bis(2-ethylhexyl) 4,4’-{6-[4-tert-butylcarbamoyl)anilino]-1,3,5-triazine-2,4-diyldiimino}dibenzoate

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

Study period:

1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

For the limit test 270 mg was dissolved in 10 mL of DMSO, from which 100 mL was dispersed in one litre of medium, so as to yield a test substance concentration of 2.7 mg/L.

Test organisms (species):

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

Details on test organisms:

The fresh water green alga Selenastrum capricornutum was supplied by the 'American Type Culture
Collection', c/o Sales Department, USA.

Test type:

not specified

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

68 h

pH:

The pH was measured at the start and after 68h in selected cultures. The pH was found to have remained stable during the test (pH 8.2-8.4)

Reference substance (positive control):

yes

Remarks:

K2Cr2O7 and/or 3.5-dichlorophenol

Key result

Duration:

68 h

Dose descriptor:

EC50

Effect conc.:

> 2.7 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Remarks on result:

other: Basis for effect relates also to biomass

Key result

Duration:

68 h

Dose descriptor:

NOEC

Effect conc.:

>= 2.7 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Remarks on result:

other: Basis for effect relates also to biomass

Parameters	Initial nominal conc. of the test substance (mg/L)	Final nominal conc. of the test substance (mg/L)	% Inhibition
Inoculum (10^6 cells/mL)	0.46	0.41	11
Growth rate (h^-1)	0.061	0.063	-3
Area under the growth curve	712	678	5

Validity criteria fulfilled:

yes

Conclusions:

No inhibition of any significance was observed with the test substance. Of the three parameters involved, the effect on the viability of the inoculum was considered less reliable and less relevant than the other parameters.

Description of key information

Freshwater, 68-h ErC50 > 2.7 mg/L (nominal concentrations), Raphidocelis subcapitata, OECD TG 201 and EU method C.3, 1997

Freshwater, 68-h NOErC >= 2.7 mg/L (nominal concentrations), Raphidocelis subcapitata, OECD TG 201 and EU method C.3, 1997

Key value for chemical safety assessment

EC50 for freshwater algae:

2.7 mg/L

EC10 or NOEC for freshwater algae:

2.7 mg/L

Additional information

A GLP limit study on green algae (Raphidocelis subcapitata) is available for this endpoint. The study followed the OECD TG 201 and the EU method C.3 (Reliability 1). The algae were exposed to the test substance at a nominal concentration of 2.7 mg/L with an initial cell density of 1E+06 cells/mL. The test was carried out under the following conditions: temperature 23 ± 1 °C, light intensity within the standard range of 60-120 µmol/s/m2, pH 8.2-8.4. The 68-h ErC50 and NOErC were determined to be > 2.7 and >= 2.7 mg/L, respectively, based on nominal concentrations (1997).