Three fire engines, an aerial ladder platform and a High Volume Pump remain on scene at the industrial fire on Great North Road in Newark.
Firefighters are in the process of damping down and are working with on-site staff to move materials apart.
Station Manager Andy Lindley, said: “We are continuing to work alongside our partner agencies at the scene, who have supported us while we deal with this incident.
“The A616 Great North Road remains closed at this time, however this will be reassessed in conjunction with Nottinghamshire Police throughout the course of the incident.
“We are aware that this incident has caused traffic disruption in the surrounding area, and we thank you for your patience.
“Further updates will follow on our social media channels throughout the day.”