Tris(2-ethylhexyl) phosphate

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:

1998-02-23 to 1998-03-31

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP guideline study. The study is a well reported and conducted, it is considered to be al imit test for the substance in question, and is in fact tested above the limit of its solubility.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

Stock solutions of test substance were made by adding 1000 mg of test substance to 2500 mg of dispersant (HCO-40). These were mixed and added to 1000 mL of pure water. Of the stock solution, 200 mL' was added to 5.0 L of dilution water, to make the test solution.

Test organisms (species):

Oryzias latipes

Details on test organisms:

- Name: Oryzias latipes ( orange red-Killifish)
- Source: Fisheries Sankyo Co., Ltd. (Tokyo)
- Date supplied: 1998-01-08
- Mean length (n-10): 2.02 cm (1.75 ~ 2.32 cm), n =10
- Mean weight: 0.142 g (0.078 - 0.238 g), n = 10
- 7 day acclimation period (< 5 % mortality observed)

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Post exposure observation period:

none

Hardness:

63 mg CaCO3/L

Test temperature:

23.4 - 24.0 °C measured at each test vessel at the beginning and the end of the test

pH:

7.0 - 7.7 measured at each test vessel at the beginning and the end of the test

Dissolved oxygen:

5.5 - 8.4 mg O2/L measured at each test vessel at the beginning and the end of the test

Nominal and measured concentrations:

(nominal values) control, vehicle control, 40.0 mg/L. Measured concntrations of test substance were 39.5 mg/L and 39.9 mg/L. Measured did not deviate from nominal by more than 20 %, therefore nominal values were used in data reporting and analysis.

Details on test conditions:

TEST SYSTEM
- Test solution volume: 5.0 L
- Renewal rate of test solution (frequency/flow rate): total amount of test solution every 24 hours
- No. of organisms per vessel: 10 per concentration
- No. of vessels per concentration (replicates): 1
OTHER TEST CONDITIONS
- Photoperiod: 16 hours light - 8 hours dark

Reference substance (positive control):

yes

Remarks:

Copper Sulphate (II)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 40 mg/L

Nominal / measured:

nominal

Remarks on result:

other: Percentages of measurement concentrations for nominal concentrations were within ±20 %. Accordingly, the result was calculated based on nominal concentration

Details on results:

No mortality or abnormal behaviour was observed throughout the test in the control or test substance exposure. There was one mortality at the end of the test in the solvent (dispersent HCO-40) control group.

Results with reference substance (positive control):

0.73 mg/L (95 % C.I. 0.53-1.0 mg/L)

Reported statistics and error estimates:

The median lethal concentration (LC50) could not be calculated because no deaths were observed in the limit test of the maximum dispersible concentration (40.0 mg/L) in water.

Sublethal observations / clinical signs:

Measured concentration of the test substance during a 96 -Hour exposure

Nominal concentration [mg/L]	Measured concentration [mg/L]		Mean measured concentration [mg/L]
	0 hour	24 hour	geometric mean
control	< 0.02	< 0.02	-
solvent control	< 0.02	< 0.02	-
40.0	39.5(99 %)	39.9(100 %)	39.7(99 %)

Validity criteria fulfilled:

yes

Conclusions:

The toxicity to fish (Oryzias latipes) of the test item was determinated at LC50 of > 40 mg/L after 96 hours.

Executive summary:

The acute toxicity of the substance was tested to fish (Oryzias latipes) under semi-static conditions. The study was conducted in accordance with the OECD Guideline for Testing of Chemical No. 203 "Fish, acute toxicity Test" (1997) with minor deviation (i.e. limit test was conducted at test substance limit of solubility with solvent carrier not at 100 mg/L as recommended by the guideline).

After 96 hours of exposure a LC50 was estimated > 40 mg/L.

Description of key information

96 hr LC50 (Oryzias latipes); > 40 mg/L OECD 203; Anon. 1998

Additional information

The key study showed no effects to fish during a 96 hour exposure to the substance at 40 mg/L when utilising a dispersant to maximise solubility in the test medium Anon (1998a). This study was conducted as a limit test at the maximum achievable concentration when utilising a dispersant, which is orders of magnitude higher than the water solubility. It was concluded that the substance is not acutely toxic to fish at the limit of water solubility.

Supporting studies comprise a 14 d test conducted at 40 mg/L displaying no mortality in fish conducted according to the redundant OECD 204 guideline (Anon, 1998b) and a further 2 studies conducted by other international guidelines similar to that of OECD 2003 also showing no mortality at 100 mg/L (96 hr), which is the limit concentration for testing in aquatic toxicity fish testing as per OECD guidelines, and 500 mg/L (48 hr) well over the limit test level.

Due to the substance not causing mortality at, or above, the limit of water solubility the substance was concluded as not acutely toxic to fish and no hazard has been identified for this endpoint in accordance with REACH Annex I (section 3).