Triphenyl phosphite

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

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 of each test concentration were drawn by mixing identical volumes of the test solutions taken from the approximate center of the test vessels. They were taken immediately before exposure and after 48 hours exposure and kept at - 18°C to-22"C until analysis.

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Concentration of vehicle in test medium (stock solution and final test solution): 50.9 mg test substance and 2 ml of a TWEEN 80 solution in water (0.1% w/w) were mixed by polytron for 5 minutes and made up to 500 ml with water.

Calculated amounts of the stock solution to produce the desired test concentrations and vehicle to achieve identical vehicle concentrations were given into the
water and were homogeneously distributed. After an equilibration time of 24 hours, the daphnia were transferred into the beakers.

- Evidence of undissolved material (e.g. precipitate, surface film, etc):
The test concentration 10 mg/l was visibly above the limit of solubility. Inspite this fact the test substance was homogeneously distributed in the test vessels at all test times and test concentrations.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Straus 1820
- Source: Ciba-Geigy Ltd testing facility
- Age at study initiation (mean and range, SD): 0-24h (separated 24h before begin of exposure)
- Length at study initiation (length definition, mean, range and SD): 800 microm
- Method of breeding: Cultures of daphnia are maintained in glass vessels containing approx. 2.5 1 of reconstituted water (see below) at 20 ± 1 °C (water is renewed partially thrice weekly). At each renewal the daphnia are fed with a suspension of green algae (Scenedesmus subspicatus) supplemented by a suspension of TETRAMIN-extract in such quantities that the food is consumed after 24h.


Pre-treatment:
24 hours before the begin of the exposure reproductive daphnia are separated from the young by sieving all individuals through a 800 |.im sieve.
This operation is repeated immediately before the exposure and the young (0-24h of age) are retained for the test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

20-23°C

pH:

8-8.1

Dissolved oxygen:

measured at: 0, 48h
99-100%

Nominal and measured concentrations:

nominal: 0.58,1.0,1.8, 3.2, 5.8 and 10 mg test substance/l
measured (start of exposure)0.50, 0.86,1.58, 2.75, 5.12 and 8.54 mg/l
measured (end of exposure): 0.43, 0.74,1.39, 2.51,4.57 and 8.08 mg/l
measured (mean): 0.47, 0.80,1.49, 2.63, 4.85, 8.31 mg test substance /I
blank: water
vehicle: 0.4 mg polyoxy-ethylene-sorbitan-monooleate (TWEEN80)

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers covered with watch glasses
- Fill volume: 100mL
- Aeration: none


TEST MEDIUM / WATER PARAMETERS
reconstituted water containing
65 mg NaHCO3
294 mg CaCl2 x 2 H2O
123 mg MgSO4 x 7 H2O
6 mg KCl
in 1000 ml bidistilled water.
Total hardness: 240 mg CaCOa/l
The water was aerated with clean air for at least 24 hours before use.


- Intervals of water quality measurement: The oxygen content, pH and temperature were measured at 0 and 48 hours.

OTHER TEST CONDITIONS
- Photoperiod: Fluorescent light, 16 hours daily approx. 1500 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobilizations were recorded after 24 and 48 hours exposure

TEST CONCENTRATIONS
- Results used to determine the conditions for the definitive study: Pretests showed that the EC 50 will be between 0.58 and 10 mg/I.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.94 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

mobility

Remarks on result:

other: calculated and graphically determined

Effect concentrations 2

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

16.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

mobility

Remarks on result:

other: calculated

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 8.31 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

mobility

Remarks on result:

other: observed

Effect concentrations 4

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

< 0.47 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

mobility

Remarks on result:

other: observed

Effect concentrations 5

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

< 0.48 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

mobility

Remarks on result:

other: observed

Details on results:

The test concentration 10 mg/l was visibly above the limit of solubility. Inspite this fact the test substance was homogeneously distributed in the test vessels at all test times and test concentrations.

The actual test concentrations were within 80± 20% of the nominal concentrations, therefore following values were calculated based on actual mean
concentrations: 0.47, 0.80,1.49, 2.63, 4.85 and 8.31 mg/l.

The EC-50 values were calculated according to BERKSON,JASA 48 (1953), 569- 599. EC-values were graphically determined on gausso-Iogarithmic paper