Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.57 µg/L
Assessment factor:
10
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
1.34 µg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.057 µg/L
Assessment factor:
100
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
0.71 mg/L
Assessment factor:
100
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
4.9 µg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.49 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:
0.64 µg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Conclusion on classification

Short-term E/LC50 values are available for algae (growth rate 72hEC50 = 0.330 mg/L), daphnia (48hEC50 = 0.134 mg/L) and fish (96hLC50 = 0.638 mg/L) based on measured initial concentrations. The lowest EC50 is obtained in the daphnia immobilisation test showing that the substance is very toxic to the aquatic organisms and that the acute M factor should be 1. However, based on the official classification, the acute M factor is considered to be 10.

Additionally, Hydroquinone is readily biodegradable and due to the log Kow <3 there is no tendency to bioaccumulate. Chronic toxicity data are available for fish, daphnia and algae showing a 32d NOEC of 0.1 mg/L (corresponding to 0.066 mg/L in mean measured concentration), a 21d NOEC of 0.0057 mg/L and a 72hNOEC = 0.019 mg/L respectively. Based on this information, Hydroquinone is very toxic to aquatic life with long lasting effects with a chronic M factor of 1.

This results in a classification of:

Aquatic acute 1, H400

Multiplication factor for mixtures: 10

Aquatic chronic 1, H410

Multiplication factor for mixtures: 1