2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)-1,3-propanediol hydrochloride

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to section 13 for the read-across justification.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Description of key information

The effect of the read-across substance on algal growth was assessed using the unicellular green alga Raphidocelis subcapitata according to OECD TG 201 showed the following results: The No Observed Effect Concentration (NOEC) was determined to be 100 mg/L and the Lowest Observed Effect Concentration (LOEC) was determined to be >100 mg/L. The 72-h EC50 values based on growth rate and yield were determined to be > 100 mg/L. No abnormal appearance of the algal cells was observed during the experiment (reference 6.1.5 -1).

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

No study data with the test item is available for short-term toxicity to aquatic algae and cyanobacteria. Therefore, a read-across to the read-across substance with a very similar chemical structure and comparable physico-chemical parameters is used to evaluate the potential for short-term toxicity to aquatic algae of the test item.

 

The acute toxicity of the read-across substance was investigated in a GLP-study according to OECD test guideline 201 using unicellular freshwater green alga Raphidocelis subcapitata. At the start and at the end of the test, the content of the read-across substance in the test solutions was determined by HPLC. The recovery after 72 hours was 102 % of the start concentration. Therefore, the determination of the results was based on the nominal concentrations. Exponentially-growing cultures of Raphidocelis subcapitata were exposed to the read-across substance over several generations under defined conditions (static test). The algal growth was determined over a fixed test period of 72 hours in relation to a concurrent untreated control culture. The results of the statistical evaluation showed that the 0-72 h average specific growth rate and yield in the treatment group (100 mg/L) were not statistically significantly different from the untreated concurrent control. All validity criteria were met. Therefore, the study was considered as valid. The No Observed Effect Concentration (NOEC) was determined to be 100 mg/L and the Lowest Observed Effect Concentration (LOEC) was determined to be >100 mg/L (limit concentration). Consequently, the 72-h EC50 values based on growth rate and yield were also > 100 mg/L. As a limit test was performed and as no effects were observed, no further statistical analysis was performed.