3-aminopropyldiethylamine

Toxicity to aquatic algae and cyanobacteria

Description of key information

DEAPA can be considered as harmful to algae. 

Key value for chemical safety assessment

EC50 for freshwater algae:

34 mg/L

EC10 or NOEC for freshwater algae:

19.53 mg/L

Additional information

The determination of the growth inhibition of the fresh algae Pseudokirchneriella subcapitata exposed to diethylaminopropylamine (DEAPA) for a duration of 72h was performed following the method OECD 201 and according to GLP (Arkema, 2000). Algae were exposed to the following nominal concentrations for 72h: 0, 4.77, 7.63, 12.21, 19.53, 31.25 and 50 mg/L. The final concentrations of DEAPA were maintained within the designated limit of 80% of the initial concentrations in non inoculated flasks. Therefore, the effect concentrations and NOEC have been calculated using the nominal concentrations. The validity criteria of the study were fulfilled.The ErC50_72h and NOEC_72h were determined to be 34 and 19.53 mg/L, respectively.

As a supportive study, acute toxicity to Desmodesmus subspicatus was investigated according to German Industrial Standard DIN 38 412/9 (BASF, 1990). EC50_72h was determined to be between 100 and 150 mg/L.

The concentrations were not measured in the vessels during the test but DEAPA is expected to be stable in water as showed in the test carried out by Arkema. Moreover, DEAPA is miscible in water, its vapor pressure is low and it is not subject to hydrolysis. Therefore there are no cause of significant deviation from nominal to real substance concentrations.

Another test was conducted according to German Industrial Standard DIN 38 412/9 (BASF, 1990). But the stock solution of DEAPA was neutralised with 1N HCl to pH7. In this study, ErC10_72h and ErC50_72h were determined to be 3.45 g/L and 7.12 g/L, respectively. The result of the study suggests that the toxicity of DEAPA is related to the increase of the medium pH but not to a specific mode of toxic action.