CANADA recently lowered its Threshold Limit Value (TLV) for manganese, which is the primary substance in every type of welding and is predominantly what comes off in fumes.
Which can mean only one thing: The United States will not be far behind.
“The US is going to be forced to lower its manganese levels over the next couple years,” said Jim Reid, president of RoboVent, which provides air filtration and ventilation for weld smoke, metal cutting, and dust collection. “It is a topic of discussion majorly in the marketplace—the dangers of fumes.”
In February 2013, the American Conference of Governmental Industrial Hygienists (ACGIH) adopted a proposed change to the TLV for manganese and included it in the 2013 edition of its “Threshold Limit Values and Biological Exposure Indices” publication. The new TLV of 0.02 mg/m3 for respirable particulate matter is a ten-fold reduction from the previous TLV of 0.2 mg/m3. The new TLV for manganese includes a 0.1 mg/m3 limit for inhalable manganese particulate.
The ACGIH is a non-profit, non-governmental corporation with a mission of promoting worker health and reducing exposures to environmental stressors in the workplace. Its TLV is not a regulatory limit like the Occupational Safety and Health Administration’s (OSHA) Permissible Exposure Limit (PEL)—which is 5.0 mg/m3, and remains the US exposure limit for manganese—but some governmental entities utilize its TLVs in adopting standards.
The Canada Occupational Health and Safety Regulations’ (COHSR) Subsection 10.19 (1)(a) requires that an employee be kept free from exposure to a concentration of an airborne chemical agent in excess of the value for that chemical agent adopted by the ACGIH in “Threshold Limit Values and Biological Exposure Indices.”
And with the US likely to follow Canada’s move, welding fumes are moving back to the forefront.
“Welding fumes for years were not deemed as dangerous or a problem,” Reid said. “Back in the ‘80s, manufacturers wouldn’t worry about it. They just let guys breathe it. One of the things that’s changed is that manufacturing production has increased. Manufacturers have figured out with robotic welding and other types of welding that they are going to pump out more fumes in a smaller space than they did 30 years ago. With that have come higher concentrations.”
The whole world has shifted to more of a health-and-safety focus—the result of court cases and research.
In October 2003, former welder Larry Elam received $1 million from an Illinois jury that ruled against Lincoln Electric, Hobart Brothers, and the BOC Group. The jury ruled that welding-rod manufacturers didn’t warn Elam about the potential health risks associated with breathing welding rod fumes—which he claimed resulted in manganese-induced parkinsonism, a group of diseases characterized by tremor, rigidity or stiffness, slow movements, and difficulty maintaining balance.
In July 2005, a federal panel ruled that a large number of welding-fumes lawsuits would be consolidated before US District Judge Kathleen McDonald O’Malley in Cleveland. An increasing number of welders have started to file worker compensation claims for welding-fumes exposure. West Virginia is a battleground for a class-action lawsuit involving 3700 plaintiffs.
Also in 2005, a Mayo Clinic case series analysis identified syndromes associated with toxic damage to the brain and nervous system from manganese fumes produced during welding: Parkinsonian syndrome (a form of parkinsonism); multi-focal myoclonus (lightning-fast twitches that occur all over the body; vestibular-auditory dysfunction (issues with dizziness, balance, or hearing); and mild cognitive impairment (concentration impairment characterized by a lack of attention).
The study also revealed that all affected patients shared a risk factor: welding with inadequate ventilation.
“There’s a welding-fumes-control revolution in the market,” Reid said. “There’s a clean-air revolution where manufacturers are cleaning up their air to avoid safety risks, but also because of the welder shortage in marketplace. There is a major shortage in the manufacturing marketplace for welders. Because of this, in order for a manufacturer to compete, he has to be able to attract and retain good workers. But if you have a dirty shop and the other guy on the street doesn’t, you can guess where workers are going to end up. From a competitive as well as safety perspective, manufacturers are cleaning up their air. Every day we’re hearing companies call us. They recognize they have no choice in order to stay in business.
“If you let fumes hang in the air, you will have black walls in no time, and you just ruined your $300,000 paint job, and you have to repaint every few years. Manufacturers that don’t clean up their fumes don’t clean up their plant. They don’t paint their walls because they can’t afford to. It’s a multi-faceted problem, kind of a domino effect. Cleaning up the air is big on everyone’s agenda.”
According to the Canadian Centre for Occupational Health and Safety (CCOHS), welding fumes are “a complex mixture of metallic oxides, silicates, and fluorides. Fumes are formed when a metal is heated above its boiling point and its vapors condense into very fine, particles (solid particulates).”
The CCOHS says welding fumes contain oxides of the metals in the material being welded:
• Fluxes containing silica or fluoride produce amorphous silica, metallic silicates, and fluoride fumes.
• Fumes from mild steel welding contain mostly iron with small amounts of additive metals (chromium, nickel, manganese, molybdenum, vanadium, titanium, cobalt, copper, etcetera).
• Stainless steels have larger amounts of chromium or nickel in the fume and lesser amounts of iron.
• Nickel alloys have much more nickel in the fume and very little iron.
It says welding gases are “gases used or produced during welding and cutting processes like shielding gases or gases produced by the decomposition of fluxes or from the interaction of ultraviolet light or high temperatures with gases or vapors in the air.”
The CCOHS says exposure to welding gases can be prevented by: following manufacturer’s instructions and safety protocols to minimize the hazards of welding gases; using substitute materials such as water-based cleaners or high-flash-point solvents; covering the degreaser baths or containers; not welding on surfaces that are still wet with a degreasing solvent; not welding near degreasing baths; not using chlorinated hydrocarbon degreasers; and having adequate ventilation in a workplace to prevent the displacement or enrichment of oxygen and to prevent the accumulation of flammable atmospheres. ♦