Effectively managing dust can be a challenge for small to mid-sized stores.Below are answers to questions frequently asked by small and medium welding shop managers about air quality management.Getty Images
Welding, plasma cutting, and laser cutting produce fumes, commonly referred to as fumes, which consist of airborne dust particles that are made up of tiny dry solid matter.This dust can reduce air quality, irritate the eyes or skin, damage the lungs, and become a hazard when it settles on surfaces.
Processing fumes may contain lead oxide, iron oxide, nickel, manganese, copper, chromium, cadmium and zinc oxide.Some welding processes also generate toxic gases such as nitrogen dioxide, carbon monoxide and ozone.
Proper management of dust and fumes in the workplace is important for the safety of your workers, equipment and environment.The best way to capture dust is to use a collection system that removes it from the air, discharges it outside, and returns the clean air indoors.
However, managing dust effectively can be a challenge for small to mid-sized stores due to cost and other priorities.Some of these facilities will try to control dust and fumes on their own, assuming their stores don’t need a dust collection system.
Whether you are just starting out or have been in business for many years, you may be interested in answers to questions frequently asked by small and medium welding shop managers about air quality management.
First, proactively develop a health risk and mitigation plan.For example, an industrial hygiene assessment will help you identify harmful elements in dust and determine exposure levels.This assessment should include evaluating your facility to ensure you meet the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits (PELs) for dust particles generated by your application.
Ask your dust extraction equipment supplier if they can recommend an industrial hygienist or environmental engineering firm experienced in identifying dust and fumes specific to metalworking facilities.
If you are recirculating clean air back to your facility, make sure it stays below the operational limits set by OSHA PEL for contaminants.If you emit air outdoors, remember that you must comply with the Environmental Protection Agency (EPA) National Emission Standards for Hazardous Air Pollutants.
Finally, when designing your dust extraction system, you must ensure that you create a safe welding workplace in accordance with the three Cs of dust extraction and fume removal: capture, convey, and contain.This design typically includes some type of fume capture hood or method, ducting to the capture point, properly sizing the ducts returning to the collector, and selecting a fan that can handle system volume and static.
This is an example of a cartridge industrial dust collector located outside a welding facility.Image: Camfil APC
A dust collector system designed for your operation is a proven and proven engineering control that captures, delivers and contains harmful air pollutants.Dry media dust collectors with high efficiency cartridge filters and secondary filters are suitable for capturing respirable dust particles.
Source capture systems are popular in applications involving welding of small parts and fixtures.Typically, they include fume extraction guns (suction tips), flexible extraction arms, and slotted fume hoods or small fume extraction hoods with side shields.These are usually customized to be application-specific with minimal disruption to the workflow.
Enclosures and canopy covers are typically used in areas with footprints of 12 feet by 20 feet or less.Curtains or hard walls can be added to the sides of the hood to create a compartment or enclosure.In the case of robotic welding cells, it is often possible to use a complete enclosure over and around the application.This applies to single- and dual-arm welding robots and multi-axis plasma cutting robots.
When your application is not compatible with the recommendations outlined earlier, an environmental system can be designed to remove smoke from most, if not the entire facility.Keep in mind that as you go from source capture, enclosure and hood to ambient collection, the airflow required increases significantly, as does the price tag of the system.
Many small and medium-sized stores tend to respond only after trying to use money-saving DIY methods, such as opening doors and windows and creating their own exhaust systems, to control the smoke.The problem is that nasty fumes end up being a bigger problem and tend to overwhelm these methods while increasing energy costs or creating dangerously high negative pressures in the facility.
The first thing you need to do is find out where the most common problems occur in your facility.This could be plasma table fumes, freehand arc gouging, or welding on a workbench.From there, tackle the process that produces the most smoke first.Depending on the amount of smoke produced, a portable system may help you get through.
The best way to reduce worker exposure to harmful fumes is to work with a quality dust collector manufacturer who can help you identify and create a custom system for your facility.Typically, this includes installing a dust collection system with a primary cartridge filter and a high-efficiency secondary safety filter.
The primary filter media you choose for each application should be based on dust particle size, flow characteristics, quantity and distribution.Secondary safety monitoring filters, such as HEPA filters, increase particle capture efficiency to 0.3 microns or greater (capturing a high percentage of PM1) and prevent harmful fumes from being released into the air in the event of a primary filter failure.
If you already have a smoke management system, carefully monitor your store for conditions that indicate it is not working properly.Some warning signs include:
Watch out for clouds of smoke that thicken and hang in the air throughout the day after your welding event.However, a large accumulation of smoke does not necessarily mean that your extraction system is not working properly, it may mean that you have exceeded the capabilities of your current system.If you have recently increased production, you may need to reassess your current setup and make changes to accommodate the increase in activity.
Proper management of dust and fumes is critical to the safety of your workers, equipment and workshop environment.
Finally, it’s always important to listen, observe, and question your employees.They can let you know if your current engineering controls are effectively managing dust in your facility and suggest areas for improvement.
OSHA rules for small businesses can be complicated, especially when it comes to knowing which rules you must follow and which ones you are exempt from.Too often, small stores think they can fly under the radar of OSHA regulations—until an employee complains.Let’s be clear: Ignoring regulations doesn’t eliminate employee health risks.
According to Section 5(a)(1) of OSHA’s General Responsibility Provisions, employers must identify and reduce workplace hazards.This means that employers must keep records identifying all hazards (dust) generated in their facilities.If the dust is flammable and explosive, the dust management must be carried out in accordance with the standards of the National Fire Protection Association, if not, the inspection records need to be kept.
OSHA also sets PEL thresholds for airborne particulate pollutants from welding and metalworking.These PELs are based on an 8-hour time-weighted average of hundreds of dusts, including those contained in welding and metalworking fumes listed in the Annotated PEL table.When initial air monitoring shows exposure levels above action levels, facility operators need to implement additional requirements under OSHA.
As mentioned, smoke can irritate eyes and skin.However, you should also be aware of more toxic effects.
Particulate matter (PM) with a diameter of 10 microns or less (≤ PM10) can reach the respiratory tract, while particles 2.5 microns or less (≤ PM2.5) can penetrate deep into the lungs.Respirable particles with a diameter of 1.0 microns or less (≤ PM1) cause more damage because they can penetrate the lung barrier and enter the blood system.
Regular exposure to PM increases the risk of respiratory diseases, including lung cancer.Many particles from welding and metalworking fall within this hazard range, and the nature and severity of the hazard will vary depending on the type of material being processed.Whether you use stainless steel, mild steel, aluminum, galvanized, or other materials, material safety data sheets are a good starting point for identifying health risks.
Manganese is the main metal in welding wire and can cause headaches, fatigue, listlessness and weakness.Prolonged exposure to manganese fumes can cause neurological problems.
Exposure to hexavalent chromium (hexavalent chromium), a carcinogen produced during welding of chromium-containing metals, can cause short-term upper respiratory illness and eye or skin irritation.
Zinc oxide from hot working of galvanized steel can cause metal fume fever, a short-term illness with severe flu-like symptoms after get off work hours, such as weekends or after holidays.
If you already have a smoke management system, monitor your store carefully for conditions that indicate it’s not working properly, such as clouds of smoke that thicken throughout the day.
Signs and symptoms of beryllium exposure may include shortness of breath, cough, fatigue, weight loss, fever, and night sweats.
In welding and thermal cutting operations, a well-designed and maintained dust extraction system prevents respiratory problems for employees and keeps facilities in compliance with current air quality requirements.
Yes.Smoke-laden air can coat heat exchangers and cooling coils, causing HVAC systems to require frequent maintenance.Welding fumes can penetrate standard HVAC filters, cause heating systems to fail and clog air conditioning condensing coils.Ongoing service of an HVAC system can become expensive, but a poorly functioning system can create dangerous conditions for workers.
A simple but important safety rule is to replace the dust filter before it becomes too much.Replace the filter if you notice any of the following:
Some long-life cartridge filters can run for two years or more between changes.However, applications with heavy dust loads often require more frequent filter changes.
Choosing the right replacement filter for your cartridge collector can have a significant impact on the cost and performance of the system.Be careful when purchasing replacement filters for your cartridge collector – not all filters are the same.
Often, buyers are stuck with the best value.However, the list price is not the best guide to buying a cartridge filter.
Overall, protecting you and your employees with a proper dust collection system will go a long way towards helping your small to medium business thrive.
WELDER, formerly Practical Welding Today, showcases the real people who make the products we use and work with every day.This magazine has served the welding community in North America for over 20 years.
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