As you get ready for planting season, here's one job that will be fun to carry out: Take a felt marker and scribble on your polyethylene tanks. Then whack 'em with a baseball bat.
Sound silly? Well, we're dead serious. Inspecting your tanks—and making sure you have the right ones for each task—could prevent a chemical spill that could eat up hours of your time and untold dollars in cleanup costs and penalties, smack in the middle of planting or spraying season.
Like many farmers, Fred Whitford, Purdue University's coordinator of pesticide programs, never gave much thought to the disaster potential contained in an innocuous-looking plastic tank. That changed when he received a call from a farmer. "A 2,500-gal. tank actually exploded," he says.
Whitford set out to learn about poly tanks and educate farmers about the innocent-appearing containers. He shared his knowledge with attendees at the 2008 Farm Journal Corn College.
"Poly tanks have a limited useful life, depending on a number of factors. At some point, every one will fail," he says.
A tank's useful life, he explains, depends on the quality of the polyethylene material, the materials stored in the tank and whether it is used for storage or transport. Ultraviolet (UV) radiation from the sun is also a major enemy of tanks, making the tough polyethylene hard and brittle and ultimately setting the stage for a spill.
Which tank to buy. The first step in avoiding expensive and possibly catastrophic chemical spills is to buy a tank that is strong enough for the task.
Tanks are made from two materials, Whitford explains: high-density linear polyethylene (HDLPE) or high-density cross-linked polyethylene (XLPE).
"In general, both materials can be used to store and transport most pesticides and fertilizers," he says. "But XLPE is more chemical-resistant and durable and generally more expensive. Contact the chemical manufacturer if you are not certain whether a HDLPE tank will work for the products you store or haul."
The strength of poly tanks is rated in terms of specific gravity. A rating of 1.0 means the tank is designed to withstand the internal force of water, which weighs 8.334 lb. per gallon, or anything lighter than water.
- March 2009