L-arabinose

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:

supporting study

Study period:

February 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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No. of test material: AD16081001
- Expiration date of the batch: 2019-08-09

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature
- Stability under test conditions: Stable under ambient conditions

Analytical monitoring:

yes

Details on sampling:

Eight replicate samples (2 mL per replicate) were taken from the test solution (100 mg/L) and from the control at the start and at the end of the test.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
The test solution used in the test was prepared by mechanical dispersion without using of any solubilising agent.
- Method: The test solution used in the test was prepared by mechanical dispersion. 0.0501 g of test item was dissolved in 501 mL dilution water (ISO Medium) in order to obtain the concentration of 100 mg/L. The test solution was prepared just before introduction of Daphnia (start of the experiment).
- Controls: Blank control (test water only), positive control (with Potassium dichromate)
- Introduction of Individuals: Twenty Daphnia per test group, divided into four replicates (glass beaker) of five animals, each replicates in ~40 mL test medium.
- Evidence of undissolved material: No

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Straus
- Source: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Age at test start: Less than 24 hours old
- Feeding during test: no

ACCLIMATION
- Acclimation period: no, breeding conditions same as test conditions

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

No

Hardness:

249 mg/L (as CaCO3)

Test temperature:

19.7 – 21.0 °C

pH:

8.06– 8.29

Dissolved oxygen:

7.37 – 7.51 mg/L

Salinity:

Not applicable

Conductivity:

Not specified

Nominal and measured concentrations:

Nominal: 100 mg/L
Measured mean: 114 mg/L at the start of the test (114 % of the nominal value), 97.7 mg/L at the end of the test (98 % of the nominal value)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers
- Material, fill volume: glass, 40 mL medium
- Aeration: No
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4

TEST MEDIUM / WATER PARAMETERS
- Preparation of dilution water: ISO medium, according to OECD 202

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light (artificial illumination) and 8 hours darkness
- Light intensity: 895 lux

EFFECT PARAMETERS MEASURED
- Visual observation of immobility or mortality after 24 and 48 h of exposure

PRELIMINARY EXPERIMENT
A non-GLP preliminary test was performed at the nominal concentration of 100 mg/L in order to check the toxicity of the test item on the daphnids. Ten daphnids (divided into two replicates) in the test concentration and control were exposed for 48 hours (respectively). In the preliminary test no immobility or any sub-lethal effect was detected in the treated test concentration and in the control group during the 48-h exposure period.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

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:

48 h

Dose descriptor:

EL10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

other: EC20

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

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:

In this 48-hour acute toxicity test on Daphnia magna, the obtained results showed that the test item had no significant toxic effects on the mobility of the daphnids up to the limit concentration of 100 mg/L. The 48h-EC50 was determined to be greater than 100 mg/L. All validity criteria were met. The results are based on the nominal test item concentration.

Results with reference substance (positive control):

The 24h EC50 was determined to be 1.41 mg/L (95% conf. limits: 1.19 – 1.68 mg/L).

Reported statistics and error estimates:

A limit test was performed and no immobility was observed in the treated group, therefore, statistical analysis was not performed. The NOEC, LOEC and ECx values of the test item were determined directly from the raw data.

Table 1: Immobilization of the test animals

Nominal concentration [mg/L]	Number of Daphnia tested	Number of immobilised Daphnia after		% of immobilised Daphnia after
		24 h	48 h	24 h	48 h
Control	20	0	0	0	0
100	20	0	0	0	0

 

Table 2: Concentration of Test Item measured in the Test Solutions

Nominal concentration mg/L	Start (June 06, 2018)		End (June 08, 2018)
	Concentration (mg/L)	% of the nominal	Concentration (mg/L)	% of the nominal
Control	not detected	-	not detected	-
100	97.4	97	99.8	100
	125	125	99.9	100
	122	122	96.7	97
	118	118	97.1	97
	118	118	96.2	96
	111	111	97.9	98
	113	113	96.6	97
	110	110	97.6	98
Mean:	114	114	97.7	98
RSD:	8	8	1	1

Validity criteria fulfilled:

yes

Conclusions:

In an Acute Immobilisation Test with Daphnia magna according to OECD TG 202 and EU Method C.2 the 48-h EC50 of the test item was determined to be > 100 mg/L.

Executive summary:

The acute immobilisation of the test item to Daphnia magna was determined in compliance with OECD TG 202 and EU Method C.2. A limit test was performed in which the test animals (5 animals per vessel) were exposed for 48 hours to aqueous test media containing the test item at the nominal concentration of 100 mg/L (4 replicates), a blank control containing test water only (4 replicates) and a positive control with potassium dichromate as reference item (last study: 2018 -02 -28 to 2018 -03 -01). The test item concentration was verified by LC-MS/MS analysis to be ± 20 % of the nominal concentration and hence results are based on nominal concentrations. There was no immobilisation observed in the twenty daphnids exposed to the test item treated group and there was no immobilization observed in the the blank control. Accordingly, the 48-h NOEC was determined as 100 mg/L (nominal) and the 48-h LOEC, EC10, EC20 and EC50 values were determined to be higher than 100 mg/L (nominal, directly from the raw data).The 24h EC50 for the reference substance potsassium dichtomate was determined to be 1.41 mg/L, confirming the suitability of the test system. All validity criteria of the guidelines were fulfilled.

Description of key information

In an Acute Immobilisation Test with Daphnia magna according to OECD TG 202 and EU Method C.2 the 48-h EC50 of the test item was determined to be > 100 mg/L.

Additional information

Key study

The acute immobilisation of the test item to Daphnia magna was determined in compliance with OECD TG 202 and EU Method C.2. A limit test was performed in which the test animals (5 animals per vessel) were exposed for 48 hours to aqueous test media containing the test item at the nominal concentration of 100 mg/L (4 replicates), a blank control containing test water only (4 replicates) and a positive control with potassium dichromate as reference item. The test item concentration was verified by LC-MS/MS analysis to be ± 20 % of the nominal concentration and hence results are based on nominal concentrations. There was no immobilisation observed in the twenty daphnids exposed to the test item treated group and there was no immobilization observed in the blank control. Accordingly, the 48-h NOEC was determined as 100 mg/L (nominal) and the 48-h LOEC, EC10, EC20 and EC50 values were determined to be higher than 100 mg/L (nominal, directly from the raw data). The 24h EC50 for the reference substance potassium dichtomate was determined to be 1.41 mg/L, confirming the suitability of the test system. All validity criteria of the guidelines were fulfilled (Toxi-Coop ZRT, 2018).

Supporting study

The short-term toxicity of the test item to daphnids was calculated using ECOSAR v1.11 class-specific estimation for Aldehydes (Mono). The test item falls in the applicability domain of the model. In result, the 48-h LC50 was calculated to be 12217.028 mg/L (SCC GmbH, 2018).

Disclaimer: In accordance with Article 13 and taking into account the conditions set out in Annex XI of Regulation (EC) No 1907/2006, information on intrinsic properties of substances might be generated by alternative methods other than tests if the (Q)SAR model has been proven to be valid, the substance falls in the applicability domain of the model, results are sufficient for the classification and labeling and/or risk assessment and the applied method is reliably and adequately documented. These criteria are considered to be fulfilled and, hence, the result to be suitable for classification and labelling purposes and/or risk assessment.

Conclusion

Based on results of a GLP-compliant guideline study (Toxi-Coop ZRT, 2018) the 48-h EC50 is considered to be > 100 mg/L (nominal). This result is supported by an ECOSAR estimation (SCC GmbH, 2018) since the calculated 48-h EC50 of the test item was even higher (48-h LC50 = 12217.028mg/L).