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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report Date:
1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
other: APHA, 1985; US-EPA, 1977; ASTM, 1985
Deviations:
yes
Remarks:
Initial cell density is a factor of 10 below standard guideline recommendations.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): ortho-phenylenediamine
- Storage condition of test material: in amber glass bottle at room temperature in darkness

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Sampling method: duplicate subsamples (10 mL)
- Sample storage conditions before analysis: Placed in plastic, screw top scintillation vial, purged with nitrogen, wrapped in aluminum foil and immediately frozen at -15°C and transported in a cooler with blue-ice to DuPont Haskell Laboratory.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM:
- Source: Culture Collection of Algae, University of Texas, Austin (USA)
- Age of inoculum (at test initiation): 7 days

ACCLIMATION:
- Culturing media and conditions: culturing conditions similar to test conditions

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h

Test conditions

Hardness:
5.3 mg/L CaCO3 (based on nominal Ca- and Mg-content)
Test temperature:
20 ± 2 °C
Nominal and measured concentrations:
Nominal: 0, 0.1, 0.5, 1.0, 5.0, 10.0 mg/L
Measured (day 0): not detected, not detected, 0.28, 0.63, 4.31, 9.32 mg/L
Measured (day 4): not detected, not detected, 0.21, 0.19, 0.07, not detected mg/L
Details on test conditions:
TEST SYSTEM:
- Test vessel:
- Type: closed
- Material, size, headspace, fill volume: 250 mL glass Erlenmeyer flasks covered with inverted 150 mL beakers, and filled with 100 mL test solution.
- Initial cells density: 1000 cells/mL
- Control end cells density: 57667 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

GROWTH MEDIUM:
- Standard medium used: No, Bristol's medium was used instead.
- Detailed composition if non-standard medium was used:
NaNO3: 25 mg/L
CaCl2: 2.5 mg/L
MgSO4.7H2O: 7.5 mg/L
K2HPO4: 7.5 mg/L
KH2PO4: 17.5 mg/L
NaCl2: 2.5 mg/L
FeCl3: 0.5 mg/L

TEST MEDIUM / WATER PARAMETERS:
- Source/preparation of dilution water: Bristol's medium: autoclaved (108 kPa ar 121°C) 48 hours prior to use

OTHER TEST CONDITIONS:
- Sterile test conditions: yes
- Photoperiod: constant illumination
- Light intensity and quality: cool-white fluorescent light, 400 foot candles

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : cell density at end of the test
- Determination of cell concentrations: dual haemocytometer counts

Results and discussion

Effect concentrations
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
0.16 mg/L
Nominal / measured:
nominal
Basis for effect:
growth rate
Details on results:
End parameter used in study was percentage effect based on cell density (no standard parameter).

Any other information on results incl. tables

Table 1

 

Nominal Concentration (mg/L)

Replicate

Number of algal cells per mL after 96-hr exposure

0

1

77000

 

2

50000

 

3

46000

0.1

1

46000

 

2

24000

 

3

57000

0.5

1

0

 

2

0

 

3

0

1.0

1

0

 

2

0

 

3

0

5.0

1

0

 

2

0

 

3

0

10.0

1

0

 

2

0

 

3

0

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
This study established a 96-hr EC50 for o-phenylenediamine of 0.16 mg/L (nominal concentration).
Executive summary:

The test substance was tested for static acute toxicity to the freshwater algae, Selenastrum capricornutum during a 96-hour exposure period at nominal concentrations of 0, 0.1, 0.5, 1.0, 5.0, and 10.0 mg/L. Based on the nominal test concentrations, the test substance was extremely toxic with a 96-hour EC50 of 0.16 mg/L.