Toxic Tuesdays

CHEJ highlights several toxic chemicals and the communities fighting to keep their citizens safe from harm.


2-Butanone is an industrial chemical that is also known as methyl ethyl ketone (MEK). It manifests itself as a colorless liquid under standard conditions, tends to evaporate into the air (volatize) quickly, and is quite flammable. 2-Butanone is manufactured in large amounts for use in paints, glues, and other finishes because of its properties as a strong solvent and because of how quickly it can evaporate. It is also released into the air from the combustion process of vehicles.

Exposure to 2-butanone causes severe irritation to the eyes, nose, throat, and skin at high concentrations. Nervous system effects such as headaches, nausea, and dizziness have also been reported. Chronic health effects, those that develop due to long-term exposure to small quantities, are much less well understood.

Damage to the peripheral nervous system has been documented in individuals who sniffed glue, with 2-butanone being a significant part of the volatizing chemicals from glues. Liver, kidney, and respiratory effects were also observed in detailed studies of 2-butanone exposure in animals, while birth defects and malformations were observed in one rat study.

Exposure to 2-butanone can happen from a number of sources. Landfills and other contaminated industrial sites or factories tend to be significant sources. Although 2-butanone tends to evaporate into the air in these sites, because it has strong solvent properties, it also tends to sift through the soil into groundwater. Once there, it can remain trapped for several weeks. Active landfills that receive constant streams of paints, glues and similar products; or factories that produce or utilize 2-butanone can become significant hubs for exposure. If 2-butanone finds its way into drinking water sources, it can create a major exposure problem given its ability to remain present in water for an extended period of time.

Although groundwater and, potentially, drinking water can be easily contaminated by 2-butanone near factories and landfills, there is no federal drinking water standard for it. Certain states have taken a more precautionary approach and established local drinking water limits. For instance, Massachusetts, New Hampshire, and Minnesota have all set a guidance level of 4 mg/L. This proactive decision to limit the quantity of this potentially dangerous chemical should be an example to other states and the federal government.

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