Fatty acids, C18-unsatd., phosphates

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February- May 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)

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures

Version / remarks:

OECD series on testing and assessment number 23, 2000

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 0101891886
- Expiration date of the lot/batch: 02 November 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/vehicle: Not indicated

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
Test item dosing formulations (w/w) were homogenized to visually acceptable levels at appropriate concentrations to meet dose level requirements.

Analytical monitoring:

yes

Details on sampling:

Samples for possible analysis were taken from all test concentrations and the control according to the schedule. In addition, the glasswool containing undissolved residue was kept for possible analysis.

Frequency at t=0 h and t=48 h
Volume 2.7 mL from the approximate centre of the test vessels
Storage Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility.

At the end of the exposure period, the replicates were pooled at each concentration before sampling.

Vehicle:

no

Details on test solutions:

The batch of Fatty acids, C18-unsatd., phosphates tested was a yellow liquid UVCB and not completely soluble in test medium at the loading rates initially prepared. No correction was made for the purity/composition of the test item.
Preparation of test solutions started with loading rates individually prepared at loading rates of 1.0 to 100 mg/L. A two-day period of magnetic stirring was applied to ensure maximum dissolution of the test item in medium. The obtained mixtures were allowed to settle overnight. Thereafter, the aqueous Water Accommodated Fractions (WAFs) were collected by means of siphoning through glass wool and used as test concentrations. All test solutions were clear and colorless at the end of the preparation procedure.
Due to the observed degree of adsorption during the analytical method development, all glassware employed in this study was silanized prior to use.

Test organisms (species):

Daphnia magna

Details on test organisms:

4.7. Test System
Species Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by a cyclical parthenogenesis under specified breeding conditions.
Source In-house laboratory culture with a known history.
Reason for selection This system has been selected as an internationally accepted invertebrate species.
Validity of batch Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.
Characteristics For the test selection of young daphnids with an age of < 24 hours, from parental daphnids of more than two weeks old.
4.8. Breeding
Start of each batch With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel.
Maximum age of the cultures 4 weeks
Renewal of the cultures After 7 days of cultivation half of the medium twice a week.
Temperature of medium 18-22°C
Feeding Daily, a suspension of fresh water algae.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

180 mg/L

Test temperature:

19-20 °C

pH:

7.3-8

Dissolved oxygen:

8.5-9.4

Nominal and measured concentrations:

blank control, 1.0, 10 and 100 mg/l

Details on test conditions:

Test item: WAFs prepared at loading rates of 1.0, 10 and 100 mg/L.
Controls: Test medium without test item or other additives.
Test vessels: 60 mL, all-glass, silanized
Medium: Adjusted ISO medium
Number of daphnids: 20 each in the control and the highest test concentration,
10 per intermediate test concentration.
Loading: 5 per vessel containing 50 mL of test solution
Light: 16 hours photoperiod daily
Aeration: No aeration of the test solutions.
Introduction of daphnids : Within 25 minutes after preparation of the test solutions.
Immobility (including mortality): At 24 hours and at 48 hours.
Dissolved oxygen & pH: At the beginning and at the end of the test, for the highest test concentrations and the control.
Temperature of medium: Continuously in a temperature control vessel, beginning at the start of the test.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7, art. 1.04864, batch no. K44879664). The 24h-EC50 was 0.80 mg/L with a 95% confidence interval between 0.71 and 0.90 mg/L. The 48h-EC50 was 0.33 mg/L with a 95% confidence interval between 0.29 and 0.38 mg/L.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: immobility

Details on results:

The results of analysis of the samples taken during the test are described in Table 3 and Table 4.
Samples taken from the control and the highest test concentration were analysed employing two out of several peaks observed in the chromatograms of the test item.
Based on the peak at m/z 151.0, the concentration at the start of the test was 109 mg/L in the WAF prepared at a loading rate of 100 mg/L. The measured concentration remained stable throughout the test duration, i.e was at 107% of the initial concentrations at the end of the test.
Based on the peak at m/z 391.3, the concentration at the start of the test was 19 mg/L in the WAF prepared at a loading rate of 100 mg/L. At the end of the test, the measured concentration had decreased 13% of the initial concentration.
Following the worst-case assumption, the effect parameters were based on the results obtained for the peak at m/z 391.3. The geometric mean concentration of the highest test concentration was calculated to be 6.9 mg/L and used to determine the effect parameters.

Table 3

Number of Introduced Daphnids and Incidence of Immobility

Time (h)	Replicate	Fatty acids, C18-unsatd., phosphates; WAF loading rate (mg/L)
		Control	1.0	10	100
0	A	5	5	5	5
	B	5	5	5	5
	C	5			5
	D	5			5
	Total introduced	20	10	10	20
24	A	0	0	0	0
	B	0	0	0	0
	C	0			0
	D	0			0
	Total immobilised	0	0	0	0
	Effect %	0	0	0	0
48	A	0	0	0	0
	B	0	0	0	0
	C	0			0
	D	0			0
	Total immobilised	0	0	0	0
	Effect %	0	0	0	0

 

Table 4

Effect Parameters

Parameter	Fatty acids, C18-unsatd., phosphates Average conc. (mg/L)
24h & 48h-EC50	> 6.9

Table 5

pH and Oxygen Concentrations (mg/L)

Fatty acids, C18-unsatd., phosphates Average conc. (mg/L	Start (t=0 h)		End (t=48 h)
	pH	O2	pH	O2
Control	7.8	9.2	8.0	9.4
6.9	7.3	8.5	7.7	9.2

 

Validity criteria fulfilled:

yes

Remarks:

The study met the acceptability criteria : -In the control, no daphnids became immobilised or showed other signs of disease or stress. -The oxygen concentration at the end of the test was ≥3 mg/L in control and test vessels.

Conclusions:

The 48-hour toxicity of water flea (Daphnia magna) to Fatty acids, C18-unsatd., phosphates was determined according to OECD 202 guideline in compliance with GLP. The study was conducted as a limit test and it was based on nominal concentration of 100 mg/l. As a result, EC 50 was determined.
 

Executive summary:

The objective of the study was to evaluate Fatty acids, C18-unsatd., phosphates for its ability to generate acute toxic effects on the mobility of Daphnia magna during an exposure period of 48 hours and, if possible, to determine the EC50 at 24 and 48 hours of exposure. The study procedures described in this report were based on the OECD guideline No. 202, 2004. In addition, procedures were based on the test methods described in the OECD series on testing and assessment number 23, 2000.

The batch of Fatty acids, C18-unsatd., phosphates tested was a yellow liquid UVCB and not completely soluble in test medium at the loading rates initially prepared. Due to the observed degree of adsorption during the analytical method development, all glass ware employed in this study was silanized prior to use. Water Accommodated Fractions (WAFs) were individually prepared at loading rates of 1.0 to 100 mg/L and used as test concentrations.

A combined limit/range-finding test was performed. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control and to a WAF prepared at a loading rate of 100 mg/L, in a limit test. In addition ten daphnids per group (5 per replicate, duplicate) were exposed to WAFs prepared at loading rates of 1.0 and 10 mg/L in the combined range-finding test. The total exposure period was 48 hours and samples for analytical confirmation of exposure concentrations were taken at the start and at the end of the test.  No immobility was recorded in the control or any of the concentrations tested throughout the test duration.  Samples taken from the control and the highest test concentration were analysed employing two out of several peaks observed in the chromatograms of the test item. Based on the peak at m/z 151.0, the concentration at the start of the test was 109 mg/L in the WAF prepared at a loading rate of 100 mg/L. The measured concentration remained stable throughout the test duration, i.e was at 107% of the initial concentrations at the end of the test. Based on the peak at m/z 391.3, the concentration at the start of the test was 19 mg/L in the WAF prepared at a loading rate of 100 mg/L. At the end of the test, the measured concentration had decreased 13% of the initial concentration. Following the worst-case assumption, the effect parameters were based on the results obtained for the peak at m/z 391.3. The geometric mean concentration of the highest test concentration was calculated to be 6.9 mg/L and used to determine the effect parameters.  In conclusion, the 48h-EC50 for Daphnia magna exposed to Fatty acids, C18-unsatd., phosphates was beyond the range tested, i.e. exceeded an average concentration of 6.9 mg/L being considered the maximum soluble concentration of the test item in test medium at a loading rate of 100 mg/L.

Description of key information

The acute test (OECD 202) of water flea (Daphnia magna) to Fatty acids, C-18 -unsatd., phosphates was determined using static test system and it was performed as a limit test using a nominal concentration of 100 mg/l. . The study was conducted according to OECD 202 and followed OECD Principles of Good Laboratory Practice (GLP). No unusual observations or deviations from standard test protocol were noted. As a result, 48-h EC50 was calculated as >100 mg/L.

Based on the available data, the 48-h EC50-value was selected as a key value.

The data obtained from testing on freshwater species has been used as basis for assessment of effects in marine environment as well as for extrapolation of the measured effects to other compartments within the aquatic ecosystem (e.g. sediment) and soil.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

100 mg/L