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Ecotoxicological information

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:
9. 9. - 27. 9. 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Meets National standards method (ČSN EN ISO).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
ISO 8692 (Water Quality - Fresh Water Algal Growth Inhibition Test with Scenedesmus subspicatus and Selenastrum capricornutum)
Deviations:
yes
Remarks:
In preliminary test was not fulfilled test quality criterion No.1. This deviation has not impact on the test, because result was calculated from limit test.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 1,1,1,2,3-pentachloropropane
- Substance type: organic
- Physical state: liquid
- Analytical purity: 99.940 % (w/w)
- Impurities (identity and concentrations): chlorinated hydrocarbons - 0.048 % (w/w)
- Lot/batch No.: 2-750
- Expiration date of the lot/batch: august 2014
- Storage condition of test material: dry place at room temperature

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
The stock solution of the test substance was prepared in the test medium. 100 mg of the test substance was weighed into 1000 mL of the test medium for the preliminary and limit test. The concentrations of solutions used in the preliminary test were obtained by dilution of the stock solution with test medium.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: Desmodesmus subspicatus
- Strain: Brinkmann 1953/SAG 86.81
- Source (laboratory, culture collection): Botanic Institute of the Czech academy of Science, Třeboň

ACCLIMATION
- Acclimation period: 3 days
- Culturing media and conditions (same as test or not): same as at test

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h

Test conditions

Test temperature:
21 - 24°C
pH:
7.5 - 7.7
Nominal and measured concentrations:
Nominal concentrations:
- preliminary test: 1, 5, 10, 50 and 100 mg/L
- limit test: 100 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer flask
- Material, size, headspace, fill volume: 50 mL of the test solution
- Aeration: no
- Initial cells density: 10000 cells/mL
- Control end cells density: Burker's counting chamber
- No. of vessels per concentration (replicates): 1 (preliminary test), 6 (limit test)
- No. of vessels per control (replicates): 1 (preliminary test), 6 (limit test)

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Conductivity: < 5 µS/cm

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: continuous white light
- Light intensity and quality: 4400 - 8800 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Burker's counting chamber
- Observation intervals: 0, 24, 48 and 72 hours
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
see table No. 1 and 2
Results with reference substance (positive control):
The sensitivity of the test species and correctness of test performance were verified by testing the reference substance, potassium dichromate. The results of the verification test with potassium dichromate are the following:
ErC50 (72 h) = 0.95 mg/L (95% confidence limit: 0.75 – 1.15 mg/L)

From the results of the last interlaboratory test were obtained data for potassium dichromate ErC50 (72 h) generated at 14 laboratories. The following reference range of values could be calculated from those data:
Interlaboratory test data: ErC50 (72 h) = 0.50 – 1.18 mg/L
The value EC50 (72 h) for inhibition of growth rate obtained from thies reference test meets the calculated range from the interlaboratory test.

Any other information on results incl. tables

Table No. 1: Preliminary test

Nominal concentration

(mg/L)

Cell density in 1 mL

Growth rate

0 hours

24 hours

48 hours

72 hours

Mean growth

Reduction (%)

100

10000

12500

62500

331250

1.17

1.0

50

10000

12500

56250

337500

1.17

0.5

10

10000

25000

62500

343750

1.18

0.0

5

10000

25000

62500

337500

1.17

0.5

1

10000

31250

68750

387500

1.22

-3.4

Control

10000

25000

93750

343750

1.18

0.0

Table No. 2: Limit test

Nominal concentration

(mg/L)

Cell density in 1 mL

Growth rate

0-72 h

0 hours

24 hours

48 hours

72 hours

 

mean

100

10000

50000

118750

656250

1.39

1.39

(reduction 2.8 %)

10000

62500

125000

625000

1.38

10000

62500

118750

618750

1.38

10000

62500

137500

556250

1.34

10000

68750

125000

706250

1.42

10000

50000

125000

681250

1.41

Control

10000

43750

106250

681250

1.41

1.43

10000

43750

112500

718750

1.42

10000

50000

100000

675000

1.40

10000

50000

106250

762500

1.44

10000

50000

106250

806250

1.46

10000

43750

187500

687500

1.41

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Alga, Growth Inhibition test was performed according to the standard ČSN EN ISO 8692 (2012), Kvalita vod – Zkouška inhibice růstu sladkovodních zelených řas. The mentioned testing procedure is accredited as test method T20 in the testing laboratory.
The highest inhibition of growth rate was 2.8 % in the limit test for concentration 100 mg/L.
Therefore exact value of ErC50 could not be calculated and the value of EC are given in the form of a range.
ErC50 (72 hour) > 100 mg/L (nominal concentration, growth rate)
Executive summary:

Alga, Growth Inhibition test was performed according to the standard ČSN EN ISO 8692 (2012), Kvalita vod – Zkouška inhibice růstu sladkovodních zelených řas. The mentioned testing procedure is accredited as test method T20 in the testing laboratory.

The highest inhibition of growth rate was 2.8 % in the limit test for concentration 100 mg/L.

Therefore exact value of ErC50could not be calculated and the value of EC are given in the form of a range.

ErC50(72 hour) > 100 mg/L (nominal concentration, growth rate)