Electromagnetic energy given off by an arc or flame can injure workers’ eyes and is commonly referred to as raidant energy or light radiation. The intensity of light or radiant energy produced by welding, cutting or brazing operations varies according to the number of factors including the tasks producing the light, the electrode size and the arc current.
Certain types of UV radiation can produce an injury to the surface and mucous membrane (conjunctiva) of the eye called “arc eye,” “welders’ eye” or “flash burn.” The symptoms include:
- pain – ranging from a mild feeling of pressure in the eyes to intense pain in severe instances
- tearing and reddening of the eye and membranes around the eye
- sensation of “sand in the eye” or abnormal sensitivity to light
- inability to look at light sources (photophobia)
The amount of time required to cause these effects depends on several factors such as the intensity of the radiation, the distance from the welding arc, the angle at which the radiation enters the eye, and type of eye protection that the welder or bystander is using. However, exposure to just a few seconds of intense UV light can cause arc eye. These symptoms may not be felt until several hours after exposure. Long-term exposure to UV light can produce cataracts in some persons.
For protection from radiant energy, workers must use personal protective equipment, such as safety glasses, goggles, welding helmets or welding face shields. This equipment must have filters lenses with a shafe number that provides the appropriate level of protection. A shade number indicates the intensity of light radiation that is allowed to pass through a filter to one’s eyes. Therefore the higher the shade number, the darker the filter and the less light radiation that will pass through the lens.