By Clare Goldsberry, Associate Editor
| One form of portable ventilation equipment, Lincoln Electric’s Mobiflex unit. |
The issue of fume exhaust and ventilation systems in welding came to the forefront with lawsuits over welding fumes, and was reinforced with standards for hexavalent chromium [Cr(VI)] that were developed by the Occupational Safety and Health Administration.
As it applies to the welding industry, OSHA’s new standard for hexavalent chromium lowered exposures to 5 micrograms per cubic meter from 52 micrograms per cubic meter, and the change in that standard is changing the way the welding industry addresses exhaust and ventilation systems.
“There is a sea change in awareness, and the new hexavalent chromium standard has created an increase in awareness of the importance of ventilation,” Chris Cole said. Cole is the welding health and safety coordinator for the Environmental Systems Group at The Lincoln Electric Co. (www.lincolnelectric.com). He also is author of a paper on hexavalent chromium.
Cole said changes in the standard for Cr(VI), coupled with soc i e t a l dr ive r s me ans tha t employers are becoming more aware of the impact of the hidden costs on productivity.
Addressing the issues of proper exhaust and ventilation requires that an employer look at his options, which include engineering solutions such as central ventilation, mobile and portable systems, and personal protection gear such as respirators.
“Long term, OSHA requires an employer to implement engineering controls that are practicable, which means both feasible and doable,” Cole said.
Dick Smith, business segment director for environmental welding for Lincoln Electric, also said that the change made by OSHA brought about a greater awareness to ventilation and safe work practices, and companies are more closely examining what they do on the factory floor and how that impacts the health and well-being of employees.
“Wellness is a huge issue among companies, small or large, and healthcare costs are something companies are looking at more closely and taking a more proactive view of safety issues,” Smith said.
Another thing driving this new level of awareness is that skilled employees – particularly welders – are harder to find. “The environment of the shop floor becomes critical to attracting young people into the welding trade who want to come and work for you day in and day out,” Smith said.
Welding can be done in confined spaces beyond the primary welding area where built-in ventilation systems would be more common.
In instances in which the welding operation is portable, the portability of the ventilation or fume exhaust system is equally important.
For example: Much portable welding is done for maintenance purposes. There also are situations that call for welding inside a tank, or in close quarters where facility maintenance welding is required. That makes the issue of ventilation extremely important for the health and safety of the worker.
Welding fume control at the source of the fumes is particularly useful indoors. A mobile or portable system typically has an arm or flexible duct that can position the system’s hood at the source.
Note that the difference between the term “portability” and being able to physically carry with a handle compared with “mobility” in which the fume-exhaust system is on wheels and can be taken to the job.
While The Lincoln Electric Company offers both types of exhaust and ventilation systems, it recently made available to the market its trademarked Mobiflex fume extractor, a mobile, low vacuum system that is designed for the intermittent and continuous removal or filtration of welding fumes.
The combination of mobility and flexibility of the Mobiflex’s extraction arms, available in 3.1 meters (10 ft.) and 4.1 meters (13 ft.), are designed to make the welding point easier to reach.
The Mobiflex increases worker flexibility through its ability to adapt to various work locations and welding applications, including stick, TIG, MIG and flux cored. Its lightweight design, standard rear wheels and front caster wheels gives the Mobiflex enhanced portability, making it great for shops such as maintenance departments and general fabrication and welding shops that need a mobile fume extraction system.
The Mobiflex is available in two models. The Mobiflex 200-M draws air through the extraction arm and spark arrester, capturing welding fumes inside the LongLife filter. Particulates are collected on the inside of the cartridge, keeping hands clean during filter maintenance.
The Mobiflex 400-MS uses a RotaPulse self-cleaning filter process. The cleaning of the filter is done segment by segment, with compressed air, and results in a consistently high airflow.
When the filter becomes dirty, a pressure sensor activates the cleaning system. Compressed air from the tank releases through multiple air jets to clean one section of the filter at a time. A complete cleaning cycle can be activated by a manual switch. Dust is knocked off the cartridge into a collection bin accessed through a hatch at the bottom of the unit.
For most companies, there’s no one solution to the issues of fume exhaust and ventilation. There’s a movement toward a two-pronged approach: a central or “fixed” ventilation system that covers the entire shop welding space along with mobile or portable units that can be used at the specific job site.
“The disadvantage to the central ventilation system is that it is fixed so shop floor has to be laid out properly to encompass all the welding activities,” Smith said.
“If you need flexibility on the shop floor, then maybe a number of mobile systems will give you the ability to do that. One big advantage of engineering solutions over personal protection such as a respirator is the discomfort of the respirator. But respirators have their place too.”
Cole emphasized that there is no one solution to solve all the issues surrounding fume exhaust and ventilation. “You might have to have two or three solutions working in tandem with each other. You have to invest some time up front to ask the right questions, look at the applications, and explore all the options so that you can develop the best solution for your specific welding needs.”