SERGEANT BLUFF, Iowa (AP) – A 320-foot-tall structure that shoots flames into the air has been put into service at an Iowa nitrogen fertilizer complex. The Sioux City Journal reports CF Industries announced Thursday that the flare stack has been placed into service during commissioning of its new ammonia and urea plants at Port Neal. The stack is designed to safely combust gases during certain times at the plant. Flames can extend as far as 200 feet beyond the tip of the stack, when it’s ignited.

Officials say the stack will be used intermittently, but will burn continuously for a couple of weeks as the new plants come online and production begins. The company is nearing completion of a $2 billion expansion.