Safety Considerations For Welding Indoors and in Enclosed Spaces
Welding is a hazardous occupation, especially when working indoors and in enclosed spaces. Welding dangers become increasingly hazardous the tighter the welding space gets. So, welding fume extractors, eye protection, fire safety measures, and other safety protocols and devices use become that much more critical.
Welding indoors, especially in tight spots like pressure vessel welding, can easily expose the welding operators to hazardous levels of welding fumes, arc flash, burns, physical injuries, electrocution, and other welding hazards.
Introduction to Welding Indoors and in Enclosed Spaces
While welding outside is unsafe, welding indoors can be significantly more dangerous. The tighter the welding space, the higher the risk of welding accidents and hazardous exposure.
Enclosed spaces have a relatively low volume of fresh air. So, welding can quickly make the air hazardous to breathe. Depending on the air volume in the room, welding fumes can easily breach safe thresholds for dangerous compounds like hexavalent chromium, zinc oxide, cadmium, aluminum, manganese, fluorides, and lead.
Importance of Safety in Indoor Welding Environments
It’s crucial for all indoor welding operations to strictly follow OSHA and other applicable safety measures. Indoor welding can quickly turn into a life-threatening hazard. But, it can also contribute to chronic health hazards. So, even if no accidents occur, indoor welding can pose a significant health hazard by causing cancer, heart disease, respiratory issues, nervous system damage, and other severe health issues.
Unique Challenges of Welding in Enclosed Spaces
Welding in enclosed spaces is particularly challenging and dangerous due to low air volume and a higher chance of electrocution and fire hazards. In addition, welding in tight spaces can cause physical injuries and burns.
Types of Ventilation Systems for Indoor Welding
Indoor welding requires adequately engineered and implemented ventilation, especially for fabrication facilities with multiple welding booths. You can employ several ventilation systems, but some work better than others to keep the air safe and under permissible exposure limits (PEL).
Importance of Adequate Ventilation
Welding melts the base and filler metals, which creates hazardous welding fumes as molten metal evaporates in the air. In addition, welding fluxes and shielding gasses can release toxic compounds. If you don’t have adequate ventilation, you or your welders will be exposed to respiratory hazards, leading to severe acute or chronic health problems.
The shielding gasses like argon, helium, and carbon dioxide can displace air in enclosed spaces and cause suffocation to the welder. But, certain welding processes can provide too much oxygen as well, leading to increased fire risks. Ventilation prevents such hazards by providing enough clean air.
Air quality management when welding must meet OSHA standards. Besides health issues, you risk fines and lost business hours if your ventilation system doesn’t prevent hazardous fumes from reaching the welders’ lungs. But, even more importantly, adequate ventilation protects you and your workers. Having a safe and healthy work environment attracts the best welding talent and helps you retain the most valuable welders longer. Nobody wants to suffocate in fumes and get cancer later in their career, so providing ventilation is a must on any fabrication business’ to-do list.
General Ventilation Systems
Natural ventilation is most often insufficient when welding indoors. Therefore, forced ventilation is necessary. General ventilation systems dilute the hazardous fumes in the welding area by bringing in fresh air. However, more often than not, general ventilation systems aren’t sufficient to keep toxic elements below their PEL. These systems work best when paired with the local exhaust ventilation (LEV) systems.
Understanding Local Exhaust Ventilation (LEV) Systems
If designed and installed correctly, the local exhaust ventilation provides the most efficient fume extraction and prevents air contaminants from breaching the PEL limits.
Welding fume extractors use flexible or fixed exhaust hoods placed near the welding joint to capture and extract the welding fume close to the source. As a result, almost the entirety of the welding plume never disperses in the work area, keeping the air clean and below exposure limits.
Portable Ventilation Solutions
Portable LEV solutions like the SMOKEY SE1200D are an excellent choice for flexible shop operations or welding in enclosed on-site areas like ships, inside large pressure vessels, basements, and other places where flexible fume extraction is necessary.
You can move and position portable smoke extractors with little effort. They provide the most versatile solution for small and medium-sized shops. Unlike fixed LEVs, portable local ventilation systems allow you to position the extraction hood directly at the source, regardless of the current shop configuration.
Proper Airflow and Fume Extraction
It’s crucial to design and apply airflow and fume extraction in your shop for maximum air quality without disturbing the arc, open flame, or shielding gas action.
Positioning of Welding Equipment and Workpieces
Welding equipment and workpieces should be positioned in the work area so that the general ventilation system doesn’t push contaminated air from one welder to the next. In general, the equipment and work areas should avoid cross-contamination. When LEV systems are used, the welding torch and the workpiece should be positioned directly beneath the extraction hood, and the welder should keep its head away from the fume path as it flows from the welded joint and into the extraction hood.
Managing Airflow to Minimize Fume Exposure
It’s vital to consider the entire welding operations in your fabrication line or a welding shop. A large manufacturing facility can have numerous metal shaping processes taking place interchangeably with various welding processes as the part travels through the facility. But, through intelligent planning and some logistics brainstorming, you may be able to reduce the workers’ fume exposure simply by managing how, where, and when welds are made.
You can dramatically reduce workers’ exposure by organizing the welding booths or other welding areas so that welding activities don’t spread the fumes to the rest of the facility. So, it’s crucial to consider the airflow and the sources of the welding fume as a whole in your shop or a fabrication line.
Use of Fume Extraction Systems and Filters
Welding fume extractors with filters can capture contaminants as small as 0.5 microns. By positioning the extraction hood above the workpiece, you can direct the fumes into the extractor. Next, the fumes enter the filter, which captures the hazardous compounds and releases clean air.
Precautions for Welding in Confined Spaces
Welding in confined spaces requires certain precautions to prevent health and injury hazards. So, let’s see how to approach the enclosed areas from the welding safety point of view.
Assessing the Confined Space for Potential Hazards
Ensure a proper confined space assessment before welding. Take particular note of the following safety risks:
- Chlorinated hydrocarbons (degreasing or cleaning solvents) can interact with the UV radiation from the welding arc to form extremely poisonous gasses.
- A low air volume can lead to suffocation.
- High moisture in the area, paired with cramped welding space, puts the welder at a higher risk of electrocution.
- Consider your movement in the area before welding. Can you perform all welding maneuvers in the confined space safely?
- Some tight areas pose a risk of physical injury if sharp elements protrude from the surrounding walls, floor, and ceiling.
- Confined spaces can easily catch fire when welding if any of the surrounding material is flammable.
- It’s easy to get burned when welding in a tight space. Consider the direction from where the molten slag will fall on you, and use fireproof apparel.
Proper Ventilation and Air Monitoring
It’s vital to use adequate air ventilation, as we already discussed. But, to know if the air you breathe is safe, you must monitor it. You can monitor the fumes on the area or personal level. By monitoring the fumes in the work area, you can determine the effectiveness of the ventilation, the impact on other workers, and analyze what is migrating out of the welding area.
Personal monitoring can provide details on what’s getting under the welding mask of the worker and if additional engineering controls or PPE are necessary.
Fire and Explosion Hazards in Indoor Welding
Welding indoors poses a fire and explosion risk if combustible or explosive materials are nearby. At the very least, pressurized cylinders used as a welding fuel or a shielding gas are at risk of exploding. So, it’s always important to assess your environment thoroughly before welding.
Understanding Fire and Explosion Risks
Whether welding with an open flame (oxy-fuel) or using an electrical arc welding process, you’ll create immense heat by welding. In addition, some arc welding processes, like GMAW, FCAW, and SMAW, produce a significant amount of hot sparks and slag, which can ignite flammable materials. So, welding is classified as “hot work” and requires fire prevention safety steps, especially when welding indoors.
Fire Prevention Measures in Indoor Welding Environments
- Thoroughly assess the welding area for fire hazards before striking an arc.
- Whenever possible, weld away from the combustible materials.
- Combustible floors must be covered with damp sand, sheet metal, or other non-flammable covering.
- Move all flammable materials and items away from the welded area. Clear a distance of at least 35 feet from the welding area. If not possible, cover them with fireproof blankets.
- All indoor welding operations must have appropriate fire extinguishers
- Never obstruct fire emergency exit routes.
- Emergency contact numbers should be visible at all times.
- Fire watchers must be qualified and knowledgeable about emergency procedures.
- Indoor welding atmosphere should never have elevated levels of oxygen.
Safe Handling and Storage of Flammable Materials
You must be aware of all combustible materials at all times. Only begin the welding procedure after assessing the environment for flammable materials.
Remove all cardboard boxes, nylons, rags, plastic, paper bags, food, dry leaves, wood, cans of paints and solvents, dust, gas cylinders, and anything else that can catch fire from the welding sparks or generated heat. You must clear a distance of at least 35 feet from the welding arc.
Pay particular care to the shielding and welding fuel gas cylinders. They must never be exposed to welding sparks, molten slag, and the welding arc.
Personal Protective Equipment (PPE) for Indoor Welding
Many injuries and health hazards can be prevented by adequately using PPE. Your welding crew must receive appropriate training on efficient PPE use for indoor welding. While the PPE protects the individual from workplace hazards, it also indirectly contributes to a safer work environment, especially when welding in enclosed spaces. The PPE keeps everyone safe and reduces the chances of fire, electrocution, and resulting bodily harm.
Eye and Face Protection
Welders must wear the appropriate welding hoods to protect themselves from UV/IR radiation from the welding arc. But, the welding helmet may not protect you from the physical impact. So, it’s crucial to wear the safety glasses underneath it.
Indoor welding can also expose others in the welding area to the arc flash, resulting in eye cornea burns. So, everyone must be aware of any welding activities in the shop and either be shielded from the direct line of the welding arc or wear an appropriate welding helmet/goggles.
If the local exhaust ventilation and general mechanical ventilation can’t keep the workplace beneath the PEL, all exposed workers must wear a respirator or other type of respiratory protection. Welders working in cramped spaces often must use advanced respiratory protection like PAPR and SCBA systems.
Clothing and Body Protection
Welders must wear fireproof jackets, pants, boots, and apparel. The clothes shouldn’t have crevices where hot slag can latch on. If you are welding indoors, it’s important to have a fire watcher inspecting welders before they leave the welding area into another shop area. A hot piece of slag can get trapped in the clothes, and an unaware welder can spread the fire hazard elsewhere.
Welder clothing should cover the neck, ankle, and wrist areas to prevent sparks and slag from falling underneath the protective clothes.
Electrical Safety in Indoor Welding
Welding machines operate with high input voltage and extreme output amperage. A stick welder with an open circuit voltage of 80V and a 200A output can quickly kill or severely injure anyone who finds themselves in the circuit. But, alternating current is dramatically more dangerous. A brief contact with 20 milliamps of AC can be fatal. So, it’s vital to follow all electrical safety measures when welding, especially when working indoors. Since enclosed spaces can have higher moisture in the air, there can be an increased chance of electrocution.
Proper Grounding and Electrical Connections
Always insert the plug of the welding power source into a grounded receptacle. You can use receptacle circuit testers to check the continuity of the grounding conductor. A ground connection is crucial in preventing fatal electric shocks from your welder. Never remove the ground pin from the welder’s electric plug.
The welding power source ground from the plug should not be confused with the workpiece (ground) clamp that is used to close the welding circuit.
You have two electrical circuits. One is from the wall, which powers the welding machine, and the other is from the welding machine. The circuit that originates from the machine is a closed loop between the power source, terminals, welding cables, workpiece connection (often called ground clamp), welding torch, and welded metal. You must ground this circuit as well by grounding the welding table directly to earth (as in genuine land where trees grow), which is often not possible, or to the metal building frame that is connected with the earth.
So, do not mistake the workpiece clamp as a grounding clamp. Merely attaching a workpiece clamp to the welded metal does not ground the welding circuit and won’t protect you from the shock. The table or the welded metal must be directly tied to the earth. The workpiece clamp is there just to close the welding circuit and nothing else.
Ensuring Safety with Electrical Cords and Welding Machines
- Always use adequate welding cables and leads as specified in the machine’s manual. It’s vital to use a correct diameter for welding cables, or you risk fire and electrocution hazards.
- Never lay the cables on the ground where they are exposed to foot traffic.
- If the cable or the stinger are damaged, don’t use them.
- Test extension cords for ground continuity frequently. They may get damaged by foot traffic. If the ground continuity gets severed, you risk electrocution.
- Never use a welding machine that behaves erratically or unexpectedly. Stop and call your supervisor.
- Don’t touch live wires or electrodes, including the wire spool inside the machine or the wire feeding unit.
Electrical Hazard Awareness and Prevention
Keep electrical hazard warning signs visible in your shop and isolate high-voltage areas from unauthorized personnel. It’s vital for all workers to be aware of the electric hazards in the shop and to receive appropriate electric safety training.
Safe Work Practices for Indoor Welding
Since indoor welding can expose you to additional risks, it’s essential to follow safe work practices for hazard prevention.
Pre-Welding Preparation and Workspace Setup
- Assess the indoor welding environment for hazards before welding.
- Move all flammable materials at least 35 feet away from the welding area.
- Inspect welding equipment pre-welding and make sure you are aware of the changes in equipment setup from the previous shift, if any.
- Position the fume extraction equipment to pull the smoke away from your face.
- If welding in an unfamiliar indoor area, ensure the fire extinguishers are appropriate for the possible fire and have been inspected and serviced recently.
- Check your PPE for signs of wear and replace it if necessary.
- Do not weld if you haven’t undergone the appropriate training for the fire and electrical hazards at the location. For example, if you don’t know how to use a fire extinguisher for metal fires, don’t weld combustible metals like magnesium.
- Cover all holes and crevices where the sparks can fall through and reach flammable materials.
- Set up welding screens to prevent non-welding personnel from arc flashes.
- Do not weld until everyone in the work area is fully aware of the possible respiratory, fire, electrical, and other hazards. For example, don’t begin with the welding work if unrelated tradespeople are present on site and they haven’t been briefed on the possibility of arc flashes and other hazards.
- Ensure that the area is free from solvent vapors before welding.
- Place welding hazard warning signs in visible locations.
- Consider the sparks and slag path trajectory before you start welding. Ensure that you and everyone else won’t get burned by them.
- Always ensure the cut metals are securely clamped or that their fall trajectory won’t injure you or others.
- Plan your movement around the welding area and remove any tripping hazards.
Handling and Storing Welding Equipment and Consumables
Welding equipment and consumables like stick electrodes, GMAW/FCAW wires, and shielding gasses must be stored according to the manufacturer’s instructions and OSHA safety regulations (where applicable).
Communication and Emergency Response Planning
All welding and non-welding personnel should know the emergency response procedures, especially when running large-scale fabrication. It’s vital to implement emergency alarms, fire extinguishers, and exit routes. Plan ahead for emergencies and develop plans that include major fire hazards, severe worker injury, employee evacuation, power failure, and other emergencies. Contact your local fire brigade and have them inspect your fabrication line so that they are aware of any tight spots and critical areas.
It’s paramount to make emergency communication with all employees as clear and simple as possible. If someone gets electrocuted or a fire breaks out, the situation can quickly get out of hand. So, if the emergency response plans aren’t easy to implement, more people can get injured.
Training and Education for Indoor Welding Safety
Since indoor welding poses a significant safety hazard, all welders and workers exposed to welding hazards must receive proper training for hazard prevention.
Importance of Proper Training and Certification
OSHA mandates employee training on workplace hazards. Every employee must be trained on hazardous materials, confined spaces, electrical hazards, fall protection, respiratory safety, fire hazards, and other safety hazards when welding indoors.
Ongoing Education and Knowledge Updates
You can never know enough about welding safety because safety systems and hazard prevention methods are continuously updated and improved. So, it’s vital to stay in the learning mode for the rest of your welding career. What works today may become significantly better in the future and make the workplace even more safe.
Follow organizations like the OSHA, NIOSH, and American Welding Society to stay updated on the changes in welding safety practices and policies:
- OSHA – Welding, Cutting, and Brazing
- AWS – Safety In Welding
- The National Institute for Occupational Safety and Health (NIOSH)
Promoting a Safety Culture in Indoor Welding Environments
A healthy safety culture is implemented across verticals in any fabrication business. While safety culture starts at the top, it should be implemented in a way that the operators on the floor want to enforce it themselves.
It’s vital to lead by example, but this also means that you should consider what the welders and other employees have to say. Unless their safety concerns are taken into account, they may feel like the safety rules are imposed upon them, making them reluctant to follow the safety systems. Likewise, employees who don’t fully understand the dangers may feel like the safety rules are a burden. But if they are fully aware of how they can get injured or suffer chronic health issues, they will be more inclined to follow the safety protocols.
Everyone must participate in a healthy safety culture. If you are a welder and you see your workmate ditch safety glasses, let them know that they are endangering themselves and others around them. A healthy safety culture begins when everyone understands they are responsible for their health and coworkers. Of course, it’s up to the employer to provide proper training, safety equipment, and PPE, but ultimately, it’s up to the employees on the ground to use it. While a safety officer can enforce safety rules, nobody can supervise the entire operation 100% of the time. So, it’s vital that everyone feels the need to make their workplace safer and healthier.
Conclusion: Prioritizing Safety in Indoor Welding and Enclosed Spaces
Welding in enclosed spaces has unique safety challenges that can quickly cause severe injuries or act as a silent killer and cause cancer and chronic health issues down the line. Therefore, it’s paramount to prioritize safety when welding indoors.
Red-D-Arc Welderentals™ an Airgas company rents and leases welders, welding positioners, welding-related equipment, and electric power generators – anywhere in the world. Our rental welders, positioners and specialty products have been engineered and built to provide Extreme-Duty™ performance and reliability in even the harshest environments, and are available through over 70 Red-D-Arc Service Centers, strategically located throughout the United States, Canada, the United Kingdom, France, and the Netherlands, as well as through strategic alliances in the Middle East, Spain, Italy, Croatia, and the Caribbean. From our rental fleet of over 60,000 welders, 3,700 weld positioners, and 3,700 electric-power generators, we can supply you with the equipment you need – where you need it – when you need it.