Eyewear producers address reluctance to wear goggles

Regular use of

protective eyewear, backed up by

engineering and

administrative controls, is still the best means of preventing laser-based accidents in the workplace.

Karl Hejlik

As the use of lasers becomes more widespread, there is increased need for protective measures to reduce the likelihood of laser-related accidents. Safety professionals and researchers have made great strides in recent years to minimize the risks of working with such useful but powerful tools.

The most common type of injury caused by a laser involves beam exposure to the eye. In 1988, for example, a technician aligning a 10-W argon-ion laser was accidentally exposed to laser light in his left eye. Two lesions of the retina resulted, causing a permanent blind spot. When the accident occurred, the technician was not wearing eye protection because his goggles had fogged up, rendering them useless, according to Rockwell Laser Industries (RLI; Cinncinnati, OH), which maintains a database of laser-related incidents.

Fortunately this is the kind of product shortcoming researchers have been able to remedy. Uvex Safety (Smithfield, RI), a manufacturer of laser eye protection, recently introduced an anti-fog coating that allows workers to move back and forth between radically different environments, including air-conditioned laboratories and freezers to factory floors and outdoor loading docks, without removing their eye protection. Had this breakthrough been available 10 years ago, the technician would likely have full vision today.

This example also illustrates another trend in eye injuries. "Accidents often happen when people are performing alignment procedures," says Mark McLear, Uvex`s national sales manager for laser products. "The purpose of laser eyewear is to block the wavelength. Well, that means you can`t see the beam you are trying to align, so people just take [their goggles] off."

In response, Uvex is working to design alignment eyewear that will stop enough of the beam to prevent injury but allow enough through so the beam is visible, essentially turning a Class 4 laser into a Class 2, for example. Currently, these products are available only for visible, continuous-wave (CW) lasers and are power and wavelength specific, but Uvex researchers see great potential for this kind of product, McLear says.

Medical applications of lasers pose unique hazards regarding protective eyewear. Tattoo removal, for example, often requires different wavelengths to remove different colors from the skin. While it would be easy to develop eyewear to block all the wavelengths used, such a product might also block every wavelength in between, making it difficult or impossible to see. Researchers at Glendale Protective Technologies (Lakeland, FL) are exploring possibilities of making eyewear that would block out multiple narrow groupings of wavelengths while allowing other (visible) wavelengths to pass through. "Whenever you have a situation where you have to change eyewear every time you change wavelength, there is a possibility that someone will forget or grab the wrong pair," explains John Clark, manager of laser and specialty products for Glendale. "We want to make it easier on the doctor or nurse using the lasers."

There is an especially strong need for more laser eye protection in medicine, Clark notes. "In industry and R&D, the lasers are often enclosed and stationary, but in medicine, it is often a fiberoptic delivery system and the doctor is holding it. Now, you have an unstable source from which that beam originates. Everyone in that room should be wearing eye protection."

According to RLI, injuries have also resulted from the poor fit of laser eye protection. In 1979, a production worker received a permanent retinal burn when his goggles slid up as he bent over working with an Nd:YAG laser. Similarly, a technician suffered a lesion of the fovea in 1992 from a ruby laser. The technician reported that a poor head strap allowed laser radiation to "leak" in from the sides.

Fortunately, most laser protective eyewear on the market today is designed to avoid slipping, and many have lenses that wrap around, providing protection from the side. The most recent designs, for example, not only offer side protection but are frameless for maximum field of view and are optically correct. "You have to make all this stuff just like you would prescription lenses," McLear says. "Some goggles out there are optically correct only in the center. It`s important to make the entire lens correct."

Nobody likes goggles

All of these factors contribute to eye-related injuries, but the single most important reason such accidents happen is that people simply choose not to wear safety goggles, referred to in the industry as personal protective equipment or PPE. "Historically, a goggle has been the traditional device. This is changing considerably because we have learned that people simply will not wear goggles," Clark says.

Glendale is working on de signing PPE products that people will want to wear. "When you keep these things on for a while, they get hot and uncomfortable," Clark says. "So, the pro ducts we`re working on are more spectacle-type eyewear with an Oakley-like frame. They`re lightweight and comfortable, with a wider field of vision."

Uvex agrees that eyewear designers need to consider what makes someone want to wear their products. "Fashion, believe it or not, is a big component of that," McLear says. To this end, protective eyewear frames now come in multiple styles and colors. They also offer comforts like duo-flex and cushioned temples and can fit over prescription glasses (see photo on p. 149).

Despite these efforts at user-friendly eyewear, however, the Occupational Safety and Health Administration (OSHA) documents more than 400 violations (both laser-related and non-laser-related) a year of its standard 1910.133, which covers the use of PPE to protect the eyes and face. With laser use skyrocketing, it is impossible to say what impact advances in eyewear are making on accidents or PPE compliance, but it is clear that many, many people are still working with lasers without proper protection for their eyes.

"Even though eyewear manufacturers are making great strides forward, you will always have troubles with PPE," states Gordon Miller, the laser safety officer for Lawrence Livermore National Laboratory (LLNL; Livermore, CA). "No matter how you cut it, PPE is uncomfortable. You`re wearing something, and, boy, do you know it." It`s an interesting statement from a laser safety officer, whose responsibilities include getting employees to wear PPE.

Three-way approach to protection

To do this, Miller has divided safety procedures into three categories of control: engineering, administrative, and personal protection (see table, p. 150). He believes that wherever possible, engineering and then administrative controls should be used rather than relying on PPE. "With a good engineering control, the operator has to do little or nothing at all. It`s like a 401K retirement plan--it`s just there," he says.

Miller practices what he preaches at LLNL. Beam enclosures, interlocks, and similar measures are his organization`s first line of defense. "With our best engineering controls, the most you have to do is pull a switch, or better yet, the control comes on automatically with the laser," he says.

Lawrence Livermore also employs extensive administrative controls, including flashing lights, signs, and an intercom system. The signs and warnings are made more visible with LED displays. "A typical laboratory entrance here has two types of displays--one is the ANSI (American National Standards Institute) sign and the other is an electronic display," Miller says. A light outside each lab notifies anyone entering if lasers are operating--flashing yellow means stay out. By interconnecting rooms with speakers and microphones, no one has to enter a workspace just to talk to another worker there. Thus, fewer people enter a potentially hazardous area.

Ensuring employee compliance

Despite his preference for these kinds of measures, Miller admits that "any hazard has to be resolved using a combination of engineering, administrative, and PPE controls." Gaining employee compliance regarding protective equipment is critical to a company. In 1992, a university found out just how critical when it was sued by a research assistant who injured both eyes using a laser. The assistant did not wear the available eyewear and ignored the university`s policy that supervision was required to operate the lasers, claiming instead that the research professor did not wear eye protection either and that the safety protocols were simply "paper policies." The student sued the university for $39 million and collected an out-of-court settlement, reportedly $1 million.

So, how does a laser safety officer ensure that his or her organization`s regulations regarding personal protective equipment are not simply paper policies? "Talk to the laser users," Miller advises. "You have to negotiate what the controls are going to be. You should use ANSI Z136.1 `For the Safe Use of Lasers` as a starting point, but you have to remember that it`s the operators who are going to make it work or not work."

If the operators feel that controls are too stringent, they are likely to simply ignore them. "Sometimes safety professionals and laser safety officers, who aren`t working with the lasers day in and day out, can cook up something that is wildly unpractical," Miller warns. It is also a good idea to communicate to the users the information they need most. For example, instead of signs that simply display the power of a laser, signs at LLNL also tell the user the required optical density of the appropriate eyewear.

As lasers become increasingly more prevalent in the workplace, the need for personal protective equipment that laser users will actually wear also increases, as does the need to require its use to prevent laser-related accidents. Promoting laser safety is one of the main goals of the Laser Institute of America. For more information about PPE or ANSI safety standards, call (800) 34-LASER or visit the LIA Website at www.laserinstitute.org. o

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Eyewear manufacturers are trying to make products people will be more willing to wear. Safety glasses now come in a wide variety of fashionable lens and frame styles and colors.

Hierarchy of laser-safety controls for hazardous environments