Reaction products of decanoic acid and lauric acid with glycerol and polyglycerol

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:

2013-02-25 to 2013-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

23 rd, March 2006 corrected 28th July 2011

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The highest loading (100 mg test item/L) was prepared by dissolving 100.01 mg of the test item in 1000 mL growth medium and stirring for 4 h at room temperature. The other test loadings were prepared by serial dilution of the 100 mg/L solution in growth medium.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Source (laboratory, culture collection): SAG, Culture Collection of Algae at Pflanzenphysiologisches lnstitut of the University at Göttingen, Albrecht von Haller lnstitut, Untere Klarspüle 2, D-37073 Göttingen, Catalog No 61.81 SAG.
- Method of cultivation: The stock cultures are maintained fulfiling the criteria of the OECD guideline (OECD No. 201)

ACCLIMATION
- Culturing media and conditions (same as test or not): identical to test medium

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.0°C

pH:

7.85-7.86 to 8.22-9.02

Nominal and measured concentrations:

0, 6.25, 12.50, 25.00, 50.00 and 100.00 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: conical flasks
- Type: closed with air-permeable silicone-,sponge caps
- Material, size, headspace, fill volume: Glass flasks with 250 mL fill volume, filled with 100 mL test medium
- 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
- Source/preparation of dilution water: All stock solutions and the medium were prepared with purified water processed using an ELGA ‘PURELAB Ultra’.
- Culture medium different from test medium: No

- Light intensity and quality: The culture vessels were continuously illuminated with a light intensity (day light: OSRAM “day light") adjusted to 4440 — 8880 lux close to the surface of the liquid (equivalent to 60- 120 µmol/m²/s²). Light measurements [lux] were made using a cosine (2π) receptor (Ll-189 with radiation sensor, Ll-COR) each day.

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: electronic particle counter (CASY 1 Model TT, Roche Diagnostics GmbH, Germany) or microscopic counting.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study: Non-GLP Study
- Test concentrations: 1, 10, 100 mg/L
- Results used to determine the conditions for the definitive study: Growth rate was maintained until and inhibition occurred at a concentration of 100 mg/L

Reference substance (positive control):

yes

Remarks:

routinely checked with 3,5-dichlorophenol

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): not reported

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: 2.42 (95% confidence limits 1.95 - 3.03 mg/L)

Validity criteria fulfilled:

yes

Conclusions:

The 72 h NOEC of polyglycerin caprylate/caprinate to Pseudokirchneriella subcapitata was 50 mg a.i./L (nominal) based on growth rate and yield.
The 72 hr ErC50 was > 100 mg a.i./L.

Executive summary:

In a 72 hour toxicity study, the cultures of Pseudokirchneriella subcapitata were exposed topolyglycerin caprylate/caprinateat nominal concentrations of 6.25, 12.50, 25.00, 50.00 and 100.00 mg a.i./L under static conditions in accordance with the OECD Test Guideline 201 (2006/2011). 

For growth rate, there was no inhibition above 50 % compared to the controls up to the highest test loading. Therefore, the ErL50 was estimated to be > 100 mg a.i./L. The inhibition of yield was above 50 % compared to the controls at the highest treatment and an EyL50 of 99.8 mg a.i./L was calculated. A NOEL of 50 mg/L was estimated for both growth rate and yield

 

Results Synopsis

Test Organism: Pseudokirchneriella subcapitata

Test Type: Static

72 hr ErC50: > 100 mg a.i./L                95% C.I.:  n.d.

72 h ErC10: not determined

72 hr EyC50: 99.8 mg a.i./L                  95% C.I.:  59.4 – 561 mg a.i./L

72 h EyC10: 11.2 mg a.i./L                   95% C.I.: 0.52 – 22.6 mg a.i./L

72 hr NOEC(yield, growth rate): 50 mg a.i./L          Probit Slope: 1.3478

Endpoint(s) Effected:  growth rate and yield

Description of key information

72 h ErC50: > 100 mg a.i./L; 95% C.I.:  n.d.

72 h ErC10: not demermined

72 h NOEC: 50 mg a.i./L

(OECD TG 201; RL1; GLP: static, Pseudokirchneriella subcapitata)

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

50 mg/L

Additional information

In a 72 hour toxicity study, the cultures of Pseudokirchneriella subcapitata were exposed to polyglycerin caprylate/caprinate at nominal concentrations of 6.25, 12.50, 25.00, 50.00 and 100.00 mg a.i./L under static conditions in accordance with the OECD Test Guideline 201 (2006/2011). 

For growth rate, there was no inhibition above 50 % compared to the controls up to the highest test loading. Therefore, the ErL50 was estimated to be > 100 mg a.i./L. The inhibition of yield was above 50 % compared to the controls at the highest treatment and an EyL50 of 99.8 mg a.i./L was calculated. A NOEL of 50 mg/L was estimated for both growth rate and yield.