The bomb squad has been called to an incident in Buckshaw Village near Chorley.
The alert was raised this morning after reports that a suspicious package had been delivered.
A spokesman for Lancashire Police said: “We were called at around 10.15am following reports of a suspicious package at Cellmark Forensics, Ordnance Road, Buckshaw Village.
“The EOD (Explosive Ordnance Disposal) have been notified and are on route.
“As a precaution, the premises and all surrounding buildings within 100m have been evacuated and officers remain on the scene.”