Zinc bis(dinonylnaphthalenesulphonate)

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

4 µg/L

Assessment factor:

50

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

2.3 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.4 µg/L

Assessment factor:

500

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

10 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

25.43 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

2.54 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:

10.1 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

22.2 mg/kg food

Assessment factor:

90

Additional information

In a semi-static daphnia reproduction study (OECD 211) on a structural analog, daphnids were exposed during 21 days at loading rates of 0, 0.46, 1.0, 2.2, 4.6 and 10 mg/L (WAF). Mean measured concentrations were NA, 0.0052, 0.17, 0.14, 0.20 and 0.28 mg/L. Effects on growth were reported at a loading rate of 2.2 mg/L. The NOEL for reproduction and mortality were 4.6 and 10 mg/L(expressed as loading rate). The starting concentration for risk assessment is 0.20 mg/L. AF (Assessment factor) of 50 is applied to derive the PNECwater based on the availability of the algae study and the daphnia reporduction study. Thus, PNECwater is 4 µg/L. For lacking the toxicity data for marine water organisms and AF of 500 is applied to derive PNECsaltwater. Thus, the PNECsaltwater is 0.4 µg/L. The short-term toxicity data of the three trophic levels for fresh water were available and showed no effects at the water solubility level. Therefore starting point for the risk is the water solubility of 0.23 mg/L as derived. An AF of 100 is applied to derive PNECaqua (intermittent releases), thus PNECaqua (intermittent release) is 2.3 µg/L.

The NOECmicro-organism was 100 mg/L based on the active sludge respiration inhibition test. An AF of 10 is applied. Thus, the PNECstp is 10 mg/L.

As no data on sediment dwelling organisms and terrestrial organisms is available, EPM is applied to derive PNECsed, PNECmarine-sed and PNECsoil. Based on the available Koc, water solubility, molecular weight and vapour pressure, the PNECsed, PNECmarine-sed and PNECsoil are 11.7, 1.17 and 4.6 mg/kg dw respectively according to guidance on information requirements and chemical safety assessment chapter R.10.: characterisation of dose[concentration]-response for environment.

PNEC oral is derived based on the NOAEL of 100 mg/kg bw as derived from the 90-day toxicity study on a structural analog and applying an assessment factor of 90 and a conversion to food factor of 20 as outlined in the May 2008 version of Chapter R.10 of the REACH guidance documents. PNECoral = (100*20)/90 = 22.2 mg/kg food..

The VP of the substance is very low (0.00000001 Pa at 20 degree C), thus the very limited hazard for air is expected.

Conclusion on classification

In none of the acute aquatic toxicity tests performed on fish, daphnia and algae, an LC50 or EC50 could be achieved within limits of solubility. Likewise, the NOAEC in a chronic study with Daphnia magna was found to be 0.2 mg/L and, for Algae, 1.2 mg/L. Thus, effects on all three trophic levels is considered above water solubility and no classification for acute aquatic toxicity is derived according to CLP (Regulation EC No 1272/2008). Although the log of n-octanol/water partitioning coefficient was > 6.5, the molecular size is > 19A, thus hampering passage of the biomembranes. A valid BCF QSAR showed that the BCF is expected to be < 2000. Therefore the substance is not expected to bioaccumulate. Thus, the substance is also not classifiable for chronic aquatic toxicity according to CLP.