Registration Dossier
Registration Dossier
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EC number: 204-617-8 | CAS number: 123-31-9
Ecotoxicological Summary
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
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