Controlling exposure to ultraviolet (UV) radiation when welding

How welding generates UV radiation and why it is dangerous

Welding can be hazardous to the health and safety of welders and those in close proximity to where the welding is taking place. During the electric arc welding process, the electric welding arc produces UV radiation, exposing the welder to direct UV radiation or UV radiation that is reflected off hard smooth surfaces in close proximity to the welder.

The International Agency for Research on Cancer (IARC) has classified UV radiation emitted from electric welding arc as a Group 1 carcinogen (IARC Monograph 118). This follows evidence identifying the carcinogenicity of ultraviolet radiation produced during electric arc welding potentially causing ocular melanoma in humans.

UV radiation may damage eyes

Exposure to UV radiation may cause:

• ocular melanoma (also referred to as eye melanoma)
• conjunctivitis (also known as welder’s flash or arc eye)

Acute overexposure of the eye to UV radiation is common among electric arc welders and, as a result of repeated exposure, a welder may develop a rare cancer known as ocular (eye) melanoma . Some people with ocular melanoma may experience no symptoms at all, while others may have ongoing symptoms, such as light flashes, blurred vision or seeing dark spots.

Conjunctivitis is an inflammation of the mucus membrane at the front of the eye. Symptoms for conjunctivitis include:

• inflammation, ranging from mild tenderness to intense pain
• tearing and reddening of the eye and surrounding area
• sensation of sand or grit in the eyes
• abnormal sensitivity to light
• inability to look at light sources

These symptoms may not be felt until several hours after exposure to the electric welding arc, and may remain for one or two days.

UV radiation may burn skin

UV radiation produced by electric arc welding and/or reflected from metal surfaces may burn unprotected skin. Continuous or repeated exposure to UV radiation over a long period of time (years) may also cause skin cancer.

How to identify the risks of exposure to UV radiation

Employees directly involved in the welding process are at greatest risk of exposure to UV radiation. However, other people in the workplace may also be exposed to UV radiation if they are present during the welding process and there are insufficient control measures in place.

When assessing the risk to employees, the following factors should be considered by employers:

• type of electric arc welding being undertaken and the material being welded. For example:
  1. Gas Metal Arc Welding (GMAW) emits the most radiation of all the welding processes.
  2. Aluminium increases radiation exposure compared to other metals, such as stainless steel or iron.
  3. Argon, as a shielding gas, increases radiation exposure when compared with helium or 100% carbon dioxide used as a shielding gas.
• intensity of the welding currents used - more radiation is emitted at higher welding currents than at lower welding currents
• distance between the welder and other persons, including employees or visitors to the site, who are not involved in the welding processes – even maintaining a distance of 5m from the welding process could still expose a person to a radiation hazard
• duration and frequency of exposure to the welding task – prolonged exposure increases the risk of health effects from exposure to radiation
• proximity of reflective surfaces
• operator's welding posture or position

Employers must control the risks to health from exposure to UV radiation

Under the Occupational Health and Safety Act 2004, an employer must, so far as is reasonably practicable, provide and maintain for employees of the employer a working environment that is safe and without risks to health. 

To do this, an employer must eliminate risks to health and safety so far as is reasonably practicable.

If it is not reasonably practicable to eliminate risks then the risks must be reduced, so far as reasonably practicable. This can be achieved by effectively applying the hierarchy of control:

1. elimination
2. substitution
3. isolation / engineering
4. administrative controls
5. Personal Protective Equipment

Hierarchy of control

Employers must use the hierarchy of control as a system for controlling risks in the workplace.

Following the hierarchy of controls, measures to eliminate or reduce the risk of exposure to UV radiation, so far as reasonably practicable, may include:

Ensure protection against welding fumes

Ventilation controls and/or respiratory protection is required to protect against welding fumes.