To be approved for installation in Baltimore City, appliances, accessories and equipment must: be listed by a nationally recognized testing agency such as the American Gas Association, Inc., Laboratories and Underwriters Laboratories, Inc., qualified and equipped for experimental testing and maintaining an adequate periodic inspection of current production of listed models and whose listing states that the appliance, accessory or equipment complies with nationally recognized safety requirements or has been tested and found safe for use in a specified manner; or comply with American National Standards Approval or Listing Requirements covering safe operation, substantial and durable construction and acceptable performance and be registered with the Commissioner of Housing and Community Development of Baltimore City. City Code, 1976/83, art. 13, §58(f) Ord. 82-642