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EC number: 213-234-5 | CAS number: 931-36-2
- 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

Endpoint summary
Administrative data
Description of key information
Additional information
Data are available for the three trophic levels fish, aquatic invertebrates and algae. The most sensitive species is fish with a 96-h LC50 of 68.1 mg/L.
Short-term toxicity to fish
Acutely harmful to fish
The acute toxicity of 2-ethyl-4-methylimidazole (CAS 931-36-2) to fish was tested in a static test according to the national guideline German Industrial Standard DIN 38412, part 15). The test species was Leuciscus idus. The 96-h LC50 was determined to be 68.1 mg/L (nominal; BASF AG, 1990; report no. 10F0166/895233).
Long-term toxicity to fish
No data available.
In Annex IX of Regulation (EC) No 1907/2006, it is laid down that long-term toxicity to fish shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on fish.
According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or is assessed to be a PBT or vPvB.
2 -ethyl-4 -methylimidazole is readily biodegradable. Based on the measured log Kow of 1.13, significant bioaccumulation is not to be expected, the lowest acute toxicity value was 68.1 mg/L (fish, 96 -h LC50).
The hazard assessment of 2 -ethyl-4 -methylimidazole reveals neither a need to classify the substance as dangerous to the environment, nor is it a PBT of vPvB substance, nor are there any further indications that the substance may be hazardous to the environment.
Therefore, and for reasons of animal welfare, a long-term study on the toxicity to fish is not provided.
Short-term toxicity to aquatic invertebrates
With high probability acutely not harmful to aquatic invertebrates.
The acute toxicity of 2-ethyl-4-methylimidazole (CAS 931-36-2) to aquatic invertebrates was test in a static test according to the EU method C2 of Annex V to Directive 79/831/EEC. The test species was Daphnia magna. The test concentrations were not analytically verified but are assumed to be stable. The 48-h EC50 was determined to be 297 mg/L (nominal; BASF AG, 1990; report no. 1/0245/2/89-0245/89). It can be concluded that with high probability 2-ethyl-4-methylimidazole is acutely not harmful to aquatic invertebrates.
Long-term toxicity to aquatic invertebrates
No data available.
In Annex IX of Regulation (EC) No. 1907/2006, it is laid down that long-term toxicity testing on invertebrates (preferred species Daphnia) shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on aquatic invertebrates.
According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or is assessed to be a PBT or vPvB.
The hazard assessment of 2-ethyl-4-methylimidazole reveals neither a need to classify the substance as dangerous to the environment, nor is it a PBT or vPvB substance, nor are there any further indications that the substance may be hazardous to the environment.
Therefore, long-term toxicity in aquatic invertebrates is not provided.
Toxicity to aquatic algae and cyanobacteria
With high probability acutely not harmful to aquatic algae.
The toxicity of 2-ethyl-4-methylimidazole (CAS 931-36-2) was tested in a growth inhibition test according to the German Industrial Standard DIN 38412, Part 9. The test species was Desmodesmus subspicatus. The test item was studied in two separate assays with either pH-adjusted or not pH-adjusted test solutions. The 72-h ErC50 was determined to be 124.8 mg/L if the test solutions were not pH-adjusted (nominal; BASF AG 1990; Study no. 2/0245/89). The test item concentrations were not analytically verified, but are assumed to be stable.
Toxicity to microorganisms
The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriately low concentrations.
The toxicity of 2-ethyl-4-methylimidazole (CAS 931-36-2) to microorganisms was studied in a respiration inhibition test according to Annex of EEC Directive 88/302/EEC, which corresponds to OECD Guideline 209 and ISO Standard 8192. Activated sludge from a wwtp treating municipal sewage was used as the test system. The 30-min EC20 was determined to be 650 mg/L, the 30-min EC50 was > 1000 mg/L (BASF AG, 2005; report no. 08G0379/053111).
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