Reaction products of stearic acid with 2-aminoethanol, maleic anhydride and sodium sulphite

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:

From December 14th, 2017 to APril 12th, 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The test item is a complex substance composed of various organic constituents having substantially different chemical structures. As the potential ecotoxicity of the test item cannot be assigned to a specific constituent, no appropriate analytical method for an accurate analysis could be developed and the biological endpoints were therefore expressed based on nominal test concentrations (loading rates).

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

The initial 0.2 L instead of 0.1 L of the filtrates were discarded for each treatment in an attempt to adapt the filter-conditioning procedure to address a potential adsorptivity of the test item to the filter matrix.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Remarks:

Analytical confirmation of the test concentrations were not performed due to technical reasons. As the test item is a complex substance composed of various organic constituents, no appropriate analytical method for an accurate analysis could be developed.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The test solutions were prepared at nominal loading rates by directly mixing the corresponding amounts of test item in test medium. The test solutions were stirred for 24 h at ambient temperature in the dark using a magnetic stirrer. Thereafter the test solutions were left to settle for at least 20 minutes. All stock solutions were a white suspension. The stock solutions were filtered using a glass fibre filter with an average
retention capacity of 0.4 μm (MN 85/220). The initial 0.2 L of the filtrates were discarded for each treatment. A Tyndall effect was not observed in the respective filtrates. The filtrates were directly used for the test.

The stock solutions were prepared once to prepare the test solutions. The volume of the stock solutions was large enough to prepare the test concentrations and all analytical samples.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Straus).
- Strain/clone: clone M10.
- Source: the organisms were originally supplied by KU Leuven, Belgium. Cultured at ECT Oekotoxikologie GmbH since December 22, 2011.
- Age of parental daphnids: less than 35 d.
- Age of the daphnids at the beginning of the test: less than 24 h.
The selected holding vessels designated for production of the neonates for the test were cleared of all mixed-aged young daphnids on the day before test start. These vessels contained parental daphnids aged less than 35 days. On the day of test start (day 0) all newly produced neonates of these vessels were < 24 hours old. These neonates were collected for the test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg CaCO3/L

Test temperature:

19.7-20.8°C

pH:

7.6-7.8

Dissolved oxygen:

8.1-8.4 mg/L (equivalent to 80-92% air saturation value)

Conductivity:

663 µS/cm

Nominal and measured concentrations:

Nominal concentrations (loading rates): 0.0 (control), 24.9, 49.8, 99.6, 199.2 and 398.4 mg test item/L, equivalent to 0.0 (control), 6.25, 12.5, 25.0, 50.0 and 100.0 mg active ingredients/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers (nominal 100 mL) covered with watch glasses.
- Volume of test solution per test vessel: 50-60 mL.
- Aeration: none.
- Renewal rate of test solution (frequency/flow rate): none (static system).
- No. of organisms per vessel: 5.
- No. of vessels per concentration (replicates): 4.
- No. of vessels per control (replicates): 4.


TEST MEDIUM / WATER PARAMETERS
- Test medium: medium M4 (OECD 2004).
Elendt medium M4 was used to dilute the test item and to keep the daphnids during the period of the test. The medium consists of trace elements, vitamins and macro-nutrients in the following final concentrations (in mg/L):
Trace elements: Macronutrients:
H3BO3 2.86 CaCl2 × 2 H2O 293.8
MnCl2 × 4 H2O 0.361 MgSO4 × 7 H2O 123.3
LiCl 0.306 KCl 5.8
RbCl 0.071 NaHCO3 64.8
SrCl2 × 6 H2O 0.152 Na2SiO3 × 9 H2O 10.0
NaBr 0.016 NaNO3 0.274
Na2MoO4 × 2 H2O 0.063 KH2PO4 0.143
CuCl2 × 2 H2O 0.017 K2HPO4 0.184
ZnCl2 0.013
CoCl2 × 6 H2O 0.010
KI 0.0033 Vitamins:
Na2SeO3 0.0022 Thiamine hydrochloride 0.075
NH4VO3 0.00058 Cyanocobalamin 0.001
Na2EDTA × 2 H2O 2.5 Biotine 0.00075
FeSO4 × 7 H2O 1.0
The required volume of medium was prepared within one month prior to use. During storage, the medium was aerated. Test item dissolved in Medium M4 applied once at the beginning of the test
- Intervals of water quality measurement: at start of the test, after temperature adaptation of the test solutions, and at the end of the test the following parameters were measured and recorded in one replicate test vessel of the control and the highest test concentration: temperature, pH, dissolved oxygen content in % of air saturation value (ASV) and in mg/L.

OTHER TEST CONDITIONS
- Adjustment of pH: none.
- Photoperiod: 16h light/8h dark.
- Light intensity: 50 to 1000 lx.
- Feeding during exposure: none.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
- Biological parameter: immobility.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 398.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Results with reference substance (positive control):

The most recent reference test with potassium dichromate performed in a separate study (Study No. IDA1711, November 2017) resulted in an EC50(24h) of 0.74 mg/L. According to the OECD guideline No. 202 (OECD, April 2004) EC50(24h)-values for potassium dichromate obtained from different laboratories should range between 0.6 mg/L and 2.1 mg/L. The toxicity of the reference item is within this range. Therefore the results of this reference test are acceptable and the test conditions are reliable and the sensitivity of the test system could be demonstrated.

Reported statistics and error estimates:

Determination of ECx based on nominal concentrations (mg/L). Probit analysis.

Biological Results

Sublethal effects on the mobile daphnids were not observed. A summary of the immobility data for Daphnia magna is shown in the following table.

Nominal concentration	Total number of introduced daphnids	Total number of immobile daphnids	Immobile daphnids (% of introduced)	Total number of immobile daphnids	Immobile daphnids (% of introduced)
[Saturated solution at a loading rate of mg test item/L]		[24 h]	[24 h]	[48 h]	[48 h]
Control	20	0	0.0	0	0.0
24.9	20	0	0.0	0	0.0
49.8	20	0	0.0	0	0.0
99.6	20	1	5.0	1	5.0
199.2	20	0	0.0	0	0.0
398.4	20	0	0.0	0	0.0

No clear concentration-response relationship was observed between the control and the saturated solutions at loading rates of 398.4, 199.2, 99.6, 49.8 and 24.9 mg test item. No considerable effect was found up to and including the highest concentration tested. It is therefore concluded that the EC50 of the test item is higher than the highest concentration tested (nominal: a saturated solution at a loading rate of 398.4 mg test item equivalent to 100 mg active ingredients/L).

Validity criteria fulfilled:

yes

Remarks:

All validity criteria were fulfilled as required by the test guideline (immobile daphnids in the control: ≤10%; dissolved oxygen concentration in control and test vessels at the end of the test: ≥3 mg/L).

Conclusions:

No considerable effect was found up to and including the highest concentration tested. The EC50 is higher than the highest concentration tested (loading rate of 398.4 mg test item/L, equivalent to 100 mg active ingredients/L).

Executive summary:

The acute toxicity to the water flea Daphnia magna of the REACH substance "Stearic acid, reaction product with 2-aminoethanol, maleic anhydride and sodium sulfite" (UVCB) was investigated in a GLP-compliant study performed according to OECD Guideline 202. No clear concentration-response relationship was observed between the control and the saturated solutions at loading rates of 398.4, 199.2, 99.6, 49.8 and 24.9 mg test item/L, equivalent to 100, 50, 25, 12.5 and 6.3 mg active ingredients/L. No considerable effect was found up to and including the highest concentration tested. It is therefore concluded that the EC50 is higher than 398.4 mg test item/L, equivalent to 100 mg active ingredients/L.

Description of key information

The acute toxicity to the water flea Daphnia magna of the REACH substance "Stearic acid, reaction product with 2-aminoethanol, maleic anhydride and sodium sulfite" (UVCB) was investigated in a GLP-compliant study performed according to OECD Guideline 202. No clear concentration-response relationship was observed between the control and the saturated solutions at loading rates of 398.4, 199.2, 99.6, 49.8 and 24.9 mg test item/L, equivalent to 100, 50, 25, 12.5 and 6.3 mg active ingredients/L. No considerable effect was found up to and including the highest concentration tested. It is therefore concluded that the EC50 is higher than 398.4 mg test item/L ,equivalent to 100 mg active ingredients/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

One reliable experimental study is available and is selected as key study (ECT, 2018). It was performed according to OECD Guideline 202 and under GLP principles.