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Short-term toxicity to aquatic invertebrates

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Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
6 October - 28 October 2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP - guideline study
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
2004-04-13
Deviations:
yes
Remarks:
: The temperature for the pre-test lay in a range of 22.1 to 22.3 °C and therefore higher than stated in the guidelines. As no immobility occurred during the test, this deviation was stated as uncritical.
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Version / remarks:
1992-07-31
Deviations:
yes
Remarks:
: The temperature for the pre-test lay in a range of 22.1 to 22.3 °C and therefore higher than stated in the guidelines. As no immobility occurred during the test, this deviation was stated as uncritical.
Qualifier:
according to
Guideline:
ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))
Version / remarks:
June 1996
Deviations:
yes
Remarks:
: The temperature for the pre-test lay in a range of 22.1 to 22.3 °C and therefore higher than stated in the guidelines. As no immobility occurred during the test, this deviation was stated as uncritical.
GLP compliance:
yes (incl. certificate)
Analytical monitoring:
yes
Details on sampling:
At the beginning and at the end of the test, the concentration of the test item in the test solutions was determined .
Vehicle:
no
Details on test solutions:
Preparation of the test solutions

Pre-Test : A stock solution containing 1000 mg/L in dilution water was prepared . Treatments : 1000 / 100 / 10 / 1 mg/L

Main Study : A test solution containing 1000 mg/L test item in dilution water was prepared. Treatments : 1000 mg/L

Reference Test : A stock solution containing 250 mg K2Cr2O7/L in deionised water was diluted with dilution water to give a series of concentrations ranging from 0.625 to 3.0 mg/L.

Dilution Water : Drinking water with an enrichment of certain minerals (as demanded in the guidelines) is used in the test.
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name : Water flea
- Source : Origin : Umweltbundesamt Berlin ; The animals are kept for the use in toxicity tests. They multiply by parthenogenesis, thus being genetically identical . The holding is performed similar to the method described in EN ISO 6341 .
- Age at study initiation (mean and range, SD): < 24 h
- Method of breeding: maintained in glass beakers with a nominal volume 2 L containing M4-Medium (see "Any other information on materials and methods incl. tables") at temperature 20+-2°C; 16 hours light, 8 hours dark , using neon tubes ; Food : green algae (Desmodesmus subspicatus) ; changing of medium twice a week
- Feeding during test : none

Selection of Daphnia
24 hours before the start of the test, the adult animals were separated from the youngs . 23 hours later, the adults were caught with the help of a glass tube, and the newborn daphnia , aged between 0 and 23 hours, were sieved from the medium and immediately placed into a 250 ml-beaker containing dilution water. After a settling-in period of 30 minutes, animals which showed no apparent damage were used for the test.
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h
Hardness:
250 mg CaCO3/L
Test temperature:
Pre-Test :
The temperature for the pre-test lay in a range of 22.1 to 22.3 °C and therefore higher than stated in the guidelines. As no immobility occurred during the test, this deviation was stated as uncritical.
Main Study : 20.4°C - 21.2°C
pH:
Pre-Test : 7.7 - 8.0
Main Study : 7.8 - 8.1
Reference Test : 7.7 - 8.1
Dissolved oxygen:
Pre-Test : 8.0 - 9.6 mg/L
Main Study : 8.1 - 8.4 mg/L
Reference Test : 8.2 - 8.5 mg/L
Nominal and measured concentrations:
The measured concentration after 48 hours was 99 % of the start concentration. The correlation between measured and nominal concentrations was very good. Therefore, the test item was stated as stable under the conditions of the test and the determination of the biological results was based on the nominal concentration.
(For details see "Any other information on materials and methods incl. tables")
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type : open
- Material, size, headspace, fill volume : glass beakers , nominal volume 50 ml containing 20 ml test solution , tall shape
- Aeration : none
- Renewal rate of test solution (frequency/flow rate) :The test vessels were left to stand for 48 hours
- No. of organisms per vessel : 5
- No. of vessels per concentration (replicates) : 4
- No. of vessels per control (replicates) : 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water : Drinking water with an enrichment of certain minerals (as demanded in the guidelines) was used in the test.
Dilution water :
Ca2+ : 80.09 mg/L
Mg2+ : 12.16 mg/L
Na+ : 18.12 mg/L
K+ : 3.10 mg/L
Resulting hardness : 2.502 mmol/L
Resulting hardness : 250 mg CaCO3/L
After preparation, the dilution water was aerated, and the pH was adjusted to 7,8 ± 0,2.


OTHER TEST CONDITIONS
- Lighting : none

TEST CONCENTRATIONS
- Pre-Test : 1000/100/10/1 mg/L
- Main study : 1000 mg/L
Reference substance (positive control):
yes
Remarks:
Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9)
Duration:
24 h
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: immobilization
Duration:
24 h
Dose descriptor:
other: EC50i
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: immobilization
Duration:
24 h
Dose descriptor:
other: EC100i
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: immobilization
Key result
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: immobilization
Key result
Duration:
48 h
Dose descriptor:
other: EC50i
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: immobilization
Duration:
48 h
Dose descriptor:
other: EC100i
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: immobilization
Details on results:
In the initial experiment, four concentrations of the test item in a geometric series (spaced by factor 10, the highest being 1000 mg/L) were used. For each concentration, ten daphnia were exposed to the test item for 48 hours.
None of the daphnia were immobilised in the treatments and the control.

The main study was performed as a limit test using the nominal concentration 1000 mg/L, which showed no effect on the daphnia. The real concentration of the test item in the treatment was determined before and after the test. The test item can be stated as stable under the test conditions. Therefore the nominal concentration was used to estimate the results.
Results with reference substance (positive control):
The 24h-EC50i of potassium dichromate was determined in a currently performed reference study as 2.0 mg/L, which lies within the demanded range of 0.6 - 2.1 mg/L.
Validity criteria fulfilled:
yes
Remarks:
Validity criteria of the test guideline fulfilled.
Conclusions:
The study is regarded as a valid guideline study with certificated GLP compliance. The acute toxicity of 1-(2-Hydroxy-3-sulfopropyI)-pyridinium-betain to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50i value of >1000 mg/l. The No Observed Effect Concentration at 48 hours was 1000 mg/I. No classification as hazardous to the environment is triggered, neither acute nor chronic.
Executive summary:

This study was performed in order to evaluate the toxic potential of 1-(2-Hydroxy-3- sulfopropyl)-pyridinium-betain towards freshwater shrimp, using the species Daphnia magna. Daphnia magna STRAUS, which belongs to the family of crustacea, was chosen in the guideline as a typical part of zoo-plancton. The study was conducted in accordance with the following guidelines:

♦OECD Guideline for Testing of Chemicals No. 202, adopted April 13th 2004: „Daphnia sp., Acute Immobilisation Test "

♦EU-Guideline C.2. ,Acute Toxicity for Daphnia", adopted July 31st 1992

♦EN ISO 6341 „Bestimmung der Hemmung der Beweglichkeit von Daphnia magna Straus (Cladocera, Crustacea) - Akuter Toxizitätstest" as of June 1996

In the initial experiment, four concentrations of the test item in a geometric series (spaced by factor 10, the highest being 1000 mg/L) were used. For each concentration, ten daphnia were exposed to the test item for 48 hours. None of the daphnia were immobilised in the treatments and the control.

The main study was performed as a limit test at the concentration 1000 mg/L. Twenty daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised daphnia were counted. The 24h-EC50i of potassium dichromate (reference item) was determined in a currently performed reference study as 2.0 mg/L, which lies within the demanded range of 0.6 - 2.1 mg/L.

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using TOC-determination. The recovery after 48 hours was 99 % of the start concentration, the correlation between nominal and measured concentration was very good (98 %). Therefore, the test item was stated as stable under the conditions of the test and the determination of the biological results was based an the nominal concentration.

The following results were determined for the test item 1 -(2-Hydroxy-3-sulfopropyl)-pyridinium-betain (species: Daphnia magna).

24h-NOEC : 1000 mg/L

48h-NOEC : 1000 mg/L

24h-EC50i : > 1000 mg/L

48h-EC50i : > 1000 mg/L

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Study period:
2001-09-18 - 2001-09-20
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

1. HYPOTHESIS FOR THE ANALOGUE APPROACH

According to ECHA’s guidance document on information requirements and chemical safety assessment Chapter R.6 „QSARs and grouping of chemicals”, there are two techniques for grouping chemicals known when reading across to cover data gaps, i.e., category approach and analogue approach [ECHA, 2008].
A chemical category is a group of chemicals whose physico-chemical and human health and/or environmental toxicological properties and/or environmental fate properties are likely to be similar or follow a regular pattern as a result of structural similarity (or other similarity characteristic). The term analogue approach is used when the grouping is based on a very limited number of chemicals, where trends in properties are not apparent. Categories of chemicals are selected based on the hypothesis that the properties of a series of chemicals with common structural features will show coherent trends in their physico-chemical properties, and more importantly, in their toxicological (human health / ecotoxicity) effects or environmental fate properties [ECHA, 2008].
As set out in the guidance document, a chemical category is a group of chemicals whose physico-chemical and human health and/or environmental toxicological properties and/or environmental fate properties are likely to be similar or follow a regular pattern as a result of structural similarity. The similarities may be based on the following:
- common functional group(s) (e.g. aldehyde, epoxide, ester, specific metal ion);
- common constituents or chemical classes, e.g., similar carbon range numbers;
- an incremental and constant change across the category (e.g. a chain-length category), often observed in physico-chemical properties, e.g. boiling point range;
- the likelihood of common precursors and/or breakdown products, via physical or biological processes, which result in structurally similar chemicals (e.g. the metabolic pathway approach of examining related chemicals such as acid/ester/salt) [ECHA, 2008].

It is aimed to combine similarity patterns in order to cover data gaps for PPSOH. One rational for the analogue approach is the high structural similarity between the source and the target substance. 3-pyridinium-1-ylpropane-1-sulfonate (PPS) (source) and 1-(2-hydroxy-3-sulphonatopropyl)pyridinium, inner salt (PPSOH) (target) are structurally identical except an additional hydroxyl group on position 2 of the propyl moiety of the target substance. Despite the fact that a hydroxyl group may alter the toxicological or toxicokinetic behaviour of a substance, this effect is considered 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 propyl moiety and the pyridine. 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 toxicodynamic and toxicological behaviour. Second, the target substance is not only a metabolite of the source chemical, resulting from CYP450 metabolization (ToxTree estimation, Ideaconsult Ltd (2004-2013). Estimation of Toxic Hazard – A decision Tree approach, version 2.6.6, http://toxtree.sourceforge.net/), but they also share common metabolites, as shown from additional modelling of the source chemical metabolites (see respective table in the attachment).
Further, both substances show similar (eco-)toxicological properties in the endpoints for which data for both substances is available, which is considered proof of the suitability of the analogue approach, i.e. cross-reading from PPS to PPSOH.

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

Source Chemical: 3-pyridinium-1-ylpropane-1-sulfonate / Pyridinium, 1-(3-sulfopropyl)-, hydroxide, inner salt / CAS 15471-17-7 / EC 239-491-3 (PPS), SMILES [O-]S(=O)(=O)CCC[n+]1ccccc1, MW 201.2428, C8H11NO3S

Target Chemical: Pyridinium, 1-(2-hydroxy-3sulfopropyl)-, hydroxide, inner salt / 2-hydroxy-3-pyridinium-1-ylpropane-1-sulfonate / CAS 3918-73-8 / EC 223-485-2 (PPSOH) SMILES OC(C[n+]1ccccc1)CS(=O)(=O)[O-], MW 217.2422, C8H11NO4S

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 hydroxyl group of the target chemical becomes obvious. All relevant information on similar metabolites can be retrieved from the respective table, in brief, the target substance is not only a metabolite of the source chemical, resulting from CYP450 metabolization, but they also share common metabolites, as shown from additional modelling of the source chemical metabolites. Considering the non-metabolized source and target chemicals only, the molecular weight only differs in the weight of a hydroxyl group and is hence in the same range, i.e. 201.24 g/mol and 217.24 g/mol, indicating per se the potential for absorption.
Both substances are solids which melt under decomposition at rather high temperatures, i.e. ≥ 245°C and have hence a negligible vapour pressure. Both compounds are very soluble in water, and their logPow is in a negative range.

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 molecular weights below 500 are favourable for absorption). Relevant for the endpoint acute toxicity dermal and skin sensitisation is the absorption resp. retention in the skin. In order to cross the skin, a compound must first penetrate into the stratum corneum and may subsequently reach the epidermis, the dermis and the vascular network. The stratum corneum provides its greatest barrier function against hydrophilic compounds, whereas the epidermis is most resistant to penetration by highly lipophilic compounds. Substances with a molecular weight below 100 are favourable for penetration through the skin and substances above 500 are normally not able to penetrate. The substance must be sufficiently soluble in water to partition from the stratum corneum into the epidermis. Therefore if the water solubility is below 1 mg/L, dermal uptake is likely to be low. Additionally logPow values between 1 and 4 favour dermal absorption. In the case of both the target and source chemical, due to their high water solubility and very low logPow, their absorption is very likely to be hindered in the stratum corneum. Nevertheless, once reaching the epidermis, i.a. due to their common small size, their absorption is favoured.
Besides the common physico-chemical and toxicokinetic properties, they exhibit a similar toxicological behaviour. Both substances are relatively non-toxic, with oral LD50 values >5000 mg/kg bw, and are non-irritating the skin and eyes.
Hence, due to the above-mentioned similarities of the source and target chemical, with regard to their structure, functional groups, toxicokinetic and toxicological behaviour, it can be reasonably concluded that a similar behaviour of the target chemical regarding its acute dermal toxicity and skin-sensitizing properties compared to the source chemical can be expected.
As indicated by studies on gene mutations in bacteria (both substances), chromosome aberrations in mammalian cells (PPS) and gene mutations in mammalian cells (PPSOH), both substances are not genotoxic. It can hence be reasonable concluded that a positive result in a chromosome mutation test on PPSOH can be excluded and read-across is justified, an underestimation of the actual hazard for genotoxic insults is unlikely. Further, as both substances are not acutely toxic, i.e. oral LD50 values are >5000 mg/kg, due to their physico-chemical properties a relevant accumulation in the body can be neglected, and no systemic or reprotoxic effects at all were noted in the OECD 422 study on PPS at the limit dose of 1000 mg/kg, the target chemical PPSOH does not need to be regarded as harmful upon repeated exposure or reproductive toxicant, too.

Besides the common physico-chemical and toxicokinetic properties, they exhibit a similar ecotoxicological behaviour. Both substances are relatively non-toxic towards aquatic invertebrates, both 48h EC50 values and even NOECs were above the limit value for classification, the EC50(48h) was even shown to be > 1000 mg/l for PPSOH. PPS showed results of LC50 (96h) > 1000 mg/L and NOEC (96h) > 1000 mg/L in the trout in an acute fish toxicity study acc. OECD 203. The EC50(72h) in algae in a study acc. OECD 201 is also above 100 mg/l, allowing in summary the conclusion that acute toxicity testing in fish would also not indicate any hazardous properties of PPSOH, so the assumption of a similar ecotoxicity profile and so read-across from PPS is also justified here.
In consequence, a similar behaviour can be expected in microorganisms. PPS is non-toxic to microorganisms, in a OECD 209 no toxicity was observed at a concentration of 1000 mg/l, so the following values were obtained for activated sludge: EC50(3h) > 1000 mg/L, NOEC(3h) = 1000 mg/L. This allows the conclusion that the substance is relatively non-toxic towards microorganisms.

Hence, due to the above-mentioned similarities of the source and target chemical, with regard to their structure, functional groups, common metabolites, toxicokinetic and ecotoxicological behaviour, it can be reasonably concluded that a similar behaviour of the target chemical regarding its ecotoxicological and toxicological properties compared to the source chemical can be expected. In summary, the target chemical PPSOH needs to be regarded as relatively non-toxic.


4. DATA MATRIX
The following table shows the available data relevant to justify the read-across from the source to the target chemical for several endpoints in order to omit testing for animal welfare:

Endpoint Source: PPS Target: PPSOH
Molecular weight 201.24 g/mol 217.24 g/mol
Physical state solid solid
Partition coefficient logPow < -2.78 at 21.5°C logPow < -2
Water solubility 240.5 g/L at 25°C (EpiSuite estimation) 1280 g/l at 23°C
Biodegradation 86 % degradation after 28 days Not readily biodegradable: no degradation observed (DOC) (OECD 301E)
readily biodegradable
Hydrolysis Not expected to undergo hydrolysis Hydrolysis can be excluded
Short-term toxicity to fish LC50 (96h) > 1000 mg/L, n/a
NOEC (96h) > 1000 mg/L (trout, OECD 203)
Short-term toxicity to aquatic invertebrates 24&48h NOEC ≥ 100 mg/L EC50(48h) > 1000 mg/l
24&48h EC50 > 100 mg/L (OECD 202) NOEC(48h) = 1000 mg/l (OECD 202)
Short-term toxicity to aquatic algae n/a EC50(72h) > 100 mg/l (OECD 201)
Toxicity to microorganisms EC50(3h) > 1000 mg/L, n/a
NOEC(3h) = 1000 mg/L (activated sludge, OECD 209)
MIC = 0.12 g/mL (Pseudomonas putida)
Acute toxicity oral LD50 > 5000 mg/kg (rat, OECD 401) LD50 > 5000 mg/kg (rat, OECD 423))
Acute toxicity dermal LD50 > 2000 mg/kg (rat, OECD 402) n/a
Skin irritation Not irritating (in vivo, rabbit) not corrosive (OECD 431, EpiDerm)
Eye irritation Not irritating (in vivo, rabbit) moderately irritant (HET-CAM, GLP)
Skin sensitization Not sensitizing (GPMT, OECD 406) n/a
Gene mutation in bacteria Negative ± S9 (OECD 471) negative ± S9 (OECD 471)
Chromosome aberration in mammalian cells Negative ± S9 (OECD 487) n/a
Gene mutation in mammalian cells n/a negative ± S9 (OECD 490)
Repeated dose toxicity NOAEL ≥ 1000 mg/kg (rat, OECD 422) n/a
Toxicity to reproduction NOAEL ≥ 1000 mg/kg (rat, OECD 422) n/a
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
SI 1999/3106
Analytical monitoring:
yes
Details on sampling:
- Concentrations: 100 mg/L (An amount of test material (200 mg) was dissolved in reconstituted water with the aid of ultrasonication for approximately 1 minute and the volume adjusted to 2 litres to give a 100 mg/L test concentration.)
Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): water
- Evidence of undissolved material (e.g. precipitate, surface film, etc): The test preparations were observed to be clear, colourless solutions throughout the definitive study.
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Strain:1st instar Daphnia magna
- Source: from in-house laboratory cultures
- Age at study initiation (mean and range, SD): less than 24 hours old
- Method of breeding: Adult Daphnia were maintained in polypropylene vessels containing approximately 2 litres of reconstituted water in a temperature controlled room at 21°C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing. The diet and diluent water are considered not to contain any contaminant that would affect the integrity or outcome of the study.
- Feeding during test: no feeding during substance incubation
- Food type: a suspension of algae (Chlorella sp.).
- Frequency: daily
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h
Post exposure observation period:
No details about the post exposure observation period are reported.
Hardness:
The reconstituted water had an approx. theoretical total hardness of 250 mg/L as CaCO3.
Test temperature:
21°C
pH:
7.8 - 7.9
(Control: 7.8 - 7.9)
Dissolved oxygen:
8.2 - 8.5 mg O2/L
(Control: 8.3 - 8.5 mg O2/L)
Salinity:
No salinity details are reported.
Nominal and measured concentrations:
100 mg/L
(concentration was selected based on the preliminary range-finding study)
Details on test conditions:
Air saturation volume (ASV): 92 - 96 % (Control: 93 - 96 %)
Reference substance (positive control):
not required
Remarks:
Not mandatory according to OECD Guideline.
Duration:
48 h
Dose descriptor:
EC50
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:
No further details of results are reported.
Results with reference substance (positive control):
Not applicable.
Reported statistics and error estimates:
No statistics and error estimates are reported.
Validity criteria fulfilled:
yes
Remarks:
Validity criteria of the test guideline fulfilled.
Conclusions:
The study is regarded as a valid guideline study with certificated GLP compliance. According to the reported EC50 value (> 100 mg/L) the test substance is not classified as toxic to aquatic invertebrates. No classification as hazardous to the environment is triggered, neither acute nor chronic.
Executive summary:

The acute toxicity to aquatic invertebrates of the test substance was tested according to OECD Guideline 202 (EU Method C.2) in a static freshwater test with Daphnia magna as test organisms (Wetton and Mullee, 2001). The study was conducted under certificated GLP compliance. The test duration was 48 hours with a substance concentration of 100 mg/L, which was selected based on the preliminary range-finding study. No reference substance was used since it is not essential according to the guideline description. A temperature of 21 °C was held constant, the pH range was 7.8 - 7.9 for the test compound as well as for the control. The dissolved oxygen value was 8.2 - 8.5 mg O2/L (Control: 8.3 - 8.5 mg O2/L) and a air saturation volume (ASV) of 92 - 96 % (Control: 93 - 96 %) was measured. The reconstituted water had a theoretical hardness of 250 mg/L CaCO3. No immobility of daphnids was detected at the tested concentration, thus as result an EC50 (48h) > 100 mg/L and a NOEC value of 100 mg/L was reported. It was considered unnecessary and unrealistic to test at concentrations in excess of 100 mg/L.

Description of key information

Short-term toxicity to aquatic invertebrates: EC50(48h) > 1000 mg/l, NOEC(48h) = 1000 mg/l, based on immobilization, for Daphnia magna (OECD 202, EU method C.2, GLP)

Short-term toxicity to aquatic invertebrates: EC50(48h) > 100 mg/l, NOEC(48h) = 100 mg/l, based on immobilization, for Daphnia magna (read-across from PPS, OECD 202, EU method C.2, GLP)

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
1 000 mg/L

Additional information