Reaction products of 2-hydroxyethyl methacrylate and diphosphorous pentoxide and water

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:

key study

Study period:

30-03-2018 to 24-08-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Guideline study performed under GLP. All relevant validity criteria were met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23 (2000)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: Not applicable.
- Specific activity: Not applicable.
- Locations of the label: Not applicable.
- Expiration date of radiochemical substance: Not applicable.

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
(i) test item (prior to testing): In refrigerator (2 - 8°C), container protected from light
(ii) test solution samples were stored in a freezer (≤-15°C) until analysis.
- Stability under test conditions: Stable (full details available in the full study report). (i) Stability of Stock Solutions: The coefficient of variation on the response factors of the calibration solutions prepared with fresh and stored stock solutions was 3.0%. Since the value was ≤ 10% the stock solutions were stable when stored at room temperature for at least 12 days. (ii) Storage Stability of Samples: The results of the storage stability of the test item in the freezer (≤ -15°C) was demonstrated. Since the mean accuracy of the frozen QC samples fell in the criterion 70-110% the samples were stable when stored in the freezer (≤ -15°C). On the day of analysis, the test samples were thawed at room temperature. Afterwards, the samples were diluted in a 3:1 (v:v) ratio with acetonitrile and analysed. If necessary, the samples were further diluted with 25/75 (v/v) acetonitrile/test-medium to obtain concentrations within the calibration range. (iii) Stability of the Analytical System and End Solutions: The results of the stability of the analytical system and end solutions are given in Table 4. Since the coefficient of variation at all concentration levels was ≤ 20% the analytical system and end solutions were stable over at least a 4.60 hour time interval.
- Solubility and stability of the test substance in the solvent/vehicle: Soluble up to 100 mg/L in water and/or M2 medium and stable (full details available in the full study report). Further information also provided above.
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: Not applicable.

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Not applicable.
- Preliminary purification step (if any): Not applicable.
- Final dilution of a dissolved solid, stock liquid or gel: Not applicable.
- Final preparation of a solid: Not applicable.

FORM AS APPLIED IN THE TEST (if different from that of starting material): Not applicable.

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable): Not applicable.

OTHER SPECIFICS: Not applicable.

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Definitive test: nominal concentrations: Solutions containing test item: Test concentration(s): 0 (control), 0.10, 1.0, 10, and 100 mg/L (nominal) ; controls; Test medium without test item or other additives. Preparation of test solutions started with the highest concentration of 100 mg/L applying four hours of magnetic stirring to ensure complete dissolution of the test item in test medium.
Since the test item was visually completely dissolved in test medium, lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. The concentrations measured in the solution prepared at nominally 100 mg/L were: 101 mg/L, 100 mg/L, 98 mg/L, and 96 mg/L after 4, 24, 48, and 72 hours of stirring, respectively based on quantification of a marker analyte (i.e. chromatographic peak). Furthermore, based on qualitative analysis of the test item peaks which reflect the whole substance, the peak intensity was the same at each time point showing equilibrium for the entire substance was reached within 4 hours. Based on these results, it was concluded that the test item was completely dissolved in test medium after ≤4 hours of stirring, and therefore, 4 hours of stirring was considered adequate for preparation of test solutions in the combined limit/range-finding test. Samples taken from the highest test concentration and the control were analysed. The measured concentration at nominally 100 mg/L was 96 mg/L at the start of the test. This concentration remained at the level of nominal throughout the test, i.e. was at 94% of the nominal value the end of the 48-hour exposure period. No test item was detected in the samples taken from the control solution. Based on these results, effect parameters were expressed in terms of the analytically confirmed nominal concentration of 100 mg/L.
- Sampling method: Singular samples for possible analysis were taken from all test concentrations and the control according to the schedule:
at t=0 h and t=48 h, Volume: 1.5 mL from the approximate centre of the test vessels.
- Sample storage conditions before analysis: Samples were stored in a freezer until analysis (≤ -15°C). Reserve samples of 1.5 mL were taken for possible analysis. If not used, these samples were stored in a freezer.

Vehicle:

no

Details on test solutions:

PPREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of test solutions started with (loading rates) individually prepared in the range of 1.0 to 100 mg/L. Preparation of test solutions started with the highest concentration of 100 mg/L applying four hours of magnetic stirring to ensure complete dissolution of the test item in test medium. Since the test item was visually completely dissolved in test medium, lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. These dilutions were used for the range-finding test, intended to determine the range of toxicity to select an appropriate concentration series for the final test. Since no effects were recorded at the highest concentration tested (i.e. 100 mg/L), no further testing was required for conclusion of the study. Therefore, the lower concentrations prepared by serial dilution were of no use in the current study. See “Other:” for further information.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Not applicable.
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): Not applicable.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): None.
- Other: Since the test item was visually completely dissolved in test medium, lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. In the saturation test: the concentrations measured in the solution prepared at nominally 100 mg/L were: 101 mg/L, 100 mg/L, 98 mg/L, and 96 mg/L after 4, 24, 48, and 72 hours of stirring, respectively based on quantification of a marker analyte (i.e. chromatographic peak). Furthermore, based on qualitative analysis of the test item peaks which reflect the whole substance, the peak intensity was the same at each time point showing equilibrium for the entire substance was reached within 4 hours. Based on these results, it was concluded that the test item was completely dissolved in test medium after ≤4 hours of stirring, and therefore, 4 hours of stirring was considered adequate for preparation of test solutions in the combined limit/range-finding test. Samples taken from the highest test concentration and the control were analysed. The measured concentration at nominally 100 mg/L was 96 mg/L at the start of the test. This concentration remained at the level of nominal throughout the test, i.e. was at 94% of the nominal value the end of the 48-hour exposure period. No test item was detected in the samples taken from the control solution. Based on these results, effect parameters were expressed in terms of the analytically confirmed nominal concentration of 100 mg/L.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphinds
- Strain/clone: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by a cyclical parthenogenesis under specified breeding conditions.
- Justification for species other than prescribed by test guideline: Not applicable.
- Age at study initiation (mean and range, SD): < 24 hours old daphnids from a healthy stock were used for the study
- Weight at study initiation (mean and range, SD): Not applicable.
- Length at study initiation (length definition, mean, range and SD): Not applicable.
- Stage and instar at study initiation: Juvenile ; < 24 hours
- Valve height at study initiation, for shell deposition study (mean and range, SD): Not applicable.
- Peripheral shell growth removed prior to test initiation: Not applicable.
- Method of breeding: Parthenogenesis
- Source: in-house laboratory cultures
- Age of parental stock (mean and range, SD):
- Feeding during test: No. The daphnids were not fed during the study. During culture: Daily, a suspension of fresh water algae. The algae are cultured at the test facility
- Food type: Not applicable.
- Amount: Not applicable.
- Frequency: Not applicable.

ACCLIMATION
- Acclimation period: None.
- Acclimation conditions (same as test or not): Not applicable.
- Type and amount of food: Not applicable.
- Feeding frequency: Not applicable.
- Health during acclimation (any mortality observed): Not applicable.

QUARANTINE (wild caught)
- Duration: Not applicable.
- Health/mortality: Not applicable.

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS: Not applicable.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

In accordance with OECD TG 202

Hardness:

The adjusted-ISO medium M7 hardness: 180 mg/L expressed as CaCO3 and the pH: 6.9 to 8.0 (see "pH for further information")

Test temperature:

The temperature continuously measured in a temperature control vessel varied between 19.0 and 20.0°C during the test, and complied with the requirements as laid down in the protocol (18-22°C, constant within 2°C).

pH:

Test conditions remained within the limits prescribed by the guideline; pH: 6-9 not varying by 1.5 units the end of the test. Actual pH: 7.5 - 6.9
The pH remained within the limits prescribed by the study plan (pH 6 9), however, varied more than 1.5 units in the highest test concentration (at 100 mg/L) between start (pH of 8.0) and the end of the test (pH of 6.3). This seemed to be test item related as pH decreased with increasing concentration of the test item. Since the exceedance of this 1.5 units variation was very minor (0.2 units), and no immobility or other symptoms were recorded in this group, the decrease in pH was considered to have not impacted the outcome of the study.

Dissolved oxygen:

Test conditions remained within the limits prescribed by the guideline; oxygen:>3 mg/L at the end of the test. Actual oxygen: start: 9.8 ± 0.1 mg/L and end: 8.4 ± 0.1 mg/L

Nominal and measured concentrations:

Combined range-finding / limit test: nominal concentrations: 0 (control), 0.1, 1.0, 10.0 and 100.0 mg/L (which were analytically confirmed)
In the saturation test: the concentrations measured in the solution prepared at nominally 100 mg/L were: 101 mg/L, 100 mg/L, 98 mg/L, and 96 mg/L after 4, 24, 48, and 72 hours of stirring, respectively based on quantification of a marker analyte (i.e. chromatographic peak). Furthermore, based on qualitative analysis of the test item peaks which reflect the whole substance, the peak intensity was the same at each time point showing equilibrium for the entire substance was reached within 4 hours. Based on these results, it was concluded that the test item was completely dissolved in test medium after ≤4 hours of stirring, and therefore, 4 hours of stirring was considered adequate for preparation of test solutions in the combined limit/range-finding test. Samples taken from the highest test concentration and the control were analysed. The measured concentration at nominally 100 mg/L was 96 mg/L at the start of the test. This concentration remained at the level of nominal throughout the test, i.e. was at 94% of the nominal value the end of the 48-hour exposure period. No test item was detected in the samples taken from the control solution. Based on these results, effect parameters were expressed in terms of the analytically confirmed nominal concentration of 100 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 60 mL all glass, closed
- Type (delete if not applicable): all glass, closed ; static.
- Material, size, headspace, fill volume: Glass, headspace: 10 mL, fill volume: 50 mL
- Volume of solution: ca. 50 mL
- Aeration: No aeration of the test solutions.
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable.
- Renewal rate of test solution (frequency/flow rate): Not applicable.
- No. of organisms per vessel: Control and test item: 20 per concentration, 5 per vessel containing 50 mL of test solution
- No. of vessels per concentration (replicates): 4 (four replicates, 5 daphnia per vessel) at 0 (control) and 100 mg/L (maximum concentration) ; 2 (two replicates ; 5 daphnia per vessel) other concentrations
- No. of vessels per control (replicates): 4 (four replicates, 5 daphnia per vessel).
- No. of vessels per vehicle control (replicates): Not applicable.
- Biomass loading rate: See above.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reverse Osmosis (RO-water, GEON Waterbehandeling, The Netherlands); used to prepare ISO Medium M7 (culture medium) and/or test medium
- Total organic carbon: Not applicable.
- Particulate matter: Not applicable.
- Metals: Not applicable.
- Pesticides: Not applicable.
- Chlorine: Not applicable.
- Alkalinity: Not applicable.
- Ca/mg ratio: See below.
- Conductivity: Not applicable.
- Salinity: Not applicable.
- Culture medium different from test medium: Yes. The following were added to Reverse Osmosis (RO-water, GEON), dilution water: CaCl2.2H2O 211.5 mg/L ; MgSO4.7H2O 88.8 mg/L ; NaHCO3 46.7 mg/L ; KCl 4.2 mg/L and the hardness of test medium expressed as CaCO3: 180 mg/L
- Intervals of water quality measurement: pH and dissolved oxygen: 0 hours (start) and 48 hours (end) of test for pH, and oxygen concentration. Temperature was monitored continuously.

OTHER TEST CONDITIONS
- Adjustment of pH: Not applicable.
- Photoperiod: The study was performed in the dark due to (any potential) the light sensitivity of the test item
- Light intensity: Not reported.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobility (including mortality), 24 hours and at 48 hours. Any other unusual behaviour was also recorded.

VEHICLE CONTROL PERFORMED: Not applicable.

RANGE-FINDING STUDY
- Test concentrations: Definitive test was a combined range-finding / limit test: nominal concentrations: 0 (control), 0.1, 1.0, 10.0 and 100.0 mg/L (that were analytically confirmed)
- Results used to determine the conditions for the definitive study: Not applicable.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence interval: - mg/L ; analytically confirmed nominal concentrations

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

Remarks on result:

other: 95% confidence interval: - mg/L ; analytically confirmed nominal concentrations

Details on results:

- Behavioural abnormalities: None
- Observations on body length and weight: Not applicable.
- Other biological observations: None.
- Mortality of control: No mortalities.
- Other adverse effects control: None.
- Abnormal responses: None.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None. In the saturation test: the concentrations measured in the solution prepared at nominally 100 mg/L were: 101 mg/L, 100 mg/L, 98 mg/L, and 96 mg/L after 4, 24, 48, and 72 hours of stirring, respectively based on quantification of a marker analyte (i.e. chromatographic peak). Furthermore, based on qualitative analysis of the test item peaks which reflect the whole substance, the peak intensity was the same at each time point showing equilibrium for the entire substance was reached within 4 hours. Based on these results, it was concluded that the test item was completely dissolved in test medium after ≤4 hours of stirring, and therefore, 4 hours of stirring was considered adequate for preparation of test solutions in the combined limit/range-finding test. Samples taken from the highest test concentration and the control were analysed. The measured concentration at nominally 100 mg/L was 96 mg/L at the start of the test. This concentration remained at the level of nominal throughout the test, i.e. was at 94% of the nominal value the end of the 48-hour exposure period. No test item was detected in the samples taken from the control solution. Based on these results, effect parameters were expressed in terms of the analytically confirmed nominal concentration of 100 mg/L.
- Effect concentrations exceeding solubility of substance in test medium: No.

Results with reference substance (positive control):

- Results with reference substance valid?: Yes.
- Mortality: None. Acute immobilisation observed only.
- Relevant effect levels: See below.
- Dose-response test: Yes.
- EC50/LC50: 24h-EC50 was 0.77 (C.I. 0.70 – 0.86) mg/L. 48h-EC50 was 0.45 (C.I. 0.41 – 0.50) mg/L
- Other: The actual responses in this reference test with K2Cr2O7 are within the ranges of the expected responses at the different concentrations, i.e. the 48h-EC50 was between 0.28 and 0.59 mg/L. Hence, the sensitivity of this batch of test organism was in agreement with the historical data.

Table 1.0 : pH and oxygen (mg/L) concentrations during the final test

Test item nominal concentration (mg/L)	Start (t=0 h)		End (t=48 h)
	O2	pH	O2	pH
Control	9.8	8.0	8.5	7.5
0.10	n.d.	n.d.	8.4	7.4
1.0	n.d.	n.d.	8.5	7.4
10	n.d.	n.d.	8.3	7.3
100	9.8	8.0	8.3	6.3

n.d. = not determined

 

Table 2.0 : Immobilisation Rates after 24 and 48 h of Exposure in the Combined range-finder/limit test:

Control and highest test concentration: 4 replicates containing 5 daphnids each. Lower concentrations: 2 replicates containing 5 daphnids each.

Test item, WSF loading rate concentration (mg/L)	Immobilisation [%]
	24 hours					48 hours
	Replicates					Replicates
	1	2	3	4	MV (%)	1	2	3	4	MV (%)
0 (control)	0	0	0	0	0	0	0	0	0	0
0.1	0	0	-	-	0	0	0	-	-	0
1.0	0	0	-	-	0	0	0	-	-	0
10.0	0	0	-	-	0	0	0	-	-	0
100	0	0	0	0	0	0	0	0	0	0

* analytically confirmed nominal concentrations

 

In the saturation test: the concentrations measured in the solution prepared at nominally 100 mg/L were: 101 mg/L, 100 mg/L, 98 mg/L, and 96 mg/L after 4, 24, 48, and 72 hours of stirring, respectively based on quantification of a marker analyte (i.e. chromatographic peak). Furthermore, based on qualitative analysis of the test item peaks which reflect the whole substance, the peak intensity was the same at each time point showing equilibrium for the entire substance was reached within 4 hours. Based on these results, it was concluded that the test item was completely dissolved in test medium after ≤4 hours of stirring, and therefore, 4 hours of stirring was considered adequate for preparation of test solutions in the combined limit/range-finding test. Samples taken from the highest test concentration and the control were analysed. The measured concentration at nominally 100 mg/L was 96 mg/L at the start of the test. This concentration remained at the level of nominal throughout the test, i.e. was at 94% of the nominal value the end of the 48-hour exposure period. No test item was detected in the samples taken from the control solution. Based on these results, effect parameters were expressed in terms of the analytically confirmed nominal concentration of 100 mg/L.

 

Analytical information:

Based on qualitative analysis of all 4 chromatographic peaks attributable to the test item (in the sample analysis) which it was considered reflect the whole substance, the peak intensity was the same at each time point showing equilibrium for the entire substance was reached within 4 hours within the test system. Further, qualitatively it can be seen peak intensity in the static limit test of these peaks was almost identical at 0 and 48 hours, showing the substance was stable over the duration of the testing period. Quantitatively, the substance was also shown to be stable based on the marker analyte with concentrations remaining > 90 % of nominal and measured over time. Representative chromatograms of test samples and control samples taken during combined limit/range-finding test were presented (in the full study report). In the figures all the signal associated with the test item are visible including the signal that was used for quantitative purposes. Only one signal was used for quantitative calculations since for the other signals the intensity was too low to be able to quantify at low concentration levels or matrix signals could disturb or interfere the signals at lower concentration levels as was observed during method development. Qualitatively it can be observed that the ratios between the different signals are constant between the different concentration levels, although at the lower concentration levels not all signals are visible due to their low original intensity and not being detectable at the low concentration.

Validity criteria fulfilled:

yes

Conclusions:

The test item 48h-EC50 was > 100 mg/L based on analytically confirmed nominal concentrations.

Executive summary:

The acute toxicity to Daphnia magna was carried out according to OECD TG 202 Daphnia sp., Acute Immobilisation Test under GLP. A limit test was combined with a range-finding test using static conditions was initially performed. Twenty Daphnia magna per test group (4 replicates, 5 daphnia per replicate vessel) were exposed to untreated control medium and to a test item concentration of 1.0, 10.0 and 100 mg/L. No immobilisation was seen at 1.0 mg/L whereas 100% immobilisation was observed at 10 to 100 mg/L at the 48-hour time point. A final test was performed based on the results of a finding test. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to nominal concentration: 0 (control), 1.0, 1.8, 3.2, 5.6 and 10 mg/L. 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. Analysis of the samples taken at the start of the final test showed equivalent measured concentrations of 0 (control), 1.0, 2.2, 2.3, 4.9 and 9.6 mg/L. Initially measured concentrations remained stable throughout the exposure period (90 – 100% relative to initial), except for the solution prepared at 5.6 mg/L which was measured to be 6.4 mg/L (i.e. 129% relative to initial) at the end of the test. Based on these results, the geometric mean measured exposure concentrations were calculated to be 0.96, 2.2, 2.3, 5.6, and 9.2 mg/L, respectively. No biologically relevant immobility (i.e. >10%) was observed in the control and at the three lowest test concentrations throughout the test. Complete immobility was observed at the two highest test concentrations at the end of the test. The study met the acceptability criteria. The 48h-EC50 was 3.5 mg/L (C.I: 3.4 – 3.7 mg/L) based on geometric mean measured concentrations.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
Estimation Programme Interface (EPI) Suite programme for Microsoft Windows v4.11
Contact EPISuite:
U.S. Environmental Protection Agency
1200 Pennsylvania Ave.
N.W. (Mail Code 7406M)
Washington, DC 20460

2. MODEL (incl. version number)
ECOSAR v1.11 – Daphnid 48h LC50
19 June 2012 (model development)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See attached: ‘Aquatic Toxicity Predictions: Reaction products of 2-hydroxyethyl methacrylate and diphosphorous pentoxide and water’ version 1.0; dated 30 May 2018.

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
Full details of the method are provided in the attached QMRF named ‘QMRF Title: ECOSAR v1.11 Daphnid 48h LC50’ version 1.2; dated 30 May 2018

5. APPLICABILITY DOMAIN
See ‘any other information on results incl. tables’.
See attached: ‘Aquatic Toxicity Predictions: Reaction products of 2-hydroxyethyl methacrylate and diphosphorous pentoxide and water’ version 1.0; dated 30 May 2018.

6. ADEQUACY OF THE RESULT
1) QSAR model is scientifically valid. 2) The substance falls within the applicability domain of the QSAR model. 3) The prediction is fit for regulatory purpose.
The prediction is adequate for the Classification and Labelling or risk assessment of the substance as indicated in REACH Regulation (EC) 1907/2006: Annex XI Section 1.3. Specifically when combined with further information such as physico-chemistry and environmental fate testing and modelling.

Guideline:

other: REACH Guidance on QSARs R.6, May/July 2008

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

This guideline is preferred for the training set but not obligatory

Principles of method if other than guideline:

1. ECOSAR v1.11 - Daphnid 48h LC50
2. Aquatic Toxicity Assessment of UVCB substances using the Additivity Approach
3. Assessment of Degradability for the purpose of Classification and Labelling

Specific details on test material used for the study:

Detailed information on the 'test material identity' is provided in the attached QSAR Prediction Reporting Format (QPRF) document including information on individual constituents according to point '2. Aquatic Toxicity Assessment of UVCB substances using the Additivity Approach' requirements.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.37 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: Additive Endpoint Values calculated in line with Block Method Approach

1. Defined Endpoint:

QMRF 3. Ecotoxic effects

QMRF 3.1. Short-term toxicity to Daphnia (immobilisation)

Reference to type of model used and description of results:

ECOSAR v1.11 - Daphnid 48h LC50 ; 24 July 2012

 Note: Effect levels for each trophic group derived from the associated ECOSAR v1.11 model classes above are provided here for completeness.

 

2. Description of results and assessment of reliability of the prediction:

The test item ‘Reaction products of 2-hydroxyethyl methacrylate and diphosphorous pentoxide and water’ is a substance of Unknown or Variable composition, Complex reaction products or Biological Materials (UVCB). This complex substance falls under the category of substances difficult to test defined in ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R7.b: Endpoint Specific Guidance, Appendix R.7.8-1. As the test item is difficult to test and assessment has been conducted using the block method (reference: Redman et al. PETROTOX: An Aquatic Toxicity Model for Petroleum Substances.: Env, Toxicol. Chem. 31: 2487-2506).

 

1) ECOSAR v1.11 - Daphnid 48h LC50

2) Aquatic Toxicity Assessment of UVCB substances using the Additivity Approach

Inputs Used for Test Item: All modelling was based on input of SMILES notation for each constituent of the test item and respective hydrolysis products (presented in the attached Aquatic Toxicity Predictions 30-05-2018 QPRF report), meaning that the process relied on modelled values for Kow and water solubility to define the blocks. This approach is in line with the PETROTOX methodology and ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R7.b for hazard assessment of complex mixtures.

Table 1. ECOSAR Output for Consolidated Blocks of Test Item Constituents

Block	Block Identifier	Typical Concentration in Test Item (% (w/w))	Log Kow KOWWIN	Water Solubility (mg/L) WSKOWWIN	Daphnid 48 h EC50 (mg/L)	Algae 96 h EC50 (mg/L)	Fish 96 h LC50 (mg/L)
1	Partially soluble – Ester (phosphates)/ Methacrylates	C.B.I.	2.1995	24.73	0.015	0.633	8.029
2	Soluble -Methacrylates	C.B.I.	-1.72 to 1.06	1124 to 1.37 x10^5	202.88	0.951	269.189
3	Soluble – Esters / phosphine oxides	C.B.I.	-0.7699 to 0.6535	11200 to 5.39 x10^5	9.087	213.229	168.576

Note: Concentration in the test item contributing to the additive endpoint values are presented in the attached Aquatic Toxicity Predictions 30-05-2018 QPRF report.

 

For the purpose of concluding on classification and labelling for this substance the additivity formula from Annex I, Section 4.1.3.5.2 of CLP Regulation (EC) 1272/2008 is applied to data on the known components of the substance. The effect values for the test item for each relevant trophic group are presented in the following table.

 

Table 2. Additive Endpoint Values for the Test Item for each Trophic Group

Trophic Level	Endpoint	Endpoint Value (mg/L)
Daphnid	48 h EC50	0.37
Algae	96 h EC50	1.1
Fish	96h LC50	111.7

 

Substance rapidly degradable: YES (OECD TG 301B, 2018)

Log Kow < 4.0: YES. (Block Method, KOWWIN v1.68, US EPA, 2018

 

3) Assessment of Degradability for the purpose of Classification and Labelling

The following data are considered for conclusion on classification and labelling of the test item:

Aquatic toxicity data availability:            Acute

96 h EC50 for Daphnia:                           0.37 mg/L

Substance rapidly degradable:                  YES

Log Kow:                                                  < 4

 

Based on the above considerations, the substance is precautionarily classified as hazardous to the environment under CLP Regulation (EC) 1272/2008: Acute Category 1: H400: Very toxic to aquatic life. Further evidence, generated at a later date may confirm the suggestion that no classification and labelling is warranted. For example: at REACH Regulation (EC) 1907/2006: Annex VIII information requirements.

 

Assessment of the substance within the applicability domain as documented within the corresponding QMRF named ‘QMRF Title: ECOSAR v1.11 Daphnid 48h LC50’ version 1.2; dated 30 May 2018 – section 5; indicates the substance:

(i) Falls within the Log Kow domain of < 5 (general domain for the model; and relevant chemical classes specific cut off);

(ii) Molecular weights of all constituents are < 1000 g/mol and;

(iii) Effect levels are predicted below the water solubility.

 

The ECOSAR QSAR model as detailed is not known to function by specific modes of action associated with the chemical class(es) assigned. Full references to training set data are presented within ECOSAR v1.1 Help System; if not proprietary (in such cases the chemical identification is listed as CBI, but the relevant descriptor data are provided). A summary of this information is presented by the applicant. The substances in the training set are considered analogues to the target substance since they possess relevant chemical groups and log Kow < 5 and MW < 1000 g/mol. The substance and the structural analogues share a common functional group and physico-chemical domains versus a neutral organics class (baseline toxicity). The ECOSAR class is based on similar relationships between toxicity and the various types of pharmacologic properties.

 

3. Uncertainty of the prediction and mechanistic domain:

No external validation set is available for the chemical class used in this prediction.

Consistency of ECOSAR data compared to measured toxicity showed 64-67 % of Daphnia predictions (all chemical classes assessed) were within a tolerance factor of 10, comparable to that seen in Hulzebos & Posthumus (2003).

Uncertainty in the prediction relates to:

Limited external validation on the relevant chemical classes Model predictivity could be improved by the assignment of additional chemical categories and expansion of sub-structure rules, in addition further substances addition to the training set and rules for stereochemical effects within the model would improve predictivity. The ECOSAR QSAR model as detailed is not known to function by specific modes of action associated with the chemical class(es) assigned. ECOSAR classes are grouped based on similar relationships between toxicity and the various types of pharmacologic properties. The model does not apply a mechanistic approach to assessment of toxicity other than assignment of chemical classes (to identify potential toxicity in excess of baseline narcosis) using an expert decision tree.

Validity criteria fulfilled:

yes

Conclusions:

The results are adequate for the for the regulatory purpose.

Executive summary:

ECOSAR v1.11 - Daphnid 48h LC50 ; 24 July 2012

Additive endpoint values: Daphnid 48-hr EC50: 0.37 mg/L

 

Adequacy of the QSAR:

1) QSAR model is scientifically valid. 2) The substance falls within the applicability domain of the QSAR model. 3) The prediction is fit for regulatory purpose.

The prediction is adequate for the Classification and Labelling or risk assessment of the substance as indicated in REACH Regulation (EC) 1907/2006: Annex XI Section 1.3.

Description of key information

48-h EC50 (invertebrates) : > 100 mg/L based on analytically confirmed nominal concentrations, freshwater, OECD TG 202, 2021

48-h NOEC (invertebrates) : > 100 mg/L based on analytically confirmed nominal concentrations, freshwater, OECD TG 202, 2021

 

Supporting previous information:

QSAR: Daphnia EC50-48h = 0.37 mg/L (additive endpoint values), ECOSAR v1.11, US EPA, 2018

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Key study : OECD TG 202, 2021 : The acute toxicity to Daphnia magna was carried out according to OECD 202 Daphnia sp., Acute Immobilisation Test and EU Method C.2 guidelines under GLP. In the preceding saturation test: the concentrations measured in the solution prepared at nominally 100 mg/L were: 101 mg/L, 100 mg/L, 98 mg/L, and 96 mg/L after 4, 24, 48, and 72 hours of stirring, respectively based on quantification of a marker analyte (i.e. chromatographic peak). Furthermore, based on qualitative analysis of the test item peaks which reflect the whole substance, the peak intensity was the same at each time point showing equilibrium for the entire substance was reached within 4 hours. Based on these results, it was concluded that the test item was completely dissolved in test medium after ≤ 4 hours of stirring, and therefore, 4 hours of stirring was considered adequate for preparation of test solutions in the combined limit/range-finding definitive test. In the combined limit/range-finding test, twenty daphnids were exposed in the control and to a nominal concentration of 100 mg/L, while ten daphnids per group were exposed to nominally 0.10, 1.0, and 10 mg/L. Samples taken from the highest test concentration and the control were analysed. The measured concentration at nominally 100 mg/L was 96 mg/L at the start of the test. This concentration remained at the level of nominal throughout the test, i.e. was at 94% of the nominal value the end of the 48-hour exposure period. No test item was detected in the samples taken from the control solution. Based on these results, effect parameters were expressed in terms of the analytically confirmed nominal concentration of 100 mg/L. No immobility of daphnids or other effects were found at any of the test concentrations throughout the 48-hour exposure period. Based on these results, samples taken from the control and highest test concentration were analysed. At 0 hours the concentration in the highest test item concentration (100 mg/L nominal) was 96.3 mg/L (96%) and at 48 hours was 94.0 mg/L (94% of nominal and 98% of initial concentration).The study met all the relevant acceptability criteria and was considered valid. Under the conditions of this study, the 48h-EC50 was > 100 mg/L based on analytically confirmed nominal concentrations.

 

Supporting previous information:

QSAR: Daphnia EC50-48h= 0.37 mg/L (additive endpoint values), ECOSAR v1.11, US EPA, 2018