Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.001 mg/L
Assessment factor:
50
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.047 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0 mg/L
Assessment factor:
500
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:
PNEC sediment (freshwater)
PNEC value:
0.005 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

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

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

PNECs were derived from the most sensitive test available for each compartment/endpoint.

Conclusion on classification

Acute toxicity:

Daphnia magna is the most sensitive species with an acute EC50 value of 4.7 mg/L. According to Regulation (EC) No 1272/2008 (CLP, GHS) sodium cyanate has not to be classified regarding acute toxicity to the environment as the lowest LD50 value is above 1 mg/L.

 

Chronic toxicity:

Daphnia magna is the most sensitive species in chronic studies with a NOEC value of 0.05 mg/L. As chronic data from algae and daphnia (most sensitive species) are available the classification is based on these chronic data and represents worst case assumption as compared with a C+L derivation based on acute values.

The test on ready biodegradability is technically not feasible (see section 5.2.1). Nevertheless, within the aborted study, a significant reduction of the TOC was observed after three hours. Without much doubt the cyanate was degraded by abiotic processes and decomposed to CO2 and NH3.

With regard to classification cyanate is thus regarded as degradable in nature.

Thus, in conclusion, sodium cyanate has to be classified as env. chronic tox. cat 2 (H411: Toxic to aquatic life with long lasting effects.) according to Regulation (EC) No 1272/2008 (CLP/GHS), as amended for the tenth time in Regulation (EU) No 2017/776.