Reaction mass of 2,2',2''-nitrilotriethanol and 2,2'-[[2-[(2-hydroxyethyl)amino]ethyl]imino]bisethanol and 2,2'-iminodiethanol

Short-term toxicity to fish

Description of key information

The substance is not harmful to fish, based on results from the two major constituents. The 96 h LC50 value is >1300 mg/L.

Additional information

In the key study for DEA, one of the constituents, a static test according to ASTM-Standard E 729-80, 1980, the acute toxicity of DEA to Pimephales promelas was assessed. Fry (n = 20 per test vessel), juvenile and subadult fish (n = 10 per test vessel) were exposed for 96 hours to various nominal concentrations of DEA and to control water. The stability of the test concentrations was not verified analytically. Dissolved oxygen, pH, and temperature were measured daily. The test concentrations were not adjusted to neutral levels and measured pH values ranged from 8 to 10.5. Therefore, it is likely that alkaline pH-effects might have contributed to the observed mortality. Based on nominal concentrations, the range of the 96 hour LC₅₀values was 1360 - 1630 mg/l for the fry, 1300 - 1990 mg/l for the juveniles and 1200 - 1580 for the subadult fish. The most sensitive result was obtained with the subadult fish (96-hour LC₅₀= 1370 mg/l) and this is selected as the key result for this endpoint. The geometric mean of the 96 hour LC₅₀values was 1460 mg/l (DOW Chemical, 1982a; Mayes et al., 1983).

To determine the toxicity of 2,2’,2’’-nitrilotriethanol to fish, a non-GLP study similiar to APHA method using Pimephales promelas and a flow-through procedure was performed by Geiger et al. (1990). The calculated LC50 value after 96 hours in this study was 11800 mg/l related to the nominal concentrations (confirmed by concentration control analytics). Hence, the chemical is considered to be acutely not harmful for fish.