1,1'-(methylimino)dipropan-2-ol

Toxicity to aquatic algae and cyanobacteria

Description of key information

With high probability acutely not  harmful to aquatic algae

Additional information

Experimental data on the toxcity to aquatic algae are available for 1,1'-(methylimino)dipropan-2 -ol (CAS 4402 -30 -6). However, these data are from a screening test according to OECD 201 with a lower number of test concentrations and a higher spacing factor between test concentrations. Algae (Pseudokirchneriella subcapitata) were exposed for 72 h in a static growth inhibition test according to OECD 201. With regard to growth rate, the 72-h ErC10 and the ErC50 were determined to be greater than 100 mg/L (BASF SE, 2012; report no. 60E0383/11E125). The test concentrations were not analytically verified but are assumed to be stable based on the low biodegradability potential, the high water solubility, the low adsorption potential and the low Henry's Law constant.

In addition to this screening test, experimental data from two structurally similar substances are used in a weight-of-evidence approach for the toxicity assessment.

1,1',nitrilotripropan-2 -ol (CAS 122 -20 -3) was tested according to German Industrial Standard DIN 38412-9. In the static growth inhibition test, algae (Desmodesmus subspicatus) were exposed to a series of test solutions for 72 hours. The highest test concentration (100 mg/L) was also tested in parallel after pH-adjustment. Analytical monitoring was not performed; however, the test concentrations are assumed to be stable as the substance is sufficiently soluble in water, has a low potential for adsorption and a low Henry's Law constant. With regard to growth rate, the 72-h ErC50 was determined to be >100 mg/L, the 72-h ErC10 was 19.5 mg/L (nominal; BASF AG, 1990; report no. 01/88/1090). The pH-adjusted sample showed a reduced growth inhibition (biomass) compared to the not pH-adjusted test solution (43% inhibition compared to 60% after 72 h).

Further information on the growth inhibiting effect are available for 1,1'-iminodipropan-2 -ol (CAS 110 -97 -4). The test followed DIN 38412-9. In the static test, algae (Desmodesmus subspicatus) were exposed to a series of test solutions for 72 hours. The highest test concentration (500 mg/L) was also tested in parallel after pH-adjustment. Analytical monitoring was not performed; however, the test concentrations are assumed to be stable as the test substance is miscible with water, has a low potential for adsorption and a low Henry's Law Constant. With regard to growth rate, the 72-h ErC50 was determined to be 339 mg/L, the 72-h ErC10 was 219 mg/L (nominal; BASF AG, 1988; report no. 01/88/1092). The pH-adjusted sample showed a reduced growth inhibition (biomass) compared to the not pH-adjusted test solution (14% inhibition compared to 95% after 72 h).

Based on the available data it can be concluded that the substance is acutely not harmful to aquatic algae with high probability.