Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

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

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
4.47 µg/L
Assessment factor:
100
Extrapolation method:
assessment factor
PNEC marine water (intermittent releases):
0.9 µg/L

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
3.24 mg/L
Assessment factor:
1
Extrapolation method:
sensitivity distribution

Sediment (freshwater)

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

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.36 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:
0.694 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Although measured acute toxicity data is available for fish, invertebrates and algae the HC5 QSAR equation was selected to calculate the PNEC. The reason for selecting this approach to calculate the PNEC is because the equation was generated using data measured data for over 1000 hydrocarbon chemical structures and represents a more holistic evaluation of hydrocarbons’ fate and behaviour and toxicity in the environment.

Conclusion on classification

Cyclohexane has a harmonised classification of Acute Category 1 and Chronic Category 1.

An acute dataset is available for cylochexane and the lowest acute reported result was a 48 hour EC50 for Daphnia magna of 0.9 mg/L A chronic dataset is not available for cyclohexane but a 72 hour NOEC for algae is available which reports a value of 0.925 mg/L.

The results would indicate that cyclohexane would not meet the criteria for toxic in the PBT assessment. The results would meet the criteria for Acute Category 1, with the phrase H400: very toxic to aquatic life. As cyclohexane is considered to be readily biodegradable, the results would meet the criteria for Chronic Category 3, with the phrase H412: harmful to aquatic life with long lasting effects. These have been included in the dossier as a self-classification.