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Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

PNECsoil = 5 mg/kg dw based on one long term earthworm study.

The EPM based PNECsoil is 4 mg/kg dw based on an aquatic PNEC of 1 µg/L and a Kp soil o 3986 L/kg (without correction for additional exposure via ingestion).

Additional information

No short term terrestrial test data is available for Tetramine di-C16-18. There is however one long term terrestrial toxicity test result available for Tetramine diC16 -18. The long earthworm test resulted in a NOEC of 500 mg/kg dw. Because the applicability of the equilibrium partitioning method is questioned for this use of cationic surfactants the reliability of the long term earthworm test is considered higher than the results of the EPM. The observed NOEC of 500 mg/kg dw is therefore used for the derivation of the PNECsoil. With an assessment factor of 100 a PNECsoil is calculated of 5 mg/kg dw

For comparison reasons the PNECsoil was also calculated using the equilibrium partitioning method as presented below.

The EPM based terrestrial PNEC (without the correction for additional uptake via food) of 4 mg/kg dw is close to the PNEC as based on the long term earthworm study of 5 mg/kg dw.

Distribution constants for Tetramine di-C16-18 as used in the calculation of the PNECsoil.

 

Kpsoil

3986 L/kg

Ksoil-water

5979 m3/m3

Kpsusp

7972 L/kg

Ksusp-water

1993 m3/m3

Kpsed

3986 L/kg

Ksed-water

1993 m3/m3

 

The PNECsoil is then calculated using the equations detailed in REACH guidance R.16:

                         PNECsoil                         =   Ksoil-water* PNECaquatic dissolved* 1000 * 1 / RHOsoil

Where:         PNECaquatic            =      1 µg/L

                         Ksoil-water                      =      5979 m3/m3

                         RHOsoil                          =      1700 kg.m-3(TGD, equ. 18)

                         PNECsoil-EPM                = 3.51 mg/kg ww

                                                                = 3.97 mg/kg dw

                          

*More than 95% of the currently available ecotoxicity data on sediment and soil organisms show that the additional safety factor for exposure via ingestion is over conservative when these data are compared to the EPM based toxicity.