Ammonium (xylenes and 4-ethylbenzene)sulfonates

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.1 mg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

1 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.01 mg/L

Assessment factor:

10 000

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

100 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.372 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.037 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:

0.016 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

 

Short-term toxicity data for each type of organism indicate the Hydrotropes are of low toxicity to aquatic organisms. The available fish studies for sodium cumen sulphonate, sodium xylenesulphonate and calcium xylenesulphonate report similar acute toxicity values of > 100 and 1580 mg/L. Short-term data for aquatic invertebrates ranged from 100 to > 1020 mg/L corresponding to four Hydrotrope category substances. Toxicity was not observed in the studies where the results are reported as “>” or “=>” . Short-term toxicity to algae was reported in three studies corresponding to three different Hydrotrope category substances. The EC50 based on growth rates ranged from 150 mg/L to 758 mg/L. The consistent trend is for low toxicity to algae across the Hydrotrope category. A conservative representative value of 100 mg/L has been chosen for PNEC derivation.

 

Two activated sludge respiration inhibition studies were available for sodium toluenesulphonate and sodium cumenesulphonate. Both reported no toxicity at the limit test concentration, which was 1000 mg/L for both substances. These studies indicate Hydrotropes are of comparable and low toxicities to microorganisms involved in sewage treatment processes.

 

From the available short-term toxicity data it can be concluded that aquatic organisms are of low sensitivity to Hydrotrope category substances. Most studies across the three trophic levels report no toxicity at the highest concentration tested. The Hydrotrope category substance with the lowest toxicity values for invertebrates and algae appears to be sodium toluenesulphonate. In addition, the studies relating to microbial activity (respiration) indicate low potential for toxicity at similar concentrations to fish, invertebrates and algae. As a combined body of evidence the toxicity data for these test substances can be considered to be representative of the Hydrotropes category. Long-term toxicity data are not required based on the low acute toxicity and ready biodegradability of the Hydrotropes. The reliable aquatic toxicity data are used in PNEC development across the category in accordance with guidance set out in Chapter R.6 (ECHA, 2008).

Conclusion on classification

The EC/LC50 values are above 100 mg/L and the substances of the hydrotrope category have been shown to be readily biodegradable. Therefore a classification for environmental effects is not required.