disodium 7-{[4-chloro-6-(dodecylamino)-1,3,5-triazin-2-yl]amino}-4-hydroxy-3-[{4-[(4-sulfonatophenyl)diazen-1-yl]phenyl}diazen-1-yl]naphthalene-2-sulfonate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

36 µg/L

Assessment factor:

50

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

360 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

3.6 µg/L

Assessment factor:

500

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

1 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

141 µg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

14.1 µg/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:

7.08 µg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Calculation of PNEC_water was based on the result obtained in a long-term study on daphnia, namely a NOEC of 1.8 mg/l. This result was generated for the trophic level showing the lowest EC50 in short-term tests, i.e. EC50 > 36 mg/l for crustacea; in addition, a NOEC of 41.2 mg/l was found in a 72 -h study on algae. Assessment factors of 50 and 500 were used for fresh water and marine water, respectively.

The derivation of PNEC_{water, intermittent} was done by applying an assessment factor of 100 to the lowest value obtained in at least three short-term aquatic toxicity studies from three trophic levels. Accordingly, an EC50 > 36 mg/l on daphnia was used.

The value of PNEC_stp was derived from the result of the activated sludge respiration inhibition test EC50 > 100 mg/l by using an assessment factor of 100.

Due to the lack of ecotoxicological data, PNEC_sediment for fresh water and marine water were calculated using equilibrium partitioning method. This method uses PNEC_water for aquatic organisms and suspended matter/water partition coefficients as inputs. Note that this approach is used only as a rough screening since it may result in both an overestimation or underestimation of toxicity. As no experimental data was available, the suspended matter-water partition coefficient was computed and resulted as 0.979 m³/m³, starting from a Koc of 3.16 l/kg for non-hydrophobic substances. A correction factor of 4.6 from wet weight to dry weigth was applied to obtain the final PNEC_sediment.

The amount of test substance in the air compartment was expected to be very low, since the substance is a solid with a negligible vapour pressure. Therefore, no hazard was identified.

The calculation of PNEC_soil was done using the equilibrium partitioning method, based on the assumption that soil toxicity, expressed in terms of freely-dissolved substance concentration in the pore water, is the same as aquatic toxicity. The pore water concentration is correlated with the bioavailable fraction. Note that this approach was originally developed for sediments but it may be applied to soil. In the calculation of PNEC_soil,

PNEC_water for aquatic organisms and soil/water partition coefficient are used as inputs. As no experimental data was available, the soil-water partition coefficient was computed and resulted as 0.295 m³/m³, starting from a Koc of 3.16 l/kg for non-hydrophobic substances. A correction factor of 1.13 from wet weight to dry weight was applied to obtain the final PNEC_soil.Secondary poisoning concerns toxic effects in the higher members of the food chain which result from ingestion of organisms from lower trophic levels that contain accumulated substances. It is relevant for lipophilic organic chemicals. Therefore, due to the absence of potential for bioaccumulation, test substance was considered as not hazardous with respect to secondary poisoning.

Conclusion on classification

According to the CLP Regulation (EC 1272/2008), the threshold of classification of a substance for acute aquatic toxicity is 1 mg/l. This limit is compared with a LC50 (96h) for fish, an EC50 (48 h) for crustacea, e.g. daphnia, or an EC50 (72 - 96 h) for algae or aquatic plants.

The toxicity to fish was determined in a 96 -hour limit test where no mortality was seen at the tested concentration. Hence a LC50 (96 h) > 86 mg/l (measured concentration) was found.

Exposure of daphnia to a filtrate solution did not induce acute immobilisation at measured concentrations ranging from 47 to 24 mg/l after 48 h. Hence an EC50 > 36 mg/l on average was found. Exposure to a supersaturated solution caused immobilisation, due to substance deposition rather than to substance toxicity.

The toxicity on algae was determined in a 72 -hour test. As proved by a modified test specifically developed for dyes, effects on algal biomass and growth rate, with a NOEC of 6.7 mg/l, were only due to the indirect action of the test substance, namely light absorption.

Any toxic effect of the test substance on the algal cells could be excluded up to the highest tested concentration of 41.2 mg/l. Hence an EC50 > 41.2 mg/l was found. Based on these findings, the substance is not classified for acute aquatic toxicity in the CLP Regulation (EC 1272/2008).

Concerning the long-term aquatic toxicity, the CLP Regulation (EC 1272/2008) sets the threshold of classification of a non-rapidly degradable substance at 1 mg/l, when chronic toxicity data is available. In case of lack of chronic data, the potential for chronic toxicity is identified by appropriate combinations of acute toxicity data and lack of biodegradability and the threshold of classification is 100 mg/l. Classification based on acute toxicity data may be removed if chronic toxicity data on the same species (or one of equivalent or higher sensitivity) does not imply a classification.

In the available acute toxicity studies, daphnia and algae resulted as the most sensitive species with an EC50 > 36 mg/l and EC50 > 41.2 mg/l, respectively. Chronic toxicity of test substance on daphnia was assessed in a 22 -day test., where a NOEC of 1.8 mg/l was determined, based on the survival rate and the reproduction rate. In the 72 -hour study on algae, a NOEC of 6.7 mg/l was determined. Accordingly, the substance is not classified for chronic aquatic toxicity in the CLP Regulation (EC 1272/2008).