7-azatridecane-1,13-diamine

Endpoint summary

Description of key information

No hydrolysis study is required as the substance is ready biodegradable.

The biochemical degradability of the test substance Bis(hexamethylene)triamine at 293 K (20 deg C) was determined according to the OECD Guideline No. 301 D and to EC Method C.4 -E and compliant to GLP (reliability category 1).

Control- and blank-series without test substance were run simultaneously and the effectiveness of the inoculum was confirmed.

For the test substance, the following biodegradability was found:

1 % after 7 days,

49 % after 14 days,

100 % after 17 days,

100 % after 21 dayS,

100 % after 28 days.

Additionally, nitrate measurements in the 28 d samples confirmed a total nitrification of the test substance during the test period.

Therefore the test substance is classified as readily biodegradable according to the guidelines, meeting the 10 days window. Moreover it was found that an inhibitory effect of the test substance on the biochemical degradation of the reference substance at the concentration tested could not be excluded.

The adsorption/desorption behaviour of BHT amine containing the main constituents BHT (64.8%) and HMD (13.8%)

was investigated using four soil types covering a range of different soil properties: Speyer 2.1 (soil I, sand), Speyer 6S (soil II, clay), Empingham (soil III, clay loam), Mechtildshausen (soil IV, loam) and sediment of the River Rhine (soil V, sandy loam). Sorption of BHT to the investigated soils was strong but showed a dependency on the soil involved and on the soil-to-solution ratio used. Sorption was strongest to the clay soil (soil II) and weakest to the sand soil (soil I). With the exception of the river sediment (Soil V), sorption increased with increasing clay content. No correlation of sorption and the soil properties pH value, cation exchange capacity and organic carbon content was observed. The sorbed fraction of analyte increased with the amount of soil used in the batch systems. Apparent equilibrium distribution was reached within 48h. Desorption was investigated for 120h after the 48h adsorption phase. Little desorption was observed and constant solution phase concentrations were reached between 24h and 120h. The adsorption coefficients were calculated after 48h of adsorption, whereas desorption coefficients were calculated after 120h of desorption.

Kd values for BHT were between 201 (soil I) and >51000 (soil II) L/kg (log Kd between 2.3 and >4.7, respectively), for the sediment sample the Kd value was 152 L/kg (log Kd 2.2).

The calculated adsorption and desorption distribution coefficients were independent of the organic carbon content. Therefore, any environmental fate assessment should preferably be based on Kd_ads or Kd_des values.