Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

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:
2015-05-04~2015-05-07
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reference:
Composition 1
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes
Test material information:
Composition 1
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Water media type:
freshwater
Total exposure duration:
3 d
Key result
Duration:
3 d
Dose descriptor:
EC50
Effect conc.:
59.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate

Table 2 : Preliminary test for average growth rate

Group

0~3 Day

0~3 Day

Average growth rate

Growth inhibition rate

Control

1.03

0.00

Test group (mg/L)

 

100

0.46

56.82

50

0.54

49.39

25

0.90

12.77

12.5

0.94

8.59

6.25

0.98

4.89

Table 3 : pH value variation of Alga Growth Inhibition experiment

Group

0 Day

3 Day

pH values

Control

8.99 ± 0.02

8.38 ± 0.04

-0.61

Test group (mg/L)

 

100

8.10 ± 0.05

7.95 ± 0.02

-0.15

50

8.16 ± 0.04

7.84 ± 0.03

-0.32

25

8.21 ± 0.07

7.80 ± 0.01

-0.41

12.5

8.48 ± 0.01

8.02 ± 0.06

-0.46

6.25

8.87 ± 0.03

8.30 ± 0.04

-0.57

Table 5 : Average growth rate of Algo Growth Inhibition experiment

Group

Average growth rate

Day 0~1

Day 1~2

Day 2~3

Day 0~3

Control

0.69

1.43

1.18

1.10

Test group (mg/L)

 

 

100

0.00

0.85

0.62

0.49

50

0.00

0.85

0.89

0.58

25

0.69

0.85

1.00

0.85

12.5

0.69

0.98

1.16

0.94

6.25

0.69

1.15

1.17

1.00

Table 6 : Growth inhibition rates of test substances

Test group (mg/L)

Specific growth inhibition rates (%)

EC50 (mg/L)

Day 0~1

Day 1~2

Day 2~3

Day 0~3

100

69.31

57.98

55.65

60.98

59.21

50

69.31

57.98

28.83

52.04

25

0.00

57.98

17.70

25.23

12.5

0.00

44.63

1.63

15.42

6.25

0.00

27.44

0.91

9.45

Validity criteria fulfilled:
yes
Conclusions:
The data in this test were valid and EC50 of the test substance was 59.21 mg/L.
Executive summary:

According to OECD Guideline 201 (Alga, Growth Inhibition Test), EC50 of the test substance was 59.21 mg/L.

Description of key information

EC50 of the test substance was 59.21 mg/L.

Key value for chemical safety assessment

EC50/LC50 for freshwater algae:
59.21 mg/L

Additional information

In Preliminary test, the test substance has been tested in 100 mg/L and the result of test was 56.82% growth inhibition to Pseudokirchneriella subcapitata. The value was less than 75%, so that the highest does of test substance was 100 mg/L. The pH values at 100, 50, 25, 12.5 and 6.25 mg/L were less than ± 1.5. The specific growth rate of control group in this test came up to quality requirements, so that the data in this test were valid. According to OECD Guideline 201 (Alga, Growth Inhibition Test), EC50of the test substance was 59.21 mg/L.