4,5-dihydroxy-1,3-dimethylimidazolidin-2-one

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:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Test organisms (species):

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

Details on test organisms:

-Test species and strain: Pseudokirchneriella subcapitata KORSHIKOV (SAG 61.81)
- Age (on study day 0): A stock algal culture is maintained continuously at the test facility. Before the exposure an inoculum culture is prepared from the stock culture and incubated for 4 days at 21 – 24 °C (max. temperature difference 2 °C). After this time, the inoculum culture is in exponential growth phase and can be used to initiate the test (study day 0).
- Supplier: Collection of algal cultures in University of Göttingen/Germany

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: Erlenmeyer flasks (nominal volume 250 mL) plugged with gas permeable silicone sponge caps, 100 mL fill volume
- Initial cells density: 0.5 x 104 cells/mL
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6


GROWTH MEDIUM
- USEPA media

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: permanent illumination
- Light intensity and quality: Average 7065 lux (within ±15% variability) at a wave length of 400 - 700 nm

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 293 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: At the nominal concentration of the test substance (293 mg/L) the concentration of the main component is 118 mg/L.

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 293 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: At the nominal concentration of the test substance (293 mg/L) the concentration of the main component is 118 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

In an Algae Growth Inhibition Test according to OECD guideline 201, the EC50 and NOAC were both above 293 mg/L.

Description of key information

EC50 (72 h) > 293 mg/L (nominal, P. subcapitata, OECD 201)

 

At the nominal concentration of the test substance (293 mg/L) the concentration of the main component is 118 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

293 mg/L