Residents near a Fife chemical plant have been warned that flaring is set to begin on Monday and it will last for five days.
ExxonMobil has apologised ahead of the flaring at the Fife Ethylene Plant in Mossmoran, and said it was connected to "essential maintenance" work.
Residents in the area said they were "bracing" themselves for flaring.
Previously flaring has sparked complaints about noise and caused houses to vibrate in the area.
James Glen, Mossmorran Action Group chairman, told the BBC Scotland news website: "People are very angry and fed up about this happening yet again.
"They don't trust the plant and think it's unsafe.
"This is a controlled event so it's not as extreme as we have had it before but it can be.
"We are bracing ourselves."
A statement from ExxonMobil's Fife Ethylene Plant said: "To allow essential maintenance, our flare will be in operation from tomorrow.
"We understand flaring can cause concern but we must always put safe operations first.
"Flaring will be kept to a minimum.
"Work will take an estimated five days. Please accept our apologies ahead of the work."