Hexafluorosilicic acid

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish early-life stage toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

see read across justification

Reason / purpose for cross-reference:

read-across source

Duration:

32 d

Dose descriptor:

NOEC

Effect conc.:

66.6 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Fluoride

Basis for effect:

growth rate

Key result

Duration:

32 d

Dose descriptor:

NOEC

Effect conc.:

83.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

weight

Remarks on result:

other: Applying the conversion factor from F- to hexafluorosilicic acid, the concentration range corresponds to 83.9 mg hexafluorosilicic acid/L.

Remarks:

Applying the conversion factor from F- to hexafluorosilicic acid, the concentration range corresponds to 83.9 mg hexafluorosilicic acid/L.

Details on results:

- Mortality/survival at embryo, larval, juvenile, and adult stages:control and up to nominal 150 mg/L > 80% in each replicate. no mortality in any of the test solutions up to 150 mg/L.
- Days to hatch: 4.5
- Numbers hatched: tpyically > 80 %, 100% in all test solutions.
- Number of healthy fish at end of test: 90% in control, 100% in test solutions up to 150 mg/L, 18 % at nominal 300 mg/L
- Effect concentrations exceeding solubility of substance in test medium: none
- Incidents in the course of the test which might have influenced the results: none

Applying the conversion factor from F- to hexafluorosilicic acid, the concentration range corresponds to 83.9 mg hexafluorosilicic acid/L.

Reported statistics and error estimates:

Dunnetts test

Validity criteria fulfilled:

yes

Conclusions:

32d-NOEC 66.6 mg F-/L (applied as NaF, measured F- concentration), this NOEC corresponds to 83.9 mg hexafluorosilicic acid/L.

Executive summary:

In an ELS study similar to OECD 210, the 32d-NOEC was determined to be 66.6 mg F-/L (applied as NaF, measured F- concentration). The study is considered to be reliable with restrictions (no GLP statement). All relevant raw data were reported. This information has been reviewed by the US-EPA (D. Bush, 2007) and been considered in general relevant for the risk assessment of fluorides.

Applying the conversion factor from F- to hexafluorosilicic acid, the NOEC corresponds to 83.9 mg hexafluorosilicic acid/L.

In accordance with the US-EPA (D. Bush, 2007) this study is considered relevant for the risk assessment of fluorides and hence also hexafluorosilicic acid.

Description of key information

32d-NOEC: 83.9 mg hexafluorosilicic acid/L

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

83.9 mg/L

Additional information

In the key ELS study similar to OECD 210, the 32d-NOEC was determined to be 66.6 mg F-/L (applied as NaF, measured F- concentration). The study is considered to be reliable with restrictions (no GLP statement; Klimisch 2). All relevant raw data were reported. This information has been reviewed by the US-EPA (D. Bush, 2007) and been considered in general relevant for the risk assessment of fluorides. Applying the conversion factor from F- to hexafluorosilicic acid, the NOEC corresponds to 83.9 mg hexafluorosilicic acid/L. In accordance with the US-EPA (D. Bush, 2007) this study is considered relevant for the risk assessment of fluorides and hence also hexafluorosilicic acid.

In a disregarded Klimisch 3 21 day test with Oncorhynchus mykiss a LC5 value of 4 mg F-/L was reported (actual concentration).  In the original publication this value is considered to be equivalent to the NOEC for mortality.  The test was conducted in very soft (12 mg CaCO3/L) natural water with daily renewal of the test water. Applying the conversion factor from F- to hexafluorosilicic acid, the concentration corresponds to 5.04 mg hexafluorsilicic acid/L. Due to methodological differences to modern test guidelines for long-term toxicity testing for fish, this study is disregarded and considered as not relevant for the risk assessment of hexafluorosilicic acid.