ethyl N2-dodecanoyl-.sc.l.sc.-argininate hydrochloride

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:

From March 3, 2000 to February 12, 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Guideline study with GLP.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Directive 92/69/EC Method C2

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Substance: L.A.E.
Purity: 90%
Batch number: 2625
Expiry date March 14, 2001.

Analytical monitoring:

yes

Details on sampling:

- Sampling method: At the start of the definitive test, two samples (20 ml) were taken from the freshly-prepared control and test media; they were stored overnight in a refrigerator before one sample from each set was analysed. After 48 hours, the contents of the test vessels from each group were pooled and further samples taken for analysis. One sample was analysed immediately and the other was stored in a refrigerator in case further
analysis was required.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance (20 mg) was added directly to the dilution medium (1.5 l) in a volumetric flask. The contents of the flask were treated with ultrasound for eight minutes before being made up to volume (2 l) with dilution medium. This preparation was either used directly at the highest test concentration or diluted to provide the test media at the four lower concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name:Daphnia magna
- Source:Institute National de Recherche Chimique Appliqué, France
- Strain: Originating from the Institute National de Recherche Chimique Appliqué (IRChA), France.
- Age at study initiation (mean and range, SD): <24 hours old
- Method of breeding: Stock cultures of Daphnia magna were maintained in glass vessels containing approximately 800 ml of Elendt M4 culture medium in a temperature-controlled laboratory at nominally 20 ± 2°C. A photoperiod of 16 hours light : 8 hours dark was maintained. The culture medium was renewed at least twice each week. Cultures were fed daily with a suspension of the unicellular green alga, Chlorella vulgaris, to provide
approximately 0.1 to 0.2 mg carbon per daphnid, per day.
- Feeding during test: No

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

246 mg CaCO3/L

Test temperature:

19.4-20.3 ºC

pH:

7.7-8.0

Dissolved oxygen:

94-103% air saturation value

Nominal and measured concentrations:

- Concentrations (Nominal): 0.427, 0.939, 2.07, 4.55 and 10 mg/L
- Concentrations (Measured): 0.3, 0.746, 1.66, 4.00 and 8.98 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: Glass vessels containing approximately 100 ml of Elendt M4 culture medium in a controlled temperature.
- Aeration: No
- Renewal rate of test solution (frequency/flow rate): No
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 medium prepared using analytical grade reagents in ultra high purity water produced by reverse osmosis.
- Intervals of water quality measurement: The temperature, pH and dissolved oxygen levels of control and test media were recorded at the start and
at the end of the study; the total hardness and alkalinity of the dilution medium were recorded at the start of the test.

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16 hours light/8 hours dark maintained.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The numbers of mobile, immobile and floating Daphnia were counted 24 and 48 hours after the start of the study.

TEST CONCENTRATIONS
- Range finding study: Range finding test conducted at concentrations of 1, 10 and 100 mg/L.
- Test concentrations:
- Concentrations (Nominal): 0.427, 0.939, 2.07, 4.55 and 10 mg/L
- Concentrations (Measured): 0.3, 0.746, 1.66, 4.00 and 8.98 mg/L

Reference substance (positive control):

yes

Remarks:

(The sensitivity is periodically assessed using the reference substance potassium dichromate).

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

6.54 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL= 4-8.98

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 8.98 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

4 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Evaluation data of EC50 values were calculated using a computer program: Stephan; (1977, 1982) which uses the number of Daphnia exposed and the number immobile at each concentration.

Results with reference substance (positive control):

The results are within the range typically obtained in this laboratory, 0.3 to 0.8 mg/L.

Cummulative immobilisation, below:

Initial measured dehydrated LAE conc., mg/L	CUMULATIVE NUMBERS OF IMMOBILE DAPHNIA AT EACH NOMINAL CONCENTRATION (mg/L)
	24 hours						48 hours
	R1	R2	R3	R4	TOTAL	%	R1	R2	R3	R4	TOTAL	%
nd	0	0	0	0	0	0	0	0	0	0	0	0
0.3	0	0	0	0	0	0	0	0	0	0	0	0
0.746	0	0	0	0	0	0	0	0	0	0	0	0
1.66	0	0	0	0	0	0	0	0	0	0	0	0
4	0	0	0	0	0	0	0	0	0	0	0	0
8.98	5	4	4	4	17	85	5	4	4	5	18	90

R: replicate numbernd: none detected (<0.0284 mg/L)

Validity criteria fulfilled:

yes

Remarks:

(No immobilization was observed in the controls and the dissolved oxygen concentrations were in the acceptable range).

Conclusions:

The 48 hour EC50 of L.A.E. for the immobilisation of Daphnia magna was 6.54 (95% confidence limits of 4.00 and 8.98 mg/L). No observed effect concentration was at 4.00mg/L.

Executive summary:

The acute toxicity to Daphnia magna was realised according to OECD 202 and EU method C2. The 48 hour EC50 of dehydrated N^α-Lauroyl-L-arginine ethyl ester monohydrochloride (L.A.E) for the immobilisation of Daphnia magna was 6.54 (95% confidence limits of 4.00 and 8.98 mg/L). No observed effect concentration was at 4.00mg/L.

Description of key information

Key study: Test method according to OECD 202 and EU method C.2. GLP Study. The 48 hour EC50 of dehydrated L.A.E. for the immobilisation of Daphnia magna was 6.54 mg/L (95% confidence limits of 4.00 and 8.98 mg/L). No observed effect concentration was at 4.00mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

6.54 mg/L