While there were relatively few changes to eyewear used to protect from optical radiation, chemical splash, dust or heat, there are some changes to the impact resistance requirements for non-plano (prescription) lenses.
"The most significant change to the standard is the separation into two impact categories," said Daniel Torgersen, technical director at the Optical Laboratories Association (OLA) and vice chair of the ANSI Z-87 committee. "When safety directors are conducting their job hazard analysis, it gives them greater latitude to say, 'This worker doesn't need to wear high impact-level glasses, but another worker, who is doing a grinding operation, has a high potential exposure to impact and should wear high impact-level safety glasses.'"
According to Torgersen, the two levels of performance for non-plano lenses are Basic Impact and High Impact, and the new standard requires prescription safety frames meet the High Impact test requirement with 2.0 mm lenses.
The standard also requires manufacturers to use new ANSI testing requirements. These requirements include:
High-impact Level Prescription Lenses
- Lenses must not be less than 2.0 mm thick.
- Lenses passing high-impact test requirement will include "+" mark.
- Marking of high-impact lenses by manufacturer with a trademark will include the trademark and the "+". For example, if the lens is trademarked with a "W", then the mark would look like this: W+
- Lens shades and tints will continue to be marked with an "S" for special purposes, the shade number and a "V" for photochromic.
- Lenses will be tested to the high-velocity impact test. The lenses will be mounted on a test holder (150ft/s) and three lenses shall be tested. Lenses fail the test if there is: any posterior displacement of the lens completely through the test holder; any fracture of the lens; any detachment of a portion of the lens from its inner surface; or any full thickness penetration of a lens. If all test lenses pass, then any non-plano lens of the same or greater thickness at its thinnest point, which is made by the same manufacturer from the same material with the same coatings can bear the "+" mark.
Basic-impact Level Prescription Lenses
- Lenses shall be a minimum of 3.0 mm thick except for those lenses having a plus power of 3.00D or greater, which shall have a minimum thickness of 2.5 mm (no change from the 1989 standard).
- 100 percent of glass lenses shall be tested. Plastic lenses can be statistically sampled.
- Basic impact lenses will not be marked with a "+"
- Protectors with basic impact lenses will be delivered to the wearer bearing a warning label indicating the protector only meets the Basic Impact Standard.
- Warning labels are available from the OLA. Employees subjected to high impact may not be adequately protected if wearing lenses tested only for basic impact.
- All prescription safety frames must meet high-velocity and high-mass impact-resistance tests while retaining the lenses.
- The frames will be marked with Z87-2.
- All frames marked with Z87-2 can be used for basic-impact lenses and high-impact lenses.
- Lateral protection shall be assessed using a rotation point 10 mm behind the corneal vertex, which means that shields must now provide more coverage.
Torgersen explained that the materials used to make the high impact level lenses offer more protection at a lighter weight than the materials used to make the basic impact-level lenses, which explains why the high impact-level lenses can be as thin as 2.0 mm.
"One of the issues we tried to address was the objection of some workers to safety glasses. They complained some of the glasses were heavy and uncomfortable and ugly," said Torgersen. "Now, with thinner lenses, safety glasses are more comfortable and don't look so thick or ugly. And if they are more comfortable, then workers will wear them."