Police and firefighters were called to a council building in West Cumbria after a suspicious letter was received.
Emergency services were called to Allerdale House after concerns were raised about a possible suspicious letter.
Officers were called at around 10.40am yesterday alongside partners from Cumbria Fire and Rescue Service.
Tests carried out by Cumbria Fire and Rescue on the small amount of substance could not identify anything hazardous.
There was no risk to the wider public.