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

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

Pyrochlore:

The chemical and physiological properties of pyrochlore are characterised by inertness because of the specific synthetic process (calcination at high temperatures, approximately 1000°C), rendering the substance to be of a unique, stable crystalline structure in which the majority of atoms are tightly bound and not prone to dissolution in environmental and physiological media. This has been shown in transformation/dissolution testing for antimony, in which dissolved Sb concentrations were below 27 µg/L (after 7 days at a loading of 0.1g/L) and 2 µg/L (after 28 days at a loading of 1 mg/L); thus implying a solubility of < 0.03% of antimony. Hence, Sb can be considered as not bioavailable and is not regarded concerning toxicological and environmental effects. This assumption is affirmed by the values for ecotoxicological effects (aquatic toxicity) given in the RAR for antimony trioxide.

According to the European Union Risk Assessment Report for diantimony trioxide, the lowest effect values for antimony for aquatic species are the following:

Trophic level

Species

Acute toxicity mg Sb/l

Chronic toxicity mg Sb/l

 

Fish

Pargus major

Pimephales promelas

LC50 (96 hr) = 6.9 (measured total)

NOEC = 1.13 (measured total)

 
 

Invertebrates

Daphnia magna

Hydra (Chlorohydra viridissima - Hydra oligactis)

LC50 (48 hr) = 12.2 (measured total)

LC50 (72 hr) = 1.77 – 1.95 (measured filtered)

NOEC = 1.74 (measured total)

 
 
 Algae and aquatic plants  Raphidocelis subcapitata Lemna minor EC50 (72 hr) > 36.6 (measured total) EC50 (96 hr) > 25.5 (measured dissolved)  NOEC (72 hr) = 2.1 (measured total) NOEC (96 hr) = 12.5 (measured dissolved)   

On the other hand, lead concentrations were much higher (>2.9 mg/L at a loading of 100 mg/L after 7 days at pH 6; 105 µg/L at a loading of 1 mg/L after 28 days at pH 6 ) and have to be regarded concerning toxicological and environmental aspects. No substance specific data on ecotoxicity of pyrochlore are available. For this purpose, read-across to lead oxide and sparingly soluble lead compounds has been performed.

Lead:

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

Pyrochlore:

Antimony:

Taking into account the dataset contained in the European Union Risk Assessment Report for diantimony trioxide, and comparing the lowest effect values for antimony for aquatic species to the very low dissolution of antimony observed in TDp testing (27 µg/L after 7 days at a loading of 0.1g/L and 2 µg/L after 28 days at a loading of 1 mg/L; Pardo-Martinez, 2010), no classification of the pigment based on this element is anticipated.

Lead:

A TDp 24 h screening test is available for Lead oxide although limited to pH8 information. Given the lower acute toxicity reference values at pH6 (79,4 µg/l) and pH7 (56,1 µg/l) and the expected higher solubility at this pH (> 100 µg/l), it can be deduced/concluded that with the information available, PbO would fail the 24h screening test and should therefore be classified as the soluble Pb ion, 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

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 oxide redundant.

Transformation Dissolution data in accordance to the OECD protocol are available for Lead oxide but to a limited extend (24h screening test at pH 8 only). There is therefore no absolute need for further developing Transformation Dissolution data on Lead-oxide given a default classification of R50-53 or Acute 1-Chronic 1, could be derived

It is however noted that due to the default nature of this assessment that further Transformation Dissolution testing on the compound has the potential to alter the classification to a lower classification category.