Tips for using reformulated gas

    The other day I came home to find the whole neighborhood abuzz with the whine of small engine noise and smoke. There was a lawnmower mowing, a weed whacker whacking, and a chainsaw chewing through some leftover winter storm damage.
    Although it’s seemingly indispensable in our modern lifestyle, gasoline is one of the most dangerous chemicals with which we routinely come in contact. It is flammable and toxic and — when spilled on the ground — can contaminate groundwater.
    Despite our being familiar with gasoline, all the compounds found in gasoline are toxic, and some (like benzene) are known to cause cancer in humans. Gasoline, with or without ethanol, is nothing we want to pour on our corn flakes!
    Recently there has been much concern about engine performance and storage issues with gasoline containing ethanol. Because of ethanol’s affinity for water, improperly stored ethanol-blended gasoline can undergo something called “phase separation”. Phase separation occurs when the ethanol in the gasoline absorbs excess water until it actually separates from the gasoline. The gasoline then floats on top of this water/ethanol combination that sits in the bottom of the tank. Because most small engines receive their fuel from the bottom of the tank, the engine will not work. Ethanol is also a powerful solvent that will clean out the gunk and “build up” in fuel tanks and engines, resulting in clogged fuel filters and carburetors.
    So how do you prevent these issues from occurring? Properly storing gasoline, in approved containers away from your living area, is one way to make sure that groundwater contamination and fire from gasoline spills don’t endanger us and our families.
    Only buying what we need for each job ensures we’re not stuck with “old” gas at the end of the season. If you store gasoline for more than 30 days, add a stabilizer (available at most hardware and small engine repair shops) approved for use with ethanol. Keep the container or tank 95 percent full to allow for thermal expansion of the fuel, and limit the air space, which reduces condensation and therefore water build up. If you do find yourself with old gummy or phase separated gasoline you should consider it a hazardous waste. The only safe way to dispose of it is to take it to a local hazardous waste drop off day or an approved hazardous waste disposal site. (A list of towns and organizations sponsoring these throughout the year is available from DEP.)
    Where gasoline is concerned, less is best, storing only what gas we need, and preventing spillage. It’s best that we limit our exposure to gasoline, no matter how useful, because it is, and always will be, a hazardous material.
    For more information on the safe use and storage of household gasoline, check out www.MaineDEP.com.
    This column was submitted by David McCaskill, a senior environmental engineer with the Maine Department of Environmental Protection’s Bureau of Remediation and Waste Management. In Our Back Yard is a column developed by the Maine DEP. E-mail your questions to infodep@maine.gov or send them to In Our Back Yard, Maine DEP, 17 State House Station, Augusta, ME 04333.