Tris(2-hydroxyethyl)-1,3,5-triazinetrione

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study under GLP

Remarks:

(as given in OECD SIDS)

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Analytical monitoring:

yes

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Nominal concentrations (as mg/L): 1,000

Measured concentrations (as mg/L): 954 (Day 0)- 927 (Day 3)

Unit [results expressed in what unit]: Cell density (cells/mL)

Element value: ErC50 > 1,000 mg/L (24-72 h); NOEC(r) >= 1,000 mg/L,

EbC50 > 1,000 mg/L (0-72 h); NOEC(b) >= 1,000 mg/L calculated based on nominal concentration.

Was control response satisfactory: Yes: mean cell density increased to 2.78 E6 cells/mL in control after 72 h.

Statistical results: Significant difference was not detected between values at 1,000 mg/L and in control.

 

- Biological observations

· Cell density at each flask at each measuring point: 

   

Nominal Concentration	Measured concentration	Cell concentration for each exposure (x E4 cells/mL)b
(mg/L)	(mg/L)	0 h	24 h	48 h	72 h
Control	-	1.0	5.2±0.2	44.6±4.7	278.3±8.5
1,000	927-954a	1.0	5.6±0.7	46.0±3.1	270.6±10.5

 

a : value at start and end of the test

b : mean ± standard deviation

Growth curves:

Percent biomass/growth rate inhibition per concentration:

1.1 % for area under growth curve (0-72 h) 

2.0 % for growth rate (24-48 h) 

2.5 % growth rate (24-72 h) 

Reference substance result: 72h-EbC50 of potassium bichromate; 0.423 mg/L

Conclusions:

There was no statistical significant difference in inhibition rate compared with the Control, and 72h-EC50 were greater than 1,000 mg/L and 72h-NOEC were more than 1,000 mg/L.

Description of key information

EC50 (growth and biomass) >1000 mg/L, NOEC (growth and biomass) ≥1000 mg/L for Pseudokirchneriella subcapitata (OECD TG 201)

Additional information

Value used for CSA:

EC50/LC50 for freshwater algae: >1000 mg/L

EC10, LC10 or NOEC for freshwater algae: ≥1000 mg/L