N-[3-(dimethylamino)propyl]stearamide

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-03-19 to 2013-04-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-[3-(dimethylamino)propyl]stearamide

EC Number:

231-609-1

EC Name:

N-[3-(dimethylamino)propyl]stearamide

Cas Number:

7651-02-7

Molecular formula:

C23H48N2O

IUPAC Name:

N-[3-(dimethylamino)propyl]octadecanamide

Test material form:

solid: pellets

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 25.0 - 50.0 - 100 - 200 - 400 µg/L
- Sampling method:
All concentration levels of the test item and the control were analysed by LC-MS/MS at the start of the exposure intervals on days 0, 2, 8, 15 (0 h) and at the end of the exposure intervals on days 1, 3, 9, 16 (24 h).
Samples at the start of an exposure interval (0 h) were taken immediately after preparation of the test concentrations.
Samples at the end of an exposure interval (24 h) were taken directly from the test vessels containing daphnids and food algae.
Additionally, the freshly prepared stock solution of 100 mg/L in demineralised water was analysed at the start of the respective exposure intervals (0 h).
Sorption of the test item to the glass walls of the test vessels was checked as specified below. For this purpose, additional replicates without daphnids and food algae were prepared and incubated under test conditions for quantification of the sorption to the glassware. Due to the test item properties, the nominal concentrations were used for calculation of the effect values.
The sorption of the test item on glass was quantified. Additional replicates of the three highest concentration levels without daphnids and food algae were prepared. After sampling for the test medium analysis (aqueous phase), the glassware was emptied and an appropriate amount of a suitable solvent was added. The concentration of the test item in this solution was measured and the adsorbed test item amount was calculated from this concentration. Before this procedure, the test vessels were carefully rinsed with demineralised water to remove the remaining test media.

- Sample storage conditions before analysis:
All original samples were stored at room temperature until sample preparation. Prepared samples were stored at room temperature until analysis.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The stock solution (100 mg/L test item were weighed out) was prepared with demineralised water adjusted with 1 M HCl to a pH of 2 ± 0.2 one day before the start of each exposure interval. The stock solution was stirred with approximately 1100 rpm for 24 h at room temperature.

- Eluate: Dilution water
- Differential loading: 25.0 - 50.0 - 100 - 200 - 400 µg/L
- Controls: 10 replicates of dilution water without test item

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Strain/clone: Clone 5
- Justification for species other than prescribed by test guideline: Daphnia magna STRAUS is recommended in the guideline
- Source: Own breeding (Origin: Institut fuer Wasser- Boden- und Lufthygiene)
- Age of parental stock (mean and range, SD): > 14 days
- Feeding during test
- Food type: Mix of Pseudokirchneriella subcapitata and Desmodesmus subspicatus
- Amount: 0.2 mg C/daphnia per day
- Frequency: daily renewal of the test solutions


ACCLIMATION
- Acclimation period: 2 h in dilution water
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food: During acclimation the daphnids were not fed
- Feeding frequency: None
- Health during acclimation (any mortality observed): Healthy

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: The parent animals were removed from the culture medium and the juveniles collected over a sieve and flushed into fresh medium

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

Not observed

Test conditions

Hardness:

Total Hardness [mg/L] as CaCO3
Nominal
test item
concentration
[µg/L] I F I F I F
Day 0 Day 1 Day 8 Day 9 Day 15 Day 16
2013-03-25 2013-03-26 2013-04-02 2013-04-03 2013-04-09 2013-04-10
400 228 219 Not determined due to 100 % adult mortality
200 Not determined 260 208 292 242
Control 235 233 265 235 295 249

Test temperature:

Temperature [°C]
Nominal
test item
concentration
[µg/L] I F I F I F
Day 0 Day 1 Day 8 Day 9 Day 15 Day 16
2013-03-25 2013-03-26 2013-04-02 2013-04-03 2013-04-09 2013-04-10
400 20.0 20.5 Not determined due to 100 % adult mortality
200 Not determined 19.4 20.7 20.2 20.5
Control 19.0 20.4 19.0 20.5 19.1 20.8

pH:

pH-Values
Nominal
test item
concentration
[µg/L] I F I F I F
Day 0 Day 1 Day 8 Day 9 Day 15 Day 16
2013-03-25 2013-03-26 2013-04-02 2013-04-03 2013-04-09 2013-04-10
400 7.80 8.19 Not determied due to 100 % adult mortality
200 Not determined 8.11 8.00 8.08 8.07
Control 8.10 7.97 8.10 8.00 7.82 8.09

Dissolved oxygen:

Dissolved Oxygen Concentration [mg/L]
Nominal
test item
concentration
[µg/L] I F I F I F
Day 0 Day 1 Day 8 Day 9 Day 15 Day 16
2013-03-25 2013-03-26 2013-04-02 2013-04-03 2013-04-09 2013-04-10
400 8.91 9.21 Not determied due to 100 % adult mortality
200 Not determined 10.35 7.93 9.08 8.21
Control 9.41 8.21 10.43 7.77 11.28 7.54

Salinity:

Not measured, freshwater

Nominal and measured concentrations:

Please refer to "Any other information on materials and methods"

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed with parafilm
- Material, size, headspace, fill volume: 100 mL glass beaker, filled with 50 mL test solution
- Aeration: No
- Renewal rate of test solution (frequency): Daily renewal of the test solutions
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Natural river water of the river Innerste was used. This river is located near 31157 Sarstedt, Germany (52.24°, 9.84°). The natural river water was stored at 15 ± 2 °C until use in the test.
Water Quality Parameters of the Natural River Water
River Innerste
Location Ruther Strasse, 31157 Sarstedt, Germany
latitude:52.24°, longitude: 9.84°
Sampling date 2012-08-02
Weather on day of sampling Sunny, approx. 25 °C
Colour Slightly yellowish , clear
pH 8.11
Conductivity [µS/cm] 997
Dissolved oxygen [mg O2/L] 8.82
DOC [mg C/L] 2.72
TOC [mg C/L] 3.01
Ammonium-N [mg NH4-N/L] 0.11
Nitrate-N [mg NO3-N/L] 2.3
Total nitrogen [mg N/L] 4.6
o-phosphate-p [mg P/L] < 0.20
Total phosphate [mg P/L] < 0.20
Suspended matter [mg/L] 11.4
Total hardness [mg CO3/L] 299
Storage conditions 15 ± 2°C


OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h light : 8 h dark per day
- Light intensity: Max. 20 µE*m-2*s-1


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Adult mortality: daily
- Number of juveniles: daily
- Stillborn juveniles and aborted eggs: daily
- Appearance of first brood: between days 8 and 9
- Intrinsic rate of natural increase: test end
- Growth (total length and dry weight): test end


RANGE-FINDING STUDY
Based on the results of the acute immobilisation test (NOACK Lab-ID: 120426EG/DAI15256) conducted at the test facility, the definitive reproduction test was carried out with 5 concentration levels of the test item in the range of 25 to 400 µg/L, prepared with natural river water as specified above.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

200 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Mortality of parent animals:
Biologically significant adult mortality of 100 % was observed at the concentration level of 400 µg/L during the test period of 21 days. At the concentration level of 200 µg/L, the adult mortality was 10 %, which is not biologically significant (> 20 %). In the concentration levels of 25.0 to 100 µg/L and in the control, all parental daphnids survived until the end of the test after 21 days. The EC10 for the adult mortality was calculated by sigmoidal dose-response regression to be 200 µg/L (95% confidence limits: 100 – 400 µg/L). The EC50 was calculated accordingly to be 212 µg/L (95 % confidence limits: 100 – 400 µg/L).
- No. of offspring produced per day per female:
The number of juveniles in all replicates of the control and the test groups was counted and recorded every day.
The average number of living juveniles per surviving parental daphnid at the end of the test after 21 days was 81 in the control group. The reproductive output of the surviving daphnids was not statistically significant reduced in comparison to the control at any of the tested concentration levels of 25.0 to 200 µg/L (One Way Analysis of Variance, DUNNETT’S method, p = 0.05). At the concentration level of 400 µg/L, all daphnids died until day 5. Due to the absence of effects concerning the reproduction, no EC10- or EC50-value could be determined. The coefficient of variation of the number of living offspring produced per parent was 6 % in the control. In the test groups the coefficient of variation was in the range of 4 to 13 %. Due to 100 % adult mortality, no offspring was observed at the concentration level of 400 µg/L.
- Body length and weight of parent animals:
The mean values of the body length of the surviving parental daphnids in the tested concentration levels of 25.0 to 200 µg/L were in the range of 5.19 to 5.40 mm per daphnid and 5.38 mm per daphnid in the control group.
The mean dry body weight of the surviving parental daphnids was determined to be in the range of 0.77 to 1.03 mg per daphnid in the concentration levels 25.0 to 200 µg/L and 0.92 mg per daphnid in the control.

- Type and number of morphological / behavioural abnormalities:
please refer to the respective table
- Time to first brood release or time to hatch:
The first brood was released on days 8 and 9 by all surviving parental daphnids of the control and the concentration levels of 25.0 to 200 µg/L.
At the tested concentration levels of 25.0 to 200 µg/L and in the control, 4 broods were produced by the surviving parental daphnids. Due to 100 % adult mortality, no offspring was observed at the concentration level of 400 µg/L.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC50 (24 h) = 1.60 (CI 1.54 - 1.65) mg/L

Reported statistics and error estimates:

The NOEC and the LOEC based on the adult mortality were deduced directly from the results.
Significant deviations of the reproduction rates and the intrinsic rates of natural increase were determined in comparison to the control using statistical standard procedures as normality test, equal variance test and analysis of variance (One Way Analysis of Variance, DUNNETT’S method). Prior to running the analysis of variance, a normality test and an equal variance test were performed. P-values of the normality and equal variance tests should be 0.05. For the determination of significant deviations of the reproduction rates, the P-value was actually < 0.05 and therefore the equal variance test failed.
The -value (acceptable probability of incorrectly concluding that there is a difference) was =0.05.
The coefficients of variation around the mean number of living offspring produced per parent in the control and the test groups were evaluated. The EC10- and the EC50-value for the adult mortality after 21 days were calculated by sigmoidal dose-response regression. The confidence limits were deduced directly from the observation data without calculation, because only a partial effect was observed. The highest concentration level with 0 % adult mortality and the lowest concentration level with 100 % adult mortality were used as confidence limits. The EC100-value for the adult mortality after 21 days was deduced directly from the observation data.
Due to the absence of effects concerning the reproduction, no EC10- or EC50-value could be determined. The EC50-value for the reference item was calculated by sigmoidal dose-response regression. The confidence interval for the EC50 was calculated from the best-fit values, the standard error and the t-distribution with the software GraphPad prism5.

Any other information on results incl. tables

Number of Juveniles in the Control and Test Groups after 21 Days

Nominal test item conc. [µg/L]												No. of parents prod. juv.	Mean no. of juveniles per parent producing juveniles			Comparison versus control
	Number of living juveniles in replicate no.										Total no.				CV
																Red.	Stat.
	1	2	3	4	5	6	7	8	9	10	å	N	MV ± SD		[%]	[%]
400	--	--	--	--	--	--	--	--	--	--	n.a.	0	n.a.		n.a.	n.a.	n.a.
200	88	92	88	--	77	88	75	73	73	64	718	9	80 ±	10	12	1	no
100	92	82	83	63	72	75	84	75	66	93	785	10	79 ±	10	13	3	no
50.0	96	81	82	89	73	77	77	67	84	74	800	10	80 ±	8	10	1	no
25.0	77	82	75	85	80	79	82	82	85	80	807	10	81 ±	3	4	1	no
Control	79	81	72	80	89	78	85	83	84	77	808	10	81 ±	5	6	—	—

Mortality [%] of the Adult Daphnids after 7, 14 and 21 Days of Exposure

                 (n = 10)

Nominal test item concentration [µg/L]	Adult Mortality [%]
	7 days	14 days	21 days
400	100*	100*	100*
200	0	0	10
100	0	0	0
50.0	0	0	0
25.0	0	0	0
Control	0	0	0

Relative Number of Dead (Stillborn + Aborted Eggs) to Total Number of Juveniles

Nominal test item concentration [µg/L]	Number of juveniles			Percentage of dead juveniles^#) [%]
	Dead	Alive	Total
400	n.a.	n.a.	n.a.	n.a.
200	31	718	749	4
100	38	785	823	5
50.0	44	800	844	5
25.0	4	807	811	1
Control	0	808	808	0

First Appearance of Living Juveniles in the Individual Groups

Nominal test item concentration [µg/L]	Day of first appearance of living juveniles										First	Mean
	in replicate no.										appearance	number
	1	2	3	4	5	6	7	8	9	10	mean day	of broods
400	--	--	--	--	--	--	--	--	--	--	n.a.	n.a.
200	9	9	9	--	8	9	9	9	9	8	8.8	4.0
100	9	9	9	9	9	9	9	9	8	9	8.9	4.0
50.0	9	9	9	9	9	9	9	8	9	9	8.9	4.0
25.0	9	9	9	9	9	9	9	9	9	9	9.0	4.0
Control	9	9	9	9	9	9	8	9	9	9	8.9	4.0

Total Body Length of the Parental Daphnids

Nominal test item concentration [µg/L]	Total length of the parent animals [mm]										MV	N	Dry weight [mg]
	Replicate no.
	1	2	3	4	5	6	7	8	9	10	[mm]		S	MV
400	--	--	--	--	--	--	--	--	--	--	n.a.	0	n.a.	n.a.
200	5.00	5.25	5.00	--	5.25	5.00	5.50	5.25	5.50	5.00	5.19	9	6.9	0.77
100	5.75	5.50	5.50	5.00	5.00	5.25	5.25	5.25	5.25	5.25	5.30	10	9.6	0.96
50.0	5.50	5.75	5.25	5.50	5.50	5.50	5.25	5.25	5.00	5.25	5.38	10	10.3	1.03
25.0	5.25	5.50	5.50	5.25	5.75	5.25	5.50	5.25	5.25	5.50	5.40	10	8.8	0.88
Control	5.25	5.25	5.50	5.50	5.50	5.25	5.50	5.50	5.50	5.00	5.38	10	9.2	0.92

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The adult mortality was the only significant effect in this study. Effects concerning the reproduction were not observed during the test period of 21 days.
Based on the significant adult mortality of 100 % at the concentration level of 400 µg/L, the No Observed Effect Concentration (NOEC) after 21 days was assessed at 200 µg/L and the Lowest Observed Effect Concentration (LOEC) was assessed at 400 µg/L.
The EC10 for the adult mortality was calculated by sigmoidal dose-response regression to be 200 µg/L (95% confidence limits: 100 – 400 µg/L). The EC50 was calculated accordingly to be 212 µg/L (95 % confidence limits: 100 – 400 µg/L).


Endpoints assessed N-[3-(dimethylamino)propyl]stearamide
Nominal test item concentration
[µg/L]
EC10 Adult mortality
(with 95 % confidence limits) 200 µg/L (100 – 400 µg/L)
EC50 Adult mortality
(with 95 % confidence limits) 212 µg/L (100 – 400 µg/L)
EC100 Adult mortality 400 µg/L
NOECAdult mortality 200 µg/L
LOECAdult mortality 400 µg/L

Executive summary:

The Daphnia magna Reproduction Test (semi-static, 21 d) of the test item N-[3-(dimethylamino)propyl]stearamide (batch number: PA02309460) was conducted according to OECD 211 (2008) from 2013-03-19 to 2013-04-24, with the definitive exposure phase from 2013-03-25 to 2013-04-15, at Dr.U.Noack-Laboratorien, Käthe-Paulus-Str. 1, 31157Sarstedt, Germany.

Test species was Daphnia magna STRAUS (Clone 5). Ten daphnids, individually held, were used per concentration level, and control. At test start the daphnids were 2 to 24 hours old. The study was carried out undersemi-static conditions with a daily renewal of the test solutions. Aim of the Daphnia Reproduction Test over 21 days was to assess effects on the reproduction capacity and other test item-related effects or parameters such as time of production of first brood, adult mortality, intrinsic rate of natural increase, occurrence of aborted eggs and stillborn juveniles and body length of the parental daphnids. Nominal concentrations of the test item N-[3-(dimethylamino)propyl]stearamide were selected based on the results of an acute immobilization test performed at the test facility [Noack, M. (2013): N-[3-(dimethylamino)propyl]stearamide - Acute Immobilization Test to Daphnia magna, Semi-static, 48 h, with Natural River Water (Study-No./Project No. DAI15256/120426EG), Dr.U.Noack-Laboratorien, , ] as follows: 25.0 – 50.0 –100 – 200 –400 µg/L. N-[3-(dimethylamino)propyl]stearamide is a tertiary straight chain amine. The test item has a low water solubility of 10 mg/L 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 artificial water (e.g. sorption to the test organism and walls of the test vessel). Natural river water contains particulate as well as dissolved organic carbon to which the test item can sorb partially 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. Nevertheless the test item is present in the test system and therefore available for exposure (dissolved in water and sorbed). Due to the properties of the test item nominal concentrations have to be used instead of measured ones. The concentrations of the test item N-[3-(dimethylamino)propyl]stearamide were analytically verified by LC-MS/MS of samples taken at the start of the exposure intervals on days 0, 2, 8, 15 (0 h) and at the end of the exposure intervals on days 1, 3, 9, 16 (24 h) of all concentration levels and the control. Additionally, the freshly prepared stock solutions of 100 mg/L, prepared in demineralised water (adjusted with 1 M HCl to pH 2 ± 0.2), were analysed at the start of the exposure intervals (0 h) on days 0, 2, 8 and 15.

The measured concentrations of the test item at the start of the exposure intervals (0 h) were in the range of 96 to 118 % of the nominal values. At the end of the exposure intervals (24 h), the measured concentrations of the test item were in the range of LOQ_Mto 30 % of the nominal values. The measured concentrations of the stock solution of 100 mg/L were in the range of 98 to 103 % of the nominal concentration of the test item.

Adsorption to the glass walls of the test vessels was determined exemplarily at the three highest concentration levels in separate replicates without daphnids. Due to 100 % adult mortality at the concentration level of 400 µg/L on day 5, adsorption was determined on days 9 and 16 at the concentration level of 50.0 µg/L instead. Adsorption to the glass walls in the range of 9 to 31 % of the nominal test item concentrations was determined at the concentration levels of 50.0 to 400 µg/L.

·   Biologically significant adult mortalityof 100 % was observed at the concentration level of 400 µg/L during the test period of 21 days.At the concentration level of 200 µg/L, the adult mortality was 10 %, which is not biologically significant (> 20 %). In the concentration levels of 25.0 to 100 µg/L and in the control, all parental daphnids survived until the end of the test after 21 days. The EC₁₀ for the adult mortality was calculated by sigmoidal dose-response regression to be 200 µg/L (95% confidence limits: 100 – 400 µg/L). The EC₅₀ was calculated accordingly to be 212 µg/L (95 % confidence limits: 100 – 400 µg/L).

·   Based on the significant adult mortality at the concentration level of 400 µg/L, the No Observed Effect Concentration (NOEC) after 21 days was assessed at 200 µg/L and the Lowest Observed Effect Concentration (LOEC) was assessed at 400 µg/L.
The adult mortality was the only significant effect in this study. Effects concerning the reproduction were not observed during the test period of 21 days.

·   The average number of living juveniles per surviving parental daphnid at the end of the test after 21 days was 81 in the control group. The reproductive output of the surviving daphnids was not statistically significant reduced in comparison to the control at any of the tested concentration levels of 25.0 to 200 µg/L (One Way Analysis of Variance, Dunnett’s method, p = 0.05). At the concentration level of 400 µg/L, all daphnids died until day 5. Due to the absence of effects concerning the reproduction, no EC₁₀- or EC₅₀-value could be determined.

·   The coefficient of variation of the number of living offspring produced per parent was 6 % in the control. In the test groups the coefficient of variation was in the range of 4 to 13 %. Due to 100 % adult mortality, no offspring was observed at the concentration level of 400 µg/L.

·   The intrinsic rates of natural increase (IR) of the surviving parental daphnids accounting for generation time and number of offspring were used for calculation of population growth and maintenance. The intrinsic rates of natural increase determined for the surviving daphnids at the concentration levels of 25.0 to 200 µg/L were comparable to the IR at the control (One Way Analysis of Variance, Dunnett’s method, p = 0.05). Due to 100 % adult mortality, no IR could be calculated for the concentration level of 400 µg/L.

·   No stillborn juveniles or aborted eggs were observed in the control group during the exposure period of 21 days. Related to the total number of produced juveniles (dead + alive) the percentage of dead juveniles was in the range of 1 to 5 % in the tested concentration levels of 25.0 to 200 µg/L. Due to 100 % adult mortality, no offspring was observed at the concentration level of 400 µg/L.

·   The first brood was released on days 8 and 9 by all surviving parental daphnids of the control and the concentration levels of 25.0 to 200 µg/L.
At the tested concentration levels of 25.0 to 200 µg/L and in the control, 4 broods were produced by the surviving parental daphnids. Due to 100 % adult mortality, no offspring was observed at the concentration level of 400 µg/L.

·   The mean values of the body length of the surviving parental daphnids in the tested concentration levels of 25.0 to 200 µg/L were in the range of 5.19 to 5.40 mm per daphnid and 5.38 mm per daphnid in the control group.

     The mean dry body weight of the surviving parental daphnids was determined to be in the range of 0.77 to 1.03 mg per daphnid in the concentration levels 25.0 to 200 µg/L and 0.92 mg per daphnid in the control.

No males or ephippia (winter eggs) were observed in the control or in the test groups.

A summary of all test item related effects and the assessed endpoints based on the nominal test item concentrations is given in Table 1.

Table 1:           Test Item Related Effects (NOEC, LOEC, EC₁₀, EC₅₀ and EC₁₀₀)

                         (based on the nominal concentrations of the test item TEGO AMID S 18)

Effects	N-[3-(dimethylamino)propyl]stearamide Nominal concentrations of the test item [µg/L]
	Control	25.0	50.0	100	200	400
Adult Mortality after 21 Days [%]	0	0	0	0	10	100^1)
Mean Number of Living Juveniles per Producing Parent (Reproduction Rate ± SD)	81 ± 5	81 ± 3	80 ± 8	79 ± 10	80 ± 10	n.a.
Coefficient of Variation of the Mean Number of Juveniles per Producing Parent [%]	6	4	10	13	12	n.a.
Mean Intrinsic Rates of Natural Increase	0.44	0.44	0.45	0.43	0.44	n.a.
Percentage of Dead Juveniles Related to the Total Number of Juveniles [%]	0	1	5	5	4	n.a.
Mean Number of Broods	4.00	4.00	4.00	4.00	4.00	n.a.
Appearance of First Brood [Mean Day]	8.9	9.0	8.9	8.9	8.8	n.a.
Parental Daphnids: Mean Dry Weight [mg]	0.92	0.88	1.03	0.96	0.77	n.a.
Parental Daphnids: Mean Body Length [mm]	5.38	5.40	5.38	5.30	5.19	n.a.
EC10 Adult mortality (with 95 % confidence limits)	200 µg/L (100 – 400 µg/L)
EC50 Adult mortality (with 95 % confidence limits)	212 µg/L (100 – 400 µg/L)
EC100 Adult mortality	400 µg/L
NOECAdult mortality	200 µg/L
LOECAdult mortality	400 µg/L