Safety glasses are divided into low impact and high impact ratings. High impact rated glasses are highly recommended, even for home use, and are required in many occupations including machinists, carpenters, and millwrights.
When working with safety glasses, it is important to know the standards. The last thing any employee wants is to work in a hazardous environment using safety gear that will not perform if an accident occurs. Safety eyewear includes faceshields, sideshields, goggles, and prescription or non prescription safety glasses. Non prescription safety glasses are usually made of light weight polycarbonate, and have a “wrap around” style. They often sit close to the head, cost less, and are available from most hardware and home supply stores. Non prescription safety eyewear will be permanently marked with the manufacturer’s trademark, as well as “Z87” for basic impact or “Z87+” for high impact. Prescription safety lenses are purchased from an eye doctor. If these lenses pass a high impact rating, a “+” will be seen next to the manufacturer’s trademark, as well as “Z87-2” on the inside of the temples. Bi focal safety lenses are useful when a prescription is only needed to read, not to see.
How do they test product management leader salary safety eyewear?
Safety eyewear must undergo what is known as the “drop ball” test. A steel ball is dropped from a certain height, and the lenses must not crack, chip, or break in any way. Every lens must be tested before being rated. If a lens passes the drop ball test it can be rated as a basic impact lens. In order to obtain a high impact rating, steel balls are not dropped but instead shot at the lens at a speed of 150 ft. per second.
The frames for both high impact lenses and basic impact lenses must undergo a similar battery of tests. Safety frames must pass durability tests like flammability-resistance and corrosion resistance. When it comes to impact testing, safety frames undergo both high mass and high velocity impact tests. In high mass testing, a one inch steel ball weighing 17.6 ounces is dropped through a tube from a height of 50 inches technology transfer cell therapy onto a set of frames containing lenses. No parts of the lenses can detach from the frames or the test is failed. In the high velocity impact test, a smaller quarter inch steel ball is shot at the lens and frame from a distance of just under 10 inches, at a velocity of one hundred fifty feet per second. This test is performed at different angles and positions, and must meet the same criteria as the high mass test.
