Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The 72-h EC50 value and the 72-h NOEC for monoethanolamine in Pseudokirchneriella subcapitata are 2.5 and 1 mg/L respectively. The 3-h toxicity threshold (equivalent to an EC3) for citric acid in Scenedesmus quadricauda is 640 mg/L.
After correction for molecular weight the effect concentrations for tris[(2-hydroxyethyl)ammonium] citrate are 15.4, 6.15 and 1,250 mg/L respectively. The values of 10.4 and 4.14 mg/Lwill be used in the assessment.

Key value for chemical safety assessment

EC50 for freshwater algae:
15.4 mg/L
EC10 or NOEC for freshwater algae:
6.15 mg/L

Additional information

No studies with algae are available for tris[(2-hydroxyethyl)ammonium] citrate. Tris[(2-hydroxyethyl)ammonium] citrate is the neutral salt of monoethanolamine and citric acid. Monoethanolamine and citric acid are the starting materials for the synthesis of tris[(2-hydroxyethyl)ammonium] citrate, and the only difference is that in tris[(2-hydroxyethyl)ammonium] citrate the substances are present in their ionic forms as a monoethanolamine cation and a citrate anion. It is expected that the ecotoxicological properties of tris[(2-hydroxyethyl)ammonium] citrate shall be governed by the properties of monoethanolamine and citric acid (for more details see reporting format for the analogue approach in Appendix A.2).

A GLP-compliant OECD 201 test with Pseudokirchneriella subcapitata is available for monoethanolamine (NITE, 1996b). The72-h EC50 value and the 72-h NOEC for monoethanolamine are 2.5 and 1 mg/L respectively, a safety factor need not to be applied to these values. Instead, the effect concentration will be corrected for molecular weight. The effect concentrations for tris[(2-hydroxyethyl)ammonium] citrate are 15.4 and 6.15 mg/L.

For citric acid a non-GLP growth inhibition study with Scenedesmus quadricauda is available (Bringmann and Kühn, 1977). The 8-d toxicity threshold (equivalent to an EC3 value) is 640 mg/L, a safety factor need not to be applied to this value. Instead, the effect concentration will be corrected for molecular weight. The effect concentration for tris[(2-hydroxyethyl)ammonium] citrate is 1,250 mg/L.

The effect concentrations of 10.4 and 4.14 mg/L will be used in the assessment.