U.S. Department of Labor
Process: Hot Work
Hazard: Over Exposure to Harmful Substances
The welding, cutting, and heating of some materials onboard a vessel in enclosed and confined spaces will produce fumes and gasses at levels which may be harmful. Such exposures may not cause immediate symptoms and workers may be unaware of these over exposures until they are discovered through either medical surveillance or the onset of illness.
Local exhaust ventilation is the best method for removing toxic fumes. Care should be taken when placing exhaust ("sucker") tubes to ensure that fumes are pulled away from the breathing zone as shown here. Hot work performed on beryllium-containing materials requires the use of airline respirators in addition to mechanical or local exhaust ventilation. For specific requirements regarding ventilation see OSHA regulation 29CFR 1915.51
Hot work performed on potentially toxic materials in open air may result in over exposures if adequate precautions to protect workers are not taken. This employee assumed incorrectly, that because he is working outside that he need not wear his respirator.
Filter type respirators such as the one being worn by this worker may be used in most cases for open air hot work on potentially toxic materials. Employees must be properly trained in respirator usage and fit-tested. Additionally, tool room or other personnel who dispense respirators and cartridges should receive training in order to ensure that the correct equipment is being issued. Hot work on beryllium-containing materials will require the use of airline respirators even when performed outdoors.
Hot work performed on surfaces coated with toxic preservative coatings may also result in employee illness. As noxious fumes, gasses, and particularly odors are frequently emitted by these coatings when heated, workers are prone to report such exposures immediately. Even when the coating is not hazardous the fume produced can be very irritating.
In this photograph, the paint has been ground off in preparation for welding of bulkhead attachments. Toxic coatings such as epoxies and lead based paints must be stripped back a minimum of 4" before hot work can be performed or airline respirators must be used to protect workers.