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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
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
2,2'-dithiodi(benzoic acid)
EC Number:
204-352-8
EC Name:
2,2'-dithiodi(benzoic acid)
Cas Number:
119-80-2
Molecular formula:
C14H10O4S2
IUPAC Name:
2-[(2-carboxyphenyl)disulfanyl]benzoic acid
Test material form:
other: Solid
Details on test material:
The test material had a purity of 75.7%

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
-cell density determinations: Coulter counter model ZB counting at lower threshoold equivalent spherical diameter of 2.3um
-sampling interval: 24, 48, 72h

Test solutions

Details on test solutions:
-dose preparation: 1600ml of 96mg/l test substance solution was prepared by direct addition to sterile culture medium. All lower test concentrations were prepared by diluting requisite volume of 96mg/l solution to 1l sterile medium.

Test organisms

Test organisms (species):
Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
-Strain: ATCC22662
- Source (laboratory, culture collection): laboratory culture

Study design

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

Test conditions

Test temperature:
23-25degreesC
pH:
-method: Corning Model 240 pH meter
-4.5-9.6
Nominal and measured concentrations:
-nominal: 0, 0.75, 1.5, 3.0, 6.0, 12, 24, 48, 96mg/l
-measured: 0.94, 1.4, 2.7, 5.7, 12, 30, 41, 60mg/l
Details on test conditions:
-test vessels: 250ml glass beakers containing 100ml test solution
-incubation: continuous "cool-white" illumination with orbital shaking at 160rpm
-replicates/test concentration: 3
-nominal cell density: 1x10E4 cells/ml

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
22 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
34 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
12 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: Biomass and growth rate

Any other information on results incl. tables

Mean cell densities:

Nominal conc (mg/l)

Algal cell density (x10E4 cells/ml)

24h

48h

72h

0

7.7

54.3

237

0.75

7.64

53.0

233

1.5

7.54

56.8

245

3.0

7.24

52.2

233

6.0

7.05

49.8

224

12

6.81

46.5

219

24

4.42

25.2

133

48

1.77

1.67

2.17

96

1.33

1.55

1.45

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72 hour EbC50 for algae is 22 mg/l and the ErC50 is 34 mg/l. The 72 hour NOEC was 12 mg/l.