Ethylene di(acetate)

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:

28 Nov - 01 Dec 2000

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

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control, 125 mg/L (nominal) + Light and dark control
- Sampling method: Aliquots of algal test solutions were prepared in 1.5 mL snap-cap polypropylene centrifuge tubes at 24, 48, 72 h.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: One concentration of the test substance was prepared by mixing 84.2 mg of the test substance with 100 mL of algal growth medium. The solution was vacuum-filtered using a sterile filtration unit containing a 0.45 µm nylon membrane filter. The nominal concentration of the test substance in the algal media was 125 mg/L.
- Eluate: no
- Differential loading: no
- Controls: growth medium control

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: SF-3148
- Source (laboratory, culture collection): Obtained from the American Type Culture Collection, Rockville, USA on 3 Jul 1996 and subsequently cultured in the testing facility.
- Age of inoculum: 4 d

ACCLIMATION
- Culturing media and conditions: same as test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

24 °C

pH:

7.36 - 7.63

Nominal and measured concentrations:

Nominal: 125 mg/L
Measured: 119.86 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type: secured with foam stoppers
- Material, size, headspace, fill volume: glass, 250 mL, headspace: 150 mL, fill volume: 100 mL
- Aeration: constantly shaken at 100 rpm
- Initial cells density: approx. 10 E04 cells/mL
- Control end cells density: 7.22 E05 cells/mL (mean from three replicates)
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline OECD 201
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: yes, using NaOH (7.5 ± 0.1)
- Photoperiod: continuous
- Light intensity and quality: 754 ± 13.7 foot-candles

EFFECT PARAMETERS MEASURED
- Determination of cell concentrations: Flasks were swirled to achieve a uniform cell suspension and 4 mL were removed for counting. Cells were counted using a Coulter Counter every 24 h. Prior to perform cell counts, a sample was counted using a haemocytometer and the results were used to calibrate the Coulter Counter.

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 119.86 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 119.86 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 119.86 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 119.86 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes
- Any stimulation of growth found in any treatment: no

Table 1: Summary of analytical results

Nominal concentration	Analyzed concentration [mg/L]
	0 h	24 h	48 h	72 h	mean	% Loss
125	124.93	125.31	121.05	108.87	119.86	12.855
125 (Light control)	124.93	121.54	123.69	121.52	-	2.730
125 (Dark control)	124.93	121.88	123.56	121.43	-	2.802

Description of key information

EC50 (72 h): > 119.86 mg/L for Selenastrum capricornutum (OECD 201)
NOEC (72 h): ≥ 119.86 mg/L for Selenastrum capricornutum (OECD 201)

Additional information

One experimental study investigating the toxicity of ethylene diacetate (CAS 111-55-7) to aquatic algae is available (Hirsch, 2000). The study was performed according to OECD 201 (GLP) with the freshwater green algae Selenastrum capricornutum. One test concentration of 125 mg/L (nominal, limit test) was tested in a static exposure regime. The nominal concentration was measured by GC/FID to express the effect concentrations on measured data. No effects on the growth rate of S. capricornutum were observed resulting in an EC50 (72 h) > 119.86 mg/L (meas. geom. mean) and a NOEC (72 h) ≥ 119.86 mg/L. Deviations between nominal and measured concentrations were < 10% throughout the test.