Reaction products of monoethanolamine and boric acid (1:3)

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:

July to August 2010

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Analytical monitoring:

yes

Details on sampling:

Frequency at t=0 h and t=48 h
Volume 2 and 4.9 ml from the approximate centre of the test vessels
Storage Samples were stored in a freezer until analysis.

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

Vehicle:

no

Details on test solutions:

The standard test procedures required generation of test solutions, which should contain completely dissolved test substance concentrations or stable and homogeneous mixtures or dispersions. The testing of concentrations that disturb the test system should be prevented (e.g. film of the test substance on the water surface).

The batch of MEA Polyborate 1:3 tested was a clear colourless liquid and completely soluble in test medium at the concentrations tested. The elemental composition of boron in the test substance was determined to be 11.6%. The composition of MEA in the test substance was calculated to be 17.6% (see Appendix VI). The non-water components (regarded as the active ingredient, a.i.) are 68% (w/w) of the test substance.

Preparation started with a concentration of 1000 mg active ingredient (a.i.)/l which corresponds to 1470 mg MEA Polyborate 1:3 per litre. To this end 1.15 ml of the test substance was added to 1000 ml test medium. No other treatment than vigorous shaking was needed to completely dissolve the test substance. The pH of the highest concentration was adjusted from 9.0 to 8.0 in the range-finding test and from 9.1 to 8.0 in the final test with 1M HCl (Merck, Darmstad, Germany). The lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. The final test solutions were all clear and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus, 1820
- Source:In-house laboratory culture with a known history.
- Age at study initiation (mean and range, SD): For the test selection of young daphnids with an age of < 24 hours, from parental daphnids of more than two weeks old.
- Method of breeding: With new-born 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.
- Feeding during test 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 expressed as CaCO3

Test temperature:

18 - 22°C

pH:

7.7 - 8.0

Dissolved oxygen:

8.5 - 8.9 mg/L

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal: 100, 180, 320, 560, 1000 mg/L
Measured: 147, 265, 470, 823, 1470 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml, all glass
- No. of organisms per vessel: 5 per vessel containing 80 ml of test solution
- No. of vessels per concentration (replicates): 4

Composition of medium M7:
Adjusted ISO medium: the following chemicals (analytical grade) are dissolved in tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
Macro salts: CaCl2.2H2O 211.5 mg/l
MgSO4.7H2O 88.8 mg/l
NaHCO3 46.7 mg/l
KCl 4.2 mg/l
Medium M7: trace elements, macro nutrients and vitamins are added to freshly prepared ISO medium to reach the following concentrations:
Trace elements:B 0.125 mg/l
Fe 0.05 mg/l
Mn 0.025 mg/l
Li, Rb and Sr 0.0125 mg/l
Mo 0.0063 mg/l
Br 0.0025 mg/l
Cu 0.0016 mg/l
Zn 0.0063 mg/l
Co and I 0.0025 mg/l
Se 0.0010 mg/l
V 0.0003 mg/l
Na2EDTA.2H2O 2.5 mg/l

Macro nutrients:Na2SiO3. 9H2O 10.0 mg/l
NaNO3 0.27 mg/l
KH2PO4 0.14 mg/l
K2HPO4 0.18 mg/l

Vitamins: Thiamine 75.0 µg/l
B12 1.0 µg/l
Biotin 0.75 µg/l

Reference substance (positive control):

not specified

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

496 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 457 - 563 mg/l

Details on results:

- Mortality of control: 5%

Validity criteria fulfilled:

yes

Remarks:

5% in controls

Conclusions:

Under the conditions of a GLP OECD 202 study MEA Polyborate 1:3, the 48h-EC50 was 496 mg a.i./l based on nominal concentrations (95% confidence interval between 457 and 563 mg a.i./l).

Executive summary:

Acute Toxicity Study in Daphnia magna with MEA Polyborate 1:3. 

The study procedures described in this report were based on the OECD guideline No. 202, 2004. In addition, the procedures were designed to meet the test methods of the Commission Regulation (EC) No 440/2008, Part C.2, 2008 and the ISO International Standard 6341, 1996. 

The test substance, MEA Polyborate 1:3, is a complex multi-component substance (a UVCB or unknown variable complex or biological) substance containing salt and non-salt compounds in rapid equilibrium. The test substance is prepared from monoethanolamine, borate compounds and water. The non-water components (regarded as the active ingredient, a.i.) are 68% (w/w) of the test substance. The batch of test substance used was a clear colourless liquid and completely soluble in test medium at the concentrations tested.

 

Preparation started with a concentration of 1000 mg active ingredient (a.i.)/l which corresponds to 1470 mg MEA Polyborate 1:3 per litre. To this end 1.15 ml of the test substance was added to 1000 ml test medium. No other treatment than vigorous shaking was needed to completely dissolve the test substance. The pH of the highest concentration was adjusted with 1M HCl. The lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium.

A final test was performed based on the results of a range-finding test. Twenty daphnids per group (5 per replicate, 4 replicates) were exposed to a control and concentrations of 100, 180, 320, 560 and 1000 mg a.i./l. The total test exposure time was 48 hours and samples for the analytical confirmation of the exposure concentrations were taken at the start and at the end of the test.

 

Analyses were performed on samples taken from the nominal concentrations of 470, 823 and 1470 mg/l (i.e. 320, 560 and 1000 mg a.i./l). The concentrations of both boron and MEA were determined.

 

Boron analyses: The corresponding nominal concentrations of boron in analysed samples were 55, 96 and 171 mg boron per litre, respectively.

 

Analysis of the samples taken at the start of the final test showed that the actual concentrations were in agreement with nominal, 83-87% of nominal (note that the mean recoveries of the procedural recovery samples were 84-45%). The measured concentrations remained stable during the entire test period (94-102% of initial).

                       

MEA analyses: The corresponding nominal concentrations of MEA in analysed samples were 80, 140 and 250 mg MEA per litre, respectively.

 

Analysis of the samples taken at the start of the final test showed that the actual concentrations were in agreement with nominal, i.e 114-122% of nominal and remained stable during the entire test period (96-103% of initial).

 

Based on these results, the effect concentrations were expressed in terms of the nominal concentrations of the active ingredient.

 

The study met the acceptability criteria prescribed by the protocol and was considered valid.

 

The 48h-EC₅₀was 496 mg a.i./l based on nominal concentrations (95% confidence interval between 457 and 563 mg a.i./l). This value is considered a short-term or acute endpoint under the OECD Guideline.

Description of key information

Under the conditions of a GLP OECD 202 study MEA Polyborate 1:3,the 48h-EC50 was 496 mg a.i./l based on nominal concentrations (95% confidence interval between 457 and 563 mg a.i./l).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

496 mg/L