Potassium 3-sulphopropyl methacrylate

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:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Klimisch 1 source record, but performed on read-across substance

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
[Please provide information for all of the points below. Indicate if further information is included as attachment to the same record, or elsewhere in the dataset (insert links in 'Cross-reference' table)]


1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The rational for the analogue approach is the high structural similarity between the source and the target substance. 2-Propenoic acid, 3-sulfopropyl ester, potassium salt (source) and 2-Propenoic acid, 2-methyl-,3-sulfopropylester, potassium salt (target) are structurally identical except an additional methyl group on position 2 of the target substance. Despite the fact that a methyl group may alter the toxicological behaviour of a substance, this effect is considered very minor as there are three common groups in the molecules which are considered more relevant for their toxicological behaviour, i.e. the sulfo-group, the ester and the Michael-acceptor system. Due to the similarities in structure, similar physico-chemical properties of the substances are to be expected, which would result in a similar toxicokinetic behaviour and most likely also in very similar ecotoxicological behaviour.


2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

Source Chemical: 2-Propenoic acid, 3-sulfopropyl ester, potassium salt, CAS 31098-20-1, EC 250-465-0, SMILES [K+].[O-]S(=O)(=O)CCCOC(=O)C=C, MW 232.30

Target Chemical: 2-Propenoic acid, 2-methyl-,3-sulfopropylester, potassium salt, CAS 31098-21-2, EC 250-466-6, SMILES [K+].CC(=C)C(=O)OCCCS(=O)(=O)O, MW 247.33

Both substances do not contain impurities to an extent which is expected to alter the outcome of the experimental results or read-across approach.


3. ANALOGUE APPROACH JUSTIFICATION
Comparing the actually available information on the substances with regard to their physico-chemical properties, the minor influence of the additional methyl group of the target chemical becomes obvious. So the molecular weight is in the same range, i.e. approx. 240 g/mol, indicating per se the potential for absorption. Both substances are solids which either do not melt or decompose at or above 300°C. Both compounds are very soluble in water, and their logPow is in a negative range, < -3.
In general, absorption of a chemical is possible, if the substance crosses biological membranes. In case where no transport mechanisms are involved, this process requires a substance to be soluble, both in lipid and in water, and is also dependent on its molecular weight. Substances with a molecular weight below 100 are favourable for penetration through the skin and substances above 500 are normally not able to penetrate. Hence, with a similar molecular weight and logPow, their potential for absorption can be considered very similar or even identical.
Besides the common physico-chemical and toxicokinetic properties, they exhibit a similar ecotoxicological behaviour. Both substances are relatively non-toxic towards fish, both LC50(96h) are > 100 mg/L. The experimentally determined EC50 of SPA is > 100 mg/L (NOEC ≥ 100 mg/L) for daphnids over 48h, ECOSAR estimation gives 48h EC50 values of 32 resp. 33 g/L for SPM. The 72h EC50 of SPA for algae was 25.72 mg/L, ECOSAR estimation gives 96h EC50 of SPM as 21 mg/l (ECOSA class Methacrylates-acid) resp. 8 g/L (ECOSAR class Neutral Organic SAR (Baseline Toxicity)). Hence, the assumption of a similar ecotoxicity profile is justified.
Further, SPM is inherently biodegradable as shown in a OECD 302B study, and as a >99% biodegradation after 14 days was observed, it can be concluded that SPM is easily biodegradable, which is supported by QSAR estimation indicating that the substance is readily biodegradable. SPA however is not readily biodegradable but inherently biodegradable, not fulfilling specific criteria (OECD 301D). So it can be assumed that due to the facilitated biodegradation of SPM, all values used for read-across can be considered as a worst case, clearly not underestimating a potential hazard of SPM.
Hence, due to the above-mentioned similarities of the source and target chemical, with regard to their structure, functional groups, toxicokinetic and ecotoxicological behaviour, it can be reasonably concluded that a similar behaviour of the target chemical regarding its ecotoxicological properties compared to the source chemical can be expected. In summary, the target chemical 2-Propenoic acid, 2-methyl-,3-sulfopropylester, potassium salt, needs to be regarded as non-toxic towards aquatic invertebrates, too.


4. DATA MATRIX
The following table shows the available data relevant to justify the read-across from the source to the target chemical for the endpoint toxicity towards aquatic invertebrates:

Endpoint Source: SPA Target: SPM
Molecular weight 232.30 g/mol 247.33 g/mol
Physical state solid solid
Partition coefficient logPow = -3.63 logPow = -3.1 (EpiSuite estimation)
Water solubility 3329 g/L 2570 g/L
Biodegradation not readily biodegradable; inherently biodegradable, not fulfilling specific criteria (OECD 301D) Inherently biodegradable(OECD 301B) /
Readily biodegradable (Conclusions / BIOWIN estimation
Hydrolysis Hydrolytically stable, half-life 10.6 a at pH 7 (HYDROWIN v2.00, EpiSuite estimation) Possible degradation into Methacrylic acid (non-validated method)
Short-term toxicity to fish LC50(96 h) > 100 mg/L (OECD 203) LC50(96 h) > 2000 mg/l, NOEC(96 h) = 1000 mg/l (OECD 203)
Short-term toxicity to aquatic invertebrates24&48h NOEC ≥ 100 mg/L 24&48h EC50 > 100 mg/L (OECD 202) 48h EC50 = 32 resp. 33 g/L (ECOSAR estimation)
Short-term toxicity to aquatic algae 72h EC50 = 25.72 mg/L 72h EC10 = 1.613 mg/L (growth rate, OECD 201) 96h EC50 = 21 mg/l resp. 8 g/L (ECOSAR estimation)

Reason / purpose for cross-reference:

read-across source

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 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:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: No adverse reactions were observed.
- Mortality of control: no

Validity criteria fulfilled:

yes

Conclusions:

The study was conducted under GLP according to OECD TG 202, which is a scientifically reasonable method, and the test report is sufficiently documented. Hence, there is no reason to question the reliability of the results. The acute toxicity of the test material to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50 of greater than 100 mg/L. Correspondingly the No Observed Effect Concentration was 100 mg/L. So no classification according to Regulation (EC) 1272/2008 is triggered.

Executive summary:

A study was performed to assess the acute toxicity of the test material (sulphopropylacrylate) to Daphnia magna. The method followed that described in the OECD Guidelines for Testing of Chemicals (1984) No 202, "Daphnia sp, Acute Immobilisation Test and Reproduction Test" referenced as Method C.2 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

Methods: Following a preliminary range-finding study, forty daphnids (4 replicates of 10 animals) were exposed to an aqueous solution of the test material at a concentration of l00mg/L for 48 hours under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 24 and 48 hours.

Results. The 48-Hour EC50 for the test material to Daphnia magna based on nominal test concentrations was greater than 100 mg/L and correspondingly the No Observed Effect Concentration was 100 mg/L.

It was considered unnecessary and unrealistic to test at concentrations in excess of 100 mg/L.

Analysis of the test solutions at 0 and 48 hours showed the measured test concentrations to be near nominal and so the results are based on nominal test concentrations only.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Aug - 17 Aug 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
see target record

Reason / purpose for cross-reference:

read-across source

Remarks:

link to target

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Commission Directive 92/69/EEC

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Pooled replicate water samples were taken from the control and the 100 mg/L test group at 0 and 48 h for quantitative analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: 200 mg test material was directly added to reconstituted water (ISO medium) and the volume adjusted to give a test concentration of 100 mg/L. The solution was inverted several times to ensure adequate mixing and homogeneity.
- Evidence of undissolved material: The test preparations were observed to be clear, colourless solutions throughout the study.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: in-house culture
- Age at study initiation: < 24 h
- Feeding during test: none

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

21 °C, measured at test start and after 24 and 48 h in every test vessel and the control.

pH:

7.9 - 8.0, measured at test start and after 48 h in every test vessel and the control.

Dissolved oxygen:

8.1 - 8.4 mg O2/L, (91 - 94% of saturation), measured at test start and after 48 h in every test vessel and the control.

Nominal and measured concentrations:

nominal: 0 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel
- Type: Test vessels were covered with glass lids to reduce evaporation.
- Material, size, fill volume: 250 mL glass jar containing approx. 200 mL test solution
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (ISO medium) as stated in OECD 202

OTHER TEST CONDITIONS
- Photoperiod: 16 h light/ 8 h dark with 20 min dawn and dusk transition periods

EFFECT PARAMETERS MEASURED: immobilisation and adverse reactions after 24 and 48 h

TEST CONCENTRATIONS
- Range finding study:
- Test concentrations: 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: No immobilisation was observed up to a concentration of 100 mg/L.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 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:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: No adverse reactions were observed.
- Mortality of control: no

Validity criteria fulfilled:

yes

Conclusions:

The study was conducted under GLP according to OECD TG 202, which is a scientifically reasonable method, and the test report is sufficiently documented. Hence, there is no reason to question the reliability of the results. The acute toxicity of the test material to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50 of greater than 100 mg/L. Correspondingly the No Observed Effect Concentration was 100 mg/L. So no classification according to Regulation (EC) 1272/2008 is triggered.

Executive summary:

A study was performed to assess the acute toxicity of the test material to Daphnia magna. The method followed that described in the OECD Guidelines for Testing of Chemicals (1984) No 202, "Daphnia sp, Acute Immobilisation Test and Reproduction Test" referenced as Method C.2 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

Methods: Following a preliminary range-finding study, forty daphnids (4 replicates of 10 animals) were exposed to an aqueous solution of the test material at a concentration of 100mg/L for 48 hours under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 24 and 48 hours.

Results. The 48-Hour EC50 for the test material to Daphnia magna based on nominal test concentrations was greater than 100 mg/L and correspondingly the No Observed Effect Concentration was 100 mg/L.

It was considered unnecessary and unrealistic to test at concentrations in excess of 100 mg/L.

Analysis of the test solutions at 0 and 48 hours showed the measured test concentrations to be near nominal and so the results are based on nominal test concentrations only.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically acceptable calculation method

Justification for type of information:

QSAR prediction

Guideline:

other: REACH guidance on QSARs Chapter R.6 , May 2008

Principles of method if other than guideline:

The estimation for short-term toxicity to daphnia of the test material was performed with US-EPA software ECOSAR v1.11. ECOSAR is currently programmed to identify over 120 chemical classes. For those classes, there are a more than 600 QSARs based on publicly available experimental data and confidential studies collected under the EPA New Chemicals Program. For each class, a standard EPA New Chemicals Program aquatic toxicity profile will be created using available QSARs and/or alternate QSAR approaches and professional judgment.

GLP compliance:

no

Remarks:

(not applicable)

Analytical monitoring:

not required

Details on sampling:

Not applicable

Details on test solutions:

Not applicable

Test organisms (species):

other: daphnia , not further specified

Details on test organisms:

No details available

Test type:

other: QSAR estimation

Water media type:

not specified

Total exposure duration:

48 h

Post exposure observation period:

Not applicable

Hardness:

No details available

Test temperature:

No details available

pH:

No details available

Dissolved oxygen:

No details available

Salinity:

No details available

Nominal and measured concentrations:

No details available

Details on test conditions:

No details available

Reference substance (positive control):

not required

Remarks:

(not applicable)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

32 157.898 mg/L

Remarks on result:

other: calculated value ECOSAR Class : Methacrylates-acid

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

33 447.594 mg/L

Remarks on result:

other: calculated value ECOSAR CLASS : Neutral Organic SAR (Baseline Toxicity)

Details on results:

No details available

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

Validity criteria fulfilled:

yes

Remarks:

(Scientifically accepted calculation method.)

Conclusions:

The study report describes a scientifically accepted calculation method for the prediction of short-term toxicity to daphnia using the US-EPA software ECOSAR v1.11.No GLP criteria are applicable for the usage of this tool and the QSAR estimation is easily repeatable.

Executive summary:

The prediction for short-term toxicity to daphnia of the test substance was determined by the computer program ECOSAR v1.11 by US-EPA .ECOSAR is currently programmed to identify over 120 chemical classes. For those classes, there are a more than 600 QSARs based on publicly available experimental data and confidential studies collected under the EPA New Chemicals Program. For each class, a standard EPA New Chemicals Program aquatic toxicity profile will be created using available QSARs and/or alternate QSAR approaches and professional judgment.

Potassium has been removed for proper estimation.

The prediction for ECOSAR Class Methacrylates-acid resulting in a value for daphnia LC50(48h) of 32157.898 mg/L .

The predicted value for daphnia LC50(48h) of 33447.594 mg/L use the Neutral Organics QSAR equations which represent baseline toxicity potential (minimum toxicity) assuming a simple non-polar narcosis model.

Description of key information

Short-term toxicity to aquatic invertebrates: 24&48h NOEC ≥ 100 mg/L, 24&48h EC50 > 100 mg/L for daphnia magna, static (SPA, CAS 31098-20-1, OECD 202, GLP)

Short-term toxicity to aquatic invertebrates: 48h EC50 = 32 resp. 33 g/L (ECOSAR class Methacrylates-acid resp. ECOSAR class Neutral Organic SAR (Baseline Toxicity)) (SPM, CAS 31098-21-2, ECOSAR estimation)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The relevant EC50 and NOEC values are taken from an OECD 202 GLP guideline study on a read-across substance, 2-Propenoic acid, 3-sulfopropyl ester, potassium salt (SPA). Read-across is justified as set out in the analogue approach justification in the target record.

The determined 24&48h NOEC ≥ 100 mg/L, 24&48h EC50 > 100 mg/L for daphnia magna on SPA does not trigger classification of SPM according to Regulation 1272/2008.