O,O,O-triphenyl phosphorothioate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-05-08 to 2002-06-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

No analytical dose verification

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A supersaturated dispersion with a nominal concentration of 100 mg/L was prepared by weighing 549 mg of the test item into 5500 mL test water. No auxiliary solvent or emulsifier was used. The test item was mixed into the test water as homogeneously as possible by ultrasonic treatment for 15 minutes and by intense stirring for 96 hours at room temperature in the dark. Then the supersaturated stock dispersion of the test item was filtered through a membrane filter (Schleicher & Schuell, Type NC45, pore size 0.45 µm) after the 96 hours stirring period just before the start of the test. The undiluted filtrate with the maximum concentration of dissolved test item was used as the only test medium. The test medium was prepared just before introduction of the fish.
- Controls: Blank control with test water only.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): No.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: Zoohaus Schaub, CH-4410 Liestal, Switzerland
- Length at study initiation (length definition, mean, range and SD): 2.9 ± 0.1 cm
- Weight at study initiation (mean and range, SD): 0.16 ± 0.03 g
- Loading: 0.08 g/L
- Feeding during test: None

ACCLIMATION
- Acclimation period: 14 d
- Adaption: 24 hours / no food 24 hours prior to exposure

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

250 mg CaCO3/L

Test temperature:

21°C

pH:

7.9 - 8.0

Dissolved oxygen:

85-86%

Nominal and measured concentrations:

Nominal: 100 mg/L (loading rate of undiluted filtrate)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria filled with 5 liters
- Aeration: none
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: < 1 g/l

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water
- Intervals of water quality measurement: Daily

OTHER TEST CONDITIONS
- Photoperiod: 16 hours daily with a 30 minute transition period (light intensity not reported)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, visible abnormalites, water quality parameters

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LL0

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Remarks:

100 mg/L loading rate WAF

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Remarks:

100 mg/L loading rate WAF

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LL100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Remarks:

100 mg/L loading rate WAF

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: None
- Mortality of control: None
- Other adverse effects control: None
- Abnormal responses: None
- Any observations (e.g. precipitation): Small parts of the test substance were swimming at the surface of the test solution from the start of the test. A slight deposit was observed after 24h exposure.
- Effect concentrations exceeding solubility of substance in test medium: Yes

Validity criteria fulfilled:

yes

Conclusions:

The substance is not acutely harmful to fish up the limit of solubility in water.

Description of key information

The test substance is not acutely harmful to fish up to the limit of solubility in water.

Additional information

Three studies investigating the short-term toxicity of O,O,O-triphenyl thiophosphate to fish are available.

The key study was performed according to GLP and OECD guideline 203 using zebra fish (Brachydanio rerio) as test organism (RCC 2002). Fish was exposed for 96-h to the test item at concentrations of 0 (control, solvent control) and saturation concentration (undiluted filtrate with a nominal loading rate of 100 mg/L) under static conditions. The 96h-LL50 was higher than the saturation concentration. The NOECs, based on mortality and sublethal effects, were ≥ the saturation concentration, respectively. Sublethal effects were not observed.

In addition, the 96-h acute toxicity to zebra fish (Brachydanio rerio) was determined in a supportive non-GLP study performed according to OECD guideline 203 (Ciba-Geigy 1988). In this study test organisms were exposed to test item at nominal concentrations of 0 (control, solvent control), 1.8, 3.2, 5.8, 10, 18, 32, 58 and 100 mg/L for 96-h under static conditions. The 96h-LC50 was determined to be 83 mg/L. The LC0 was 18 mg/L. However, a high vehicle concentration was used, and undissolved test item was observed in concentrations above 18 mg/L. Observed adverse effect could relate to this fact.

A second supporting study was conducted according to OECD guideline 203 with O,O,O-triphenyl phosphorothioate in a lower purity (purity > 25%; RCC 1997). A water accommodated fraction was prepared for the investigation. Zebra fish were used as test organisms and the 96h-LL50 at semi-static exposure was determined to be > saturation concentration (undiluted filtrate of a nominal loading rate of 100 mg/L). No effects were observed up to highest tested concentration and saturation concentration, respectively.

Thus, it can be concluded that the test substance is not acutely harmful to fish up to the limit of solubility in water.