o-phenylenediamine

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:

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

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

Test material information

Constituent 1

Reference substance name:

o-phenylenediamine

EC Number:

202-430-6

EC Name:

o-phenylenediamine

Cas Number:

95-54-5

Molecular formula:

C6H8N2

IUPAC Name:

benzene-1,2-diamine

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):

Raphidocelis subcapitata (previous names: Pseudokirchneriella 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.