Safe working practices can make welding enjoyable
The Welding process produces several types of hazards for the operator and whoever is in the vicinity. The operator needs to know about the kind of risks and hazards associated with the welding process and locations. It is essential to understand and identify many types of hazards.
Electric Shock
While Arc welding, live electric current is always present in the electrical circuits of welding machines, they create heat and melt metal. This enhances the risk of electric shock during the welding process and is the most serious hazard presented by the welding operation. There is also the risk of secondary electric shock if some part of the welding handle or electrode circuit touches you during welding.
The risk of injury is most hazardous when:
- Working in wet or moist conditions.
- Working in wet clothes.
- Working on a metal floor or structure
- When in working in cramped or restricted positions like lying, kneeling or crouching.
- If your welding machine earth clamp is not connected properly.
Noise Hazards
When welding activities are in progress, you may be exposed to loud sounds and prolonged noises. Noise is deemed Loud when it exceeds 85 dB Welding activities like flame-cutting, arc welding can produce a level of noise over 100 dB. This can be dangerous to the ears can result in permanent hearing loss.
Hearing loss because of Noise can have the following side effects:
- Constant ringing sound in the ears. This is known as tinnitus.
- Feeling some occasional dizziness, or vertigo.
- Increase in heart rate.
- Abnormal increase in blood pressure.
- Having a persistent headache.
Exposure of Ultraviolet (UV) and Infrared (IR) radiation
During welding intense UV light is produced as part of the process, without appropriate PPE and welding glasses it can be harmful and/or painful. Sometimes this also generates a long-lasting painful condition called Arc-eye. Other factors can affect the severity of this condition such as:
- Distance
- Duration
- Angle of penetration
Long-term exposure to arc flash can also lead to Cataracts and loss of vision. Some other reasons for eye damages are:
- Foreign particles being lodged in the eyes like arc spatter, debris, grits and dust.
- Long time direct contact with fumes and gases in eyes.
Exposure in Fumes and Gases
Welding activity can produce invisible or visible gaseous fumes present including, Ozone, Nitrous oxide, Chromium or Nickel Oxide, and carbon monoxide. These gases are easily dissolved in the human lungs. Depending on the type of gas, its concentration, and duration of exposure this can result in severe damage.
Long time exposure with gases, welder and employees in the vicinity can be affected from following diseases:
- Pneumonia. Regular exposure to welding fumes and gases can result in a lung infection which could then develop into pneumonia. While antibiotics can usually stop the infection, severe pneumonia can result in hospitalisation, serious illness and fatalities.
- Occupational asthma. Chromium oxides and nickel oxides produced by stainless steel and high nickel alloy welding can both cause asthma.
- Cancer. All welding fumes are internationally considered ‘carcinogenic’.
- Metal fume fever. Welding or hot work on galvanised metal and high steel weld fume exposure can often result in ‘flu-like’ symptoms, which are usually worse at the start of the working week. You might have heard that drinking milk before welding will help you avoid developing metal fume fever, but this is a myth.
- Throat and lung irritation, including throat dryness, tickling of the throat, coughing and tight chests.
Burns
The combination of heat, UV rays, and IR rays can result in severe burns. Welding is a high-temperature operation that can affect skin or eyes. these burns can be very serious and also happen very quickly.
Welding burns occur when the welder is careless and shortcuts precautions for some quick welding. This is bad welding practice and should never happen even for small or quick welding jobs.
Fire and Explosion
Fire and explosions may happen when hot metal parts, sparks, and drops of molten metal start a fire. Before starting welding works you should always be aware of:
- Any kind of flammable material nearby.
- Proper use of fire retardent cloth to cover welding work zone.
- Availability of a suitable fire-extinguisher close to the welding job.
- Removal of any kind container or drum that may contain (even in small amounts) oil, paint, spirits etc.
Hazards of Welding in Confined Spaces
A confined space is a place with a limited access point with no airflow and ventilation. Adequate ventilation and airflow regulation is the most important thing whilst working in a confined space. In a confined space, the dangerous concentration of toxic fumes and gases can accumulate quickly and can make a person unconscious and lead to death by of suffocation.
Continuous welding process in confined space displaces oxygen available in the air and generates toxic fumes and gases like CO. These gases are dangerous to health. High concentrations of some fumes can lead to explosive vapours too.
All welders who enter in confined space either on regular basis or for some emergency situation must follow the following precaution for their safety:
- All welders must be equipped with safety harness, Lifeline, appropriate protective clothing, and self-contained breathing apparatus. Never use any air purifying respirator as it can create suffocation in confined space.
- Gas cylinder and welding power connection source should be located in secure location outside of confined space.
- Confined space should be tested for toxic, flammable or explosive gas via a gas detector before entering.
- A well trained welding assistant must always stay outside the confined space with fire extinguisher and PPE.
- Only air ventilation should be used. Never use oxygen for ventilation.
- Use continuous ventillation when welding is in progress. Large electric fans can help with this.
- Anything unneccessary other than welding equipment and necessary protective gear should be removed from the confined space.
Welding safety precautions and Tips
Welding safety precautions are actionable steps that should be taken by welders to prevent welding-related incidents and injuries such as burns, fire, explosion, electrocution, or suffocation. In order to eliminate or reduce the welding hazards, welders should practice the following safety precautions and tips accordingly:
- Always use proper ventilation and exhaust fans for fumes and gases from welding zone.
- Be aware of any concerns and welding related hazards.
- Fire and electric resistance cloths, face shield, hand gloves, aprons and boots must be used.
- Earmuffs or earplugs always be used according to noise level of vicinity.
- Always keep a suitable class of fire extinguisher close by while welding. Make sure fire extinguisher gauge is full and in service.
- No flammable material should be nearby the welding zone.
- Always use fire retardent cloth and hot metal resistant material for protection against droplets and sparks.
- Always use inspect welding tools and machineries. Before use check for any faulty wire and welding holders on daily basis.
- Proper use of IR and UV filter glasses to protect your eyes.
- Don’t leave workplace instantly after the welding job completion. Stay while the welded metal cools to ensure nothing can ignite.
General Safety check list for welding
Every Welding job should be pre-planned and safety arrangements should be done accordingly. Before starting of welding job there are safety points that should be verified. This safety checklist for welding is useful before commencing the welding job.
- General Information
- Pre-operation information
- On-going work information
- Post-operation information
General Information
- Description of welding job should be recorded
- Location of welding work should be verified
- Type of welding should be verified
Pre-operation welding work Information
This information should be recorded in 03 stages:
Welder’s Information
- Are all welders experienced and trained?
- Are all instructions clear and understood by welders?
- Are all welders familiar with the welding machine they are going to use?
- Are all welders familiar with the type of metal to be welded?
- Are all welders wearing the required PPEs?
- Are welders aware of safety protocol during emergency?
Welding Machine
- Are all welding cables, wiring, electrode holders insulated and in good condition?
- Is welding machine properly inspected and certified for use?
- Are all welding terminals and joints in good condition?
- Is the size of cable suitable for voltage application?
- Is body earthing wire and clamp is properly connected?
Work Area
- Is work area clean and free from flammable materials?
- Is ventillation is applicable for work area?
- Is there suitable class of fire extinguisher available nearby?
- Are combustibles wetted or protected?
- Are combustible walls shielded or guarded?
- Is a fire blanket available in work location?
- Are warning sign placed in work location?
- Is work area restricted from observers?
On-going welding work information
- Is arc shield used to provide extra layer of protection?
- Are all welding machine insulated from work and ground?
- Are all welders using dry and fire retardent clothing?
- Is pressurised cylinder handle carefully?
- Are valve cylinders placed with valve end up?
- Does cylinder attached when lifting welding machine to welding location?
Post-operation welding work Information
- Are all electrode bits swept away from welding location?
- Is all welding equipment turned off and stored in proper location?
- Are gas cylinder valves closed and put away safely?
- Are any other waste of welding process disposed properly in designated area?
- Are all weld job attained its normal environment temperature?
- Is it safe to leave work location after welding?
Conclusion
Ensuring welding operation safety is all about preparation. No person should ever start welding work without the correct welding machinery, information, and safety equipment. Every new environment and situation needs an assessment of hazards and risks, so new safety measures can be introduced.
Hazards of welding may change with new technologies. Wherever hot work is going on there is always a risk of fire and explosion. Amateurs or professionals must inspect the environments closely before starting any welding projects.