Disodium oxybis[methylbenzenesulphonate]

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.112 mg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

1.122 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.011 mg/L

Assessment factor:

10 000

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

10 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.404 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.04 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:

0.015 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

The PNEC´s were derived from the most sensitive study available for each compartment.

For calculation of the PNEC water the ErC10 of 66.9 mg/L value of the Algal Growth Inhibition Test was used.

As recommended in REACH guidance document R.10, an EC10 for a long-term test which is obtained using an appropriate statistical method (usually regression analysis) will be used preferentially. The NOEC is defined as "the highest concentration tested at which the substance is observed to have no statistically significant effect (p< 0.05) when compared with the control, within a stated exposure period" (OECD 211, 1998b) or the test concentration immediately below the LOEC, which when compared with the control has no statistically significant effect (p< 0.05) within a stated period (OECD 211, 1998b). There has to be a concentration-effect relationship. In the past, the NOEC was mainly derived on the basis of ANOVA (analysis of variance) and a subordinate test (e. g. Dunett's) or determined directly from the concentration-effect curve by consideration of the deviation of the control (e. g. 10%). In older investigations, it may be difficult to find out how the NOEC was generated unless test reports or raw data are available. There has been a recommendation within OECD in 1996 to phase out the use of the NOEC, in particular as it can correspond to large and potentially biologically important magnitudes of effect. The preconditions for the use of ANOVA have to be fulfilled (normal distribution, homogeneous variances). The advantage of regression method for the estimation of ECx is that information from the whole concentration-effect relationship is taken into account and that confidence intervals can be calculated. These methods result in an ECx, where x is a low effect percentile (e. g. 5-20%).

In conclusion, it is not entirely clear as to whether the EC10 or NOEC from the algal study should be used as the main result, in the context of PNEC derivation. In this case, due to the shallow dose-response relationship seen in the study with Desmodesmus subspicatus, it is considered appropriate to use ErC10 as the primary result of the study.

 

Conclusion on classification

Ditolylether disulfonic acid disodium salt, isomer mixture is not listed in the Annex I of Directive 67/548/EEC.

According to the information summarized in this chapter, ditolylether disulfonic acid disodium salt, isomer mixture should not be classified with the following reasons:

- The acute toxicity values are all above 100 mg/l representing three trophic levels obtained in short-term toxicity tests towards algae and fish and Daphnia.

- The long-term toxicity is to algae with a 72h-ErC10 of 66.9 mg/l.

- Ditolylether disulfonic acid disodium salt, isomer mixture is not readily biodegradable.

- The bioaccumulation potential is expected to be very low, based on its log Kow of -1.54 for the dissociated form of ditolylether disulfonic acid disodium salt, isomer mixture and 1.04 for the non-water based parent acid.

With the data listed above, ditolylether disulfonic acid disodium salt, isomer mixture should not be classified according to DSD (Directive 67/548/EEC) and GHS (Regulation EC 1272/2008 including Commission Regulation EU-286/2011).