Hot Work in Confined Spaces
There are a multitude of facilities that require welding, cutting, and other hot work. Some environments lack room and become confined spaces.Limited space, entry, or exit
Poor ventilation – lack of safe breathing air and possible buildup of hazardous gases, fumes, and particles.
Confined spaces have the following characteristics:
Examples of Confined Spaces
Compartments of ships
Unventilated room areas
Reasons for Deaths and Injuries from Welding and Cutting in Confined Spaces
Exposure to hazardous air contaminants
Actions Required Before Approving Hot Work in a Confined Space
Determine if special training or a permit is required to enter the space.
Open all covers and secure them from closing.
Test atmosphere for:
(1) suitable oxygen content
Isolate lines by capping or double blocking and bleeding. Keep vents open and valves leak-free.
Lock out/tagout all systems not required during hot work.
Provide means for readily turning off power, gas, and other supplies from outside the confined space.
Protect or remove any hazardous materials or materials which may become hazardous when exposed to hot work.
(2) combustibles or reactives
Note: The testing requires special
equipment and training.
Required Actions During Hot Work in a Confined Space
Continuously ventilate and monitor air to ensure fumes and gases do not exceed safe exposure limits.
29 CFR 1910.252(c) and 1926.353(c) require the use of local exhaust ventilation or supplied air respiratory protection when hot work is performed in a confined space where there is a potential for exposure to fluorine compounds (fluxes and rod coatings), zinc, lead, cadmium, or mercury. When beryllium is present, use both local exhaust and a supplied-air respirator.
29 CFR 1926.353(c) requires the use of local exhaust ventilation or supplied air respiratory protection when hot work is performed in a confined space where there is a potential for exposure to chromium or when Gas Metal Arc Welding is performed on stainless steel.
Use NIOSH/MSHA (National Institute for Occupational Safety and Health/Mine Safety and Health Administration) approved breathing device when required by code.
Keep unnecessary persons and equipment out of, and away from, the confined space.
Do not allow equipment to block exit or rescue efforts. Place as much equipment as possible outside the confined space.
Do not enter a confined space unless a watch person, properly equipped and trained for rescue, is outside. Maintain continuous communications with the worker inside.
When possible, provide means for readily turning off power, gases, and fuel from inside the confined space, even if outside turn-off means are provided.
Resource: AWS Health and Fact Sheet No. 11 - Hot Work in Confined Spaces