Are Your Safety Glasses Tough Enough?

April 1, 1998
ANSI Z87.1 committee debates whether a more stringent standard is needed for safety eyewear.

Dr. Paul Vinger thought he knew safety eyewear very well. A clinical professor of ophthalmology at Tufts University School of Medicine and a member of the American National Standards Institute's (ANSI) Z87.1 committee on eye and face protection, Vinger has conducted several experiments on protective eyewear and recently published an article on the subject in the Journal of the American Medical Association.

But it wasn't until he decided to test the faceshield he used for carpentry work that reality hit home. After a simple test, the shield shattered, as did his illusion that the equipment would prevent a flying sliver of wood from damaging his eyes.

"I'm in the field and I didn't know I wasn't protected," he said. "Right now, there's no clear way to know whether you are fully protected. You should know if your goggles will shatter on impact. This is a big problem."

Finding an Answer

The question seems a simple one -- how can you ensure that the level of protection afforded by eyewear and faceshields is adequate for the job at hand?

Yet the answer has eluded the ANSI committee for years and has left many on the committee bitter as they move toward a planned update of the ANSI Z87.1-1989 standard, "Practice for Occupational and Educational Eye and Face Protection," later this year.

The sticking point is the designation of a baseline high-impact test for safety eyewear. The current standard covers spectacles, faceshields, goggles, welding helmets and special-purpose lenses.

The standard calls for safety eyewear to be tested in several ways. Removable lenses must pass a drop ball impact test in which a 24.5 millimeter diameter steel ball is dropped from 127 centimeters.

Eyewear frames, on the other hand, must pass a high-mass and high-velocity test in which a 500 gram projectile is dropped onto the frame from a height of 130 centimeters and a 6.35 millimeter diameter steel ball traveling at a velocity of 45.7 meters per second hits the lens and does not damage the frame.

Even though most eyewear does a good job protecting workers, the current standard does not include a high-velocity, high-mass, high-impact test many believe is necessary for safety lenses. The proposal debated by the committee would make the high-mass, high-velocity impact test the standard all lenses must meet for ANSI Z87.1 certification. Without such a test, say its proponents, workers cannot be sure that all safety eyewear will protect them from impacts such as kickback from a chisel or a spring bouncing up into the eye.

At press time, however, the majority of the committee appears to favor retaining the basic drop ball impact test for lenses. The more ambitious high-mass, high-velocity test would remain in place for all frames.

Polycarbonate and Glass

In 1995, the Bureau of Labor Statistics estimates, more than 700,000 occupational eye injuries resulted in lost workdays.

"Eye injuries account for 5 to 8 percent of all workplace injuries and account for about 4 percent of all lost workday injuries," said Larry Jackson, ANSI committee member and director of safety research, acute eye injury work group leader at the National Institute for Occupational Safety and Health. "Foreign bodies striking the eye at high impact are the most common form of injuries."

Nobody denies that eye injuries are a problem. At issue is how to provide adequate protection in a variety of scenarios without eliminating a portion of the products already on the market.

A few years ago, the Industrial Safety Equipment Association (ISEA), a trade association representing safety equipment manufacturers, submitted to the ANSI committee a proposal that all safety eyewear meet a benchmark test for high-impact resistance. The proposal is supported by several members, who believe that since these hazards are most common, protecting against them should be the focal point of the standard.

"We basically want the high-mass, high-velocity impact test to become the standard," said Dan Shipp, ISEA president and an ANSI committee member. "Most eyewear will meet the current standard requirements and we think the standard could provide more protection."

The problem is that while polycarbonate -- the material most commonly used in protective eyewear -- will pass the proposed test, other materials, such as glass and allyn resin plastic and high-index plastic, may not.

"When I started in this field 20 years ago, the standard was glass," said Alan Sankpill, committee member and president of U.S. Safety. "Now the standard is polycarbonate. We ought to recognize and use as a benchmark for performance the product that is most commonly used."

Opponents of the proposal say glass provides better optics and better protection in some environments.

"The problem with the ISEA proposal is it would be a strong predilection against glass," said Jackson Stroud, an alternative committee member who represents the American Ceramic Society. "Polycarbonate is the only material suitable under the ISEA proposal and polycarbonate doesn't really give the best vision in certain circumstances."

Stroud compared prescription polycarbonate eyewear to "looking through a pair of cheap toy binoculars." Because polycarbonate scratches easily, it is not ideal in dusty environments, Stroud said. It is also less effective in chemical splash situations where it has a tendency to cloud vision, he said.

It is possible to strengthen and laminate glass, as is done with car windshields, but Stroud said the cost is prohibitive, and several attempts to market these types of eyewear failed.

"People tried several things with glass or glass and plastic blends and there's nothing on the market now," he said. "Safety eyewear is a very competitive field where cost is a measured consideration."

ISEA's Shipp said he believes the market would adjust to the change, especially if required to do so.

"We believe that safety should be the priority here," he said. "We believe the committee should produce a standard that will provide maximum protection and that's not what is going to happen. The American Ceramic Society is a very active participant on the committee, almost a dominant force, and they don't want it."

Possible Compromise

Committee chairman Tod W. Turriff, vice president of program and information services for Prevent Blindness America, said it is unlikely the testing requirements will change in the new ANSI Z87.1 standard he hopes to release later this year.

However, he hasn't completely given up on a compromise and said the committee may decide to have a two-tiered system in which products that meet the high-impact test receive an ANSI "plus" rating. Products in this category would not only pass the basic ANSI tests for safety, but also additional high-mass, high-velocity impact tests.

The compromise would enable workers concerned about impact injuries to make more informed purchases, Turriff said. Some committee members are concerned, however, that manufacturers may begin over-labeling products and confuse purchasers.

"People are concerned that we'll end up with all sorts of labels on a product," said Turriff. "They don't want things to become that complicated."

Though it is still being debated, many committee members believe the ANSI "plus" rating will make it through the process.

"We are still having major disagreements about it...but I believe it will be in the standard," said David de Vries, of the American Society of Safety Engineers, the ANSI Z87.1 committee Secretariat organization.

A requirement considered unlikely to make it into the revision is that all safety eyewear include side protection. Advocates of side protection include Vinger, who believes the added protection will prevent eye injuries.

"It was discussed, but the committee decided that it wasn't absolutely necessary in all situations," said de Vries. "It's pretty much dead right now."

Also dropped after much discussion was a provision to have a safety eyewear certification system similar to the respirator certification program run by NIOSH.

"It wasn't even close," said Sankpill of the committee vote. "ISEA was a proponent and we thought it was the right thing to do, but most of the committee didn't agree."

Sankpill said most members felt there were too many unresolved issues -- such as who would conduct the certification program -- that needed to be settled.

New Provisions

According to de Vries, several important changes are likely to be included in the revision.

"We will define and address auto-darkening welding filters," said De Vries. "We will specify how fast the filters must change and how dark they must become within a certain time frame."

The committee also wants to simplify the standard's language and make it more accessible to end users.

"We have grappled with putting it on the Web, but there are copyright issues there," said de Vries. "We want more people to have access -- an ANSI standard that isn't read, that isn't accessible to employers, doesn't do much good."

Committee chairman Turriff said he believes certain issues, such as the high-mass, high-velocity impact test, will be debated for years to come.

Turriff said the committee may decide to break the one standard into several standards in the future.

"Basically, I think we set the stage for next time," said Turriff. "The bottom line is there are a lot of variables when you're dealing with glasses, goggles, faceshields and welding equipment. We may have to separate them so we can deal with all the issues more effectively."

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