Reaction mass of 2,2'-[methylenebis(oxymethylene)]bis[2-ethylpropane-1,3-diol]and propylidynetrimethanol and 2,2'-[oxybis(methylene)]bis[2-ethylpropane-1,3-diol]

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:

07 Dec 2020 - 25 Jan 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Guideline study to GLP standards with no deviations

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Commission Regulation (EC) No. 440/2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: A stock solution containing 100.4 mg/L test item in M4-medium was prepared. The lower treatments (4.6 / 10 / 22 / 46 mg/L nominal) were prepared by dilution of this stock solution with M4-medium.
- Sampling method: QC samples (11 mg/L)
- Sample storage conditions before analysis: closed vessel at room temperature (17.3 –23.0 °C).

Vehicle:

no

Details on test solutions:

Before measurement, the taken samples of the concentrations 22 / 46 / 100 mg/L were diluted with demineralised water as follow: 500 μL of the sample with a concentration of 22 mg/L was diluted with 500 μL demineralised water (2-fold dilution). 250 μL of the sample with a concentration of 46 mg/L was diluted with 750 μL demineralised water (4-fold dilution). 500 μL of the sample with a concentration of 100 mg/L was diluted with 500 μL demineralised water (2-fold dilution). Afterwards, 250 μL of this solution was diluted with 750 μL of demineralised water (8-fold dilution at the end).

Test organisms (species):

Daphnia magna

Details on test organisms:

The test was carried out using first instar Daphnia magna derived from in-house laboratory cultures.

Adult female daphnids were maintained in glass vessels containing Elendt M4 medium in a temperature controlled room maintaining the water temperature at 18 to 22 °C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with neon LED's. Each culture was fed with a mixture of algal suspension (Desmodesmus subspicatus). Culture conditions ensured that reproduction was by parthenogenesis. 18.75 hours before the start of the test, the adult animals were separated from the young. 0.75 hours before the test start, adults were caught with the help of a glass tube. Newborn daphnia (age < 24h) were sieved from the medium and immediately placed into a beaker containing dilution water. After the acclimation period, animals which showed no apparent damage were used for the test. The diet and diluent water are considered not to contain a contaminant that would affect the integrity or outcome of the study.

Test type:

flow-through

Water media type:

other: Reconstituted water (Elendt M4 medium)

Remarks:

The test item was melted in a water bath (max. 80°C) until it was liquid. A stock solution containing 100.4 mg/L test item in M4-medium was prepared. The lower treatments were prepared by dilution of this stock solution with M4-medium.

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

Observations at 24 and 48h

Hardness:

294 mg/L as CaCl2*2H2O

Test temperature:

20.0 – 20.4 °C

pH:

7.5-7.9

Dissolved oxygen:

8.6-8.9 mg O2/L

Salinity:

Not applicable

Conductivity:

Not stated

Nominal and measured concentrations:

4.6 / 10 / 22 / 46 / 100 mg/L (nominal concentration)
The concentrations tested are based on the result of a non-GLP pre-test.

Details on test conditions:

TEST SYSTEM
- Test vessel: 50mL glass
- Volume of solution: 20 ± 5 mL
- No. of organisms per vessel: five daphnids
- No. of vessels per concentration/control (replicates): Four replicate test and control vessels

TEST MEDIUM / WATER PARAMETERS
CaCl2.2H2O 293.8 mg/L
MgSO4.7 H2O 123.3 mg/L
NaHCO3 64.8 mg/L
KCl 5.8 mg/L
Na2SiO3.9 H2O 10.0 mg/L
NaNO3 0.274 mg/L
K2HPO4 0.184 mg/L
KH2PO4 0.143 mg/L
H3BO3 2.8595 mg/L
Na2EDTA.2 H2O 2.50 mg/L
FeSO4.7 H2O 0.9955 mg/L
MnCl2.4H2O 0.3605 mg/L
LiCl 0.306 mg/L
SrCl2.6 H2O 0.152 mg/L
RbCl 0.071 mg/L
Na2MoO4.2 H2O 0.0615 mg/L
CuCl2.2 H2O 0.0165 mg/L
NaBr 0.0160 mg/L
ZnCl2 0.0130 mg/L
CoCl2.6 H2O 0.010 mg/L
KI 0.00325 mg/L
Na2SeO3 0.00219 mg/L
NH4VO3 0.000575 mg/L
Thiamine hydrochloride 0.075 g/L
Cyanocobalamine 0.0010 g/L
D(+) biotin (Vitamin H) 0.00075 g/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

None of the animals were immobilised in the blank control. The highest tested concentration showed 5 % immobilisation, but this could be stated as not significant. Only one daphnia died in the highest tested concentration of 100 mg/L and it is not clear if this is a reaction on the test substance or only a biological reason. Therefore, 5 % immobilisation is considered not significant.

No sub-lethal effects of exposure were observed throughout the test in the test groups, however, one daphnid from the control and solvent control was observed to be coated in algae at 48 hours.

The test was considered to be valid given that less than 10% of the control and solvent control daphnids showed immobilization or other signs of disease or stress and that the oxygen concentration at the end of the test was equal to or greater than 3 mg/L

Temperature was maintained at approximately 19C to 20C throughout the test, while there were no treatment related differences for oxygen concentration or pH in the control and test vessels

At the start and throughout the test all control and test solutions were observed to be clear colorless solutions.

- Behavioural abnormalities: None stated
- Observations on body length and weight: None stated
- Other biological observations: None stated
- Mortality of control: No
- Other adverse effects control: one daphnid from the control and solvent control was observed to be coated in algae at 48 hours
- Immobilisation of control:
- Abnormal responses: None stated
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None stated
- Effect concentrations exceeding solubility of substance in test medium: Yes

Results with reference substance (positive control):

The results from the positive control with potassium dichromate were within the normal range ( 0.6 mg/L to 2.1 mg/L) for this reference item

Reported statistics and error estimates:

All validity criteria were fulfilled:
- Immobilisation in the controls may not exceed 10 %. Immobilisation in the control was 0 %.
- The concentration of dissolved oxygen at the end of the test must be at least 3 mg/L. The lowest concentration of dissolved oxygen at the end of the test was 8.6 mg/L.

Because of no significant toxicity, no statistically evaluation was performed.

Validity criteria fulfilled:

yes

Conclusions:

The 48 h EC50 value for HB TMP is above 100 mg/l (high concentration tested).

Executive summary:

The 48 hr-acute toxicity of HB TMP to Daphnia magna flow through conditions.  Test species were exposed to potassium dichromate and the test chemical at nominal concentration of 0,4, 6, 10, 22, 46, and 100 mg/L for 48 hr.  Immobilisation and sublethal effects were observed daily.  The 48 hour EC₅₀ was greater than 100 mg/l.  Based on the results of this study, HB TMP would not be classified as toxic to Daphnia magna to in accordance with the CLP classification. This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

Results Synopsis

Test Organism Age (e.g. 1st instar): Daphnia magna

Test Type (Flowthrough, Static, Static Renewal): Flowthrough                 

EC₅₀:  > 100 mg/L HB TMP                     

Endpoint(s) Effected: Immobilisation 

Description of key information

In a 48 hr GLP acute toxicity study, Daphnia magna showed to have an EC₅₀ value greater than 100 mg HB TMP/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

> 100 mg/L

Additional information

The 48 hr-acute toxicity of HB TMP to Daphnia magna flow through conditions.  Test species were exposed to potassium dichromate and the test chemical at nominal concentration of 0, 4, 6, 10, 22, 46, and 100 mg/L for 48 hr.  Immobilisation and sublethal effects were observed daily.  The 48 hour EC₅₀ was greater than 100 mg/l. Based on the results of this study, HB TMP would not be classified as toxic to Daphnia magna to in accordance with the CLP classification