Hexadecylamine

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 2006

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

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

All concentration levels and the control groups were analytically verified after 0 h (new media) and 48 h (old media).

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
Dispersion treatment: Stock solution was 5 mg/L. 6 μL/L test item were applied to 3 L natural river water. This solution was treated for 30 minutes with ultrasound at 40 °C. After a cooling period of 10 minutes the test item concentrations were prepared out of this stock solution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Daphnia magna STRAUS (Clone 5)
- Source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu); Breeder DR.U.NOACK-LABORATORIEN, D-31157 Sarstedt, Germany
- Age at study initiation: 2 - 24 h old
- Feeding during test: The daphnids were not fed during the study.

HOUSING:
- Conditions: In 2-3 L glass vessels with approximately 1.8 L culture medium, at 21 °C (temperatures of 20 - 25 °C are tolerated), in an incubator, 16 h illumination, illumination strength max. 20 μE⋅m-2 ⋅s-1.
- Culture medium: Elendt M4, according to ELENDT (1990), modified to a total hardness of 160 to 180 mg CaCO3/L.
- Type and amount of food: Feeding ad libitum with a mix of Desmodesmus subspicatus and Chlorella vulgaris, with an algae cell density of > 106 cells/mL.
- Feeding frequency: 5x weekly

ACCLIMATION
- Acclimation period: At least 2 h in dilution water

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

131.4 mg CO3/L

Test temperature:

18 - 22 +/- 1 °C

pH:

7.80 - 8.08

Dissolved oxygen:

7.75 - 9.25 mg/L

Nominal and measured concentrations:

Nominal concentrations: 5.00, 2.00, 0.80, 0.32, 0.123, 0.051 mg/L
Calculated concentrations: 3.8, 1.5, 0.64, 0.26, 0.12, 0.05 mg/L after 0 h; 0.16, 0.05, 0.02 mg/L, < LOQ after 48 h

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, fill volume: Glass beakers (5 cm x 8 cm), 50 mL; Volume of the study medium is 20 mL
- 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: A natural occurring river water (River Böhme) was used as test medium.
Test water parameter:
pH: 7.68
Conductivity [μS/cm]: 451
DOC [mg C/L]: 6.3
TOC [mg C/L]: 7.1
Ammonium-N [mg N/L]: < 1.94
Nitrate-N [mg N/L]: 3.9
o-Phosphate-P [mg P/L]: 0.029
Total Phosphate [mg P/L]: 0.080
Suspended Matter [mg/L]: 16.9
Total Hardness [mg CO3/L]: 131.4
- Culture medium different from test medium: yes
- Intervals of water quality measurement: Prior to test start (0 h) pH-value, dissolved oxygen concentration, temperature, conductivity and total hardness of the dilution water were measured. At the beginning of the test water parameters (pH value, oxygen concentration) were measured in one additional replicate per concentration and control. After 48 h the water parameters in old media were measured in all replicates per concentration and control. The room temperature was recorded throughout the test with a thermohygrograph.

OTHER TEST CONDITIONS
- Photoperiod: 16/8 h light/dark cycle
- Light intensity: Diffuse light, illumination range max. 20 μE⋅m-2 ⋅ s-1

EFFECT PARAMETERS MEASURED
The percentage immobility was determined in all test and control groups after 24 h and 48 h.

Preliminary Test:
Concentrations: 5.0, 0.5, 0.05 mg/L
Results used for main test: yes, 100% immobilisation documented at 5 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate p.a. (MERCK)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.98 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

0.76 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The test item was clearly dissolved in the tested concentrations throughout exposure. A slight yellowish coloration and brown particles were visible in the test media and on the ground of the test vessels.

Results with reference substance (positive control):

The percentage immobility for the reference item was determined after 24 h. The EC100-value was determined directly from the test results. The EC10- and EC50- with 95 % confidence interval (CI) was determined in a probability network by interpolation according to standard procedures. EC-values after 24 h of the reference item in mg/L: EC10 : 0.99; EC50 : 1.99 (CI 1.63 - 2.42); EC100 : 5.80
The EC50-value of the reference item potassium dichromate after 24 h is within the prescribed concentration range of 1.0 - 2.5 mg/L of quality criteria according to AQS P 9/2 (05/1996) for daphnids clone 5 cultured in Elendt M4 medium.

Reported statistics and error estimates:

The EC10- and EC50-values were calculated via probit analysis after 24 h and 48 h. Probits according to WEBER (1986). The concentration effect relationships are shown graphically in a probability network. Calculation of the confidence intervals was carried out using standard procedures according to BREITIG & TÜMPLING (1982). All data were computer generated and rounded for presentation from the full derived data. Consequently if calculated manually based on the given data minor variations may occur from these figures. Calculations were carried out using software: - SigmaPlot rel. 8.0 (2002), SPSS CORPORATION - Excel rel. 2000 (2000), MICROSOFT CORPORATION

Table1: Percentage of Daphnids incapable of swimming after 24 and 48 h of exposure:

Nominal conc.(mg/l)	IMMOBILISATION [%]
	24 h					48 h
	Replicates					Replicates
	1	2	3	4	MW	1	2	3	4	MW
5.00	100	100	100	100	100	100	100	100	100	100
2.00	20	20	40	40	30	100	100	100	100	100
0.80	0	0	0	0	0	0	20	20	20	15
0.32	0	0	0	0	0	0	0	20	0	5
0.128	0	0	0	0	0	0	0	0	0	0
0.051	0	0	0	0	0	0	0	0	20	5
Control	0	0	0	0	0	0	0	0	0	0

Table 2: Concentrations of (Z)-octadec-9-enylamine:

Nominal test item conc. [mg/L]	Meas. conc. [mg/L]after 0 h	Meas. conc. [mg/L]after 48 h
5.00	3.8	0.16
2.00	1.5	0.05
0.80	0.64	0.02
0.32	0.26	< detection limit
0.128	0.12	< detection limit
0.051	0.05	< detection limit
Control	< detection limit	< detection limit

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item on the mobility of Daphnia was measured according OECD 202 to be: EC50 = 0.98 mg/L

Executive summary:

The Acute Immobilisation of the test item to Daphnia magna (STRAUS) was determined according to OECD Guideline 202 / EC 92/69/EC Method C. The study was conducted with 6 nominal concentrations ranging from 0.051 to 5.00 mg/L in a geometric series with a factor of 2.5 under static conditions over 48 h. 20 test organisms were exposed to each test concentration and control. The water quality parameters pH-value and dissolved oxygen concentration were determined to be within the acceptable limits. The validity criteria of the test guideline were fulfilled. All concentration levels and the control groups were analytically verified via LC-MS/MS after 0 h (new media) and 48 h (old media). Measured initial concentrations in the test replicates (0 h) showed a good accordance with the geometrical series of dilution for the concentration range of 0.32 – 5.00 mg/L. The two lowest concentrations showed slightly higher recoveries. After a 48 h exposure all concentrations had decreased. The three lowest concentrations had dropped below the limit of quantification (10 μg/L). The three highest concentrations showed recoveries in the range of 3 – 4%. The test item has a low water solubility and sorbs to organic and inorganic materials by different mechanisms. The sorption processes are mostly non-linear, means are concentration dependent. Due to these properties the test item is difficult to test in synthetic water (e.g. sorption to the test organism and walls of the test vessel) and results from such tests depend from the test settings applied. Using natural river water which contains particulate as well as dissolved organic carbon to which the test item can sorb partially reduces the difficulties encountered in tests with synthetic water e.g. preventing that the test item settles onto surfaces. The sorbed fraction of the test item is difficult to extract from the test system which normally leads to low analytical recoveries. Due to the short exposure period these low recoveries cannot be associated to biodegradation. This means the test substance is present in the test system and therefore available for exposure (dissolved in water and sorbed also called bulk). Due to the properties of the test item nominal concentrations have to be used instead of measured ones. This so called Bulk Approach is described by ECETOC (2003). Sorption of the test item to the glass ware of the test system was monitored and found to be small. After 48h the immobilisation of the test animals was: EC50=0.98 mg/L, EC10=0.76 mg/L, EC100=2 mg/L.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to Chapter 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.98 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

0.76 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Description of key information

No test with the test item is available. The effect of the read across substance on the mobility of Daphnia was measured according OECD 202 to be: EC50 = 0.98 mg/L (reference 6.1.3 -1).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.98 mg/L

Additional information

No test with the test item is available. The Acute Immobilisation of the read-across substance to Daphnia magna (STRAUS) was determined according to OECD Guideline 202 / EC 92/69/EC Method C. The study was conducted with 6 nominal concentrations ranging from 0.051 to 5.00 mg/L in a geometric series with a factor of 2.5 under static conditions over 48 h. 20 test organisms were exposed to each test concentration and control. The water quality parameters pH-value and dissolved oxygen concentration were determined to be within the acceptable limits. The validity criteria of the test guideline were fulfilled. All concentration levels and the control groups were analytically verified via LC-MS/MS after 0 h (new media) and 48 h (old media). Measured initial concentrations in the test replicates (0 h) showed a good accordance with the geometrical series of dilution for the concentration range of 0.32 – 5.00 mg/L. The two lowest concentrations showed slightly higher recoveries. After a 48 h exposure all concentrations had decreased. The three lowest concentrations had dropped below the limit of quantification (10 μg/L). The three highest concentrations showed recoveries in the range of 3 – 4%. The test item has a low water solubility and sorbs to organic and inorganic materials by different mechanisms. The sorption processes are mostly non-linear, means are concentration dependent. Due to these properties the test item is difficult to test in synthetic water (e.g. sorption to the test organism and walls of the test vessel) and results from such tests depend from the test settings applied. Using natural river water which contains particulate as well as dissolved organic carbon to which the test item can sorb partially reduces the difficulties encountered in tests with synthetic water e.g. preventing that the test item settles onto surfaces. The sorbed fraction of the test item is difficult to extract from the test system which normally leads to low analytical recoveries. Due to the short exposure period these low recoveries cannot be associated to biodegradation. This means the test substance is present in the test system and therefore available for exposure (dissolved in water and sorbed also called bulk). Due to the properties of the test item nominal concentrations have to be used instead of measured ones. This so called Bulk Approach is described by ECETOC (2003). Sorption of the test item to the glass ware of the test system was monitored and found to be small. After 48h the immobilisation of the test animals was: EC50=0.98 mg/L, EC10=0.76 mg/L, EC100=2 mg/L.