Disposable diapers are great, but they take 200 to 400 years to biodegrade once they've been used.

But now an Aberdeen native has invented a new form that takes two years to biodegrade.Darin Dean Pratt, Aberdeen native, has invented Chemical-Free TenderCare Biodegradable diapers, manufactured by Rocky Mountain Medical Corp., a small, publicly owned company based at Montrose, Colo.

The diaper is billed as a breakthrough, designed to keep babies dry without chemicals and plastics that take centuries to disintegrate.

The diaper is made of a new plastic with a starch-free additive allowing the diapers to be attacked by insects, bacteria and enzymes in landfills.

The company that developed the plastic plans to use it in other disposable consumer products, such as garbage bags.

Rocky Mountain hired a diaper-making company to manufacture the new product. Full production is expected the end of next month. The new diaper should be available to consumers by mail or through catalogs in December.

Pratt, born in American Falls, is the son of Doris Pratt, Aberdeen. He is vice president of Rocky Mountain Medical Corp.