A ban on the apple-ripening agent Alar could take up to three years to implement, even though the Environmental Protection Agency expects to soon begin formal steps to prohibit its use.

"We are going to do it. And shortly, probably within the next 10 days," an EPA spokesman said.Consumer groups say the growth regulator presents a health risk, especially to children, and the EPA has said "inescapable" laboratory evidence exists that Alar triggered cancerous tumors in test mice.

Nonetheless, the EPA, the Agriculture Department and the Food and Drug Administration have all pronounced apples safe for consumption. An estimated 5 percent of the crop is treated with small amounts of Alar.

The EPA, which previously said it could not justify an emergency ban of Alar, announced in February that it planned within 90 days to initiate more routine procedures to eliminate its use in the future. That period elapsed without a formal rulemaking proposal.

Public fears about the use of Alar by some growers have caused the sales of apple products such as juice and sauce to drop off 20 percent.