Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
6.5 µg/L
Assessment factor:
3
Extrapolation method:
sensitivity distribution
PNEC freshwater (intermittent releases):
70 µg/L

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

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
174 mg/kg sediment dw
Assessment factor:
3
Extrapolation method:
sensitivity distribution

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
164 mg/kg sediment dw
Assessment factor:
3
Extrapolation method:
sensitivity distribution

Hazard for air

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
147 mg/kg soil dw
Assessment factor:
2
Extrapolation method:
sensitivity distribution

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
PNEC oral
PNEC value:
10.9 mg/kg food
Assessment factor:
6

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. 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.

 

Conclusion on classification

One of biodegradation products being Pb ion (46 % of Lead styphnate weight), therefore the environmental classification needs to be similar.

A precautionary read across approach based on Pb water solubility data derived from OECD 105 water solubility testing, was used to determine the environmental hazard classification. In absence of full TDp data on this compound a temporally reasonable worst case environmental classifications was derived from the water solubility test results :

· Under DSD : R50/53, with an M factor of 1 (The R53 is automatically applied by default given the failure of the TDp screening test read across)

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

This environmental classification recommendation holds all mixtures in which the compound is used if each of the mixture contains at least 25 % of the composing material.

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 redundant.

Transformation Dissolution data in accordance to the OECD protocol are not available for this compound, but water solubility data (saturation levels at relevant time intervals for the environmental classification) is available. There is no further need for developing Transformation Dissolution data given a reasonable worst case read across approach comparing the water solubility data from the OECD 105 test with the acute toxicity reference values demonstrates that the compound is sufficiently soluble to warrant a classification as R50-53 or Acute 1-Chronic 1. Further additional Transformation dissolution testing would in general not be capable to improve this situation justifying the requested waiving for TDp data.