Solving Stricter Standards: The New Manganese Challenge In Welding Operations

Recent reports from the National Institute For Occupational Safety and Health, and the American Conference of Governmental Industrial Hygienists (ACGIH) suggest that workers with prolonged exposure to manganese are at greater risk for neurological health problems than previously thought. Symptoms have included difficulty walking and balancing, weakness, trouble with memory and judgment, fever, pain and vomiting among others. New lower exposure limits under consideration will impact manufacturing.

Like it or not, OSHA seems destined to lower allowable exposure limits to manganese in the workplace. That’s because OSHA often follows recommendations made by ACGIH. The current permissible exposure limits established by OSHA (as of April 2013) for manganese compounds is 5 milligrams per cubic meter of air (5 mg/m3), though local standards may be even stricter as states are required to be at least as restrictive as those established by the Federal OSHA. However, the ACGIH had suggested an even lower rate of no more than 2 mg/m3. Now comes news that the ACGIH has recently suggested that figure is too high and recommends a significant reduction in the threshold limit value for manganese. Their latest recommendation is to limit exposure to no more than .02 mg/m3. In other words, it’s a 100-­‐fold reduction from their previous recommendation. So what does this mean for process manufacturers? Implementing new health and safety controls may be necessary.

While the risk of exposure to manganese has been known for many years, these new recommendations suggest that the hazards are more acute among metal fabricators. Workers in these facilities are commonly exposed to manganese fumes from a number of sources including welding rods, wire, filler metals and elsewhere. In arc welding especially, the heated metal reacts with oxygen to create manganese oxide fumes that are readily inhaled — unless there is proper remediation of these known toxins.

While the ACGIH’s opinion about manganese exposure limits is not law — the Federal OSHA establishes limits and laws — the risks associated with any level of exposure warrants careful attention by manufacturers to avoid the liabilities of a potentially unsafe work environment. Every welding and metal fabrication operation should take specific precautions to avoid problems. First, it may be necessary to conduct an assessment of an operation with a certified industrial hygienist in order to measure and establish baseline information, including workforce exposure to potentially hazardous materials. Once a manufacturer has this baseline data, a plan can be formulated to lower exposure rates that meet federal regulations and help ensure worker safety. The plan may include a number of engineering remedies such as the installation of dust and fume collectors, respirators, forced air breathing apparatus and others. In addition, an effective solution may include changes to a welding or fabrication process. In any case it is possible to meet Federal workplace standards with the correct process and equipment. If there are any questions regarding air quality, conducting a thorough examination including taking air samples will help determine the level of contaminants present relative to existing and proposed new laws.

This information is offered as a guide only and RoboVent makes no representation or warranty, either specifically or implied as to the accuracy or completeness of the information contained here. RoboVent will not be responsible for any damages resulting from the use or reliance of this information. If you believe you are being exposed to hazardous fumes in your workplace, consult your safety officer or management team.