Residents have been advised to keep doors and windows closed as crews continue to tackle a recycling centre fire.
Firefighters have tackled the blaze at Byrehill Place, Kilwinning, since Monday evening.
Six fire engines and a height appliance went to the scene after the alarm was raised at 10.05pm on Monday.
Police advised residents in the North Ayrshire town to stay indoors and keep their windows and doors closed as a precaution while emergency services dealt with the incident.
On Wednesday morning, the Scottish Fire and Rescue Service said there were still appliances at the scene.
There are no reports of any casualties.
At its height, around 40 firefighters were mobilised.
On Tuesday at around 6.45PM, area commander Jim Quinn said: “We continue to work with the recycling centre and partner agencies to minimise the disruption to the local community and will continue to provide updates.
“While smoke continues to be visible, we would ask that residents remain at home, and keep windows and doors closed as a precaution.
“If travelling through smoke, motorists should keep windows closed, turn off air conditioning and keep their air vents closed.”
John McKenzie, Scottish secretary of the Fire Brigades Union (FBU), warned that the health and safety of fire crews was at a heightened risk due to having been on the scene for such a long period of time.
He said the crews “have been doing a fantastic job at a challenging incident preventing the spread of the fire and keeping the public safe”.
He added: “However, we know that Scottish firefighters are up to four times more likely to get certain cancers than the general population and are therefore concerned about the potential impact of fire contaminants on firefighters at the scene.
“The FBU continues to call for much needed additional investment to ensure that all appropriate decontamination and associated measures are in place to protect firefighters across Scotland from fire contaminants.”