Reaction mass of orthophosphoric acid and potassium dihexadecyl phosphate and dipotassium hexadecyl phosphate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From February 29, 2000 to April 04, 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

no analytical monitoring was performed

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Remarks:

but visual observation of test solutions

Details on sampling:

- At the start and at the end of the experiment.
- Test solutions at 0, 1, 10 and 100 mg/L

Vehicle:

yes

Details on test solutions:

The 100 mg/L nominal stock solution was prepared by dosing 0.1 mL of acetone to 100 mg of test substance and adding to 1 L of dilution water. To further aid dissolution the stock solution was stirred for approximately 3 h and sonicated for approximately 30 minutes. The 1 and 10 mg/L test media were prepared by dilution of the 100 mg/L test medium. Two control treatments were prepared, one containing acetone at the same concentration as (be test media (0.1 mL/L) and one containing water only. At the start of the exposure period the control, solvent control and 1 mg/L, test treatments were clear and colourless and remained so for the duration of the study. At the start of the exposure period the 10 and 100 mg/L treatments were pale white and while hazy dispersions respectively with undissolved test material present. At the end of the exposure period both the 10 and 100 mg/L test treatments were colourless with undissolved test material present on the base of the test vessels.

Test organisms (species):

Daphnia magna

Details on test organisms:

Test organisms:
- Age at study initiation: < 24 h old
- Number of animals per conditions: 10
- Into duplicate glass crystallising dishes (with about 100 mL test medium)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

No

Hardness:

216 - 221 (mg CaCO3/L)

Test temperature:

19.4 - 20.4°C

pH:

7.7 - 8.2

Dissolved oxygen:

86 - 93% (% air saturation value)

Nominal and measured concentrations:

0 (acetone + water and water alone), 1, 10 and 100 mg/L nominal

Details on test conditions:

Duplicates

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Daphnid immobilisation after 24 and 48 h: no
- Mortality of control: 0%

Immobility of D. magna exposed to the test substance

Nominal concentration (mg/L)	Number of D. magna	Number of immobilised
		24 h	48 h
Control	10	0	0
1	10	0	0
10	10	0	0
100	10	0	0

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 48h EC50 (Daphnia magna) for the test substance was determined to be >100 mg/L.

Executive summary:

A study was conducted to determine the acute toxicity of the test substance, 'mono- and di- C16 PSE, K+ and H3PO4' (purity not specified) to Daphnia magna, according OECD Guideline 202, in compliance with GLP. Ten Daphnia magna were exposed to the test substance at concentrations of 0 (control: acetone + water or water alone), 1, 10 and 100 mg/L for 48 h under static conditions. No analytical monitoring was performed. The test solutions were evaluated by visual observation at the start and at the end of the experiment. D. magna were observed 24 and 48 h after treatment for mobility. D. magna were considered to be immobile if they did not swim during a 15 s period of observation. No immobilised animals were reported in the control group or in the test group. Under the study conditions, the 48h EC50 value was determined to be >100 mg/L (nominal) (Covance, 2000).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From January 02, 2018 to January 04, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

High-performance liquid chromatography (HPLC)

Details on sampling:

To demonstrate that nominal exposure concentrations were being achieved the concentrations of test substance in the test vessels were measured using the high-performance liquid chromatography method. At study start, samples were taken from excess test solutions and at study end from the test vessels of the dilution water control, solvent control and each test concentration.

Vehicle:

yes

Remarks:

Water

Details on test solutions:

The study was run with a dilution water control and nominal exposure concentrations of 0.625, 1.25, 2.5, 5 and 10 mg/L. A primary stock concentrate of Test substance, with a nominal concentration of 10 mg/L, was prepared by adding a nominal 0.020 g of test substance (actual weight 0.02015 g) and making up to 2000 mL volume with dilution water in a volumetric flask. The stock was sonicated for 45 minutes and the resultant stock observed to be a homogenous, colourless dispersion with fine particles visible. The stock was used directly as the 10 mg/L test solution and used to prepare the other test solutions by the direct addition of the appropriate amount to dilution water in a volumetric flask. The control consisted of dilution water only. All test solutions were clear and colourless. In all cases the final solutions contained nutrients.

Test organisms (species):

Daphnia magna

Details on test organisms:

The test organism was the freshwater crustacean, Daphnia magna, obtained from continuous laboratory cultures held at Scymaris. The stock cultures of D. magna were maintained in a reconstituted water medium, the same as the test dilution water, at a temperature of 20 ± 2°C. The cultures were maintained in 2 L glass vessels with a working volume of 1.6 L. A photoperiod of 16 h light:8 h dark, with 20-minute transition periods was provided. The D. magna cultures were fed on a mixed algae diet of Chlorella vulgaris, strain CCAP 211/12 and Pseudokirchneriella subcapitata, strain CCAP 278/4. The D. magna cultures were fed a daily ration depending on the age and density of the culture. Culture conditions were such that the D. magna reproduction was by diploid parthenogenesis. D. magna <24 h old, obtained from a single culture vessel, were used for testing. The parent animals were 28 ± 1 d old and had been maintained with a twice weekly renewal of reconstituted water medium since birth. The test organisms and the culture from which they were obtained showed no evidence of disease before the test period.

Test type:

static

Water media type:

other: Elendt's M4 D. magna medium

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20±1°C

pH:

7.92 to 8.03

Dissolved oxygen:

8.97 to 9.44 mg/L

Nominal and measured concentrations:

Control and 0.625, 1.25, 2.5, 5 and 10 mg/L (nominal)
Control and 0, 0, 0, 0.21 and 0.34 mg/L (measured)
A 10 mg/L test concentration was selected as the highest concentration based on the dispersibility observed in a non-GLP range finding test

Details on test conditions:

Apparatus
Glass beakers of 250 mL nominal capacity were used as test vessels, with four replicates per test concentration. Each vessel contained 200 mL of test solution providing a depth of approximately 60 mm. The beakers were covered with loose fitting glass lids. The positions of the treatments were randomly allocated within the test area.

Reference substance (positive control):

no

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.34 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Remarks on result:

other: Calculation method: Direct observation from data

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.34 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Remarks on result:

other: Calculation method: Direct observation from data

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

ca. 0.34 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 0.34 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Details on results:

Analytical data
The limit of quantification (LOQ) in this study was 0.4 mg/L for all test solutions. The instrument LOQ was 0.2 mg/L but during analysis, samples from the control and each test concentration were diluted x2, doubling the LOQ. Analytical calibrations were constructed using a minimum of 5 calibration levels, with a minimum R2 value of 0.995. The maximum percentage difference from nominal concentration for standards at the LOQ is less than 20% and less than 15% at levels greater than the LOQ. All analytical values are quoted to two significant figures and percentages to the nearest integer. On the basis of the analytical data the mean measured concentrations were used for the calculation and reporting of results.

Biological data
Based on immobility compared to the control (p <0.05) the 48 h No Observed Effect Concentration (NOEC) was determined to be 0.34mg/L and the Lowest Observed Effect Concentration (LOEC) was >0.34 mg/L. There was no immobility observed in the dilution water control. No other symptoms of toxicity were observed. It was observed that test substance was visible on the surface of the test vessels as a raft of fine particles at 24 h and 48 h in a dose dependant amount.

Table 1: Analytical results

Nominal concentration of test substance (mg/L)	Measured concentration of test substance (mg/L)				Mean measured concentration (mg/L)	Mean measured concentration (%)
	0 h		48 h
	(mg/L)	% of nominal	(mg/L)	% of nominal
Control	<LOQ	-	<LOQ	-	0	-
0.625	<LOQ	-	<LOQ	-	0	0
1.25	<LOQ^a	-	<LOQ^b	-	0	0
2.5	<LOQ	-	<LOQ	-	0	0
5	0.43	9	<LOQ	-	0.21	4
10	0.68	7	<LOQ	-	0.34	3

All analytical measurements quoted to 2 significant figures. Arithmetic means are used due to the zero values present.

^a Mean of triplicate analyses: <LOQ, <LOQ, <LOQ mg/L.

^b Mean of triplicate analyses: <LOQ, <LOQ, <LOQ mg/L.

The limit of quantification (LOQ) in this study was 0.4 mg/L for all test solutions. The instrument LOQ was 0.2 mg/L but during analysis, samples from the control and each test concentration were diluted ×2, doubling the LOQ. Values in Table 1 have been corrected for these dilutions.

Table 2: Daphnia magna response

Time (h)	Nominal concentration of test substance (mg/L)	Mean measured concentration of test substance (mg/L)	Number immobilised per replicate				Total number tested	Total number immobilised	Percentage immobilised
			A	B	C	D
24	Control	0	0	0	0	0	20	0	0
	0.625	0	0	0	0	0	20	0	0
	1.25	0	0	0	0	0	20	0	0
	2.5	0	0	0	0	0	20	0	0
	5	0.21	0	0	0	0	20	0	0
	10	0.34	0	0	0	0	20	0	0
48	Control	0	0	0	0	0	20	0	0
	0.625	0	0	0	0	0	20	0	0
	1.25	0	0	0	0	0	20	0	0
	2.5	0	0	0	0	0	20	0	0
	5	0.21	0	0	0	0	20	0	0
	10	0.34	0	0	0	0	20	0	0

Validity criteria

As no immobility or other signs of stress were observed in the control and dissolved oxygen concentration remained at ≥3 mg/L, this test has satisfied all OECD Guideline 202 validity criteria.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 48 h EC50 of the test substance for Daphnia magna was determined to be >0.34 mg/L (measured).

Executive summary:

A study was conducted to determine the acute toxicity of test substance, ‘mono- and di- C16 PSE, K+ and H3PO4’ (purity: 100 %), toDaphnia magna, according to OECD Guideline 202, in compliance with GLP. Twenty test organisms were exposed to each nominal test substance concentrations of 0, 0.625, 1.25, 2.5, 5 and 10 mg/L for 48 h under static conditions. The concentrations of test substance in the test vessels were measured at start (0 h) and end of the test (48 h), using the HPLC method. Except for the measured values of the top 2 test concentrations at 0 h (i.e., 0.43 and 0.68 mg/L), the remaining measurements at 0 and 48 h were found to be below the limit of quantification (LOQ). Therefore, the test concentrations were presented as mean measured concentrations i.e., 0, 0, 0, 0, 0.21 and 0.34 mg/L. Immobilisation was recorded at 24 and 48 h and compared with control values. Based on immobility compared to the control (p <0.05), the 48 h NOEC was determined to be 0.34 mg/L (measured) and the LOEC was >0.34 mg/L (measured). No other symptoms of toxicity were observed. Based on the study results, the 48 h EC50 was calculated to be >0.34 mg/L (measured). As no immobility or other signs of stress were observed in the control and dissolved oxygen concentration remained at ≥3 mg/L, this test had satisfied all validity criteria. Under the study conditions, the 48 h EC50 of the test substance for toxicity toDaphnia magnawas determined to be >0.34 mg/L (measured) (Scymaris, 2018).

Description of key information

Based on the results of the studies, the 48 h EC50 of the test substance for Daphnia magna was determined to be >0.34 mg/L (measured).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.34 mg/L

Additional information

Study 1:

A study was conducted to determine the acute toxicity of the test substance, 'mono- and di- C16 PSE, K+ and H3PO4' (purity not specified) to Daphnia magna, according OECD Guideline 202, in compliance with GLP. Ten Daphnia magna were exposed to the test substance at concentrations of 0 (control: acetone + water or water alone), 1, 10 and 100 mg/L for 48 h under static conditions. No analytical monitoring was performed. The test solutions were evaluated by visual observation at the start and at the end of the experiment. D. magna were observed 24 and 48 h after treatment for mobility. D. magna were considered to be immobile if they did not swim during a 15 s period of observation. No immobilised animals were reported in the control group or in the test group. Under the study conditions, the 48h EC50 value was determined to be >100 mg/L (nominal) (Covance, 2000).

Study 2

A study was conducted to determine the acute toxicity of test substance, ‘mono- and di- C16 PSE, K+ and H3PO4’ (purity: 100 %), toDaphnia magna, according to OECD Guideline 202, in compliance with GLP. Twenty test organisms were exposed to each nominal test substance concentrations of 0, 0.625, 1.25, 2.5, 5 and 10 mg/L for 48 h under static conditions. The concentrations of test substance in the test vessels were measured at start (0 h) and end of the test (48 h), using the HPLC method. Except for the measured values of the top 2 test concentrations at 0 h (i.e., 0.43 and 0.68 mg/L), the remaining measurements at 0 and 48 h were found to be below the limit of quantification (LOQ). Therefore, the test concentrations were presented as mean measured concentrations i.e., 0, 0, 0, 0, 0.21 and 0.34 mg/L. Immobilisation was recorded at 24 and 48 h and compared with control values. Based on immobility compared to the control (p <0.05), the 48 h NOEC was determined to be 0.34 mg/L (measured) and the LOEC was >0.34 mg/L (measured). No other symptoms of toxicity were observed. Based on the study results, the 48 h EC50 was calculated to be >0.34 mg/L (measured). As no immobility or other signs of stress were observed in the control and dissolved oxygen concentration remained at ≥3 mg/L, this test had satisfied all validity criteria. Under the study conditions, the 48 h EC50 of the test substance for toxicity toDaphnia magnawas determined to be >0.34 mg/L (measured) (Scymaris, 2018).