Oxirane, reaction products with ammonia, distn. residues

Toxicity to aquatic algae and cyanobacteria

Description of key information

AMIX TE (Oxirane, reaction products with ammonia, distn. residues) is with high probability acutely not harmful to algae.Chronic effects are not expected.

Key value for chemical safety assessment

EC50 for freshwater algae:

311 mg/L

EC10 or NOEC for freshwater algae:

26 mg/L

Additional information

In a GLP study according to OECD 201, the growth inhibition of AMIX TE to unicellular green algae (Desmodesmus subspicatus) was tested. The inhibition of the growth rate was determined to be 72-h ErC50 311 mg/L (measured, geometric mean) (BASF SE, 2010; Project No. 60E0085/10E005). The 72 -h ErC10 was determined to be less than 2.5 mg/L (measured, geometric mean). Since some of the analytically measured concentrations of the test substance in the test solutions deviated more than ±20% of the nominal values, the effect concentrations are based on the mean measured concentrations). The 72-h ErC10 for algae was specified as < 2.5 mg/L as AMIX TE caused an unusually broad and flat concentration response curve (BASF SE, 2010, report no. 60E0085/10E005). Despite the widely spaced concentrations chosen for this study, they did not encompass the range from 5 – 75% inhibition of algal growth, as statistically significant effects on growth rate inhibition were evident in the lowest concentration, test group 2.5 mg/L (measured). Since statistically significant effects were observed at the lowest concentrations, a NOEC value could not be determined. Based on the inhibition of the growth rate, AMIX TE is with high probability acutely not harmful to aquatic algae.

With regard to the chronic toxicity of AMIX TE, a read-across is performed to the main constituent of AMIX TE: 2,2’,2’’-nitrilotriethanol (CAS 102-71-6; typical concentration: 86%). In a study according to the German Industrial Standard DIN 38412-9 with D. subspicatus as test species, the 72-h ErC10 was ≥ 7.9 mg/L with and without adjustment of the pH in the test solutions (not pH-adjusted: 72-h ErC10 = 7.9 mg/L, pH-adjusted: 72 -h ErC10 = 26 mg/L; Amann, 1989).

In two additional studies, the toxicity of 2,2',2''-nitrilotriethanol (CAS 102 -71.6) on mainre algal species was investigated (Libralato et al., 2010; Eide-Haugmo et al., 2009/2012). As the EC50 values were above 100 mg/L, it can be concluded that the substance is with high probability acutely not hramful to marine algae. Long-term effects are not clearly defined (72-h NOEC < 28 mg/L).

It can be concluded that AMIX TE is acutely not harmful to aquatic algae (freshwater and marine). Chronic effects are not expected for freshwater species based on a read-across to 2,2',2''nitrilotriethanol.