O,O-bis(methylphenyl) hydrogen dithiophosphate

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:

OCT 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Qualifier:

according to guideline

Guideline:

ISO 7346-1 (Determination of the Acute Lethal Toxicity of Substances to a Freshwater Fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] - Part 2: Semi-static method)

GLP compliance:

yes

Remarks:

Chemical analysis was not conducted accroding to GLP

Analytical monitoring:

yes

Details on sampling:

- Sampling method: In order to verify the tested concentrations, samples were collected at test start, before and after renewal of the test solutions and after the end of the test for chemical analysis.
- Sample storage conditions before analysis: The samples were stored at -20 ± 2.0°C until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solutions of 100 mg/L were prepared by weighing out 200 mg of the test product and dissolving it in 2 L of zebra fish test medium, pH was adjusted to 8.0. The test solutions were prepared by diluting the stock solution in the zebra fish test medium. Fresh stock solutions were prepared for renewal for the test solution after 48 hours.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Zebra fish (Danio rerio) was purchased from Credo Fish ApS, Nørresundby, Denmark. The fish had the recommend length (2 ± 1 cm).

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

21.1 - 23.6 °C

pH:

7.6-8.0

Dissolved oxygen:

93-100 %

Nominal and measured concentrations:

Nominal concentrations: 0 (control); 5; 10; 20; 50 and 100 mg/L (based on test material)

The chemical analysis showed that the average measured concentrations were 115-124 % of the estimated nominal concentrations. Since, on average, the measured concentrations were not within ± 20 % of the estimated nominal concentrations, the results are reported as time-weighted avereage measured concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: aquarium
- Material, size, fill volume: Glass, 4 L, 2 litres of test soltion
- Renewal rate of test solution (frequency/flow rate): all test media were renewed after 48 hours.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM
Freshly produced synthetic medium prepared from Milipore water according to the ISO 7346 standard.

OTHER TEST CONDITIONS
- Photoperiod: 14:10 hours

Reference substance (positive control):

yes

Remarks:

48-h test with potassium dichromate (CAS: 7778-50-9)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

27.2 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 22.4 mg/L (nominal)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

42.5 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 35.0 mg/L (nominal)

Details on results:

No mortality was observed in the control; 5; 10 and 20 mg/L groups. Regarding abnormal appearance and behavior, only slight effects (pigmentation ) were observed in suviving fish (10 and 20 mg/L).

Results with reference substance (positive control):

LC50 (48 h) of the reference substance was determined to be 189 mg/L, which is just below the normal range found at DHI (299-400 mg/L). The results indicates a slightly higher sensitivity.

Validity criteria fulfilled:

yes

Conclusions:

LC50 (96 h), Danio rerio, was found to be 27.2 (22.4) mg/L (time weighted average measured concentration, nominal concentration in brackets) for test item.

Executive summary:

Short term toxicity to fish test was done according to OECD Guideline 203 under GLP compliance. Zebra fish (Danio rerio) was used for the test. The LC50 (96 h) of test item was found to be 27.2 (22.4) mg/L (time weighted average measured concentration, nominal concentration in brackets).

Description of key information

Short term toxicity to fish test was done according to OECD Guideline 203 under GLP compliance. Zebra fish (Danio rerio) was used for the test. The LC50 (96 h) of test item was found to be 27.2 (22.4) mg/L (time weighted average measured concentration, nominal concentration in brackets).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

27.2 mg/L