L-Threonine, N-coco acyl derivs., monosodium salts

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

other: Read-across information from structurally closely related substance according to REACH Annex XI, 1.5.

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with detailed documentation (read-across: study conducted with a similar substance)

Justification for type of information:

See attached read-across justification

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Fraunhofer IME

Test material

Test material information

Constituent 1

Reference substance name:

Glycine, N-coco acyl derivs., potassium salts

Cas Number:

301341-58-2

Molecular formula:

R-CO-NH-CH2-COOK (Please note: "R-CO-" is a an acyl residue (cocoyl)

IUPAC Name:

Glycine, N-coco acyl derivs., potassium salts

Sampling and analysis

Analytical monitoring:

no

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: 61.81 SAG
- Source (laboratory, culture collection): SAG, Culture Collection of Algae at Pflanzenphysiologisches Institut of the University at Göttingen, Albrecht von Haller Institut, Göttingen, Germany

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

21.5 - 22.0 °C

pH:

Control: 8.31 at test start, 8.17 – 8.63 at test end
Test cultures: initial pH 7.84 - 8.35, at test end 7.95 – 8.61

Nominal and measured concentrations:

50.0, 25.0, 12.5, 6.25 and 3.13 mg/L (nominal concentrations)

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL conical glass flasks
- Type:covered with air-permeable siliconesponge caps
- Initial cells density: 10 000 cells/mL
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 8

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Intervals of water quality measurement: pH measured in one test vessel per test concentration including the control. At the end of the test, the solution pH values were measured directly in test vessels. The test culture temperature was measured in one test vessel only at test start

OTHER TEST CONDITIONS
- Photoperiod: continuous illimination
- Light intensity and quality: 8127 - 8221 lux

EFFECT PARAMETERS MEASURED:
Cell concentrations were determined with an electronic particle counter at test start and after 24, 48 and 72 h

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

15.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI 14.0 - 17.0 mg/L

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

6.32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 95% CI 5.87 - 6.79 mg/L

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

4.45 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI 3.50 - 5.35 mg/L

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.98 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 95% CI 2.49 - 3.40 mg/L

Effect concentrations 5

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: growth rate and yield

Results with reference substance (positive control):

ErC50 2.91 mg/L (95% CI 2.35 - 3.63 mg/L)

Reported statistics and error estimates:

EC50, EC20 and EC10: Probit-analysis assuming log-normal distribution
NOEC and LOEC: ANOVA followed by Williams Multiple Sequential t-test
Computer program ToxRat used for the statistical evaluations

Any other information on results incl. tables

Growth inhibition of 3.10, 11.6, 46.8, 72.5 and 80.7 % was observed at 3.13, 6.25, 12.5, 25.0 and 50.0 mg/L respectively. Yield inhibition of 14.2, 45.6, 91.6, 98.2 and 99.0 % was observed at 3.13, 6.25, 12.5, 25.0 and 50.0 mg/L respectively. There were no compound related visual phytotoxic effects.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of the test item to Pseudokirchnerella subcapitata was investigated in a study conducted according to OECD Guideline 201. The 72 h EC50  (based on growth rate) was determined to be 15.4 mg/L based on nominal concentration.

Executive summary:

The toxicity of the test item to Pseudokirchnerella subcapitata was investigated in a study conducted according to OECD Guideline 201. The 72 h EC50  (based on growth rate) was determined to be 15.4 mg/L based on nominal concentration.