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EC number: 201-159-0 | CAS number: 78-93-3
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
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Short-term toxicity to aquatic invertebrates
Administrative data
Link to relevant study record(s)
- Endpoint:
- short-term toxicity to aquatic invertebrates
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1998
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
- Version / remarks:
- reliability scoring based on 2002 guideline
- Deviations:
- no
- GLP compliance:
- yes
- Analytical monitoring:
- yes
- Details on sampling:
- -Sampling method: water samples were collected from mid-depth of each test chamber at test inititation and at test termination to measure concentrations of the test substance. The samples were placed in glass scintillation vials and analyzed immediately.
- Vehicle:
- no
- Details on test solutions:
- PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- A primary stock solution was prepared by mixing the test substance directly with dilution water at a concentration of 4.00 mg MEK/mL. The primary stock was inverted at least 20 times to aid in solubilization of the test substance. Five test solutions were prepared by proportional dilution of the primary stock with dilution water. All test solutions appeared clear and colourless - Test organisms (species):
- Daphnia magna
- Details on test organisms:
- TEST ORGANISM
- Common name: daphnids
- Strain: not reported
- Source: Wildlife International Ltd., Easton Maryland
- Age at study initiation (mean and range, SD): 24 hours
- Feeding during test; none
ACCLIMATION
- Acclimation period: 14 days for parents
- Acclimation conditions (same as test or not): same
- Type of food: a mixture of yeast, Carophyll, and trout chow - Test type:
- static
- Water media type:
- freshwater
- Limit test:
- no
- Total exposure duration:
- 48 h
- Post exposure observation period:
- None
- Hardness:
- 132 mg/L as CaCO3
- Test temperature:
- 20 +/- degrees Celsius
- pH:
- 8.2 to 8.6
- Dissolved oxygen:
- exceeded 60%
- Salinity:
- Not applicable
- Nominal and measured concentrations:
- Nominal - 52, 86, 144, 240, and 400 mg/L
Measured (arithmetic mean of duplicate measurements at T0 and T48h)- 48, 68, 136, 234, and 345 mg/L
Measured (geometric mean of duplicate measurements at T0 and T48h)- 47, 64, 136, 233, and 340 mg/L
As the concentration of MEK in the 86 mg/L test vessels fell to 52% at T48h, endpoints were calculated on arithmetic mean basis. As these are close to the geometric mean concentrations, this is deemed suitable. - Details on test conditions:
- TEST SYSTEM
- Test vessel: 250 mL beakers with a depth of 6.8 cm.
- Type: closed with headspace
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 1
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The water used for culturing and testing was freshwater obtained from a well approximately 40 meters deep located on the Wildlife International Ltd. site. The well water is characterized as moderately-hard water. The well water was passed through a sand filter to remove particles greater than approximately 25 micro meters, and pumped into a 37800-L storage tank where the water was aerated with spray nozzles. Prior to use, the water again was filtered (0.2 micro meters) to remove microorganisms and particles.
- Total organic carbon: < 1 mg C/L
The water used for culturing and testing was freshwater obtained from a well approximately 40 meters deep located on the Wildlife International Ltd. site. The well water is characterized as moderately hard water. The water is routinely monitored to ensure there will be no interferences with ecotoxicity testing. - Reference substance (positive control):
- no
- Duration:
- 48 h
- Dose descriptor:
- EC50
- Effect conc.:
- 308 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mobility
- Remarks on result:
- other: 95% CI of 280 and 339 mg/l
- Duration:
- 48 h
- Dose descriptor:
- EC0
- Remarks:
- no mortality/immobility concentration
- Effect conc.:
- 136 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mobility
- Duration:
- 48 h
- Dose descriptor:
- NOEC
- Effect conc.:
- 68 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- behaviour
- Remarks:
- lethargy
- Duration:
- 24 h
- Dose descriptor:
- EC50
- Effect conc.:
- > 345 mg/L
- Nominal / measured:
- meas. (arithm. mean)
- Conc. based on:
- test mat.
- Basis for effect:
- mobility
- Details on results:
- Daphnids in the negative control, 48 and 68 mg/L (arithm mean) treatment groups appeared healthy and normal throughout the test. After 48-hours of exposure, mortality/immobility in the 136, 234 and 345 mg /L treatment groups was 0, 5 and 75% respectively. Although no mortality/immobility occurred in the 136 mg/L treatment group, 10% of the daphnids were observed to be lethargic at test termination.
- Results with reference substance (positive control):
- Not applicable
- Reported statistics and error estimates:
- None
- Validity criteria fulfilled:
- yes
Reference
Description of key information
The substance was not acutely toxic to Daphnia magna when tested according to OECD TG 202 (Daphnia sp. Acute Immobilisation Test). The 48-hour EC50 in Daphnia magna was 308 mg/L based on arithmetric mean measured concentrations.
Key value for chemical safety assessment
Fresh water invertebrates
Fresh water invertebrates
- Dose descriptor:
- EC50
- Effect concentration:
- 308 mg/L
Additional information
Three studies addressing short-term toxicity to aquatic invertebrates are presented in the dossier. Please refer to the document attached to Section 13 for further discussion of the key study.
Short-term toxicity to aquatic invertebrates.001 – Daphnia – 1998 – key: Acute toxicity to Daphnia magna was assessed according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test), and in compliance with GLP. Daphnia were exposed under static conditions to the substance at concentrations of 52, 86, 144, 240, and 400 mg/L (nominal) in freshwater. The test was performed with 10 daphnia per vessel and 20 daphnia per concentration. The vessels were closed with headspace. For each concentration, the percentage of immobilisation at 24 hours and 48 hours was recorded, and test concentrations were confirmed by GC analysis. The following validity criteria were met: immobilisation in the control did not exceed 10% at the end of the test; dissolved oxygen concentrations remained above 60% of the air saturation value at the end of the test; pH did not vary by more than one unit throughout the test; and the concentrations of the test substance remained close to, or within 80% of the initial concentration throughout the test for 4 out of 5 concentrations. The arithmetic mean of the measured concentrations were 48, 68, 136, 234, and 345 mg/L which were used to express the results of the test. After 48 hours immobility in the 136, 234 and 345 mg/L treatment groups was 0, 5 and 75% respectively. Under the conditions of the test, the 48-hour EC50 was 308 mg/L, and therefore the substance was not acutely toxic to Daphnia magna.
Short-term toxicity to aquatic invertebrates.002 - Daphnia - 1982: Acute toxicity to Daphnia magna was not assessed according to a specific guideline, however; it appears to follow OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) but was not conducted according to GLP (pre-dates GLP). The Daphnia were exposed to the substance under static conditions for 24 hours and the 24-hour EC50 for immobility was determined to be 7060 mg/L. This lower toxicity over a shorter exposure period is in keeping with the result of the key study.
Short-term toxicity to aquatic invertebrates.003 - Daphnia - 1977: Acute toxicity to Daphnia magna was not assessed according to a specific guideline, however; it appears to follow OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) but was not conducted according to GLP (pre-dates GLP). The Daphnia were exposed to the substance under static conditions for 24 hours and the 24-hour EC50 for immobility was determined to be 8890 mg/L. This lower toxicity over a shorter exposure period is in keeping with the result of the key study.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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