Phosphoric acid, mono and bis-linear butyl esters, potassium salts

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:

14 December 1987 to 18 December 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

verification of test item concentration was not performed

GLP compliance:

yes

Specific details on test material used for the study:

- Purity: 50 % active ingredient
- Lot: 369

Analytical monitoring:

no

Details on sampling:

- Chemical stability of the test material in well-water was not determined.

Vehicle:

no

Details on test solutions:

MATERIALS AND METHODS
- The test material, in original form, was placed into 5 L all-glass aquaria and diluted with laboratory well-water to yield the desired nominal exposure concentrations in 4 L final volumes (liquid depth 12 cm).
- Two identical vessels containing only laboratory well-water were designated as the water controls.

Test organisms (species):

Pimephales promelas

Details on test organisms:

- Juvenille unsexed fathead minnows.
- Haskell bred stock.
- Mean standard length 1.4 cm (range 1.0 to 1.8 cm).
- Mean wet weight 0.030 g (range 0.008 to 0.067 g).
- Fish were maintained for approximately 67 days, with at least 34 days in a 272 L fibreglass tank (84 cm diameter x approximately 49 cm liquid depth) before being used for the test.
- Temperature was within 3 °C of testing temperature throughout the holding period.
- Dissolved oxygen concentration during acclimatisation was assumed to be at or near saturation because air was continuously bubbled through the water.
- No treatment of fish for diseases was required during the holding period.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Hardness:

- EDTA hardness 91 mg/L as CaCO3 based on water control at zero hours.

Test temperature:

21.9 to 22.2 °C

pH:

- Total alkalinity 89 mg/L as CaCO3 based on water control at zero hours.
- pH 6.6 to 7.9 (see Table 2, attached).

Dissolved oxygen:

7.8 to 8.8 mg/L (see Table 2, attached).

Salinity:

Not applicable.

Conductivity:

- 150 μmhos/cm based on water control at zero hours.

Nominal and measured concentrations:

- Nominal concentrations of 412, 588, 840, 1200, 1720, 2450, 3500 and 5000 mg/L.

Details on test conditions:

- Ten fish were randomly placed in the test vessels (two test vessels per concentration).
- Loading was 0.075 g fish/L.
- Fathead minnows were identified by labelling the culture and test vessels.
- Fish were not fed for approximately 48 hours prior to exposure or during the 96-hour exposure period.
- Test solutions were not aerated.
- Temperature was maintained between 21.9 and 22.2 °C.
- Photoperiod was maintained at 16 hours light and 8 hours dark.
- Mortality counts and observations were made approximately every 24 hours during the test.
- Dissolved oxygen and pH were measured in the water control and in the low test concentrations at the beginning of the test and at approximately 24-hour intervals during the 96-hour exposure period.
- Dissolved oxygen and pH were measured in the medium and high test concentrations at the beginning of the test and within one hour after the test was initiated by which time all the fish had died.
- Total alkalinity, hardness (EDTA) and conductivity were measured at the beginning of the test in the water control.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1 300 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % confidence interval 1200 to 1400 mg/L

Details on results:

- Clinical signs seen in some fish exposed to concentrations of ≥ 1200 mg/L included lying on the bottom, erratic swimming, swimming at the surface, darkening colouration, gasping for air and lethargy.

Reported statistics and error estimates:

- The results of LC50 calculations are presented in the table below.
- Concentration data were not altered and the 96-hour LC50 and confidence intervals were calculated by probit analysis (Finney DJ, Probit Analysis, 3rd Ed, Cambridge University Press, 333 pp, 1971).

Sublethal observations / clinical signs:

Table 1 – Results of a 96-hour static acute toxicity test with fathead minnows

Nominal test concentration (mg/L)	Cumulative observed mortality (%)
	24 h		48 h		72 h		96 h
	A*	B*	A*	B*	A*	B*	A*	B*
5000	100	100	100	100	100	100	100	100
3500	100	100	100	100	100	100	100	100
2450	100	100	100	100	100	100	100	100
1720	100	100	100	100	100	100	100	100
1200	10	40	10	40	20	50	20	50
840	10	0	10	0	10	0	10	0
588	0	0	0	0	0	0	0	0
412	0	0	0	0	0	0	0	0
H20 control	0	0	0	0	0	0	0	0

* Replicate exposure chambers containing ten fish each

LC50 calculations

Time	LC50 (mg/L)	95 % confidence limits (mg/L)
		Lower	Upper
24 h	1300	1200	1410
48 h	1300	1200	1410
72 h	1260	1160	1370
96 h	1260	1160	1370

Validity criteria fulfilled:

yes

Conclusions:

The highest test concentration resulting in 0 % mortality was determined to be 588 mg/L and the lowest test concentration resulting in 100 % mortality was determined to be 1720 mg/L. The LC50 (96 h) value was determined to be 1300 mg/L.

Executive summary:

In a study equivalent or similar to OECD 203 fathead minnows were exposed to eight nominal concentrations of test material plus well-water as the control for 96 hours under static conditions. Ten fish were placed into the test chamber for each treatment group and the control group. Nominal concentrations of test item selected were 412, 588, 840, 1200, 1720, 2450, 3500 and 5000 mg/L. Verification of test item concentration was not performed. Clinical signs observed in fish exposed to ≥ 1200 mg/L included lying on the bottom, erratic swimming, swimming at the surface, darkening colouration, gasping for air and lethargy. The highest test concentration resulting in 0 % mortality was determined to be 588 mg/L and the lowest test concentration resulting in 100 % mortality was determined to be 1720 mg/L. The LC50 (96 h) value was determined to be 1300 mg/L.

Description of key information

Highest test concentration resulting in 0 % mortality was determined to be 588 mg/L and the lowest test concentration resulting in 100 % mortality was determined to be 1720 mg/L. The LC50 (96 h) value was determined to be 1300 mg/L (equivalent or similar to OECD 203).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1 300 mg/L

Additional information

In a study equivalent or similar to OECD 203 fathead minnows were exposed to eight nominal concentrations of test material plus well-water as the control for 96 hours under static conditions. Ten fish were placed into the test chamber for each treatment group and the control group. Nominal concentrations of test item selected were 412, 588, 840, 1200, 1720, 2450, 3500 and 5000 mg/L. Verification of test item concentration was not performed. Clinical signs observed in fish exposed to ≥ 1200 mg/L included lying on the bottom, erratic swimming, swimming at the surface, darkening colouration, gasping for air and lethargy. The highest test concentration resulting in 0 % mortality was determined to be 588 mg/L and the lowest test concentration resulting in 100 % mortality was determined to be 1720 mg/L. The LC50 (96 h) value was determined to be 1300 mg/L.