Welding Safety Checklist HAZARD FACTORS TO CONSIDER
Electric shock can • Wetness kill
• Welder in or on workpiece • Confined space
• Electrode holder and cable insulation
PRECAUTION SUMMARY
• Insulate welder from workpiece and ground using dry insulation. Rubber mat or dry wood.
• Wear dry, hole-free gloves. (Change as necessary to keep dry.) • Do not touch electrically “hot” parts or electrode with bare skin or wet clothing.
• If wet area and welder cannot be insulated from workpiece with dry insulation, use a semiautomatic, constant-voltage welder or stick welder with voltage reducing device.
• Keep electrode holder and cable insulation in good condition. Do not use if insulation damaged or missing.
Fumes and gases • Confined area
can be dangerous • Positioning of welder’s head • Use helmet and positioning of head to minimize fume in breathing zone. • Lack of general ventilation • Electrode types, i.e., manganese, chromium, etc. See MSDS
(MSDS) for electrode, requirements exist.
• Base metal coatings, galvanize, paint
Welding sparks can cause fire or explosion
combustibles • Flammable materials • Do not weld unless ventilation is adequate.
• Containers which have held • Do not weld on containers which have held combustible materials (unless strict AWS F4.1 procedures are followed). Check before welding.
• Remove flammable materials from welding area or shield from sparks, heat. • Keep a fire watch in area during and after welding. • Keep a fire extinguisher in the welding area. • Wear fire retardant clothing and hat. Use earplugs when welding overhead.
Arc rays can burn • Process: gas-shielded arc eyes and skin
most severe • Select a filter lens which is comfortable for you while welding.
• Always use helmet when welding. • Provide non-flammable shielding to protect others. • Wear clothing which protects skin while welding.
• Use ventilation or exhaust to keep air breathing zone clear, comfortable. • Read warnings on electrode container and material safety data sheet • Provide additional ventilation/exhaust where special ventilation • Use special care when welding in a confined area.
Arc Welding Fumes and Gases
The fume plume contains solid particles from the consumables, base metal, and base metal coating. For common mild steel arc welding, depending on the amount and length of exposure to these fumes, most immediate or short term effects are temporary, and include symptoms of burning eyes and skin, dizziness, nausea, and fever. Long-term exposure to welding fumes can lead to siderosis (iron deposits in the lungs) and may affect pulmonary function. Bronchitis and some lung fibrosis have been reported.
Compounds which may be in welding fume, and reported health effects of overexposure are:
Barium may cause severe stomach pain, slow pulse rate; irregular heart beat, ringing of the ears, convulsion and muscle spasms. In extreme cases can cause death.
Cadmium fumes can be fatal even under brief overexposures, with symptoms much like metal fume fever.
Chromium and its compounds are on the IARC (International Agency for Research on Cancer) and NTP (National Toxicology Program) lists as posing a cancer risk to humans. Some forms of these metals are known or suspected to cause lung cancer in processes other than welding and asthma has been reported.
Manganese: Manganese overexposure may affect the central nervous system, resulting in poor coordination, difficulty in speaking, and tremor of arms or legs. This condition is considered irreversible.
Nickel: Nickel and its compounds are on the IARC (International Agency for Research on Cancer) and NTP (National Toxicology Program) lists as posing a cancer risk to humans.
Silica: Overexposure can cause severe lung damage (silicosis). Crystalline silica is present in submerged arc flux.
Zinc: Overexposure to zinc may cause metal fume fever with symptoms similar to the common flu.
Your work area has adequate ventilation when there is enough ventilation and/or exhaust to control worker exposure to hazardous materials in the welding fumes and gases so the applicable limits for those materials is not exceeded. See the MSDS for the legal limits, the OSHA PEL (Permissible Exposure Limit), and the recommended guideline, the ACGIH TLV (Threshold Limit Value). Confirm that if the worker exposure does not exceed the applicable exposure limit for compounds in the fumes and gases by having an industrial hygienist take and analyze a sample of the breathing air. A respirator may be required if exposure cannot be controlled to the PEL or TLV.
Read the product label and material safety data sheet for the electrode posted in the work place or in the electrode or flux container to see what fumes can be reasonably expected from use of the product and to determine if special ventilation is needed. Know what the base metal is, and determine if these is any paint, plating, or coating that could expose you to toxic fumes and/or gases. Remove it from the metal being welded, if possible.
If you start to feel uncomfortable, dizzy or nauseous, you may be overexposed to fumes and gases, or suffering from oxygen deficiency. Stop welding and get some fresh air immediately. Notify your supervisor and co-workers so the situation can be corrected and other workers can avoid the hazard. Be sure you are following these safe practices, the consumable labeling and MSDS and improve the ventilation in your area. Do not continue welding until the situation has been corrected
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