Manhole locks

A manhole lock is a physical security device designed to delay unauthorized access to the chemical facility or system through a manhole. 

Physical hazards from mechanical equipment must also be locked out to ensure worker safety. Valve pits or manholes that may be flooded with water or other fluids must also be rendered safe prior to entry. If work is performed on an elevated storage tank, additional fall-protection procedures need to be followed. When workers are exposed to air contaminants such as sandblasting materials, welding fumes, or paint solvents, additional air monitoring and explosive hazards controls need to be taken. 

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