1 - Characteristics
- Synonyms: MEETCO, butanone, 2-butanone, butan-2-one, methyl acetone, methylpropanone
- Chemical formula: C4H8O or CH3COC2H5 · Molecular weight: 72,10 · MARPOL category: III
- UN n°: 1193 · CAS n°: 78-93-3 · IMDG class: 3.2 · Hazard identification n°: 33
- Appearance at ambient temperature (20°C):, colourless liquid, pleasant odour similar to acetone (DMK)
- Relative density (water = 1): 0.81 · Relative vapour density (air = 1): 2.4
- Melting point: -86°C · Boiling point: +79.6°C
- Flash point: -6 to -1°C · Vapour pressure: 77.5 mm Hg (20°C)
- Solubility in water: 353 g/L (at 10°C) / 263 g/L (at 20°C)
- % evaporation / % dissolution: 44% / 56%
2 - Physico-chemical behaviour
- Stability: stable product.
- In air: highly volatile, explosive mixture with air (LEL: 1.8 - UEL: 11.5% vol.), vapours heavier than air. Auto-ignition at 505-515°C.
- In water: no reaction but very soluble.
- Reactivity with other products: may react with oxidisers, violently with oleum, chlorosulphuric, sulphuric and nitric acids, aliphatic amines...
3 - Spill response techniques
- Emergency measures:
- Set up a 50 m radius exclusion zone
- Stay upwind
- Avoid depressions and ventilate before entering a confined space
- Remove all sources of ignition, if possible: stop the leak
- Prevent infiltration into sewer system, subsoil, confined spaces and the water body by building bunds or dykes made of earth or sand
- Avoid touching the product and inhaling its vapours (stay upwind
Transfer/transshipment possibilities: fireproof pump, plastic storage tank (polyethylene, polypropylene, butyl).
- Spill on platform area or quayside: evacuate 300 m strip downwind, contain then recover or leave to evaporate according to volume and feasibility.
- Spill in water: contain spread using floating booms, recover using skimmers if the slick is more than 1 mm thick, otherwise leave to evaporate while monitoring possible sources of ignition.
4 - Risks for responders
- Response limits: major risk = extreme flammability/explosion when mixed with air, spread of heavy vapours near to the ground or water surface (then quick spreading through sewer system, harbour basin, port...).
- Intoxication risks: 1 hour exposure limit of 100 ppm in air (290 mg/m³). Warning due to pleasant odour perceptible from 2 ppm i.e. 6 mg/m³ (according to odour sensitivity from 1 to 150 mg/m³).
- Accidental direct contact of skin with the liquid not hazardous (temporary discoloration after 5 min contact time).
- Choice of protective equipment: yes, self-contained breathing apparatus, full protective clothing, gloves and rubber boots.
5 - Risks for the environment
- Immediate effects: low toxicity for fish (LC50=1.3 at 8.9 g/L) but risk of production of organohalogen compounds that may be more toxic than the initial MEK, if the environment contains free halogens.
- Persistence: rapid photochemical decomposition in air. In the ground or an aqueous environment, no bioaccumulation (rapid biodegradation, e.g. 20 mg/L will disappear in 2 to 3 days in an aerobic aqueous environment).