Triphenyl phosphite

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:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: according to guideline and GLP, tested above water solubility, vehicle was used and undissolved particles were observed. Not clear if test substance or undissolved particles caused adverse effects

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Triphenyl phosphite

EC Number:

202-908-4

EC Name:

Triphenyl phosphite

Cas Number:

101-02-0

Molecular formula:

C18H15O3P

IUPAC Name:

triphenyl phosphite

Details on test material:

- Physical state: liquid
- Storage condition of test material: room temperature

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Composite samples (ca 150mL per concentration and control) were taken before exposure and after 72hours exposure, stock solution was taken 24 hours before exposure samples were kept at -18°C- -22°C until analysis

Test solutions

Vehicle:

yes

Details on test solutions:

100.1 mg test substance were mixed with 500mL water containing 2mg/ TWEEN 80 (polyoxyethylen-sorbitan-monooleat) by polytron (5 min) and ultrasonic and then made up with 1000mL water
Calculated amounts of the stock solution and vehicle were given into the water and were homogeneously distributed. The test solutions were equilibrated for 24 hours under test conditions. Algae were the transferredinto the flasks.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Gree algae
- Strain: 61.81 SAG
- Source (laboratory, culture collection): Collection of algae cultures, Pflanzenphysiologisches Institut, University Nikolausberger Weg 18, 37073 Goettingen, Germany
- Age of inoculum (at test initiation):
- Method of cultivation: according to guideline

ACCLIMATION
- Acclimation period: 3 days under test conditions
- Initial cell density: 10600 cells/mL

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

24+-1°C

pH:

7.6-9.0 (Blank 7.9-9.6 vehicle 7.9 - 9.4)
measured after 0 and 72 hours exposure

Nominal and measured concentrations:

nominal: 10, 18, 32, 58, 100 mg/L
measured:
7.8, 15.4, 25.4, 38.7, 94.0 mg/L (start of exposure)
0.28, 0.48, 1.33, 5.9, 36.3 mg/L (end of exposure)


blank: water
vehicle: 2.0mg polyoxyethylen-sorbitan-monooleat (TWEEN 80=/L
The test substance was homogeneously distributed in the test vessels at the start of exposure. Bad test substance distribution was observed at the end of exposure.

Details on test conditions:

3 replicates per test concentration
6 replicates for blank and vehicle control
- cell densities: measured at 24, 48, 72 hours exposure (TOA cell counter)
- Temperature was continuously measured and maintained at 24 ± 1°C.
- ligh conditions: Continuous illumination, cold white fluorescent light, 114 microE/m2 sec
- Vessels: 100 ml Erienmeyer flasks, cotton stoppers, on Lab shaker, 50 ml test solution per flask.

Pretests showed that the EC50 will be between 10 and 100 mg/l,

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72

Dose descriptor:

EC50

Effect conc.:

86 mg/L

Nominal / measured:

meas. (initial)

Basis for effect:

growth rate

Remarks on result:

other: calculated and graphically determined

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

20 mg/L

Nominal / measured:

meas. (initial)

Basis for effect:

biomass

Remarks on result:

other: calculated and graphically determined

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

7.8 mg/L

Nominal / measured:

meas. (initial)

Basis for effect:

growth rate

Remarks on result:

other: calculated

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

7.8 mg/L

Nominal / measured:

meas. (initial)

Basis for effect:

biomass

Remarks on result:

other: calculated

Details on results:

The EC-50 values were calculated according to the maximun likelihood method, logit model (Mc Cullagh, P., Nelder, J.A., 1983: Generalized linear models. Chapman & Hall, London).
EC-values were graphically determined on gausso-Iogarithmic probability paper