Lawrence Berkeley National Laboratory (LBL) maintains an active Roof Access Program. The Laboratory takes a conservative approach to roof access in order to minimize potential exposure to chemicals, magnetic fields, and radiological hazards for personnel who are working on roofs. This approach involves restricting or limiting access to building roofs when potentially hazardous materials originating from operations inside of a building may reach the roof, even though it unlikely these hazards will exceed occupational health limits.
Additional information on the program as well as building specific rooftop classifications can be found in PUB 3000, Chapter 4.10.
