When planning an event, you should never hesitate to contact the relevant authorities. In the case of large or potentially risky events, you must call together a meeting with authorities.
This meeting offers you a chance to go through the event and any possible risks. Each authority is an expert in their field and may set conditions for the event that the organiser must abide by. Depending on the event, you could invite the Central Finland Police Department, Tampere Region Rescue Department, City of Tampere Environmental Protection, The National Supervisory Authority for Welfare and Health (Valvira), City of Tampere Building Control, City of Tampere Facilities Management, and City of Tampere Planning Services.