Ethyl decanoate

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:

From 29 November 2017 to 20 March 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: supplied by the sponsor, batch no. 17040569
- Expiration date of the lot/batch: April 12, 2019
- Purity test date: October 17, 2017

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Store at room temperature, in a cool, well-ventilated place. Store in original container.
- Stability under test conditions: not stable in the test conditions (the substance concentrations decrease in the test medium)
- Solubility and stability of the test substance in the solvent/vehicle: insoluble in water and not stable in water
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not applicable

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
The test item Ethyl Decanoate is a liquid insoluble in water. First a Water Accomodated Fraction was prepared and the saturated aqueous phase was then centrifuged. The water soluble fraction obtained after centrifugation was then tested as such or after dilution.

Analytical monitoring:

yes

Remarks:

The validation of the analytical method for the determination of Ethyl decanoate in aqueous samples was performed following the EU guideline SANCO/3029/99 rev.4 (11/07/00).

Details on sampling:

- Concentrations: 1, 10, 100 mg/L (nominal)
- Sampling method: GC-MS
- Sample storage conditions before analysis:Twice a week samples of fresh test solution were taken just before distribution to the 10 replicates. A sample of the respective aged test solution were taken from a representative vessel. In each test week two day and three day incubation periods were sampled. One fresh control media was sampled per week. Samples were stored under circumstances to maintain the test item stable to the best of knowledge.

Vehicle:

no

Remarks:

A WAF followed by centifugation was used

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test item Ethyl Decanoate is insoluble in water. Therefore the test item was applied as Water Accomodated Fraction (WAF) according to OECD guidance No. 23 with a WAF loading of 100 mg test item per litre. The test loading of 100 mg/L was prepared by pipetting a volume of 176.5 µL of the test item and transferring it to a WAF bottle containing 1.5 L water. The WAF was prepared by stirring the water for 48 hours at room temperature (about 20°C). The water was stirred slowly to avoid bubble and foam formation using a star shape magnetic stirring bar.
After stirring, the saturated aqueous phase was taken out of the drain port. The first fraction (200 mL) was discarded. Approx. 600 mL were centrifuged at 15,000 x g for 15 minutes. Polypropylene tubes were used for centrifugation. After centrifugation, the centrifugation tubes were lancinated with a solid syringe - connected with a flexible tube - to purge the lower aqueous layer into a sample vessel. This aqueous solution served as highest test concentration with a nominal loading of 100 mg/L. The other two test concentrations were achieved by dilution of the 100 mg/L test solution (1:10 and 1:100). Eluates and dilutions were checked for irregularities such as foam formation prior to exposure for toxicity testing. The test solutions were freshly prepared before test start and before each renewal three times a week.
- Differential loading: . A loading of 100 mg test item per litre and a 1:10 and 1:100 dilution was prepared, resulting in three treatment levels.
- Controls: Negative control without test item
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): no vehicule used
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): not applicable
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): not observed

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia sp
- Strain/clone: Daphnia magna
- Justification for species other than prescribed by test guideline: species required in the guideline
- Source: German Federal Environmental Agency
- Age of parental stock (mean and range, SD): Adult Daphnia, at least 3 weeks old, were separated from the stock population by sieving.See below the conditions of acclimation. Newborn D. magna from the second generation were recovered and the Daphnia used for the test are 4-24 hours old at test start.
- Feeding during test : The daphnids were fed during the test
- Food type: suspensions of unicellular alga Desmodesmus subspicatus and JBL ArtemioFluid in a ratio of 9 : 1 (vol/vol).
- Amount:The content of food in the test suspensions, measured at 585 nm, was kept constant at 0.2 mg C/Daphnia * Day
- Frequency: not reported

ACCLIMATION
- Acclimation period: Adult daphnia (Batches of 30 to 50 animals) were held at room temperature in ca. 1.8 L dilution water for one week.
- Acclimation conditions (same as test or not): yes. The water was changed once per week.
- Type and amount of food: with an algal suspension (Desmodesmus subspicatus) and ArtemioFluid (JBL) 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
- Feeding frequency: fed daily
- Health during acclimation (any mortality observed): healthy specimen

QUARANTINE (wild caught)
Not applicable

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Newborn D. magna were separated by sieving, the first generation was discarded. Individuals applied in the test were transferred with a bore Pasteur pipette a few hours after sieving to ensure applying only healthy specimens.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

No post exposure observation was performed. Only length of the adults were measured by digital photography and image analysis and compared with the equally measured control animals at the study termination.

Hardness:

1.1 - 1.3 mmol/l

Test temperature:

20.2 - 20.9°C

pH:

7.8 - 9.5. The pH did not vary by more than 1.5 units except for the highest tested concentration measured at day 5.

Dissolved oxygen:

between 7.20 mg/L and 13.76 mg/L

Salinity:

Not applicable

Conductivity:

261 µS/cm

Nominal and measured concentrations:

Nominal loading rate of 100 mg/L(stock solution); 1:10 and 1:100 dilutions.
The TWA (Time weighed mean) concentrations are 88.90 µg/L for the highest tested nominal concentration, 16.93 µg/L for the middle nominal concentration and < LOQ for the lowest nominal concentration.
The mean measured concentrations in fresh media were : 430.75µg/L , 44.02 µg/l and < LOQ, for the 100 mg/L and the 1/10 and 1/100 dilutions respectively. And in the aged solutions, the measured concentrations were always < LOQ, whatever the initial tested concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers of 50-100 ml volume
- Material, size, headspace, fill volume: 50 mL
- Aeration: the beaker is closed with glass panes to prevent evaporation but permit gaseous exchange between medium and atmosphere
- Type : semi-static test
- Renewal rate of test solution (frequency/flow rate): test solution is exchanged three times per week
- No. of organisms per vessel: 1 per vessel
- No. of vessels per concentration (replicates): 10 replicates par concentrations
- No. of vessels per control (replicates): 10 replicates
- No. of vessels per vehicle control (replicates): no vehicule used
- Biomass loading rate: not specified

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.
- Total organic carbon: 0.7203 mg/L NOPC
- Particulate matter: not specified
- Metals: Cd < 0.0377 µg/L (LOD); Cr < 0.4287 µg/L (LOD); Cu =0.81 to 0.86 µg/L; Fe < 0.651 µg/L (LOQ); Mn < 0.151 µg/L (LOQ); Ni < 2.088 µg/L (LOD); Pb < 2.088 µg/L (LOD); Zn = 2.03 to 2.17 µg/L.
- Pesticides: not reported
- Chlorine: <=0.02 mg/L - Alkalinity: 1.9 mmol/l
- Ca/mg ratio: Ca hardness: 0.8 mmol/L; Mg-hardness : 0.4°d
- Conductivity: 261 µS/cm
- Culture medium different from test medium: No
- Intervals of water quality measurement: regularly, no more details

OTHER TEST CONDITIONS
- Adjustment of pH: not specified
- Photoperiod: light/dark cycle of 16/8 hours
- Light intensity: The light intensity did not exceed 15 -20 µE/(m2*s) or 1125 - 1500 lux.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The numbers of immobile daphnids were visually determined daily and the immobile daphnids were removed. Any abnormalities in appearance and behaviour were recorded.
The newborn daphnids per beaker were counted and removed daily until all daphnids started to reproduce (at least 10 days and at a maximum of 14 days). After that, newborn daphnids were counted and removed three times per week at each water renewal. Abnormalities in condition (including male sex of adults) or presence of winter eggs were checked and recorded. At study termination, length of the adults were measured by digital photography and image analysis and compared with the equally measured control animals.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: dilution factor of 10 from the stock solution
- Justification for using less concentrations than requested by guideline: not applicable
- Range finding study: not performed
- Test concentrations: 100 mg/L (stock solution), 1:10 and 1:100 dilutions
- Results used to determine the conditions for the definitive study: range finding not perfomred

Reference substance (positive control):

no

Remarks:

According to the guideline no reference item is required. However, the sensitivity of the test clone was checked twice a year in non-GLP tests determining the acute toxicity by using K2Cr2O7 as reference substance.

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 88.9 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

reproduction

Details on results:

No substance related significant difference between control and treatments concerning the number of cumulative offspring per survived parent was observed. No clinical signs were observed for the survived individuals. Adult growth (body length), survival and intrinsic rate were unaffected by Ethyl Decanoate. For Age of first brood and development rate significant differences between the control and the lowest treatment were observed. However, since chemical analysis showed that no test item could be found in the lowest treatment (< 10µg/L) and based on expert judgement, these differences were not considered to be substance related and rather be based on biological variability.

Results with reference substance (positive control):

According to the guideline no reference item is required. However, the sensitivity of the test clone was checked twice a year in non-GLP tests determining the acute toxicity by using K2Cr2O7 as reference substance. The latest 24h-EC50 (November 2017) was 1.435 mg/L (95 % confidence limits: 1.233 – 1.745 mg/L).

Reported statistics and error estimates:

For each endpoint, the NOEC and LOEC were determined by using ANOVA followed by Student-t test, Fisher`s Exact Binomial test, Dunnett’s or Williams’ test or an appropriate non-parametric test. Since the test results show no concentration-response relationship no EC10 and EC50 including the 95% confidence intervals could be calculated.
The evaluation of the concentration-effect-relationships and the calculations of effect concentrations was based on the mean measured concentrations (time weighted mean, TWM), since the deviation from the nominal concentrations was greater than ± 20%.
-
Statistical calculations were done with ToxRat® Pro 3.2.1, a statistical software package for ecotoxicity response analysis by ToxRat® Solutions

Table1:         Mean measured concentrations of EthylDecanoate.

Nominal concentration	Mean measured fresh concentration
[mg/L]	[µg/L]	% of initial
Control	< LOQ *	-
1.0	< LOQ *	-
10.0	44.02	100
100.0	430.75	100
	Mean measured aged concentration
Control	< LOQ *	-
1.0	< LOQ *	-
10.0	< LOQ *	-
100.0	< LOQ *	-
	Time weighted mean (TWA) concentration
Control	< LOQ *	-
1.0	< LOQ *	-
10.0	16.93	38.47
100.0	88.90	20.64

*LOQ = 10 µg/L

 

Table2:         Survival and growth data.

TWA concentration [µg/L]	Parental survival [%]	Length on test end [Mean ± SD]
Control	100	4.82 ± 0.179
< 10.0 *	100 (-)	4.69 ± 0.329 (-)
16.9	100 (-)	4.77 ± 0.152 (-)
88.9	100 (-)	4.86 ± 0.201 (-)

* In the lowest treatment all performed analytical measurements were below the LOQ of 10 µg/l.Thus, the half of the LOQ was used for calculations.

(+) statistically significant difference between controls and treatments / (-) no significant difference between controls and treatments

 

Table3:        Survival and reproduction data.

TWA concentration [µg/L]	Cumulative offspring per survived female [Mean ± SD]	Age at first brood [Mean ± SD]	Development rate [Mean ± SD]	Intrinsic rate of population increase [Mean ± SD]
Control	70.7 ± 10.64	10.8 ± 1.25	0.094 ± 0.010	0.280 ± 0.0216
< 10.0*	75.9 ± 11.86 (-)	12.1 ± 1.26 (+)**	0.083 ± 0.009 (+)**	0.269 ± 0.016 (-)
16.9	66.0± 66.0 (-)	11.8± 1.25 (-)	0.086± 0.011 (-)	0.275± 0.222 (-)
88.9	89.5± 89.5 (-)	10.5± 1.25 (-)	0.096± 0.011 (-)	0.300± 0.017 (-)

(+) statistically significant difference between controls and treatments / (-) no significant difference between controls and treatments

* In the lowest treatment all performed analytical measurements were below the LOQ of 10 µg/l.Thus, the half of the LOQ was used for calculations.

** According to the statistical evaluation performed with Toxrat[8] there was a statistical difference between treatment and control. However, since the concentration was below the LOQ and based on expert judgement this effect was not considered as substance related rather than on biological variability.

 

Validity criteria fulfilled:

yes

Conclusions:

Under the experimental conditions of the study, ethyl decanoate did not induce adverse effects on daphnia when exposed during 21 days. No treatment related effect on reproduction was observed. The NOEC for reproduction was determined to be ≥ 88.9 µg/L and the LOEC > 88.9 µg/L. Hence, according to CLP criteria, ethyl decanoate does not require classification for long-term aquatic toxicity to invertebrates.

Executive summary:

The aim of this GLP compliant study is to evaluate the potential toxicity of ethyl decanoate on the reproduction of Daphnia magna under long term exposure. This study was performed according to OECD TG 211 method.

A 21-day semi-static exposure to Ethyl Decanoate at a nominal test concentration of 100 mg/L and a 1:10 and 1:100 dilution was conducted according to OECD guideline 211. Untreated control replicates were run in parallel. Test solutions were renewed three times per week. Each treatment group consisted of 10 replicates with one daphnid each (individual exposure). Effects on reproductive performance, survival, growth (adult length at test termination), development rate and intrinsic rate were investigated. Due to its insolubility in water the test item was applied as Water Accommodated Fraction (WAF). A WAF loading of 100 mg test item per liter was prepared by stirring the water containing the substance for 48hours at room temperature. Then the saturated aqueous phase was taken out and centrifuged at 15,000 x g for 15 minutes and the lower aqueous layer was recovered and tested as the nominal loading of 100 mg/L. Two dilutions of this solution at 1/10 and 1/100 were also tested. The test solutions were freshly prepared before test start and before each renewal three times a week and the test item concentrations were measured in representative fresh and aged test solutions.

The concentrations of the test item was analysed by GC-MS (LOQ = 10 µg/L). The measured test item concentration in the first test concentration was below the LOQ in fresh and aged test media. The arithmetic mean measured test concentration in fresh media was 44.02 µg/L in the second concentration and 430.75 µg/L in the highest concentration. During the time interval until renewal of the test solution, test item concentrations decreased below the limit of quantification.

Since recovery rates were not in a range of 80 and 120 % of nominal throughout the test, time weighted average (TWA) concentrations were applied for the effect assessment.

The TWA of mean measured initial and mean measured aged concentration at test solution renewal was 16.93 µg/L and  88.9 µg/L in the second and highest test concentration, respectively.

No substance related significant difference between control and treatments concerning the number of cumulative offspring per survived parent was observed. No clinical signs were observed for the survived individuals. Adult growth (body length), survival and intrinsic rate were unaffected by Ethyl Decanoate. For Age of first brood and development rate significant differences between the control and the lowest treatment were observed. However, since chemical analysis showed that no test item could be found in the lowest treatment (< 10µg/L) and based on expert judgement, these differences were not considered to be substance related and rather be based on biological variability.

Under the experimental conditions of the study, ethyl decanoate did not induce any adverse effects on Daphnia when exposed during 21 days. No treatment related effect on reproduction was observed. The NOEC for reproduction was determined to be ≥ 88.9 µg/L and the LOEC > 88.9 µg/L. Hence, according to CLP criteria, ethyl decanoate did not required classification for long-term toxicity to aquatic invertebrates.

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Read-across category

Justification for type of information:

See "Assessment reports" section 13 or "Categories" section for the justification and rationale document for category approach.

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

reproduction

Table 1: Results from available key studies on the source substances of the category

Common name	CAS	Fatty acid chain length	Type of alcohol	MW	Appareance	Long-term toxicity to aquatic invertebrates
Ethyl decanoate	110-38-3	C10	ethanol	200.32	Liquid	Experimental Result : No adverse effect
Ethyl undecylenate	692-86-4	C11	ethanol	212.33	liquid	No data
Isopropyl laurate	10233-13-3	C12	Isopropanol	242,41	Liquid	no data
Octyl octanoate	2306-88-9	C8	octanol(C8)	256,42	Liquid	no data
Isopropyl myristate	110-27-0	C14	Isopropanol	270,46	Liquid	Experimental result:NOEC(21d) ≥ 100 mg/L (nom.,filt.)
Dodecanoic hexylester	34316-64-8	C12	Hexanol(C6)	284,49	Liquid	no data
Ethyl linoleate	544-35-4	C18:2	ethanol	308,5	Liquid	no data
Ethyl oleate	111-62-6	C18:1	ethanol	310.52	Liquid	no data
2-ethylhexyl laurate	20292-08-4	C12	2-Ethyl-Hexanol	312,53	Liquid	no data
Fatty acids, coco, 2-ethylhexyl esters	92044-87-6	C12-14	2-ethylhexanol	312.53 – 340.60	liquid	No data

Similar ecotoxicity profile

Based on the experimental data, the category members have low toxicity to aquatic invertebrates.

Due to their poor water solubility, these substances are difficult for aquatic testing. If undissolved test material is not properly removed from test vessels, it may cause physical effects, such as immobilization of Daphnia by getting them trapped into an oil film, and these physical effects may impact the reproduction. These indirect effects do not reflect real toxicity of the test substance towards the organisms. Therefore the reproduction test was performed on filtrated solutions of Isopropyl myristate. No adverse effects to the reproduction of Daphnia magna was observed for Isopropyl myristate.

Target substance conclusion

Based on the results obtained on the category member, the 21d-NOEC for Daphnia magna of the target substance Ethyl decanoate was considered >= 100 mg/L (nominal, filtrated).

Validity criteria fulfilled:

yes

Conclusions:

Based on the category approach, the NOEC value on daphnid reproduction of Ethyl decanoate was quantified as ≥ 100 mg/L (nominal, filtered) after 21 days exposure period. According to the CLP criteria, the registered substance is not classified for long-term toxicity to aquatic invertebrates.

Executive summary:

According to the Regulation (EC) NO. 1907/2006, Annex XI, 1.5, A read-across category for short chain fatty acid was performed in order to provide informations on ethyl decanoate CAS 110-38-3.

This category was based on common and shared properties as:

- common functional group,

- common precursors and the likelihood of common impurities resulting from common process of manufacturing,

- chemically structurally similar breakdown products obtained via the same biological processes into the organisms, and

- constant pattern in the changing of the potency of the properties across the category.

One reliable key studies on Isopropyl myristate is available for the assessment of chronic toxicity to invertebrates.The 21d-NOEC on the reproduction of Daphnia magna was defined as ≥ 100 mg/L (nom., filtrated) for Isopropyl myristate. So no adverse effect on Daphnia reproduction was observed for isopropyl myristate when tested up to its limit of solubility in the test medium.

Since the category members are expected to show the same toxicity level to aquatic organisms due to common structural and physico-chemical properties, the 21d-NOEC on the reproduction of Daphnia magna of the target substance Ethyl decanoate is considered as ≥ 100 mg/L (Nom. filtrated).

Hence, the target substance was not classified for long-term toxicity to aquatic invertebrates

Description of key information

The NOEC of Ethyl decanoate on the reproduction of Daphnia magna was determined to be ≥ 88.9 µg/L after 21 days of exposure. No treatment related effects on reproduction was observed. Hence, according to CLP criteria, ethyl decanoate does not require classification for long-term aquatic toxicity.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

88.9 µg/L

Additional information

Justification and rationale of the category approach for Ethyl decanoate

This category group covers fatty acid chains linked to alcohols via an ester function. It includes mono-constituent substances and UVCB substances with varying fatty acid chain lengths from C8 to C18-unsaturated and alcohol types (including ethanol, isopropanol, octanol, hexanol and 2-ethylhexanol). This category group was made in order to provide sufficient information for physico-chemical, environmental, ecotoxicological and toxicological characterization of ethyl decanoate (CAS 110-38-3). Some data on the target substance of the category are available.

This category includes:

-       Target substance:

o       Ethyl decanoate (CAS 110-38-3)

-       Source substances:

o       Ethyl undecylenate (CAS 692-86-4)

o       Isopropyl laurate (CAS 10233-13-3)

o       Octyl octanoate (CAS 2306-88-9)

o       Isopropyl myristate (CAS 110-27-0)

o       Dodecanoic hexyl ester (CAS 34316-64-8)

o       Ethyl linoleate (CAS 544-35-4)  

o       Ethyl oleate (CAS 111-62-6)

o       2-Ethylhexyl laurate (CAS 20292-08-4)

o       Fatty acids, coco, 2-ethylhexyl esters (CAS 92044-87-6)

Summary of available studies for long term toxicity to aquatic invertebrates

Isopropyl myristate CAS 110 -27 -0

There is one available study which is considered as relevant and reliable. This experimental study was performed according to OECD 202 part II, using source substance the isopropyl myristate. Daphnia magna were exposed to 0, 1 and 100 mg/L. No adverse effect relative to the treatment was observed. The NOEC value on daphnid reproduction was quantified ≥ 100 mg/L (nom., filtered) for a 21 days exposure period.

Ethyl decanoate (CAS 110-38-3)

Since only one substance of the category, Isopropyl myristate, was tested for the chronic toxicity on Daphnids, a test OECD 211 was performed under GLP, on the target substance Ethyl decanoate. The Daphnids were exposed to the following nominal concentrations of 100 mg/L and a 1:10 and 1:100 dilution, for 21 -days, under semi-static considtions.

Untreated control replicates were run in parallel. Test solutions were renewed three times per week. Each treatment group consisted of 10 replicates with one daphnid each (individual exposure). Effects on reproductive performance, survival, growth (adult length at test termination), development rate and intrinsic rate were investigated. Due to its insolubility in water the test item was applied as Water Accommodated Fraction (WAF). A WAF loading of 100 mg test item per liter was prepared by stirring the water containing the substance for 48hours at room temperature. Then the saturated aqueous phase was taken out and centrifuged at 15,000 x g for 15 minutes and the lower aqueous layer was recovered and tested as the nominal loading of 100 mg/L. Two dilutions of this solution at 1/10 and 1/100 were also tested. The test solutions were freshly prepared before test start and before each renewal three times a week and the test item concentrations were measured in representative fresh and aged test solutions.

The concentrations of the test item was analysed by GC-MS (LOQ = 10 µg/L). The measured test item concentration in the first test concentration was below the LOQ in fresh and aged test media. The arithmetic mean measured test concentration in fresh media was 44.02 µg/L in the second concentration and 430.75 µg/L in the highest concentration. During the time interval until renewal of the test solution, test item concentrations decreased below the limit of quantification.

Since recovery rates were not in a range of 80 and 120 % of nominal throughout the test, time weighted average (TWA) concentrations were applied for the effect assessment.

The TWA of mean measured initial and mean measured aged concentration at test solution renewal was 16.93 µg/L and  88.9 µg/L in the second and highest test concentration, respectively.

No substance related significant difference between control and treatments concerning the number of cumulative offspring per survived parent was observed. No clinical signs were observed for the survived individuals. Adult growth (body length), survival and intrinsic rate were unaffected by Ethyl Decanoate. For Age of first brood and development rate significant differences between the control and the lowest treatment were observed. However, since chemical analysis showed that no test item could be found in the lowest treatment (< 10µg/L) and based on expert judgement, these differences were not considered to be substance related and rather be based on biological variability.

Under the experimental conditions of the study, ethyl decanoate did not induce adverse effects on Daphnia swhen exposed during 21 days. No treatment related effect on reproduction was observed. The NOEC for reproduction was determined to be ≥ 88.9 µg/L and the LOEC > 88.9 µg/L.

Conclusion

Based on the category approach, the NOEC value on Daphnia reproduction of Ethyl decanoate was quantified as ≥ 100 mg/L (nominal, filtered) after 21 days exposure period.

This result based on the category approach was confirmed by a chronic toxicity test on Daphnids performed on Ethyl decanoate according to OECD 211 and under GLP. Under the experimental conditions of this study, ethyl decanoate did not induce any adverse effects on Daphnia when exposed during 21 days. No treatment related effect on reproduction was observed. The NOEC for reproduction was determined to be ≥ 88.9 µg/L and the LOEC > 88.9 µg/L (measured; TWA).

This experimental result on ethyl decanoate reinforces the category approach whose conclusion was also the lack of adverse effect of ethyl decanoate on the reproduction of Daphnia magna, when tested at its solubility limit.