Cashins & Associates Blog

Torch Cutting on Painted Surfaces - Industrial Hygiene Concerns

Posted by Mike Cashins on Mon, Aug, 13, 2012 @ 16:08 PM

Torch cutting steel It is well-known that torch cutting or welding on surfaces that are coated with a lead based paint is hazardous. The heating of the paint releases lead fume and creates an exposure hazard to the employees performing this work. The release of lead fume will also contaminate surfaces throughout the work zone which will result in a secondary source of lead exposure. The lead release poses an environmental and community concern as well.

Dealing with lead paint requires that employers comply with the Occupational Safety and Health Administration (OSHA) Lead in Construction Standard (29 CFR 1926.62). Due to this regulation, and for the safety of employees, contractors and building owners have, for many years, tested existing paint for the presence of lead. If lead is detected the paint is removed in areas where the welding or torch cutting will take place. This removal process is commonly referred to as creating “cut lines”. The paint is removed at least four (4) inches on either side of the heat application. More paint may need to be removed if a lot of welding is to take place and the heat is sufficient enough to transfer to the remaining painted areas. Here are a few items to consider: 

Removal of paint does not completely eliminate lead exposure risk.

Although the metal surface may be clean to the naked eye, there are paint particles remaining embedded in the pores of the steel. Lead exposure is dramatically reduced by the paint removal but is not completely eliminated. Our air sampling experience indicates that lead is still a concern. We frequently see lead exposures above the OSHA Action Limit of 30 µg/m and in some cases above the Permissible Exposure Limit (PEL). Some steel has enough lead impurities to cause an exposure risk in itself.

Paint is “lead free” can we burn or weld on these surfaces?

Many of our clients have been under the impression that if there is no lead detected in the paint that welding and torch cutting can then take place without paint removal or “cut lines”. This is not true; the problem is that all paints are comprised of various components that when heated release toxic decomposition products. Decomposition products may include volatile organic compounds, toxic metals (lead, cadmium, mercury etc.) and carbon monoxide to name a few. Some paints are formulated with mercury and polychlorinated bi-phenyls (PCBs).

Protective coatings may also be highly flammable. Torch cutting or welding on these paints may cause an uncontrollable fire. If a fire outbreaks on the paint this will create a physical hazard to workers and bystanders and causes a significant release of toxins to the air. Fires on protective coatings will also result in significant building damage. Physical damage from the fire itslef and from soot deposition throughout the structure.  

Due to the multitude of health and safety hazards that employees can be exposed to, all protective coatings should be removed prior to welding and/or torch cutting. Also, there is a little known OSHA Standard that covers this topic. The standard is 29 CFR 1926.354 Welding, cutting, and heating in way of preservative coatings. This standard requires removal of protective coatings while in confined areas or the use of airline respirators. Inside a building or other structure would be considered a confined area.

It is good practice and in the best interest of employee safety, environmental protection, and building safety to remove all protective coatings prior to welding or torch cutting.

It is impractical or impossible to remove the paint coating, what then?

Every effort should be made to try and remove all protective coatings. There are instances where metal is sandwiched together and it is impossible to access the backside of the metal or the beam extends into the building structure. In these instances as much paint as possible must be removed, proper respiratory protection worn, and proper exhaust ventilation must be used to capture fume at the point of operation.

Summary

Torch cutting and welding on any surface creates an exposure risk; this risk is significantly magnified when protective coatings are present on metal substrates. A qualified Industrial Hygienist should review proposed work procedures prior to work beginning that involves welding or torch cutting on previously painted surfaces. The risk to workers, community, and the building is too significant to leave to guesswork. A well thought out procedure and industrial hygiene plan is required to ensure a safe and healthy project outcome.    

Topics: industrial hygiene

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