γ-valerolactone

Toxicity to aquatic algae and cyanobacteria

Administrative data

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: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

γ-valerolactone

EC Number:

203-569-5

EC Name:

γ-valerolactone

Cas Number:

108-29-2

Molecular formula:

C5H8O2

IUPAC Name:

5-methyloxolan-2-one

Sampling and analysis

Analytical monitoring:

yes

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

-Test species and strain: Desmodesmus subspicatus CHODAT (SAG 86.81)
- 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 3 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

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Nominal and measured concentrations:

0 (control), 25, 40, 64, 102.4 and 163.8 mg/L as nominal
concentrations based on test substance mass without correction for
purity.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable):
- 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): 3
- No. of vessels per control (replicates): 6


GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8
- Light intensity and quality: Average 4900 lux (within ±15% variability) at a wave length of 400 - 700 nm

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 161 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 161 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

At start of exposure all measured concentrations of the test
substance in the test water were within ±20% of the nominal
concentration in all tested concentrations. The measured
concentrations of the test substance in the abiotic replicates in test
water were within ±20% of the nominal concentration in all tested
concentrations of the nominal concentration at start of exposure
and decreased in the lowest test concentration to 76 % of the
nominal concentration at the end of exposure most likely due to
binding of the test substance to the algal cells.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes