Sodium salts of substituted amino acid

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:

09 October 2018 - 21 November 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13 April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- The test item was handled and stored in such a way that degradation/hydrolysis and inhomogeneity were prevented.
- Solubility of the test item in water: completely miscible

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 mg/L (control) and 100 mg/L (limit test concentration)
- Sampling method: 2.0 mL samples were taken at t=0 h and at t=48 h from the approximate centre of the test vessels
- Sample storage conditions before analysis: in a freezer (≤ -15°C)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance was completely soluble in test medium at the concentrations tested. Based on the purity of the test substance and to correct for the water content, a correction factor of 3.6 was applied. Preparation of test solutions started with the highest concentration of 100 mg/L applying a 15-minute period of magnetic stirring to ensure complete dissolution of the test item in test medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium.
- Controls: a blank control was included consisting of test medium without test item or other additives.
- Evidence of undissolved material: no, all test solutions were clear and colorless at the end of the preparation procedure.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Crustacea, Cladocera)
- Strain/clone: Straus, 1820
- Age at study initiation: < 24 hours
- Validity of the batch: Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%1, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.
- Method of breeding: Approximately 250 newborn daphnids, i.e. less than 3 days old, were placed into 5 litres of medium in an allglass culture vessel. After 7 days of cultivation, the cultures were renewed. Daphnids were daily fed with a suspension of fresh water algae.
- Culture medium: M7
- Source: In-house laboratory culture with a known history.
- Age of parental stock: 4 weeks (maximum)
- Feeding during test : no

ACCLIMATION : no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

180 mg CaCO3/L

Test temperature:

19°C

pH:

Start of the test: 7.9 (control vessel) and 6.4 (vessel containing test item)
End of the test: 8.4 (control vessel) and 8.0 (vessel containing test item)

Dissolved oxygen:

Start of the test: 9.8 mg O2/L (control vessel and vessel containing test item)
End of the test: 9.6 mg O2/L (control vessel and vessel containing test item)

Nominal and measured concentrations:

Nominal: 100 mg/L
Measured: 105 mg/L at t=0 h and 103 mg/L at t=48 h
Because the measured concentration at t=0 h was 105% of the nominal concentration and the concentration was stable over the test period (98% of initial), it was valid to base the effect parameter on the nominal concentration of 100 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 60 mL, all-glass, open vessels
- Fill volume: 50 mL
- Aeration: no
- 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: tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands)
- Culture medium different from test medium: yes, test medium M7 was prepared according to OECD 202
- Intervals of water quality measurement: pH and dissolved oxygen of the medium were measured at the beginning and at the end of the test, temperature of the medium was measured continuously.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: daily photoperiod of 16 hours

EFFECT PARAMETERS MEASURED: immobility (including mortality) at 24 hours and 48 hours

RANGE-FINDING STUDY
- Test concentrations: 0.10, 1.0, 10 and 100 mg/L and a control
- Results used to determine the conditions for the definitive study: yes, as no immobility was observed in the control or any of the tested concentrations, the definitive study was performed using only a limit concentration of 100 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate (November 2018)

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:

- Any behavioural or biological abnormalities observed: no
- No immobility or mortality was observed at the limit concentration of 100 mg/L after 48 hours of exposure and therefore the 48h-EC50 was determined to be >100 mg/L
- Measured temperature and oxygen concentrations during the test complied with the requirements laid down in the study plan. The pH varied 1.6 unit but remained within the acceptable range of 6-9. Since no effects were observed it was concluded that the variation of the pH above 1.5 unit had no effect on the results.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: the 48h-EC50 was 0.40 mg/L with a 95% confidence interval between 0.33 and 0.48 mg/L.
- Test concentrations: 0.10, 0.18, 0.32, 0.56, 1.0 and 1.8 mg/L and a control
- Other: the result was in line with the historical data at the test facility (EC50 of 0.28 - 0.90 mg/L) and therefore the batch of D. magna was considered valid for testing.

Reported statistics and error estimates:

No statistics were applied as the EC50 could not be calculated because the test item proved to be non-toxic (EC50 > maximum concentration tested).

Validity criteria fulfilled:

yes

Remarks:

1) In the control, no daphnids became immobilised or showed other signs of disease or stress and 2 ) the dissolved oxygen concentration at the end of the test was ≥3 mg/L in control and test vessels.

Conclusions:

Based on the results of a short-term aquatic toxicity study, performed according to OECD 202 and GLP principles, Substituted amino acid (2) solution showed no toxicity towards Daphnia magna in a 48 hour exposure period when tested up to a limit concentration of 100 mg/L. Therefore, the 48h-EC50 was determined to exceed an analytically confirmed nominal concentration of 100 mg/L.

Executive summary:

The objective of the study was to evaluate Substituted amino acid (2) solution FC-C 13587 for its ability to generate acute toxic effects on the mobility of Daphnia magna during an exposure period of 48 hours and, if possible, to determine the EC₅₀ at 24 and 48 hours of exposure.

The study procedures described in this report were based on the OECD guideline No. 202, 2004.

The batch of Substituted amino acid (2) solution FC-C 13587 tested was a clear colourless solution with a purity of 27.8% and was completely soluble in test medium at the concentrations tested. Based on the purity/composition of the test item, a correction factor of 3.6 was applied to compensate for the water content of the test item. All further concentrations reported are based on pure test item.

A limit test was performed based on the results of a preceding range-finding test. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control and to a nominal concentration of 100 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.

No immobility was observed in the control and at the limit concentration throughout the test.

Samples taken from the limit concentration of nominally 100 mg/L were analysed. The actual exposure concentration was at 103-105% relative to nominal throughout the test.

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

In conclusion, the 48h-EC₅₀ for Daphnia magna exposed to Substituted amino acid (2) solution FC-C 13587 was beyond the range of concentrations tested, i.e. exceeded the regulatory limit concentration of 100 mg/L.

Description of key information

The ecotoxicity data in this dossier from Sodium salts of substituted amino acid are read across from Substituted amino acid (2) solution. This read across is considered to be justified because Substituted amino acid (2) solution contains about 50% of Substituted amino acid (i.e.the L stereo isomer of Substituted amino acid (2) solution) and no ecotoxicity (EC50>100 mg/L) was observed for Substituted amino acid (2) solution in the acute daphnia and algae test. There will be no significant difference in ecotoxicity of Substituted amino acid or Sodium salts of substituted amino acid because test substances are tested in very diluted form in buffered matrixes. It is therefore considered extremely unlikely that any significant aquatic ecotoxicity will be observed for Sodium salts of substituted amino acid.

Based on the results of a short-term aquatic toxicity study, performed according to OECD 202 and GLP principles, Substituted amino acid (2) solution showed no toxicity towards Daphnia magna in a 48 hour exposure period when tested up to a limit concentration of 100 mg/L. Therefore, the 48h-EC50 was determined to exceed an analytically confirmed nominal concentration of 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The objective of the study was to evaluate Substituted amino acid (2) solution FC-C 13587 for its ability to generate acute toxic effects on the mobility of Daphnia magna during an exposure period of 48 hours and, if possible, to determine the EC₅₀ at 24 and 48 hours of exposure.

The study procedures described in this report were based on the OECD guideline No. 202, 2004.

The batch of Substituted amino acid (2) solution FC-C 13587 tested was a clear colourless solution with a purity of 27.8% and was completely soluble in test medium at the concentrations tested. Based on the purity/composition of the test item, a correction factor of 3.6 was applied to compensate for the water content of the test item. All further concentrations reported are based on pure test item.

A limit test was performed based on the results of a preceding range-finding test. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control and to a nominal concentration of 100 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.

No immobility was observed in the control and at the limit concentration throughout the test.

Samples taken from the limit concentration of nominally 100 mg/L were analysed. The actual exposure concentration was at 103-105% relative to nominal throughout the test.

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

In conclusion, the 48h-EC₅₀for Daphnia magna exposed to Substituted amino acid (2) solution FC-C 13587 was beyond the range of concentrations tested, i.e. exceeded the regulatory limit concentration of 100 mg/L.