Ethyl 3,5-dichloro-4-hexadecyloxycarbonyloxybenzoate

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2003 june 24th to 2003 june 27th

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study performed according to the OECD Guidelines n° 201.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

404-740-9

EC Name:

-

Cas Number:

115895-09-5

Molecular formula:

C26H40Cl2O5

IUPAC Name:

ethyl 3,5-dichloro-4-hexadecyloxycarbonyloxybenzoate

Details on test material:

FC 16
Lot/batch No.: Charge: AF-366
Purity : 99,2 % (according to data of the sponsor)
Water solubility : 0,078 +- 0,041 mg/l (20°C)
Vapor pressure : <= 6,7 x 10-8 Pa (35°C) (according to data of the sponsor)

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Source: non-axenic strain of the species obtained from 'The Collection of Algal Cultures' of the Institute of Plant Physiology at the University of Göttingen (Germany).
Maintenance of stock cultures : exponentially-growing stock cultures are maintained in the test facility under constant temperature conditions (23 +/- 2°C) at a light intensity in the range 60-120 µE. x m-2 x s-1 (measured in the range 400-700 nm using a spherical quantum flux meter). The nutrient medium (according to BRINGMANN & KHÜN 1977) is renewed once a week. Cell density measurements are using a microcell counter.
Preparation of the pre-cultures : pre-cultures are set up three days before the start of a test. They are grown under identical exposure conditions as the stock cultures, except from the use of a different medium.
test cultures : the algal inocula for a test are taken from an exponentially-growing pre-culture and are mixed with the nutrient medium to make up to a final cell density of about 10 4 cells par millilitre in the test medium.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

21 - 25°C

pH:

8.2 - 10.3

Nominal and measured concentrations:

100 mg/l

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

ca. 70 000 other: cells/ml

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

cell number

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

ca. 200 000 other: cells/ml

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

cell number

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC0

Effect conc.:

ca. 313 333 other: cells/ml

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

cell number

Results with reference substance (positive control):

mean cell density
24 hours : 60000 cells/ml
48 hours : 165556 cells /ml
72 hours : 283889 cells/ml

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

No toxic effects against algae at 100 mg/l.
EC0 >= 100 mg/l.