Reaction products of 1H-Imidazole-1-ethanol, 4,5-dihydro-, 2-(C11-17 and C17 unsatd. alkyl) derivs. and sodium hydroxide and 2-propenoic acid

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:

2016-05-24 to 2016-09-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

2011

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

All concentration levels and the control were analytically verified via LC-MS/MS at the start (0 hours) and at the end of the exposure (72 hours) with algae.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
Preparation of stock solution: 10 mg test item/L were freshly prepared with dilution water and gently agitated until the solution was visually clear.

A coating phase was carried out. The test container were pre-treated with the appropriate test solutions for 24 hours under test conditions. Before the start of the exposure, the test container were emptied and refilled with freshly prepared test solutions.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Strain: Pseudokirchneriella subcapitata HINDÁK, SAG 61.81
- Source (laboratory, culture collection): Sammlung von Algenkulturen (SAG), Pflanzenphysiologisches Institut der Universität Göttingen, Nikolausberger Weg 18, D-37073 Göttingen
- Age of inoculum (at test initiation): three to four day old preculture, prepared in dilution water
- Method of cultivation:
Fresh stocks are prepared every month on Z-Agar. Light intensity amounted to 35 - 70 µE * m-2 * s-1 for 24 hours per day.
Nutrient medium Z according to LÜTTGE et al. (1994)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

mean 22.3°C (range: 21.5 - 23.0°C)

pH:

7.8 - 8.75

Nominal and measured concentrations:

nominal: 0.10, 0.316, 1.00, 3.16, 10 mg/L
measured (geom. mean): 0.0966, 0.317, 0.878, 2.95, 9.08 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Sterile Erlenmeyer flasks (vol. 250 mL) with cotton wool plugs, test volume: 100 mL
- Aeration: Test containers placed on a rotary shaker and oscillated at approximately 70 rpm.
- Initial cells density: 6305 cells/mL
- Control end cells density: 1859937 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- preparation of dilution water: according to guideline

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 24 h light
- Light intensity and quality: Fluorescent tubes, OSRAM L 36 W/11-865, cool daylight; Approximately 60 - 120 µE * m-2 * s-1; measured: 5328 lux (mean; CV=5.65%)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: fluorimeter
- Chlorophyll measurement: Chlorophyll-a-fluorescence, excitation at 436 nm, emission at 685 nm
- microscopical evaluation at the start and the end of the incubation period: unusual cell shapes, colour differences, differences in chloroplast morphology, flocculation, adherence of algae to test containers and agglutination of algae cells

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.16
- Range finding study
- Test concentrations: 0.1, 1, 10, 100 mg/L
- Results used to determine the conditions for the definitive study: 100% growth rate inhibition at 10 and 100 mg/L, 19% growth rat einhibition at 1 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: 95% ci

Remarks:

2.28 – 2.54 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.494 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: 95% ci

Remarks:

0.437 – 0.557 mg/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.097 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: growth rate, biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.593 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

biomass

Remarks on result:

other: 95% ci

Remarks:

0.531 – 0.659 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.174 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

biomass

Remarks on result:

other: 95% ci

Remarks:

< 0.0966 – 0.227 mg/L

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities: Microscopic evaluation of the cells at the start of exposure revealed no morphological abnormalities. At the end of the exposure, the cells of the nominal concentration levels 3.16 and 10.0 mg/L were partly rounder. The other concentration levels and the control revealed no morphological abnormalities.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: 0.460 mg/L (95% ci 0.443 – 0.481 mg/L)
- valid range: 0.780 ± 0.473 mg/L

Validity criteria:

Validity Criterion	Required	This study
Increase of the cell growth in the control cultures	Exponentially, > 16-fold corresponding to a specific growth rate of 0.92 day^-1	295-fold (specific growth rate 1.90 day^-1)
Mean coefficients of variation for section-by-section specific growth rates (days 0-1, 1-2 and 2-3) in the control cultures	≤35 %	30.3 %
Coefficient of variation of average specific growth rates during the whole test period in replicate control cultures	≤7 %	0.84 %

 

Validity criteria fulfilled:

yes

Conclusions:

The 72 h ErC50 and ErC10 of Amphopropionates C12-18 to Pseudokirchneriella subcapitata were determined to be 2.4 and 0.494 mg a.i./L, respectively.

Executive summary:

In a test conducted according to OECD Guideline 201, the cultures of Pseudokirchneriella subcapitata were exposed to Amphopropionates C12 -18 at nominal concentrations of 0 (control), 0.10, 0.316, 1.00, 3.16, 10 mg a.i./L (corresponsing to geom. mean measured concentrations of 0.0966, 0.317, 0.878, 2.95, 9.08 mg a.i./L) for 72 h under static conditions.The glass walls of the test vessels were saturated with the test solutions prior to initiating the exposure.

The 72 h ErC50 and ErC10 were determined to be 2.4 and 0.494 mg a.i./L, respectively.

Results Synopsis 

Test Organism: Pseudokirchneriella subcapitata 

Test Type: Static

Growth rate:

72 hr ErC50 = 2.40 (2.28 – 2.54) mg a.i./L

72 hr ErC10 =0.494 (0.437 – 0.557) mg a.i./L

72 hr NOEC =0.0966 mg a.i./L

Yield:

72 hr EbC50 =0.593 (0.531 – 0.659) mg a.i./L

72 hr EyC10 = 0.174 (< 0.0966 – 0.227) mg a.i./L

72 hr NOEC = 0.0966 mg a.i./L

(all values refer to geom. mean measured concentations)

Endpoint(s) Effected: growth rate, biomass

Description of key information

72 hr ErC50 = 2.40 (2.28 – 2.54) mg a.i./L

72 hr ErC10 =0.494 (0.437 – 0.557) mg a.i./L

72 hr NOEC =0.0966 mg a.i./L

(OECD TG 201; Pseudokirchneriella subcapitata; RL1; GLP)

Key value for chemical safety assessment

EC50 for freshwater algae:

2.4 mg/L

EC10 or NOEC for freshwater algae:

0.494 mg/L

Additional information

In a test conducted according to OECD Guideline 201, the cultures of Pseudokirchneriella subcapitata were exposed to Amphopropionates C12-18 at nominal concentrations of 0 (control), 0.10, 0.316, 1.00, 3.16, 10mg a.i./L (corresponsing to geom. mean measured concentrations of 0.0966, 0.317, 0.878, 2.95, 9.08 mg a.i./L) for 72 h under static conditions.The glass walls of the test vessels were saturated with the test solutions prior to initiating the exposure.

The 72 h ErC50 and ErC10 were determined to be 2.4 and 0.494 mg a.i./L, respectively.

 

Supporting data are available for the source substances Amphoacetates C8-C18, Amphopropionate C8 and Acrylic acid:

 

In a 72 hour toxicity study, the cultures of Pseudokirchneriella subcapitata, strain CCAP 278/4 were exposed to Amphoacetates C8-C18 at nominal concentrations of 0 (control), 1, 1.9, 32.6, 6.85, 13.05, 24.75, 47.05 and 89.4 mg/L expressed as solid content under static conditions in accordance with OECD guideline 201. Analytical monitoring was not performed.

The 72 h ErC50 was 28.45 mg/L (based on solid content), the 72 h EbC50: 11.3 mg/L (based on solid content), the 72 h NOEC was 3.6 mg/L (based on solid content).

 

In a 72 hour toxicity study, the cultures of Pseudokirchneriella subcapitata, strain 86.81 were exposed to Amphoacetates C8-C18 at nominal concentrations of 0 (control), 6.25, 12.5, 25, 50 and 100 mg/L under static conditions in accordance with OECD guideline 201. Analytical monitoring (TOC analysis) was performed.

The 72 h ErC50 was 10 mg/L (based on solid content), the 72 h EbC50: 7.1 mg/L (based on solid content), the 72 h NOEC was 3.2 mg/L (based on solid content).

 

In a 72 hour toxicity study, the cultures of Desmodesmus subspicatus, strain CCAP 278/4 were exposed to Amphoacetates C8-C18 at nominal concentrations of 0 (control), 0.56, 1.0, 1.8, 3.2, 5.6, 10, 18, 32, 56 and 100 mg/L expressed as solid content under static conditions in accordance with OECD guideline 201. Analytical monitoring was not performed.

The 72 h NOEC, ErC10, EbC10, ErC50 and EbC50 based on solid content were <3.1 mg/L, 6.5 mg/L, 3.4 mg/L, 30 mg/L and 11 mg/L, respectively.

In a 72 hour toxicity study, the cultures of Pseudokirchneriella subcapitata, strain NIVA CHL 1 were exposed to Amphopropionate C8 (50.6% a.i.) at nominal concentrations of 0 (control), 4.6, 10, 22, 46, 100 and 220 mg/L under static conditions in accordance with OECD guideline 201 (adopted March 23, 2006) and EU Method C.3 (1992). Analysis of the samples taken during the final test showed that measured concentrations were stable and in agreement with nominal throughout the 72-hour test period (90-97%). The lowest test group showed a slightly lower recovery between 82 and 86% relative to nominal.

The NOEC and EC50 of Amphopropionate C8 to algae based on growth rate were < 4.6 mg a.i./L and 65 mg a.i./L (95% c.i. 42-99 mg/L). The NOEC and EC50 of Amphopropionate C8 to algae based on cell yield were < 4.6 mg a.i./L and 5.2 mg a.i./L (95% c.i. 4.7-5.7 mg/L).

 

The 72 h NOEC(growth rate), ErC10, ErC50 of acrylic acid to Scenedesmus subspicatus were 0.016 mg/L, 0.03 mg/L and 0.13 mg/L, respectively.