Methyl ethyl ketone toxicity

Health and Safety Factors. MEK is slightly more toxic than acetone, but is not considered highly toxic, and nor does it exhibit cumulative toxicological properties. The OSHA time weighted average iu air is 200 ppm other measured toxicity values are shown iu Table 3. Methyl ethyl ketone is highly flammable. 

Methyl Ethyl Ketone Peroxide in Dimethyl Phthalate (4TT3)), National Toxicology Program, Toxicity Report Series Number 18, NIH Pubhcation 93-3341, United States Department of Health and Human Services, Washington D.C., Eeb. 1993. 

Solvents acetone, methyl ethyl ketone (MEK), toluene, xylene, glycol, ethers, alcohol defats and dries skin some may be absorbed may carry other components through skin high volatility, exposure possible irritation central nervous system depression (e.g. dizziness, loss of coordination) low to high toxicity, longterm effects... 

Toxicity and Environmental Fate Information for Methyl Ethyl Ketone CAS 7 -93-3... 

Toxicity. Breathing moderate amounts of methyl ethyl ketone (MEK) for short periods of time can cause adverse effects on the nervous system ranging from headaches, dizziness, nausea, and numbness in the fingers and toes to unconsciousness. Its vapors are irritating to the skin, eyes, nose, and throat and can damage the eyes. Repeated exposure to moderate to high amounts may cause liver and kidney effects. 

Dewaxing (Figure 4.17) processes also produce heater stack gas (carbon monoxide, sulfur oxides, nitrogen oxides, and particulate matter) as well as hydrocarbon emission such as fugitive propane and fugitive solvents. Steam stripping wastewater (oil and solvents) and solvent recovery wastewater (oil and propane) are also produced. The fugitive solvent emissions may be toxic (toluene, methyl ethyl ketone, methyl isobutyl ketone). 

Hexanedione was found to be a major metabolite of MBK in several animal species peripheral neuropathy occurred in rats after daily subcutaneous injection of 2,5-hexanedione at a dose of 340mg/kg 5 days/ week for 19 weeks.Nonneurotoxic aliphatic monoketones, such as methyl ethyl ketone, enhance the neurotoxicity of MBK. In one rat study, the longer the carbon chain length of the nonneurotoxic monoketone, the greater the potentiating effect on MBK. It is expected that exposure to a subneurotoxic dose of MBK, plus high doses of some aliphatic monoketones, would also produce neurotoxicity. In addition, MBK itself potentiates the toxicity of other chemicals. ... 

Toxicology. Methyl ethyl ketone (MEK) is an irritant of the eyes, mucous membranes, and skin, and at high concentrations it causes nervous system effects MEK potentiates the toxic effect of other solvents. 

Acetone, methyl ethyl ketone (2-butanone) and methyl isobutyl ketone (4-methyl-pentan-2-one) (6.8 mmol/kg bw for 3 days) increased the hepatotoxicity of carbon tetrachloride to Sprague-Dawley rats (Raymond Plaa, 1995a) this enhancement of toxicity was coincident with increased microsomal aniline hydroxylase activity (Raymond Plaa, 1995b). In addition to the effect on cytochrome P450, acetone, but not the other ketones, increased basal canalicular membrane fluidity, as measured by fluorescence polarization of 1,6-diphenyl-1,3,5 -hexatriene or 1 - [4-(trimethylammoniumphenyl)-6-phenyl] -1,3,5 -hexa-triene (Raymond Plaa, 1996). 

Less commonly used solvents include methyl ethyl ketone, b.p. 80° ethylene chloride, b.p. 84° dioxan (diethylene dioxide), b.p. 101° (vapours are toxic) toluene, b.p. 110° pyridine, b.p. 115-5° chlorobenzene, b.p. 132° cellosolve (ethylene glycol monoethvl ether), b.p. 134-5° di- -butyl ether, b.p. 141° s-tetrachloro-... 

The majority of characterized solvates are stoichiometric, with either water or organic solvents present in a Lxed ratio with the drug molecules. Glibenclamide was isolated as two nonsolvated polymorphs, a pentanol solvate, and a toluene solvate (Suleiman and Najib, 1989). Furosemide could form solvates with dimethylformamide or dioxane (Matsuda and Tatsumi, 1989). Haleblian and McCrone (1969) studied the solid forms of steroids, and found different dissolution rates for two monohydrates of Luprednisolone, a monoethanol and hemiacetone solvate of prednisolone and two monoethanolates and a hemichloroform solvate of hydrocortisone. Other solvents that have been reported to form solvates with drugs include methyl ethyl ketone, propanol, hexane, dimethylsulfoxide, acetonitrile, and pyridine. The potential toxicity concerns eliminate most of these from consideration as practical mechanisms of solubility enhancement for human therapeutics. 

Capello et al.16 applied LCA to 26 organic solvents (acetic acid, acetone, acetonitrile, butanol, butyl acetate, cyclohexane, cyclohexanone, diethyl ether, dioxane, dimethylformamide, ethanol, ethyl acetate, ethyl benzene, formaldehyde, formic acid, heptane, hexane, methyl ethyl ketone, methanol, methyl acetate, pentane, n- and isopropanol, tetrahydrofuran, toluene, and xylene). They applied the EHS Excel Tool36 to identify potential hazards resulting from the application of these substances. It was used to assess these compounds with respect to nine effect categories release potential, fire/explosion, reaction/decomposition, acute toxicity, irritation, chronic toxicity, persistency, air hazard, and water hazard. For each effect category, an index between zero and one was calculated, resulting in an overall score between zero and nine for each chemical. Figure 18.12 shows the life cycle model used by Capello et al.16... 

Acetone is the most important commercial ketone, with over 3 billion kilograms used each year. Both acetone and methyl ethyl ketone (butan-2-one) are common industrial solvents. These ketones dissolve a wide range of organic materials, have convenient boiling points for easy distillation, and have low toxicities. 

To illustrate this point consider the production of lacquers for PVC films and sheeting. Such lacquers contain a PVC homopolymer or low-acetate vinyl chloride-vinyl acetate copolymer, poly(methyl methacrylate), a plasticizer and perhaps some stabilizers, dulling agents (such as silica), pigments, and so on. Methyl ethyl ketone (MEK) is the solvent of choice because it gives the best balance of low toxicity, volatility, and low cost. Any other solvent is effectively... 

Properties Tan-colored pellets. D 1.44, melting range 99-107C. Soluble in hot methyl ethyl ketone, acetone, esters, and aromatic hydrocarbons. Hazard Toxic A carcinogen, absorbed by skin. TLV 0.02 ppm suspected human carcinogen. Use Curing agent for polyurethanes and epoxy resins. 

Solvents in use for wax removal include propane, which also serves as an autorefrigerant for the process by solvent evaporation, methyl ethyl ketone (MEK)-toluene mixtures, and methyl isobutyl ketone (MIBK). The last two systems are in widest use at present. MEK-benzene was once a common solvent combination for dewaxing but has now been abandoned from benzene toxicity considerations. 

Orthorhombic cryst mass or flakes fatty appearance, bp 247 d 3.95. Sol in water, ethanol, acetone, ether, methyl acetate, methyl ethyl ketone, isobutyl alcohol practically insol in mineral spirits, pstr naphtha, xylene. LDW i.p. in mice 66 mg/kg. Toxic Substances List, H. E. Christensen ei al. Eds. (1974) p 765. 

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