Eye witnesses reported two fire appliances plus police cars and officers at the scene and the road cordoned off during the last hour.
A fire service spokesman confirmed there has been an incident which firefighters attended, but added: "It has been handed over to the police and is now a police matter."
A Lincolnshire Police spokesman said: “At just after 7.30am we were called to reports of a concern for safety involving a man in a property on Eastgate in Sleaford.“Emergency services attended and a decision was made to ask residents in the area to vacate their properties because of concerns about a possible corrosive chemical inside the property which may have had implications on the health of others in the area. No direct threats were made to others and there is no ongoing health threat to the public.“The incident was resolved just before 9am and the man was detained by officers. All residents are now back in their homes.”One witness, Jane Peck said: “It is the fourth time police have been to that address in a month and the second time this week.“There was a fire engine, ambulance and paramedic car and four or five police cars and some drums of chemicals stood in the path. It is worrying for the neighbours as some are elderly.”She said: “My friend was coming to pick me up and rang me as she could not get down the street. “The tubs were all on clear view and then the police put them in yellow bags to take away.”