Lead bis(tetrafluoroborate)

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

6.5 µg/L

Assessment factor:

3

Extrapolation method:

sensitivity distribution

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

3.4 µg/L

Assessment factor:

3

Extrapolation method:

sensitivity distribution

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

100 µg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Additional information

In assessing the ecotoxicity of metals in the various environmental compartments (aquatic, terrestrial and sediment), it is assumed that toxicity is not controlled by the total concentration of a metal, but by the bioavailable form. For metals, this bioavailable form is generally accepted to be the free metal-ion in solution. In the absence of speciation data and as a conservative approximation, it can also be assumed that the total soluble lead pool is bioavailable and as worst case consideration lead is mor toxic than the anion tetrafluoroborate. All reliable data on ecotoxicity and environmental fate and behaviour of lead and lead substances were therefore selected based on soluble Pb salts or measured (dissolved) Pb concentration.

 

The reliable ecotoxicity data selected for effects assessment of Pb in the various environmental compartments are derived from tests with soluble Pb salts (lead (di)nitrate, lead carbonate, lead acetate, lead chloride). Since lead is the toxic component and the anions do not contribute to toxicity, all reliable data are grouped together in a read-across approach and the PNEC’s are expressed as μg Pb/L (measured dissolved concentration) or mg Pb/kg. These results can be used for all other Pb compounds without concern on toxicity of the anions, including the substance to be registered.

 

Conclusion on classification

Based on the available data lead bis(tetrafluoroborate) should be classified as the soluble Pb ion however, corrected for molecular weight, being :

· Under DSD : R50/53, with an M factor of 10

· Under CLP : Acute 1 – Chronic 1, with an M factor of 10

· Under GHS 3rd rev : Acute 1 – Chronic 1, with an acute M factor of 10 and a chronic M factor (tbd)

In line with annex 4 chapter IV.5.3 of the CLP, Metal compounds must be classified by comparing Transformation Dissolution data with toxicity date for the soluble metal ion. The availability of toxicity information on the soluble ion (developed under the Lead metal registration file) makes the requirement for aquatic ecotoxicity tests on Lead chloride redundant.

Transformation Dissolution data in accordance to the OECD protocol are not available for Lead bis(tetrafluoroborate), but water solubility data (saturation levels at relevant time intervals for the environmental classification) are available demonstrating a water solublity of > 500 g/L (approx. 20°C).

There is therefore no need for developing Transformation Dissolution data on Lead bis(tetrafluoroborate) given any further work would never be capable to change the present hazard conclusion as R50-53 (DSD) or Acute 1-Chronic 1 (CLP).