Emergency services were called to a business park in West Yorkshire this morning after a report of a suspicious package.
A male employee at a company on Emley Moor Business Park Huddersfield began to feel unwell after opening some post delivered to the premises.
The man was said to be suffering from dizzy spells and nausea when police were called shortly before noon.
Emergency services, including ambulance and fire, were sent to the business park to establish the circumstances of the incident and were able to declare the parcel safe.
Following a medical assessment, the man was deemed fit and well and has returned to work.
No-one else at the premises was affected.
Superintendent Pat Casserly, of Protective Service Operations, said: "We always treat any incident of this nature very seriously, and this morning we quickly put appropriate measures in place to ensure people's safety while this incident was dealt with.
"Thankfully once our officers and partner agencies arrived at the scene, it was quickly established that there was no apparent threat. The company's employee was assessed by the ambulance service and was deemed fit and well.
"I would like to thank everyone in the locality for their patience and support during this incident and also recognise the work of our key partner agencies in bringing today's incident to a swift and safe conclusion."