
- Humidity (%): 50 %
- Photoperiod (hrs dark / hrs light): Artificial light from 6.00 a.m. to 6.00 p.m.

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The apparatus consists of a two-chamber system and is equipped with 20 outlets for inhalation tubes
- Exposure chamber volume: 30 cm in diameter and 27 cm high, resulting in a volume of 19 L.
- Rate of air: 600 L/h
- System of generating particulates/aerosols: From TSE Systems GmbH, Bad Homburg, dust generator according to Bundschuh
- Method of particle size determination:
- Treatment of exhaust air:
- Temperature, humidity: 22ºC, 30-70%.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

>= 1 - <= 4 h

Concentrations:

0.45, 0.95 and 2.35 mg/L

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Behaviour and clinical signs each hour during the application and 1 h and 2 h after the exposure, then once a day until the end of the study
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology

Results and discussion

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

LC50

Effect level:

ca. 2.021 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Effect levels 2

Sex:

male

Dose descriptor:

LC50

Effect level:

ca. 1.673 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Effect levels 3

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 1.814 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

All animals of the low and the mid concentration group survived till the end of the study. In the high concentration group 3 males and 3 females died 1 to 4 days after the exposure. One other animal was killed because of its moribund state on day 3 after the exposure.

Clinical signs:

other: The females of the low concentration group had no symptoms during the whole observation period. In all other groups symptoms were observed. Most prominent findings were signs of reduced well-being (apathy, piloerection, arched back) and chromodacryorrhoea

Body weight:

The animals lost weight the first week after the exposure. This is in good agreement with the observed symptoms of the animals. In the second week all but two animals gained weight again.
There is no clear correlation between the dust concentration and the body weight gain between the low and mid concentration. There is however a substantial higher body weight loss in the high concentration group the first days after the exposure.

Other findings:

The symptoms were the same in both sexes but the degree of severity was higher in males in this study.

Any other information on results incl. tables

In the low and mid dose no animal died. In the high dose 4 males and 3 females died. The LC50 is therefore 1.673 mg/L for males, 2.021 mg/L for females and 1.814 mg/L for both sexes. In respect to mortalities the NOEC was the mid concentration, 0.95 mg/L. In respect to in-life observations however there was no NOEC as also in the low concentration symptoms like respiratory murmur, chromodacryorrhoe, unusual weight loss, etc. occurred.

Applicant's summary and conclusion

Interpretation of results:

toxic

Remarks:

Migrated information Criteria used for interpretation of results: EU

Executive summary:

 

sex	concentration	number of animals
	mg/L	dead	affected*	exposed
male	0.45	0	4	5
female	0.45	0	0	5
male	0.95	0	5	5
female	0.95	0	5	5
male	2.35	4	5	5
female	2.35	3	5	5

* according to in-life observations and necropsy findings.

 

LC₅₀, inhalation, 4 h, male rats: 1.67 mg/L(95 % confidence limits: 1.26 to 2.22 mg/L)

LC₅₀, inhalation, 4 h, female rats: 2.02mg/L(95 % confidence limits: 1.09 to 3.74 mg/L)

LC₅₀, inhalation, 4 h, both sexes: 1.81mg/L(95 % confidence limits: 1.37 to 2.41 mg/L)