WASHINGTON - The U.S. Agriculture Department says that starting next fall, schools can stop feeding students a common ammonia-treated ground beef filler dubbed "pink slime" by critics.

The department says it will give school systems a choice of beef patties made with the lean finely textured filler, or less lean bulk ground beef without it.

Concern about the ammonia-treated filler exploded last week as a social media topic. The Agriculture Department says the filler is safe. But it says it wants to be responsive to schools that want a choice.

The low-cost filler is heated and processed so most of the fat is removed before it is compressed into blocks for use in ground meat. It is exposed to a "puff of ammonia hydroxide gas" to kill bacteria.