undecan-2-one; methyl nonyl ketone

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Justification for type of information:

Data is from secondary source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

yes

Remarks:

dimethyl formamide was used as a vehicle.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Age at study initiation (mean and range, SD): <24 hr old

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

240 mg/L CaCO3

Test temperature:

20°C

pH:

7.7 to 8.0

Dissolved oxygen:

98 –100 % O2 saturation

Nominal and measured concentrations:

Nominal conc: 0 (control); 0 (solvent control (dimethyl formamide)); 0.13, 0.25, 0.50, 1.0, 2.0, 4.0 mg/l of test chemical.

Details on test conditions:

TEST SYSTEM
- Renewal rate of test solution (frequency/flow rate): renewal after 24 hours
- No. of organisms per vessel: 5 daphnids/test vessel
- No. of vessels per concentration (replicates): 4 replicates
- No. of vessels per control (replicates): 4 replicates
- No. of vessels per vehicle control (replicates): 4 replicates

OTHER TEST CONDITIONS
- Photoperiod: 16: 8 light:dark cycle
- Light intensity: 350 lux

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobilization occurred in the control or in the solvent control group. No immobilization was noted after 48 hours up to the treatment level of 0.25 mg/L. After 48 hours immobilization in the treatment groups of 0.50, 1.0, 2.0 and 4.0 mg/L was 15 %, 30 %, 30 % and 75 % respectively.

Validity criteria fulfilled:

not specified

Conclusions:

Based on the effect of test chemical on mobility of test daphnids, the 48 hr EC50 value was determined to be 2.3 mg/l.

Executive summary:

An acute toxicity to aquatic invertebrate study was carried out for 48 hrs. Study was performed following the principles of the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Daphnia magna (Water flea) of <24 hr old was used as a test organism. Test chemical analysis was carried out using gas chromatography with flame ionization detection. Initial recovery (0 hours) ranged from 47 – 80 % and ranged from 0.5 – 7 % after 24 hours. After renewal, initial recovery (0 hours) ranged from 38 – 91 % and ranged from 2 – 5 % after 24 hours Dimethyl formamide was used as a vehicle. Test chemical conc. used for the study were 0 (control); 0 (solvent control), 13, 0.25, 0.50, 1.0, 2.0 and 4.0 mg/l, respectively. Test daphnids (5 daphnids/test vessel) were exposed to different test chemical conc. in a semi-static system. Test conditions involve a pH 7.7 to 8.0, temperature of 20°C, total hardness of 240 mg/L CaCO3 and dissolved oxygen of 98 –100 % O2 saturation, respectively with a photoperiod of 16: 8 light:dark cycle and light intensity of 350 lux. All experiments were performed in 4 replicates. No immobilization occurred in the control or in the solvent control group. No immobilization was noted after 48 hours up to the treatment level of 0.25 mg/L.  After 48 hours immobilization in the treatment groups of 0.50, 1.0, 2.0 and 4.0 mg/L was 15 %, 30 %, 30 % and 75 % respectively. On the basis of the effect of test chemical on mobility of test daphnids, the 48 hr EC50 value was determined to be 2.3 mg/l. Thus, based on the EC50 value, test chemical can be considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic and hence, considered to be 'not classified' as per the CLP classification criteria.

Description of key information

An acute toxicity to aquatic invertebrate was carried out for assessing the effect of test chemical. Study was performed following the principles of the OECD TG 202 (Dapnia sp. Acute immobilization test). Daphnia magna (<24 hr old) obtained from Shell Research Laboratories was used as a test organism. Daphnids were cultured a temperature of 20°C with a dissolved oxygen of >60% ASV, photoperiod of 16:8 light:dark conditions. Each working day, a suspension of Chlorella vulgaris at a rate of l mg organic carbon per litre of culture water. The Daphnia magna for the test were cultured under semi-static conditions and were not fed during the test. 10 mg/l stock solution of test chemical was prepared by initially dissolving the substance in dimethyl formamide (DMF) prior to dilution in dechlorinated water. The test concentrations were prepared by addition of the appropriate volume of this stock solution to the dilution water to give the required concentrations for the test. Test chemical conc. taken for the study were 0 (control), 0.13, 0.25, 0.50, 1.0, 2.0 and 4.0mg/l, respectively. Samples of the test solutions in which the organisms were exposed were taken for analytical verification at the start of the definitive study, before and after renewal of solutions at 24 hours and at the end of the 48 hour exposure period. Test substance specific analysis of each test concentration was carried out as soon as possible after sampling. Analytical measurements were carried out GC. A further control solution was prepared containing dimethyl formamide at a concentration of 1 ml DMF/l. Daphnids (total 20 daphnids) were exposed to different test chemical conc. in each test vessel. 5 Daphnia were placed at random in each dish containing 25 ml of prepared test medium, diluent water only or diluent water plus 1 ml DMF per litre, as appropriate. The dishes were covered with a transparent perspex sheet to limit aerial contamination of the test vessels and reduce evaporative losses. The test vessels were placed into an incubator at a temperature of 20 ± 1°C, hardness of 240 mg/l as CaCO3, DO of 98-100% ASV with a light cycle of 16 hr light and 8 hr dark and without supplementary aeration or feeding during the 48 hour exposure period. The 48 hour EC50 value of test chemical to Daphnia magna and the highest no observed effect concentration (NOEC) after 48 hours were noted. Temperature, pH values and dissolved oxygen concentration were also recorded at the start of the study, before and after renewal of solutions at 24 hours and at the end of the 48-hour exposure period. Reference substance were also run simultaneously during the study. All experiments were performed in 5 replicates. The EC50 values were estimated graphically and 95% confidence limits calculated according to the method of ToxCalc™ Version 5.0 "Comprehensive Toxicity Data Analysis and Database Software". The analytical data clearly demonstrated that recovery of test chemical from solution varies with typical recovery rates at 0 hours of 47 to 80%. After 24 hours recovery is shown to have dropped significantly to only 0.5 to 7.0%. Similar values were obtained for the replacement solutions at 24 hours, with initial recovery of 38-to 91 % of the nominal value, which dropped to 2 to 5% after the solutions had aged for a further 24 hours. The water quality measurements of the test solutions were within acceptable limits. Specifically, the dissolved oxygen concentration remained greater than 60% of the air saturation value, which fulfils the validity criteria of the study. None (0%) of the twenty control Daphnia, maintained in dilution water, or in lml/l DMF were immobilised during the study, and no Daphnia were trapped at the surface of the water in the control vessels, this fulfils the validity criteria of the study which states that control immobilisation must not exceed 10% at the end of the test. The 48 hr EC50 value of the reference substance was determined to be 0.9 mg/l (95% C. I. 0.8 to 1.1 mg/l). On the basis of the effect on immobilization of test daphnids, the 48 hr EC50 value was determined to be 0.23 mg/l (based on actual measured (arithmetic mean) concentrations). Thus, based on the EC50 value, test chemical was considered as toxic to aquatic invertebrates and hence, considered to be classified in 'aquatic acute category 1/chronic category 1' as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.23 mg/L

Additional information

Various experimental studies and predicted data of the test chemical and its read across chemical were reviewed for short term toxicity to aquatic invertebrate end point which are summarized as below:

In an experimental study, an acute toxicity to aquatic invertebrate was carried out for assessing the effect of test chemical. Study was performed following the principles of the OECD TG 202 (Dapnia sp. Acute immobilization test). Daphnia magna (<24 hr old) obtained from Shell Research Laboratories was used as a test organism. Daphnids were cultured a temperature of 20°C with a dissolved oxygen of >60% ASV, photoperiod of 16:8 light:dark conditions. Each working day, a suspension of Chlorella vulgaris at a rate of l mg organic carbon per litre of culture water. The Daphnia magna for the test were cultured under semi-static conditions and were not fed during the test. 10 mg/l stock solution of test chemical was prepared by initially dissolving the substance in dimethyl formamide (DMF) prior to dilution in dechlorinated water. The test concentrations were prepared by addition of the appropriate volume of this stock solution to the dilution water to give the required concentrations for the test. Test chemical conc. taken for the study were 0 (control), 0.13, 0.25, 0.50, 1.0, 2.0 and 4.0mg/l, respectively. Samples of the test solutions in which the organisms were exposed were taken for analytical verification at the start of the definitive study, before and after renewal of solutions at 24 hours and at the end of the 48 hour exposure period. Test substance specific analysis of each test concentration was carried out as soon as possible after sampling. Analytical measurements were carried out GC. A further control solution was prepared containing dimethyl formamide at a concentration of 1 ml DMF/l. Daphnids (total 20 daphnids) were exposed to different test chemical conc. in each test vessel. 5 Daphnia were placed at random in each dish containing 25 ml of prepared test medium, diluent water only or diluent water plus 1 ml DMF per litre, as appropriate. The dishes were covered with a transparent perspex sheet to limit aerial contamination of the test vessels and reduce evaporative losses. The test vessels were placed into an incubator at a temperature of 20 ± 1°C, hardness of 240 mg/l as CaCO3, DO of 98-100% ASV with a light cycle of 16 hr light and 8 hr dark and without supplementary aeration or feeding during the 48 hour exposure period. The 48 hour EC50 value of test chemical to Daphnia magna and the highest no observed effect concentration (NOEC) after 48 hours were noted. Temperature, pH values and dissolved oxygen concentration were also recorded at the start of the study, before and after renewal of solutions at 24 hours and at the end of the 48-hour exposure period. Reference substance were also run simultaneously during the study. All experiments were performed in 5 replicates. The EC50 values were estimated graphically and 95% confidence limits calculated according to the method of ToxCalc™ Version 5.0 "Comprehensive Toxicity Data Analysis and Database Software". The analytical data clearly demonstrated that recovery of test chemical from solution varies with typical recovery rates at 0 hours of 47 to 80%. After 24 hours recovery is shown to have dropped significantly to only 0.5 to 7.0%. Similar values were obtained for the replacement solutions at 24 hours, with initial recovery of 38-to 91 % of the nominal value, which dropped to 2 to 5% after the solutions had aged for a further 24 hours. The water quality measurements of the test solutions were within acceptable limits. Specifically, the dissolved oxygen concentration remained greater than 60% of the air saturation value, which fulfils the validity criteria of the study. None (0%) of the twenty control Daphnia, maintained in dilution water, or in lml/l DMF were immobilised during the study, and no Daphnia were trapped at the surface of the water in the control vessels, this fulfils the validity criteria of the study which states that control immobilisation must not exceed 10% at the end of the test. The 48 hr EC50 value of the reference substance was determined to be 0.9 mg/l (95% C. I. 0.8 to 1.1 mg/l). On the basis of the effect on immobilization of test daphnids, the 48 hr EC50 value was determined to be 0.23 mg/l (based on actual measured (arithmetic mean) concentrations). Thus, based on the EC50 value, test chemical was considered as toxic to aquatic invertebrates and hence, considered to be classified in 'aquatic acute category 1/chronic category 1' as per the CLP classification criteria.

 

In an experimental study from secondary source, an acute toxicity to aquatic invertebrate study was carried out for 48 hrs. Study was performed following the principles of the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Daphnia magna (Water flea) of <24 hr old was used as a test organism. Test chemical analysis was carried out using gas chromatography with flame ionization detection. Initial recovery (0 hours) ranged from 47 – 80 % and ranged from 0.5 – 7 % after 24 hours. After renewal, initial recovery (0 hours) ranged from 38 – 91 % and ranged from 2 – 5 % after 24 hours Dimethyl formamide was used as a vehicle. Test chemical conc. used for the study were 0 (control); 0 (solvent control), 13, 0.25, 0.50, 1.0, 2.0 and 4.0 mg/l, respectively. Test daphnids (5 daphnids/test vessel) were exposed to different test chemical conc. in a semi-static system. Test conditions involve a pH 7.7 to 8.0, temperature of 20°C, total hardness of 240 mg/L CaCO3 and dissolved oxygen of 98 –100 % O2 saturation, respectively with a photoperiod of 16: 8 light:dark cycle and light intensity of 350 lux. All experiments were performed in 4 replicates. No immobilization occurred in the control or in the solvent control group. No immobilization was noted after 48 hours up to the treatment level of 0.25 mg/L.  After 48 hours immobilization in the treatment groups of 0.50, 1.0, 2.0 and 4.0 mg/L was 15 %, 30 %, 30 % and 75 % respectively. On the basis of the effect of test chemical on mobility of test daphnids, the 48 hr EC50 value was determined to be 2.3 mg/l. Thus, based on the EC50 value, test chemical can be considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic and hence, considered to be 'not classified' as per the CLP classification criteria.

 

Another short term toxicity to aquatic invertebrate study was carried out for 48 hrs (J-CHECK, 2021). Study was performed in accordance with the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Test was carried out under static system using Daphnia magna (Water flea) as a test organism. On the basis of the effect of test chemical on mobility of test daphnids, the 48 hr EC50 value was determined to be 1.3 mg/l. Thus, based on the EC50 value, test chemical can be considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic and hence, considered to be 'not classified' as per the CLP classification criteria.

 

In a supporting weight of evidence study from peer reviewed journals, short term toxicity to aquatic invertebrate study was carried out for 48 hrs. Study was performed in accordance with the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Test was carried out under static system using Daphnia magna (Water flea) as a test organism. On the basis of the effect of test chemical on mobility of test daphnids, the 48 hr EC50 value was determined to be 0.23 mg/l (measured conc.). Thus, based on the EC50 value, test chemical was considered as toxic to aquatic invertebrates and hence, considered to be classified in 'aquatic acute category 1/chronic category 1' as per the CLP classification criteria.

 

For the test chemical, short term toxicity to aquatic invertebrate study was carried out for 48 hrs (from authoritative databases and secondary sources). Test was carried out under static system. Daphnia magna (Water flea) of <24 hr old was used as a test organism. On the basis of the effect of test chemical on mobility of test daphnids, the 48 hr EC50 value was determined to be 0.54 mg/l (95% C. I. = 0.3 to 2.1 mg/l). Thus, based on the EC50 value, test chemical was considered as toxic to aquatic invertebrates and hence, considered to be classified in 'aquatic acute category 1/chronic category 1' as per the CLP classification criteria.

 

In a prediction done using the EPI Suite ECOSAR version 1.11, the short-term toxicity of the test chemical to aquatic invertebrates was predicted. On the basis of effect of test chemical observed in a static system on the mobility of the test organism during the 48 hr exposure duration, the lethal effect concentration (LC50) for the test chemical was estimated to be 2.797 mg/l. Thus, based on the LC50 value, test chemical can be considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic and hence, considered to be 'not classified' as per the CLP classification criteria.

 

Additional short term toxicity to aquatic invertebrate study was carried out for 48 hrs. Study was performed in accordance with the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Conc. of vehicle used in the test solution was 100 microL/L. Test was carried out under semi-static system using Daphnia magna (Water flea) as a test organism. Total amount of the test solution was renewed every 24 hours. Test daphnids (20 daphnids per concentration) were exposed to different test chemical conc. (i.e., 0 (control), 0 (vehicle control), 0.10, 0.22, 0.46, 1.0, 2.2 mg/L) for a period of 48 hrs. Test conditions involve a temperature of 24 ± 1° C under a photoperiod of 16 hours light / 8 hours dark in a room light. All experiments were performed in 4 replicates. On the basis of the effect of test chemical on mobility of test daphnids, the 48 hr EC50 value was determined to be 0.61 mg/l (95% C. I. = 0.49 to 0.75 mg/l). Thus, based on the EC50 value, test chemical was considered as toxic to aquatic invertebrates and hence, considered to be classified in 'aquatic acute category 1/chronic category 1' as per the CLP classification criteria.

 

On the basis of the above results, it can be concluded that the test chemicalwas considered as toxic to aquatic invertebrates and hence, considered to be classified in 'aquatic acute category 1/chronic category 1' as per the CLP classification criteria.