Fire crews spent three and a half hours putting out a blaze at an industrial unit in Bamber Bridge.
Three fire engines from Bamber Bridge and Penwortham, along with an aerial ladder platform from Hyndburn, dealt with the fire at a commercial premises in Walton Summit.
An extraction unit had caught fire and the area affected was 50 metres by 20 metres.
Crews from Lancashire Fire and Rescue Service were called out just before 6pm on Friday.