September 26, 2002
According to OSHA, it is estimated that 9 out of 10 occupational related eye injuries could be avoided through the use of proper safety equipment. OSHA's 1910.133 places the responsibility for eye safety squarely on the shoulders of the employer. Goggles, spectacles and face shields protect the eyes and face from impact from flying particles, hot sparks, liquid chemicals and vapors. In addition, protective eyewear constructed with special shaded lenses rated from 1-15 offer protection against injurious light radiation and glare.
Common workplace hazards that metal fabricators encounter can pose a danger to their eyes. According to the U.S. Occupational Safety and Health Administration (OSHA, www.osha.gov), an estimated nine out of 10 occupation-related eye injuries can be prevented with the use of proper safety equipment. Too often fabricators do not know what kind of protective equipment is required for their jobs. Wearing the wrong type of personal protection accounts for more than 40 percent of workers' injuries.
Today's protective eyewear comes in many configurations--prescription and nonprescription spectacles, goggles, and face shields. Spectacles are the most commonly used protective eyewear. Regular prescription glasses should not be used as safety spectacles, but they can be worn underneath qualified safety eyewear.
OSHA standard 1910.133(a) places the responsibility for eye safety squarely on the shoulders of the employer: "The employer shall ensure that each affected employee uses appropriate eye or face protection when exposed to eye or face hazards from flying particles, molten metal, liquid chemicals, acids or caustic liquids, chemical gases or vapors, or potentially injurious light radiation." OSHA directs wearers to American National Standards Institute (ANSI, www.ansi.org) standard Z87.1-1989 to select eyewear for specific hazards. Approved eyewear will be stamped "Z87" in the temple area.
The remainder of this article discusses what to look for in safety eyewear to protect fabricators against these hazards.
Most of today's safety lenses are optical-grade polycarbonate, which is significantly more impact-resistant than its heat-treated glass predecessor. Goggles should be worn as the primary eye protection against impact in grinding, sawing, drilling, fastening, and sanding applications.
Side protection is required with spectacles. Detachable clip-on or slide-on side shields meet the requirement. Some manufacturers have eliminated cumbersome and separate side shields by incorporating them into the frame's temple pieces, which gives the wearer a greater field of vision. For severe exposure, face shields provide secondary impact protection.
In Canada and Europe protective eyewear is subject to performance tests, especially impact resistance. In the U.S. eyewear must be a minimum thickness; however, ANSI is expected to adopt impact resistance performance criteria in early 2003. The revised standard will become more performance-oriented by eliminating lens thickness requirements for most products that are capable of meeting the established high-mass and high-velocity impact tests.
Face shields, goggles, and spectacles with side shields protect the face from hot sparks in welding and other applications. To protect from molten metal splash, face shields can be worn over goggles. Screen and reflective face shields guard against high-temperature exposure.
Goggles, both eyecup and cover types, are the primary eye protection against chemical splash. For severe exposure, face shields provide secondary protection. Special-purpose goggles guard against irritating mists.
Protective eyewear constructed with special shaded lenses is required to offer sufficient protection against ultraviolet (UV) and infrared radiation (IR) in laser and welding applications. A shaded lens has an optical density (OD) rating of 1 to 15, which indicates the darkness of the lens and how much IR it will protect against. The higher the OD, the greater the protection needed (see Figure 1).
The type of laser and its power and wavelength are key shade selection factors.
Light cutting or brazing requires the use of a shade 3 to 6 lens. Arc welding requires a minimum OD of 10 to 14. The ANSI standard specifies that the lenses must be marked with the shade number in order to be approved.
Although face shields, visors, and welding helmets offer secondary protection against welding light and electric arc, they are not primary eye protection. Safety spectacles always must be worn under them. Tinted and shade lenses are not filter lenses unless they are identified as such.
Safety spectacles and goggles have come a long way. However, it doesn't matter how well eye protection is designed if it isn't worn.According to a study by the Industrial Safety Equipment Association (ISEA, www.safetyequipment.org), 68 percent of all employees who should be using protective eyewear do not. Why not?
The main reason cited was that employers do not require or enforce protective eyewear use. The research reveals that only two-thirds of employees who sustained eye injuries in the U.S. said protective eyewear was provided at their site. Other barriers cited by the 215 respondents included a lack of style or comfort, job performance interference, expense, lack of information, apathy, and inattentiveness.
The more comfortable and stylish a product is, the more likely a person is to wear it. When people complain about eyewear comfort, it is probably related to weight or fit. Spectacles that have polycarbonate lenses weigh less because this plastic material is 50 percent lighter than glass.
As previously stated, ANSI is expected to revise its performance criteria in early 2003. This means U.S. manufacturers will be able to produce lighter-weight eyewear that meets or exceeds standards yet is more comfortable for wearers—thinner lenses, lighter frames.Fit is critical. According to OSHA, "Particular care should be taken in fitting devices for eye protection against dust and chemical splash to ensure that the devices are sealed to the face."
Many styles and sizes of eyewear are available today, and almost any facial contour can be accommodated. Once the eyewear is selected, it often is possible to customize the fit by changing the tilt of the spectacle or adjusting the length of the temples to prevent slippage.
Eyewear with indirect ventilation and anti-fog coatings prevent fogging and provide comfort and improved visibility.
More fashionable lenses and a departure from the traditional round frames and lenses in the 1980s initiated some dramatic design changes throughout the 1990s, culminating in the current highly curved wraparound versions that more closely resemble designer and sports glasses.
Safety spectacles with inferior optical quality can cause distorted or blurred vision and poor depth perception that can lead to headaches, nausea, and fatigue. Protective eyewear produced with no lens distortion--perfect optics--can encourage compliance. Optical-grade polycarbonate plastic can be molded with a high degree of optical clarity and is free of the distortions commonly found in heat-treated lenses.
Coatings are permanently bonded to anti-fog and anti-scratch lenses. Indoor-outdoor versions adjust to light changes to allow movement from the yard to the warehouse. Safety glasses with retainers permit the eye protection to be removed yet kept close.
Employers are required to make eye protection readily available to employees, train them in its proper use, and implement an effective program to ensure that eye protection is being used. It is a good idea to offer employees a choice of compliant eye protection.Employees need to recognize that no workplace is free from eye hazards. It makes sense to wear eye protection on the job. OSHA regulations offer guidance, but employees have to assume responsibility for protecting themselves, because, ultimately, the consequences of eye injuries are borne by the employee.