Not all HDPE containers with a "2" in the triangle are food grade. If the bucket was used in the food industry you are fine. The release agent used in the molds is a factor in the use with foods.
http://www.ehow.com/way_5819448_do-tell-food-grade-plastic_.html
Brent
http://www.ehow.com/way_5819448_do-tell-food-grade-plastic_.html
Brent