When it comes to weight, the doors on a blast resistant modular building (BRM or BRB) tip the scales around 600 pounds. When they are on customer sites like refineries, nitrogen or olefin plants, or other hazardous sites where blasts could occur, they receive more wear and tear than their occupants may realize. The weight of the doors and the number of times they are opened and closed during a 12-hour shift impact the amount of routine maintenance that should be given to them. For example: