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Toxicity to aquatic algae and cyanobacteria

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Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Read-across toxicity studies in algae on one closely structural and physicochemical related substance: OBSH (4,4'-Oxybis (benzenesulfonyl hydrazide)).
For further read-across justification se document attached in section 13
Reason / purpose:
read-across source
Related information:
Composition 1
Reason / purpose:
read-across source
Related information:
Composition 1
Test material information:
Composition 1
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
6.7 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2.2 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
biomass
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
3 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
act. ingr.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.7 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Basis for effect:
growth rate
Conclusions:
Based on read-across to OBSH, the EC50(Pseudokirchnerella subcapitata, growth rate, 72hr) was derived at 3 mg/L and the NOEC(Pseudokirchnerella subcapitata, growth rate, 72hr) was derived at 0.7 mg/L
Executive summary:

Based on read-across to OBSH, the EC50(Pseudokirchnerella subcapitata, growth rate, 72hr) was derived at 3 mg/L and the NOEC(Pseudokirchnerella subcapitata, growth rate, 72hr) was derived at 0.7 mg/L

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted according to OECD Guideline no. 201 and in compliance with GLP
Remarks:
following GLP
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study
Reference:
Composition 0
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Principles of method if other than guideline:
NA
GLP compliance:
yes
Test material information:
Composition 1
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
no data
Analytical monitoring:
yes
Details on sampling:
Test concentrations were measured at the beginning (0 hr) and the end (72 hrs) of the study
Vehicle:
no
Details on test solutions:
Stock solution was prepared by dissolving test chemical with medium. Test solutions were prepared by serial dilution of stock solution and mixed well using a homogenizer.

- Test Design
Nominal concentration: control, 0.4, 0.9, 1.9, 4.2, and 9.3 mg/L
Initial cell density: 1 x 104 cells/mL
Number of Replicate: 3
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Laboratory culture: ATCC culture medium 625 Gorham’s medium
Supplier: American Type Culture Collection, USA
Strain No.: ATCC 22662
Method of cultivation: Sterilization
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Remarks on exposure duration:
OECD media was applied
Post exposure observation period:
no
Hardness:
no data
Test temperature:
21.3 ~ 21.5 °C
pH:
8.25 ~ 9.03 at the beginning and pH 7.87 ~ 7.98 at the end of the test
Dissolved oxygen:
no data
Salinity:
NA
Nominal and measured concentrations:
Nominal concentration: control, 0.4, 0.9, 1.9, 4.2, and 9.3 mg/L
Details on test conditions:
photoperiod: 6,754 ~ 7,248 Lux, Light Periodicity: 24/0 (light/dark)
Initial cell density: 1 x 10^4 cells/mL
Shaking: 100 rpm
replicate: 1
Concentration: control; 0.4; 0.9; 1.9; 4.2 and 9.3 mg/L
spacing factor: 2.2
Analytical monitoring: HPLC with C18 column and DAD G1315 detector
Reference substance (positive control):
not specified
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
6.7 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
1.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
In the stability test, the concentration of OBSH was decreased by 50 % of the initial level (1 mg/L) after 3 hrs in algae media (See 3.1.2.).
According to the result of analytical monitoring, OBSH was not detected in all samples at the end of the test (72 hrs). It was assumed that OBSH was completely degraded and converted to other substances in aqueous solution after 72 hrs. Although several peaks for degraded or transformed products were observed, identification and measurement of them were not performed. Therefore, all test results were expressed as nominal concentrations.
Results with reference substance (positive control):
no data
Reported statistics and error estimates:
Data analysis: The EC50 value (α=0.05) were calculated by Program TOXCALC Version 5.0.12 (Tidepool Scientific Software, USA). NOEC and LOEC were analysed by Dunnett’s test (p < 0.05).
Validity criteria fulfilled:
not specified
Conclusions:
72 hr-EC50 of OBSH to Pseudokirchneriella subcapitata was 6.7 mg/L based on the growth rates. At 72 hrs, NOEC and LOEC were 0.9 and 1.9 mg/L, respectively.
Executive summary:

The toxicity of OBSH towards algae ( Pseudokirchneriella subcapitat) was tested applying the OECD Guideline no. 201. The study was conducted in accordance to GLP. The test was conducted with the nominal concentration: control, 0.4, 0.9, 1.9, 4.2, and 9.3 mg/L.

Based on the endpoint growth rate the 72 hr-EC50 was determined to be 6.7 mg/L. NOEC and LOEC were 0.9 and 1.9 mg/L, respectively.

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
following GLP
Reason / purpose:
reference to same study
Reference:
Composition 0
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Principles of method if other than guideline:
NA
GLP compliance:
yes
Test material information:
Composition 1
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
no data
Analytical monitoring:
yes
Details on sampling:
Test concentrations were measured at the beginning (0 hr) and the end (72 hrs) of the study
Vehicle:
yes
Details on test solutions:
Stock solution was prepared by diluting test chemical in dimethylformamide (100,000 mg/L). Test solutions were prepared by adding the corresponding amounts of stock solution into 1,000 mL of OECD medium. The concentration of solvent was 100 µL/L.

- Test Design
Nominal concentration: control, solvent control, 0.50, 0.82, 1.40, 2.20, 3.70, 6.10, and 10.0 mg/L
Initial cell density: 1 x 104 cells/mL
Number of Replicate: 3
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Laboratory culture: ATCC culture medium 625 Gorham’s medium
Supplier: American Type Culture Collection, USA
Strain No.: ATCC 22662
Method of cultivation: Sterilization
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
no
Hardness:
no data
Test temperature:
23 ± 2 °C
pH:
pH 7.7 ~ 7.8 at the beginning and pH 8.1 ~ 9.4 at the end of the test
Dissolved oxygen:
no data
Salinity:
NA
Nominal and measured concentrations:
Nominal
Concentration (mg/L) Measured Concentration (mg/L)
O hr % of Nominal 72 hrs % of Nominal
Control < 0.01 – < 0.01 –
Solvent control < 0.01 – < 0.01 –
0.50 0.45 90 < 0.01 < 2
0.82 0.70 85 < 0.01 < 2
1.40 1.17 84 < 0.01 < 1
2.20 1.83 83 < 0.01 < 1
3.70 3.11 84 0.04 1
6.10 5.20 85 0.04 1
10.0 8.21 82 0.08 1
Details on test conditions:
Light: 4,000 Lux, Light Periodicity: 24/0 (light/dark)
Shaking: 100 rpm
Reference substance (positive control):
not specified
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
3 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.7 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
NA
Results with reference substance (positive control):
no data
Reported statistics and error estimates:
Data analysis: The EC50 value (α=0.05) was calculated by linear regression analysis. The NOEC were determined by an analysis of variance (ANOVA), Williams test, subsequent to Bartlett test for homogenecity of variances. Statistical analyses were performed using Yukms Stalight #4 software (Yukms Corp., Tokyo) and all tests of significance were at α = 0.05, except Bartlett test, which was at α = 0.01.

Measured concentration of the test substance in test water under the static condition

Nominal

Concentration (mg/L)

Measured Concentration (mg/L)

O hr

% of Nominal

72 hrs

% of Nominal

Control

< 0.01

< 0.01

Solvent control

< 0.01

< 0.01

0.50

0.45

90

< 0.01

< 2

0.82

0.70

85

< 0.01

< 2

1.40

1.17

84

< 0.01

< 1

2.20

1.83

83

< 0.01

< 1

3.70

3.11

84

0.04

1

6.10

5.20

85

0.04

1

10.0

8.21

82

0.08

1

Cell density ofPseudokirchneriella subcapitata(ATCC 22662) during the test

Nominal Conc.

(mg/L)

Measured Con.

(mg/L)

Cell density (x 104cell/mL)

0 hr

24 hrs

48 hrs

72 hrs

Control

Control

1

6.32± 0.48

45.54± 3.7

333.92± 39.23

Solvent control

Solvent control

1

6.78± 0.39

46.87± 0.96

322.92± 5.57

0.50

0.047

1

5.75± 0.31

42.54± 0.85

346.25± 26.41

0.82

0.059

1

5.48± 0.26

38.50± 1.33

313.92± 21.17

1.40

0.076

1

4.54± 0.38

34.77±2.59

279.59± 24.01

2.20

0.096

1

4.25± 0.38

32.54± 1.53

229.59± 23.46

3.70

0.35

1

3.24± 0.15

21.37± 1.31

171.59± 14.64

6.10

0.46

1

2.57± 0.40

15.44± 2.11

131.25± 5.69

10.0

0.81

1

2.22± 0.32

11.08± 2.67

81.15± 34.53

Growth inhibition (%) of Pseudokirchneriella subcapitata

Nominal Conc.

(mg/L)

Measured Con.

(mg/L)

Area under the curve (0~72hrs)

Area

Inhibition(%)*

Control

Control

51,916,000± 5,707,000

-

Solvent control

Solvent control

51,027,000± 677,000

-

0.50

0.047

52,538,000± 2,999,000

-3.0

0.82

0.059

47,627,000± 2,780,000

6.7

1.40

0.076

42,386,000± 3,473,000

16.9**

2.20

0.096

35,780,000± 3,227,000

29.9**

3.70

0.35

25,896,000± 1,661,000

49.3**

6.10

0.46

19,472,000± 1,100,000

61.8**

10.0

0.81

12,331,000± 4,854,000

75.8**

Nominal Conc.

(mg/L)

Measured Con.

(mg/L)

Growth rates

Rate

(24~48 hrs)

Inhibition (%)*

(24~48 hrs)

Rate

(24~72hrs)

Inhibition (%)*

(24~72 hrs)

Control

Control

1.94±0.01

-

0.0826±0.0010

-

Solvent control

Solvent control

1.93±0.01

-

0.0805±0.0016

-

0.50

0.047

1.95±0.03

-3.6

0.0854±0.0015

-6.1

0.82

0.059

1.92±0.02

-0.7

0.0843±0.0022

-4.7

1.40

0.076

1.88±0.03

-5.2

0.0858±0.0020

-6.6

2.20

0.096

1.81±0.03

-5.2

0.0831±0.0004

-3.2

3.70

0.35

1.71±0.03

2.5

0.0827±0.0009

-2.7

6.10

0.46

0.0748±0.0120

7.2

0.0821±0.0041

-2.0

10.0

0.81

0.0664±0.0051

17.6**

0.0735±0.0077

8.7**

Validity criteria fulfilled:
not specified
Conclusions:
72 hr-EC50 of OBSH to Pseudokirchneriella subcapitata was 3.0 mg/L based on the growth rate. At 72 hrs, NOEC was 0.70 mg/L.
Executive summary:

The toxicity of OBSH towards aquatic algae (Pseudokirchneriella subcapitata) was tested applying the OECD Guideline no. 201. The study was conducted in compliance with GLP. The test was conducted with the following concentrations: control, solvent control, 0.50, 0.82, 1.40, 2.20, 3.70, 6.10, and 10.0 mg/L. Based on the results obtained and the nominal concentrations at the initiation of the test an ErC50 (72h) of 3.0 mg/L was calculated. The corresponding NOEC was 0.70 mg/L

Description of key information

 Based on read-across to OBSH, the EC50(Pseudokirchnerella subcapitata, growth rate, 72hr) was derived at 3 mg/L and the NOEC(Pseudokirchnerella subcapitata, growth rate, 72hr) was derived at 0.7 mg/L

Key value for chemical safety assessment

EC50/LC50 for freshwater algae:
3 mg/L
EC10, LC10 or NOEC for freshwater algae:
0.7 mg/L

Additional information

Based on read-across to OBSH, the EC50(Pseudokirchnerella subcapitata, growth rate, 72hr) was derived at 3 mg/L and the NOEC(Pseudokirchnerella subcapitata, growth rate, 72hr) was derived at 0.7 mg/L