Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
5 december 2008 - 30 january 2008
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Study performed according to an international guideline and according to GLP. The validity criteria were fulfilled except the lack of data relating to the analytical monitoring showing that the concentrations of the test item were maintained during the test. However, the test has been performed under semi-static conditions and according to the long-term toxicity to Daphnia, the substance is stable during 48 hours. Thus, we can considered that in a short-tem study, the susbtance is also stable.
Qualifier:
according to
Guideline:
ISO 10253 (Water quality - Marine Algal Growth Inhibition Test with Skeletonema costatum and Phaeodactylum tricornutum)
Deviations:
no
GLP compliance:
yes
Analytical monitoring:
no
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION :
- Method : the test solutions were prepared without using of any organic solvent
- Stock solution : 0.01006 g test item in 1000 ml treated water in order to obtain a nominal concentration of 10.06 mg/L
- Controls : treated seawater without test item
- Evidence of undissolved material (e.g; precipate, surface film, etc) : No
Test organisms (species):
Skeletonema costatum
Details on test organisms:
TEST ORGANISM
- Common name:Skeletonema costatun
- Culture number : C5B2A
- Method of cultivation: pre-cultures in the exponential growth phase were prepared from stock laboratory cultures by inoculating treated seawater with nutrient medium (culture medium) to a cell density of approximately 2 x 10E3 to 10E4 cells per millilitre. The pre-cultures were incubated at approximately 20 +/- 2°C under constant illumination for 3 days +/6 1 day, and where uses as the iniculum source for the test.

ACCLIMATION
- Acclimation period: not stated
- Culturing media and conditions: see method of cultivation above
- Any deformed or abnormal cells observed: data not available
Test type:
static
Water media type:
saltwater
Limit test:
no
Total exposure duration:
72 h
Test temperature:
At 0h : 20.2 - 21.4
At 24h : 19.1 - 21.0
At 48h : 19.9 - 21-3
At 72h : 19.7 - 21.6
pH:
- pH during the test in the control : 8.11 - 9.10
- pH at pre 0h/0h in the culture medium and the test material stocks : 8.14 - 8.16 (see table 2 below)
Dissolved oxygen:
No data
Salinity:
36 (salinity of diluent water at 0h)
Nominal and measured concentrations:
1.0 - 1.8 - 3.2 - 5.6 - 10.06 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type: Borosilicate glass conical flasks
- Material, size, headspace, fill volume: 100-mL flasks, filled with 80mL of algal suspension
- Aeration: During the test, the test solutions were continuously stirred by orbital shaker.
- Type of flow-through (e.g. peristaltic or proportional diluter): none (static test)
- Renewal rate of test solution (frequency/flow rate): a static, non-renewal exposure system was used
- Initial cells density: 10000 algal cells per mL of test medium
- Control end cells density:
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS :
Culture medium is prepared from natural seawater supplied by pump from Scapa Flow, Orkney. All seawater was UV sterilised and filtered to 0.2 µm. The filtered treated seawater was enriched with nutrients and vitamins in accordance with ISO Guidelines. The salinity of the enriched natural seawater at àh was 36 °/oo +/- 4°/oo.

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: at 0h for the test concentration of 10 mg/L
- Photoperiod: continuously illuminated
- Light intensity and quality: the measured light intensity (7160 - 8900) was achieved by four 40W tubes mounted at a distance of approximatively 40 cm directly above the test area. Light intensity values were measured daily during the test.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Counts of algal cell numbers were carried out daily by fluorometer measurements. Three readings were performed on each test vessel.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not stated
- Justification for using less concentrations than requested by guideline: Not applicable.
- Range finding study: Yes
- Test concentrations: 1 - 10 - 100 - 1000 mg/L
- Results used to determine the conditions for the definitive study: Yes
Reference substance (positive control):
yes
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
5.38 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 95% confidence limits = 4.99 - 5.84 mg/L
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2.69 mg/L
Nominal / measured:
nominal
Conc. based on:
other: solid content
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2.26 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
1.8 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.9 mg/L
Nominal / measured:
nominal
Conc. based on:
other: solid content
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.76 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth rate
Results with reference substance (positive control):
For evaluation of the quality of the aquatic organisms and the experimental conditions, 3,5-dichlorophenol is tested as a positive control.
72h EC50 = 2.19 mg/L (with 95% confidence limits : 2.03 - 2.34 mg/l)
(See results on tables 2 and 5 below)
Reported statistics and error estimates:
The raw data for each duplicate vessel and time period were averaged, to give values for each concentration of celle volume. Growth rate calculated on the basis of these measurements. Daily intrinsic growth rate was calculated for each duplicate for each time period using an exponential model :
Nt = N0.ekt where :
Nt : volume or number at time t
N0 = volume or number at beginning of test
t = time in days
k = growth rate (d -1)

The average value of k for each time interval was calculated for each concentration. Since the criterion of effect was the concentration causing 50% reduction in growth rate with respect to the controls, the response for each concentration was estimated from . Effect = 1- (control k/treatment k).

The resulting values represent proportional reduction in growth rate. The EC50 for each time interval and the 72h EC90 and NOEC values were calculating using an appropriate statistical method from the ToxCalc Version 5 software.

Table 4 - Fluorescence measurements (ppb) in test vessels after 24, 48 and 72h

Concentration

(mg/L)

24h

48h

72h

1.00a

2.195

25.606

48.091

1.00a

2.170

25.802

48.660

1.00a

2.265

25.702

49.169

1.00b

3.307

24.599

47.314

1.00b

2.309

24.662

47.756

1.00b

2.256

24.586

48.137

1.80a

1.697

20.980

40.686

1.80a

1.651

20.832

41.037

1.80a

1.647

21.025

41.390

1.80b

2.090

23.245

48.156

1.80b

2.133

23.268

48.455

1.80b

2.102

23.333

48.818

             3.20a

0.623

6.235

32.901

3.20a

0.603

6.265

32.724

3.20a

0.607

6.255

32.876

3.20b

0.536

7.087

34.907

3.20b

0.573

6.967

35.041

3.20b

0.578

6.961

35.008

5.60a

0.140

0.313

3.955

5.60a

0.132

-

3.911

5.60a

0.127

-

3.821

5.60b

0.145

0.530

4.617

5.60b

0.148

-

4.647

5.60b

0.130

-

4.630

10.0a

0.003

0.000

0.129

10.0a

0.002

-

-

10.0a

0.008

-

-

10.0b

0.009

-0.004

0.108

10.0b

0.013

-

-

10.0b

0.002

-

-

Table 5 - Fluorescence measurements (ppb) in control and referencesubstance (3,5 -DCP) after 72h

Concentrations

(mg/L)

72h

Rep growth

Mean growth

Measurement 1

Measurement 2

Measurement 3

Control 1

47.406

47.489

44.259

1.00

 

1.00

Control 2

44.461

44.858

45.081

1.03

Control 3

55.560

55.454

55.601

0.98

Control 4

49.561

49.809

49.812

0.99

1.0a

42.755

50.684

51.023

1.00

0.99

1.0b

46.574

46.256

46.355

0.99

1.8a

13.181

13.169

13.138

0.71

0.69

1.8b

11.148

11.116

11.037

0.67

3.2a

0.608

0.585

0.566

0.02

0.01

3.2b

0.473

0.479

0.478

0.00

 

Table - Coefficient of variation at 24, 48 and 72h (%)

24 h control CV %

7.59

48 h control CV %

1.53

72 h control CV %

2.10

Table - Summary of compliance guideline criteria and test values recorded

Validity criteria fulfilled:
yes
Conclusions:
The test item exhibited a 72h EC50 value of 5.38 mg/L (corresponding to 2.69 mg solid content/L and 2.26 mg active content/L) to the marine phytoplankton Skeletonema costatum in the aqueous phase.
Executive summary:

The toxicity of the test item (= substance EC 939-455-3 in aqueous commercial product) to the marine alga species Skeletonema costatum was investigated in a GLP-compliant study performed in accordance with ISO 10253 Standard (Marine Algal Growth Inhibition Test with Skeletonema costatum and Phaeodactylum tricornutum). The 72-hour 50% effective concentration EC50 (growth rate) of the test item was found to be 5.38 mg/L (corresponding to 2.69 mg solid content/L and 2.26 mg active content/L) based on nominal concentrations. The 72h-NOEC (growth rate) of the test item was found to be 1.80 mg/L (corresponding to 0.9 mg solid content/L and 0.76 mg active content/L).

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
1. HYPOTHESIS FOR THE ANALOGUE APPROACH
C8-C18 AAPHS and C12-18 AAPHS have the same functional groups, and general composition. The main variable resides in the alkyl chain distribution.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Source chemical = C8-18 cocamidopropyl hydroxysultaine (EC 939-455-3).
Target chemical = C12-18 cocamidopropyl hydroxysultaine (EC 939-457-4).

3. ANALOGUE APPROACH JUSTIFICATION
The alkyl C-chain distribution of the source chemical significantly overlaps with the one of the target chemical, the C12-alkyl derivative being the major constituent in both chemicals. The structural differences in side C-chains is not expected to lead to significant differences on phys-chem properties.

4. DATA MATRIX
See "Documentation and scientific justification of the read-across approach" in section 13.2.
Reason / purpose:
read-across source
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2.69 mg/L
Nominal / measured:
nominal
Conc. based on:
other: solid content
Basis for effect:
growth rate
Remarks on result:
other: read-across from EC 939-455-3
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.9 mg/L
Nominal / measured:
nominal
Conc. based on:
other: solid content
Basis for effect:
growth rate
Remarks on result:
other: read-across from EC 939-455-3
Conclusions:
By analogy with the source substance EC 939-455-3, a 72h-EC50 (growth rate) of 2.69 mg solid content/L and a 72h-NOEC (growth rate) of 0.9 mg solid content/L on the marine alga species Skeletonema costatum were reported for the target substance 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18(even numbered) acyl) derivs., hydroxides, inner salts (EC 939-457-4).

Description of key information

As the toxicity to aquatic algae of the substance EC 939-457-4 has not been investigated experimentally, a read-across approach was followed to fill in the endpoint. The toxicity to the marine alga species Skeletonema costatum of a structural analogue substance (= source substance EC 939-455-3) was investigated in a GLP-compliant study (Hudson, 2009) performed in accordance with ISO 10253 Standard (Marine Algal Growth Inhibition Test with Skeletonema costatum and Phaeodactylum tricornutum). The 72h-EC50 (growth rate) of the analogue substance was found to be 2.69 mg solid content/L based on nominal concentrations; the 72h-NOEC (growth rate) of the analogue substance was found to be 0.9 mg solid content/L. By analogy, the same EC50 and NOEC values were reported for the target substance 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18(even numbered) acyl) derivs., hydroxides, inner salts (EC 939-457-4).

Key value for chemical safety assessment

EC50 for marine water algae:
2.69 mg/L
EC10 or NOEC for marine water algae:
0.9 mg/L

Additional information

The toxicity to aquatic algae of the structural analogue substance (= source substance EC 939-455-3) was investigated in a GLP-compliant study (Hudson, 2009) performed in accordance with standard methods, without deviations. The study is considered as reliable with restrictions (Klimisch 2) and was selected as key study for the endpoint of the target substance EC 939-457-4.