Preventing Eye Injuries When Welding
Most are reversible, but permanent visual impairment can occur.
Eye
injuries account for one-quarter of all welding injuries, making them
by far the most common injury for welders, according to research from
the Liberty Mutual Research Institute for Safety. Those most at risk
for welding-related eye injuries are workers in industries that produce
industrial and commercial machinery, computer equipment, and fabricated
metal products.
The best way to control eye injuries is also the most simple: proper
selection and use of eye protection. Helmets alone do not offer enough
protection. Welders should wear goggles or safety glasses with
sideshields that comply with ANSI Z87.1 under welding helmets and
always wear goggles or other suitable eye protection when gas welding
or oxygen cutting. Goggles provide better protection than safety
glasses from impact, dust, and radiation hazards.
Unfortunately, workers don't always wear goggles or safety glasses
because of low perception of risk, poorly maintained lenses,
discomfort, having to wear prescription lenses underneath, and vanity.
It is important to stress to workers that welding-related eye injuries
come from a number of sources, including:
- mechanical damage from being struck by flying particles and chipped slag;
- radiation and photochemical burns from ultraviolet radiation (UVR), infrared radiation, and intense blue light; and
- irritation and chemical burns from fumes and chemicals.
To help in reducing eye injuries, you should educate workers about
all of the dangers they face and should implement an eye protection
plan that outlines proper welding behavior.
Cumulative Damage Risks
All of the most common types of welding (shielded metal-arc or
stick welding, gas metal-arc welding, and oxyacetylene welding) produce
potentially harmful ultraviolet, infrared, and visible spectrum
radiation. Damage from ultraviolet light can occur very quickly.
Normally absorbed in the cornea and lens of the eye, ultraviolet
radiation (UVR) often causes arc eye or arc flash, a very painful but
seldom permanent injury that is characterized by eye swelling, tearing,
and pain.
While most welding-related eye injuries are reversible, with more
than half of injured workers returning to work in less than two days
and 95 percent in less than seven days, some eye injuries are
irreversible and permanent visual impairment occurs. This is especially
true with infrared and visible spectrum (bright light) radiation. Both
can penetrate through to the retina and--although this is rare--can
cause permanent retinal damage, including cataracts, diminished visual
acuity, and higher sensitivity to light and glare.
And welders are not the only workers at risk. While the welding arc
is the principal source of UVR, other workers in the area can sustain
eye damage from the radiation as far as 50 feet away from UVR
reflecting off shiny surfaces, concrete, or unpainted metals. To
counteract this reflection, you should install shielding curtains where
practical or require that all workers in the area wear appropriate eye
protection.
Beyond the immediate impact from radiation, welding also exposes
workers to cumulative adverse effects that appear over time. A study in
Denmark of 217 welders showed yellow spots on the white part of the eye
in 57 percent of the welders and degeneration of the thin membrane over
the eyeball in 24 percent. Researchers also found corneal scarring in
about half of the subjects.
Yet, despite the insidious damage radiation can cause, molten and
cold metal particles striking the eye are still the most common sources
of eye injuries.
Eye Protection Goes Beyond the Helmet
Helmets and protective clothing shield welders from "sunburn" and
"welder's flash," but with the majority of their work performed with
the helmet up, welders also need to wear goggles or safety glasses with
sideshields. These will protect them from particles sent flying during
pre-job grinding, hammering, and power chipping that make it past the
helmet's protective front.
For most jobs, eye protection that conforms to ANSI Z87.1 is
sufficient. However, shields or goggles with shade ratings of 3-8
should be worn for gas welding. For arc welding, safety glasses should
be worn under shields.
Some guidelines and safety warnings for welding suggest workers
should not wear contact lenses, even though there does not appear to be
any research that would support such a recommendation. In fact, the
National Safety Council, the American Welding Society, and the FDA all
acknowledge that wearing contact lenses while welding is safe and even
can provide UV protection. The only caveat is that contact lenses
should not be used as eye protection in place of safety glasses or goggles.
Once the proper goggles/shields are in hand, you can turn your
attention to the type of helmet best suited for the job. Published
tables are available through the welding helmet vendor or the Internet,
which can help you determine the most appropriate lens shade based on
the type of welding and the amperage of the welding unit. It is a
common misconception that a darker shade provides more protection
against UV. Properly maintained welding helmets, regardless of shade,
provide 100 percent protection against UV, according to the
manufacturers.
Arc welding helmets can be fixed shade or variable shade. Typically,
fixed shade helmets are best for daily jobs that require the same type
of welding at the same current levels, and variable helmets are best
for workers with variable welding tasks. Helmet shades come in a range
of darkness levels, rated from 9 to 14 with 14 being darkest, which
adjust manually or automatically, depending on the helmet. To determine
the best helmet for the job, select a lens shade that provides
comfortable and accurate viewing of the "puddle" to ensure a quality
weld.
Now that your workers have the right eye protection for the job, it
is time to implement an ongoing eye protection plan that ensures they
use the equipment properly.
Eye Protection Plan
An effective overall eye protection program for welding covers these:
- Review and plan the area where the welding will take place.
Note that considerations of fire and explosion are particularly
important, and a welding permit may be required.
- Make sure the immediate area is free of any tripping hazards; welders have no peripheral vision with the helmet down.
- Isolate the area with curtains to absorb radiation if workers other than the welder will be in the area.
- Identify and cover any highly reflective surfaces.
- Wear the appropriate eye protection selected on the basis of type
of welding and visual requirements of the task. If using a helmet, be
sure to wear safety glasses with sideshields under the helmet.
- Others in the area should also wear eye protection, especially if chipping hammers are used.
- Keep eye protection in good condition.
- Wear clothing and gloves that protect against UV radiation.
- Anyone experiencing a flash burn should seek medical treatment to
avoid infection, which increases the potential for permanent injury.
- Educate welders and other personnel on the hazards of welding and the importance of seeking treatment for flash burns.
By implementing and enforcing an eye protection program, you can
help send your workers home at the end of the day in the same condition
in which they arrived in the morning.
This article appeared in the February 2007 issue of Occupational Health & Safety.
This article originally appeared in the February 2007 issue of Occupational Health & Safety.