Depending on where in the world you live, each country typically subscribes to their own version of the National Electric Code (NEC). The NEC is a set of specific rules intended to be used for design, installation, and uniform enforcement of electrical system installations. The NEC is used not only throughout most of the United States, but also in some other countries throughout the world, such as Mexico and Puerto Rico. Different countries and their respective states/provinces have adapted portions of the NEC to suit their bylaws and pre-existing regulatory electric, fire and building codes.
Regardless of where you live and which regulatory electrical standards your region falls under, it is imperative that all electrical panels, remain unobstructed, easily accessible and obviously recognizable.
Both commercial and residential electrical panels not only have to meet the explicit measurement standards of the Occupational Health and Safety Administration (OSHA) and the National Fire Protection Association (NFPA), they must also be reasonably considered to be "readily accessible."
In a letter to the Marshall Space Flight Center, OSHA Director Richard Fairfax further clarified the term. “If someone must use portable ladders, stools or chairs to reach the electrical equipment, it is not considered readily accessible. Climbing over or moving furniture and other impediments to reach the equipment also constitutes a violation of the ‘readily accessible’ standard.”
Covering your panel with a picture, a mirror, a bookshelf or any other object that hides it or makes it unrecognizable as an electric panel IS a fire hazard.
If, in the case of an electrical emergency, emergency workers are either unable to locate your electrical panel to disconnect power, or are delayed in shutting off power and significant damage is caused as a result, your insurance company may refuse coverage, citing inability to locate or obstruction of the electrical panel.
Covering your electric panel with a Fuse-In Designs™ covering DOES NOT violate any standards of the National Electric Code, the Ontario Electrical Safety Code, the Canadian Electrical Code OR any Occupational Safety and Health Administration (OSHA) regulations.
Please see the sections of these regulatory bodies below for clarification:
National Electrical Code (2014)
(1) At least a 3-ft clearance in front of all electrical equipment
(2) A 30-inch-wide working space in front of equipment operating at 600V or less.
Canadian Electrical Code (2015) and the Ontario Electrical Safety Code (2015)
Section 2-308 Working space around electrical equipment
(1) A minimum working space of 1 m (300 feet) secure footing shall be provided and maintained about electrical equipment such as switchboards, panelboards, control panels, and motor control centers that are enclosed in metal, except that working space is not required behind such equipment where there are no renewable parts such as fuses or switches on the back and where all connections are accessible from locations other than the back.
(2) The space referred to in Subrule (1) shall be in addition to the spare required for the operation of drawing out-type equipment in either connected test or fully disconnected position and shall be sufficient for the opening of enclosure doors and hinged panels to at least 90 degrees.
Please check with your local regulatory body to ensure that your area follows the NEC or a similar set of standards.