Impact Resistance: Protective Eyewear
A look at the standards, and how they compare
By Philip M. Johnson, Director of Technology, Sperian Eye & Face Protection, Inc.
Background
Historically, impact resistance has been regulated by agencies like FDA since the early 1970s for products furnished through medical and retail channels, such as sunglasses and prescription eyewear. It is simply a drop ball test where a 5/8 inch steel ball is dropped free-fall through a tube from a height of 50 inches onto the lens surface.
For protective eyewear meant for industrial or occupational use, the governing document is ANSI Z87.1, and it has been in existence, through several iterations, for almost 40 years. OSHA in its regulations (see CFR 1910.133) specifically cites Z87.1 as the minimum performance requirement for protective eyewear, effectively giving it the weight of law. Where a hazard assessment in the workplace indicates that eye/face protection is needed, such protection must be provided, and it must comply with this ANSI standard.
Selecting eyewear that meets or exceeds a variety of standards will afford reliable protection against hazards that are present in the workplace.
Originally, Z87.1 also specified a drop-ball test with the difference being an increase in the ball diameter to 1 inch for most lens types. Glass lenses at least 3mm (1/8 inch) thick and properly treated, could meet this test. Plastic lenses also were required to pass a penetration test wherein a weighted needle is dropped 50 inches onto the product. The lens cannot fracture or be pierced.
In 1989, the standard was upgraded to add elevated impact and lens retention tests in addition to the basic drop ball requirement. Technology, articularly the advent of polycarbonate plastic as a high performance lens material, drove this change. It recognized that more robust products could be designed which would be a benefit to those needing to wear protective eyewear where significant impact hazards existed.
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