Mixed esters of fatty acids C16 and C16-C18 unsatd. with adipic acid and pentaerythritol

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:

2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Examined by chemical analysis (DOC) at 0, 24, 48 and 72 hours.

Vehicle:

no

Details on test solutions:

PRETREATMENT OF TEST ITEM:
- 200.1 mg of the test substance was added to 2 litre of dilution water
- stirred for 24 h on a magnetic stirrer
- undissolved particles of the test item were removed by filtration using a a Sartorius stedim SARTOBRAN 150 sterile Capsule of 0.45 + 0.2 μm pore size
- pH was measured to be pH 7.8

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

- stock culture: non-axenic strain obtained from the Institute of Plant Physiology at the University of Göttingen (Germany); exponentially-growing stock cultures maintained under constant temperature conditions (23 +/- 2 °C), light intensity (60 - 120 µE. x mE-2 x sE-1), cell density measured using a microcell counter

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Hardness:

1.3 °dH, corresponding to 22.5 mg/L CaCO3

Test temperature:

21 -24 °C

pH:

7.9 at 0 hr, 8.1 after 72 hrs

Dissolved oxygen:

No data

Nominal and measured concentrations:

DOC of 100 mg/l test substance:
after 48 hrs: < 2.0 mg/l
after 72 hrs: 2.43 mg/l

Details on test conditions:

TEST SYSTEM:
- test vessels: 300 ml Erlenmeyer flasks with cotton stoppers
- culturing apparatus: light chamber, temperature 21 to 24 °C, continuous uniform illumination (spectral range 400 to 700 nm)
- light intensity: 60 - 120 µE x mE-2 x sE-1 (4000 - 8000 lx)
- test cultures: final cell density 5000 cells/ml
- method of administration: direct weighing
- test concentration: 1 (100 mg/l) plus 1 control
- replicate: 3 (per concentration), 6 (per control)
- test parameter: growth and growth rate
- stability of test concen tration/s during exposure: Examined by chemical analysis (DOC) at 0, 24, 48 and 72 hours

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Effective concentrations were below the detection limit of the DOC determination (< 2 mg/L).

Validity criteria fulfilled:

yes

Remarks:

(biomass parameter measured in the control between 0-72 h > 16; mean of the replicate coeff. of variation in the section-by-section growth rate < 35 %; coeff. of variation of the mean spec. growth rate replicates in the control between 0-72 h < 7 %)

Conclusions:

After 72 hours no toxic effects against algae were observed at a limit test concentration of 100 mg/L.

Executive summary:

The study was conducted in accordance with Commission Regulation (EC) No 761/2009 amending Regulation No 440/2008, Method C.3 which is equivalent to OECD Guideline for Testing of Chemicals No. 201 (2006). Exponentially growing algal cells were exposed for a period of 72 hours to a limit test concentration of nominally 100 mg/L of the test item dissolved in dilution water. Auxiliaries used to prepare the test media were a magnetic stirrer and an aseptic filter. The cell densities were measured at 24 hour intervals. Inhibition of the algal population was measured as reduction in growth rate (index r), relative to control cultures grown under identical conditions. No toxic effects against algae were observed at a limit test concentration of 100 mg/L.

Description of key information

After 72 hours no toxic effects against algae were observed at a limit test concentration of higher than 100 mg/L. The results are expressed in terms of nominal concentrations.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

"Should read: > 100 mg/L"

In 72 h the concentration of the test substance which reduces the growth rate of Scenedesmus subspicatus by 50 % is > 100 mg/l, relating to nominal concentration. The experiment was conducted in accordance with Commission Regulation (EC) No 761/2009 amending Regulation No 440/2008, Method C.3 which is equivalent to OECD Guideline for Testing of Chemicals No. 201 'Alga, Growth Inhibition Test' (2006).

Exponentially growing algal cells were exposed for a period of 72 hours to a limit test concentration of nominally 100 mg/L of the test item dissolved in dilution water. The cell densities were measured at 24 hour intervals. Inhibition of the algal population was measured as reduction in growth rate (index r), relative to control cultures grown under identical conditions. No toxic effects against algae were observed at a limit test concentration of 100 mg/L.

The test item is insoluble or only poorly soluble in water. A suitable selective and sensitive chromatographical method for the determination of the test item in aqueous solutions could not be established. Therefore an accompanying analysis by means of a chromatographical method could not be performed. The quantification of the test item was performed by DOC determination.