1,2-Pyrrolidinedicarboxylic acid, 4-hydroxy-, 1-(1,1-dimethylethyl) ester, (2S,4R)-

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(2S)-1-(tert-butoxycarbonyl)-4-oxopyrrolidine-2-carboxylic acid

EC Number:

617-556-0

Cas Number:

84348-37-8

Molecular formula:

C10H15NO5

IUPAC Name:

(2S)-1-(tert-butoxycarbonyl)-4-oxopyrrolidine-2-carboxylic acid

Test material form:

solid

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: All concentration levels and the control were analytically verified via HPLC-DAD at the start (0 hours) and at the end of the exposure (72 hours) with algae.
- Sampling method: At the start, samples were taken from one additional replicate of each test item concentration and the control and at the end samples were taken from pooled replicates.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Strain: Pseudokirchneriella subcapitata HINDÁK CCAP 278/4 (axenic)
- Source (laboratory, culture collection): Culture Collection of Algae and Protozoa (CCAP)
SAMS Research Services Ltd; Dunstaffnage Marine Laboratory Dunbeg, OBAN; Argyll PA37 1QA; Scotland, UK

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

34 mg CaCO3/L

Test temperature:

21 - 23°C

pH:

7.17 - 9.3

Conductivity:

136 μS/cm

Nominal and measured concentrations:

Nominal test item concentrations [mg/L]: 0, 4, 12.6, 40, 126, 400
Meas. conc. [mg/L] fresh media, 0 hours: Meas. conc. [mg/L] old media, 72 hours:

Details on test conditions:

TEST SYSTEM
- Test vessel:Sterile glass Erlenmeyer flasks, volume: 250 mL, sealed with cotton wool plugs
- Initial cells density: actual: 5416 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
- Photoperiod: 24 hours/day light
- Light intensity and quality: Approximately 4440 to 8880 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Chlorophyll measurement:Chlorophyll afluorescence, excitation at 436 nm, emission at 685 nm

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

148 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

109 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

40 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

117 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

95.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 6

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

40 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Results with reference substance (positive control):

The toxicity of potassium dichromate to the unicellular freshwater green alga Pseudokirchneriella subcapitata was determined over a period of 72 hours from 2019-10-21 to 2019-10-24. The reference item toxicity is in the valid range which was established by calculation of the average of the historic reference data since 2006, and the limits were set using the threefold standard deviation of these values.
ErC50: 0.940 mg/L 95% confidence interval: 0.732 – 1.33 mg/L
Valid Range: 0.758 ± 0.535 mg/L
EyC50: 0.660 mg/L 95% confidence interval: 0.393 – 0.700 mg/L
Valid Range: 0.414 ± 0.335 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Effect values of the test item on the growth of the freshwater green alga Pseudokirchneriella subcapitata after 72 hours were determined as follows (based on nominal test item concentrations):
The EC50-values for inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were 148 (127 -342) mg/L and 117 (44.4 - 306) mg/L, respectively.
The NOEC for both growth rate and yield was 40.0 mg/L.