Amines, N-C10-16-alkyltrimethylenedi-, reaction products with chloroacetic acid

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007-06-12 to 2007-07-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

adopted 21 September 1998

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: from each exposure concentration (0.61, 1.52, 3.79, 9.49, 23.73 µg/L) from representative fresh (day 1, 3, 5, 7, 11, 13, 14, 17, and 19) and aged (prior to renewal on day 2, 4, 6, 8, 12,14, 15, 18, and 20) test solutions.
- Sample storage conditions before analysis: stored at -18°C until analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test item was distributed to the replicate beakers using the aqueous formulation as a stock solution. The individual test solutions were prepared by diluting with dilution water and were then distributed to the test beakers.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna, water flea
- Strain/clone: clone V
- Source: German Federal Environment Agency, Institut für Wasser-, Boden- und Lufthygiene. Specimens used in the test were bred in the laboratory of the Fraunhofer IME
- Age: <24 h
- Feeding during test
- Food type: Suspensions of unicellular alga Desmodesmus subspicatus.
- Amount: Algae growing in the log-phase were centrifuged and the pellet was re-suspended in a few mL of medium. 30 mL of this suspension was given to 1 L Daphnia medium.
- Frequency: Daily
- Breeding method: Adult Daphnia, at least 3 weeks old, were separated from the stock population by sieving. Batches of 30 to 50 animals are held at room temperature in ca. 1.8 L dilution water for one week. During this week the daphnids were fed daily with an algal suspension (Desmodesmus subspicatus) and LiquizellR (HOBBY). The water was changed once per week. Newborn Daphnia were separated by sieving, the first generation was discarded.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test temperature:

19.7–20.4 °C

pH:

at start: 7.8
During the test: 7.6 (min) – 8.4 (max.)
At test end: 8.0–8.3

Dissolved oxygen:

Oxygen saturation of the overlaying water as measured as nominal values throughout the test [mg/L]:
Min: 7.6, max: 9.0
Beginning: 7.8–8.0
End: 8.4–8.7

Nominal and measured concentrations:

nominal: 4.6, 11.5, 28.75, 72.0, and 180.0 µg test item per litre, representing 0.92, 2.30, 5.75, 14.40, and 36.00 µg active substance (nominal) per litre
time weighted average: 0.78, 2.28, 2.39, 11.35, and 27.48 µg a.s./L (85.3, 99.2, 41.5, 78.8, and 76.3 % of nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: round glass beakers
- Type: open
- Material, size, headspace, fill volume: 50 mL
- Renewal rate of test solution: daily
- 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: Purified drinking water was used as holding- and dilution water. The purification included filtration with activated charcoal, passage through a limestone column, and aeration. To avoid copper contamination, plastic water pipes are used for the testing facilities.
The following water chemistry data are recorded regularly in the testing facility and are reported: pH, conductivity, dissolved oxygen content, content of nitrate, nitrite, ammonium (NH4+), phosphate, calcium, magnesium, total hardness, alkalinity, DOC content, content of metals (copper, iron, manganese and zinc).
- Total organic carbon: 0
- hardness: Ca-hardness: 0.4–0.5 mmol/L, Mg-hardness: 0.2–0.4 mmol/L


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: Light/dark cycle of 16/8 hours
- Light intensity: The light intensity did not exceed 15–20 µE/(m² × s) or 1125–1500 lx. Measurements conducted during test: min. 508 lx to max. 591 lx

EFFECT PARAMETERS MEASURED:
daily: survival, body growth, physical/pathological symptoms and changes in behaviour, reproduction and population growth

RANGE-FINDING STUDY
not performed

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

2.3 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks:

(cumulative offspring per Daphnia, intrinsic rate of increase)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

2.4 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks:

(parental survival)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

27.5 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

other: age at the first brood and growth

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

3.1 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks:

(parental survival)

Remarks on result:

other: 95% CL 1.6–6.0 µg/L

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

3.4 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks:

(Cumulative offspring per female)

Remarks on result:

other: 95% CL n.d.–8.5mg/L

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

4.4 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks:

(Intrinsic rate of increase)

Remarks on result:

other: 95% CL 1.7–7.0 µg/L

Details on results:

Neither adult mortality nor any sublethal effects were observed up to a concentration of 2.4 µg a.s./L (TWM, NOEC). The EC10, EC20, and EC50 were estimated at 3.1, 4.7, and 10.6 µg a.s./L (TWM), respectively.
Adult body length exhibited no significant differences between treatments up to the highest concentration tested (NOEC ≥ 27.5 µg a.s./L (TWM)). All surviving specimens gave the impression of healthy condition.
Survival, growth and reproduction data are given in Table A7.4.3.4-6 and Table A7.4.3.4-7. Data about parental length at day 21 are given in Table A7.4.3.4-8.
Age at first brood was between 9.0 and 10.5 days across treatment level (NOEC ≥ 27.5 µg a.s./L (TWM)).
The cumulative number of offspring per parent animal ranged from 28.0 to 67.6 across treatment levels, showing an apparent concentration-response relationship.
NOEC = 2.3 µg a.s./L, EC10 = 3.4 µg a.s./L, EC20 = 6.8 µg a.s./L, and EC50 24.6 µg a.s./L (TWM)

Reported statistics and error estimates:

Calculations were performed with the computer software ToxRat Professional version 2.09 (release 08.11.2006) by ToxRat® Solutions GmbH. A NOEC was calculated using ANOVA followed by Williams’ test or an appropriate non-parametric test suggested by the ToxRat program. Test results showing a concentration-response relationship were analysed by regression to determine the EC50 including the 95 % confidence interval as well as the EC10 using probit analysis assuming log-normal distribution of the values.

Table A7.4.3.4-5:Time weighted mean (TWM) of the measured concentrations of the four lead compounds (sum) extrapolated to total active substance (a.s.) and recovery rate.

Nominal conc. a.s. (µg/L)	Nominal conc. lead compounds (µg/L)	TWM active substance (a.s.) (µg/L)	TWM sum of lead compounds (µg/L)	TWM Recovery rate (%)
0.92	0.61	0.78	0.52	85.3
2.30	1.52	2.28	1.50	99.2
5.75	3.79	2.39	1.57	41.5
14.4	9.49	11.35	7.48	78.8
36.0	23.73	27.48	18.11	76.3

 

Table A7.4.3.4-6:Survival, growth and reproduction data. Concentrations are given as nominal concentrations. SD = standard deviation. Number of D. magna per concentration: n = 10.

Concentration (nominal a.s.)	TWM active substance (a.s.)	Parental survival	Growth (length on day 21)	Age at first brood	Cumulative offspring per female	Intrinsic rate of increase
(µg/L)	(µg/L)	(%)	Mean±SD (mm)	Mean±SD (days)	Mean±SD (Ind.)	Mean±SD (Ind./day)
Control		100	4.73±0.28	9.4±0.7	67.6±9.5	0.302±0.030
0.92	0.8	100	4.70±0.37	9.0±0.8	65.7±7.2	0.309±0.026
2.30	2.3	100	4.67±0.35	9.2±0.7	62.9±9.1	0.292±0.024
5.75	2.4	90	4.62±0.31	10.1±1.1	57.4±13.2	0.277±0.025
14.4	11.4	40	4.35±0.36	10.5±1.6	53.5±13.0	0.238±0.038
36.0	27.5	20	4.63±0.28	10.1±2.1	28.0±8.5	0.204±0.013

 

 

Table A7.4.3.4-7:Effect summary table. NOEC and EC values [µg a.s./L]. NOEC = No observed effect concentration; EC = Effect concentration; CL = Confidence level; n.d. = not determined due to mathematical reasons; Effect concentrations given as time weighted mean (a.s.).

Concentration	Parental survival	Growth (length on day 21)	Age at first brood	Cumulative offspring per female	Intrinsic rate of increase
EC50 (95% CL)	10.6 (6.5–17.1)	n.d. (n.d.)	> 27.5 (n.d.)	24.6 (11.3–>27.5)	> 27.5 (n.d.)
EC20 (95% CL)	4.7 (2.8–8.2)	n.d. (n.d.)	> 27.5 (n.d.)	6.8 (0–14.0)	11.5 (7.4–16.2)
EC10 (95% CL)	3.1 (1.6–6.0)	n.d. (n.d.)	24.2 (n.d.)	3.4 (n.d.–8.5)	4.4 (1.7–7.0)
NOEC	2.4	≥ 27.5	≥ 27.5	2.3	2.30

 

 

Table A7.4.3.4-8:Parental lengths at day 21 [mm]. a.s. = Active substance; Concentrations given as nominal values and TWM (time weighted mean); † = dead at test end.

Replicate	Control	0.92 µg a.s./L (TWM: 0.8 µg a.s./L)	2.30 µg a.s./L (TWM: 2.3 µg a.s./L)	5.75 µg a.s./L (TWM: 2.4 µg a.s./L)	14.4 µg a.s./L (TWM: 11.4 µg a.s./L)	36.0 µg a.s./L (TWM: 27.5 µg a.s./L)
1		4.78		4.33		4.48		4.49		4.45		†
2		4.93		4.75		4.13		5.18		3.75		†
3		4.22		4.07		4.23		4.25		4.59		†
4		5.07		5.04		4.68		4.44		4.33		†
5		4.34		4.37		4.89		4.35		†		4.43
6		4.66		4.86		5.17		4.56		†		†
7		4.79		4.56		4.98		†		†		†
8		5.03		4.82		4.36		4.56		4.64		4.83
9		4.91		4.88		4.81		4.73		†		†
10		4.56		5.34		4.99		5.03		†		†

Validity criteria fulfilled:

yes

Conclusions:

The 21 d NOEC of Amines, N-C10-C16-alkyltrimethylenedi-, reaction products with chloroacetic acid in Daphnia magna was 2.3 µg a.i./L (cumulative offspring per Daphnia, for intrinsic rate of increase), the EC10 was 3.1 µg a.i/L (parental survival).

Executive summary:

The influence of Amines, N-C10-C16-alkyltrimethylenedi-, reaction products with chloroacetic acid (20% a.i., as manufactured) on the reproduction of Daphnia magna was investigated. A 21-day semi-static exposure to the test item at nominal concentrations of 0.92, 2.30, 5.75, 14.40, and 36.00 µg a.i./L, with daily renewal of the test solutions was conducted according to OECD guideline 211. Untreated control replicates were run in parallel. Each treatment group consisted of 10 replicates with one daphnid each (individual exposure). Effects on growth (adult length at test termination) and reproductive performance were investigated. Samples of fresh and aged test solutions were analysed for test item concentrations.

Since the nominal concentrations varied by more than 20 %, the biological effects were re-evaluated based on mean measured concentrations. Due to a decrease of test item concentration during the renewal period, the time weighted mean values (TWM) for each treatment level were calculated. The respective TWM were 0.78, 2.28, 2.39, 11.35, and 27.48 µg a.i./L (85.3, 99.2, 41.5, 78.8, and 76.3 % of nominal).

All effect concentrations are given as time weighted mean concentrations:

The 21 d NOEC was 2.3 µg a.i./L (cumulative offspring per Daphnia, intrinsic rate of increase), the EC10 was 3.1 µg a.i/L (parental survival).

 

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2017-07-12 to 2017-09-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

adopted 02 October, 2012

Deviations:

yes

Remarks:

acclimatization in the test medium (natural river water with mineral components of the culture medium): at least 2 hours.

Principles of method if other than guideline:

The test was conducted with natural river water as test medium.
Acclimatization of daphnids in the test medium (natural river water supplemented with mineral components of the culture medium) was at least 2 hours prior to insertion in the test solutions. Longer acclimatization time is not necessary, since the test medium is supplemented with the same mineral components as the culture medium

GLP compliance:

yes (incl. QA statement)

Remarks:

Staatliches Gewerbeaufsichtsamt Hildesheim, Germany

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 2.50, 7.91, 25.0, 79.1, 250 µg/L
- Sampling method: in fresh media at the start of the exposure intervals on days 0, 9, 14 (0 hours) and in old media at the end of the exposure intervals on days 2, 12, 16 (48 and 72 hours, respectively).
- Sample storage conditions before analysis: All original samples were stored at room temperature. Prepared samples were stored at room temperature in an autosampler until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution with a nominal concentration of 1000 µg/L was prepared with natural river water and was used for the preparation of five concentration levels in the range of 2.50 to 250 µg/L by dilution with natural river water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Clone 5
- Age at study initiation: 2 -24 h
- Source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), Berlin, Germany
- Feeding during test: yes
- Food type: Pseudokirchneriella subcapitata and Desmodesmus subspicatus suspension , cell density: > 10^6 cells/mL
- Frequency: 5 times per week

ACCLIMATION
- Acclimation period: The juvenile daphnids were acclimatized in the test medium (natural river water supplemented with mineral components of the culture medium as specified above) for at least 2 hours prior to insertion in the test solutions. An acclimatization of the brood daphnids 3 weeks prior to the test as suggested by the guideline is not necessary, since the test medium is supplemented with the same mineral components as the culture medium.
- Type and amount of food: mix of unicellular green algae Pseudokirchneriella subcapitata and Desmodesmus subspicatus, 0.2 mg C per Daphnia and day
- Feeding frequency: daily

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

203 - 233 [mg/L] as CaCO3 (ccontrol and nominal substance concentration 250 µg/L)

Test temperature:

19.9 - 20.9 °C (control and nominal substance concentration 250 µg/L)

pH:

7.40 - 8.60 (ccontrol and nominal substance concentration 250 µg/L)

Dissolved oxygen:

8.02 - 11.90 mg/L (ccontrol and nominal substance concentration 250 µg/L)

Nominal and measured concentrations:

Nominal test substance concentrations: 2.50, 7.91, 25.0, 79.1, 250 µg/L
The measured test item concentrations [% of the nominal concentrations]:
Lead component C-12 PDA: fresh media (0 hours): 53 - 245%, old media: < LOQ - 99%
Lead component N’C12-Gly:fresh media (0 hours): 70 - 112%, old media: < LOQ - 114%

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers, 100 mL
- Type: loosely covered with watch glasses
- Fill volume: 50 mL
- Aeration: none
- Renewal rate of test solution: three times a week
- 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: Water of the river Grane was used as its properties in terms of organic matter content and suspended solids are considered typical for European rivers and are close to those in the EU risk assessment methods. The river water was diluted by factor 2 with demineralized water to adjust the TOC content below 2 mg C/L. Additionally, the natural river water was supplemented with the mineral components for Elendt M4 medium to ensure a sufficient reproduction of the daphnids.

- Location: Im Granetal, 38685 Langelsheim, Germany, Latitude: 51.9146°, Longitude: 10.3819°, sampling 2017-08-02
- Total organic carbon: 3.35 mg C/L
- Particulate matter: 14.2 mg/L
- Conductivity: 266 µS/cm
- Culture medium different from test medium: yes

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: max. 1500 lx

EFFECT PARAMETERS MEASURED: daily record of: mortality of parental animals, first appearance of juveniles, number of neonates (alive and dead progeny) and number of aborted eggs

TEST CONCENTRATIONS
- Spacing factor for test concentrations: separation factor of √10
- Range finding study: yes
- Test concentrations: 0.1, 1 and 10 mg/L.
- Results used to determine the conditions for the definitive study: 100% immobilisation after 48 h at 1 mg/L, 0 - 30% mortality after 48 h at 0.1 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 50.8 µg/L

Nominal / measured:

nominal

Conc. based on:

other: Nominal a.s. concentration

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 250 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21

Dose descriptor:

EC10

Effect conc.:

> 250 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

> 50.8 µg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

> 250 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

adults

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

> 50.8 µg/L

Nominal / measured:

nominal

Conc. based on:

other: Nominal a.s. concentration

Basis for effect:

mortality

Remarks:

adults

Details on results:

- Mortality of control: 0%

Results with reference substance (positive control):

EC50(24 h): 1.90 mg/L

Table: Effects on Reproduction for all Introduced and for Surviving Parents (based on the nominalconcentrations of the test item)

Nominal test item concentrations	Mean number of offspring per introduced parental daphnid			Mean number of offspring per survived parental daphnid
[µg/L]	Mean	SD	CV	Mean	SD	CV
250	113.6	16.36	14.4	113.6	16.36	14.4
79.1	107.3	12.13	11.3	109.3	10.91	10.0
25.0	82.2	31.60	38.4	94.1	11.46	12.2
7.91	70.3	33.50	47.7	83.9	17.80	21.2
2.50	92.4	13.76	14.9	92.4	13.76	14.9
Control	83.8	9.26	11.0	83.8	9.26	11.0

Validity criteria fulfilled:

yes

Conclusions:

The chronic toxicity of the substance in a study following OECD 211 with Daphnia magna resulted in a nominal based NOEC for reproduction of >= 250 μg/L (>=50.8 μg/L nominal a.s. concentration). A slightly stimulating effect on the reproduction of the daphnids was observed at the concentration levels 79.1 μg/L (30.5% stimulation) and 250 μg/L (35.6% stimulation).

Executive summary:

The chronic toxicity of the substance to aquatic invertebrates was tested in a study following OECD 211. Daphnia magna were exposed for 21 days to nominal substance concentrations of 2.50, 7.91, 25.0, 79.1, 250 µg/L. The test solutions were prepared with natural river water as test medium. The test item concentrations were analytically verified by LC-MS/MS based on the signals of the two lead components C-12 PDA and N’C12-Gly.

The measured test item concentrations based on the lead component C-12 PDA in fresh media at the start of the respective exposure intervals (0 hours) were in the range of 53 to 245% of the nominal concentrations and < LOQ to 99% in old media at the end of the respective exposure intervals (48 and 72 hours). The measured test item concentrations based on the lead component N’C12-Gly in fresh media at the start of the respective exposure intervals (0 hours) were in the range of 70 to 112% of the nominal concentrations and < LOQ to 114% in old media at the end of the respective exposure intervals (48 and 72 hours). During the course of the study the reproduction rate and the survival rate of the parental animals were recorded. The reproduction was slightly stimulated at the nominal concentrations levels 79.1 µg/L and 250µg/L. A significant effect on the survival rate of the parental animals was not observed. Thus the determined NOEC based on reproduction was >= 250 μg/L nominal (>=50.8 μg/L nominal a.s. concentration).

Description of key information

NOEC (21 d) = 2.3 µg a.i./L (TWA measured, Daphnia magna, OECD Guideline 211)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.3 µg/L

Additional information

The influence of Amines, N-C10-C16-alkyltrimethylenedi-, reaction products with chloroacetic acid (20% a.i., as manufactured) on the reproduction of Daphnia magna was investigated in two experimental studies performed according to GLP and OECD 211.

In the key study, daphnids were exposed to nominal concentrations of 0.92, 2.30, 5.75, 14.40, and 36.00 µg a.i./L for 21 days. Due to a decrease of test item concentration during the renewal period, the time weighted mean values (TWM) for each treatment level were calculated. The respective TWM were 0.78, 2.28, 2.39, 11.35, and 27.48 µg a.i./L (85.3, 99.2, 41.5, 78.8, and 76.3 % of nominal). All effect concentrations are given as time weighted mean concentrations: No significant mortality was observed up to a concentration of 2.4 µg a.i./L. The EC50 for mortality was found to be 10.6 µg a.i./L. Adult body length exhibited no significant differences between the treatments up to the highest concentration tested. The 21 d NOEC for cumulative offspring per Daphnia and intrinsic rate of increase was 2.3 µg a.i./L, the EC10 was 3.1 µg a.i/L (parental survival).

In a second study, daphnids were exposed for 21 days to nominal test item concentrations of 2.50, 7.91, 25.0, 79.1, 250 µg/L. The test item concentrations were analytically verified by LC-MS/MS based on the signals of the two lead components C-12 PDA and N’C12-Gly. The measured test item concentrations based on the lead components were in a range between < LOQ to 245% of nominal concentrations. During the course of the study the reproduction rate and the survival rate of the parental animals were recorded. The reproduction was slightly stimulated at the nominal concentrations levels 79.1 µg/L and 250µg/L. A significant effect on the survival rate of the parental animals was not observed. Thus the determined NOEC based on reproduction was >= 250 μg/L nominal (>=50.8 μg/L nominal a.s. concentration), higher compared to the NOEC of the key study.