Oxy-Acetylene is the problem due to its characteristics, in the event that a fire was to develop the emergency services would observe the situation whilst implementing a cordon around the immediate area, probably for many hours. This can have major commercial implications especially when local business & communities are evacuated until such time the situation has been declared safe by the emergency services. With regards to the business of repairing vehicles, this would be mandated through your local authority when you declare the business intentions i.e. vehicle repair centre, they will either reject or approve the proposal for the business undertakings.