2,6-bis(4-ethylphenyl)perhydro-1,3,5,7-tetraoxanaphth-4-ylethane-1,2-diol

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

185 ng/L

Assessment factor:

100

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

1.85 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

18.5 ng/L

Assessment factor:

1 000

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:

no exposure of sediment expected

Sediment (marine water)

Hazard assessment conclusion:

no exposure of sediment expected

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no exposure of soil expected

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

In the derivation of aquatic PNECs, the NOEC result from the algal inhibition test was used as the starting point on the basis that it is the most modern test, conducted according to modern OECD and EC test guidelines and in compliance with GLP, and the reported NOEC value was based on the analysed concentration of NC-4 in medium, rather than the nominal vaules reported in the acute fish toxicity test and the acute daphnia immobilisation test.

In each case (freshwater, salt water, and intermitten releases), the PNEC_aqua was calculated according to REACH Guidance Document R10 (Dose [Concentration]-Response Regarding Environment, ECHA 2008); in each case the assessment factors used were the minimum values recommended in the guidance document; 100 for fresh water, 1000 for marine water, and 10 for intermitten release. The minimum recommended factor was used on the basis that in each trophic level assessed, no harmful effects were seen at or above the limit of solubility in water; the results quoted are not effect levels, but rather the highest concentrations assessed. In addition, long-term effects are not anticipated, as the logPow of NC-4 is 1.6; as the logPow is less than 3, NC-4 is expected to have a low potential for bioaccumulation.

As recommended in the above guidance document, an assessment factor of 10 was applied to the NOEC of the sludge respiration test in the calculation of the PNEC_STP.

PNECs were not calculated for the Sediment, Soil, or Oral compartments, as on consideration of the use pattern for NC-4, no release to these compartments is anticipated.

Conclusion on classification

No evidence of toxicity (mortality in the fish test, immobilisation in the Daphnia test, or respiration inhibition in the algal test) was seen for NC-4 when tested at or above the limit concentration for fish and daphnia, and above the stated water solubility level for the algal test. In retrospect, it may be noted that both the fish actute toxicity test and the acute daphnia immobilisation test were both conducted at concentrations much higher than the limit of solubility in water of NC-4, and so it may be assumed that in these tests, the concentrations to which the fish and daphnia were actually exposed were lower than those quoted.

As no toxic effects were seen for NC-4 when tested above the limit of water solubility, there is no basis on which to classify the material as Hazardous to the environment.