Reaction products of sodium glucoheptonate with zinc sulfate and sodium hydroxide

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.032 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

8.9 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.003 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

0.89 µg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

0.63 mg/L

Assessment factor:

1

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

3.25 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.325 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.629 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Derivation of PNECs

The PNECfreshwater, PNECmarine water, PNECintermittent release (freshwater and marine water) and PNEC STP were derived by application of an assessment factor. This procedure is described in detail in the ECHA REACH Guidance of May 2008, Chapter R.10 ("Characterisation of dose [concentration]-response for environment").

The PNECs for sediment (freshwater and marine water) and soil are derived using the Equilibrium Partitioning Method (EPM) which is in concordance with ECHA REACH Guidance R.10 (“Guidance of Information Requirements and Chemical Safety Assessment, Chapter R.10: Characterisation of dose-response for environment”). The required normalized organic-carbon soil coefficient (Koc) value for zinc glucoheptonate was estimated by QSAR prediction (Chemservice, 2017). The applied Henry's Law Constant was calculated under consideration of the vapour pressure and the water solubility (Chemservice, 2017).

Furthermore, no PNEC for the atmospheric compartment (PNECair) has been calculated. It is considered as not relevant based on the chemical structure and intrinsic properties of zinc glucoheptonate.

Secondary poisoning (PNECoral) was not calculated either since the substance has no potential for bioaccumulation.

Conclusion on classification

Regarding all available data of the acute and/or chronic toxicity tests on aquatic organisms and taking into account the provisions laid down in Council Directive 67/548/EEC and CLP Regulation (EC) No 1272/2008, the registered substance does not need to be classified as hazardous to the environment.

Experimental results of the source substances have been transferred and/or converted in a worst-case approach in order to account for Zinc glucoheptonate.

For the endpoint aquatic toxicity two GLP-compliant key studies with the test item were conducted. The acute toxicity to D. magna was studied with an Acute Immobilisation test according to the OECD Guideline 202. The EC50 (48 h) value was 24.9 mg/L. The toxicity to aquatic algae was investigated with a Growth Inhibition study on P. subcapitata according to the OECD Guideline 201. The EC50 (72 h) value (referring the growth rate) was 0.89 mg/L. The key values are in a range of zinc toxicities identified in a number of studies. The key value of 0.89 mg/L obtained in the Growth Inhibition key study according to the OECD Guideline 201 (Kamle, 2017) is just below the limit of 1 mg/L for classification as hazardous to the aquatic environment, acute category 1. Due to the fact that there is evidence that the toxicity of zinc strongly depends on environmental factors not accounted for in laboratory studies, laboratory results may lead to an overestimation of zinc toxicity when compared to the situation in field. There is evidence that the toxicity of zinc strongly depends on the chemical properties of the water, like dissolved organic carbon (DOC) content (De Schampelaere et al. 2005, Fisher and Frood, 1980), pH-value (Wilde et al., 2006; De Schamphelaere, 2005), salinity (Eklund, 2005) and metal concentration (De Schamphelaere et al., 2005). These factors are not accounted for in the standardised laboratory studys. Therefore, the registered substance is not intended to be classified as hazardous to the environment, taking into account the provisions laid down in Council Directive 67/548/EEC and CLP Regulation (EC) No 1272/2008.