Safety Glasses, Goggles and Face Shields–Know What to Use When

Many of us have probably heard the horror stories or seen the gruesome photos of nails stuck in the eyes of employees and other such grisly accidents. Many research laboratory professionals are familiar with basic eye protection, but did you know that about 2,000 eye injuries occur on the job every day?¹ And did you ever stop to think that even “minor” eye injuries can cause long-term vision problems and suffering? For example, a simple scratch from a fine dust particle can lead to corneal erosion and lifetime recurring pain. Have you ever considered that simply passing through an area can result in an eye injury? Or, that workers around and next to you may be generating the hazard? Consider these examples compiled by the American Industrial Hygiene Association’s Laboratory Health and Safety Committee:

Case #1: A laboratory worker was pouring chloroform though a gel column inside a fume hood. Due to incorrect equipment configuration, pressure built up in the column and caused the glassware at the top of the column to break, spraying chloroform out of the hood, onto the worker’s face, eyes and clothing.

The laboratory worker was wearing safety glasses, rather than chemical splash goggles. The chloroform seeped through the opening at the top of the glasses and burned both eyes. The lenses of the safety glasses were partially dissolved by the chloroform.

Case #2: An undergraduate student was working on an experiment in a hood. When she removed the reflux condenser, the solution bumped, splashing her face and chest. Despite the fact that she was wearing goggles, the solution managed to go past the seal and into her eyes.

Many injuries happen every day in construction and manufacturing. However, research laboratories have their own unique eye hazards and some that are not so unique. So, take a few minutes and answer these questions:

• What are the potential eye hazards in my laboratory? Or in my facility?
• What are the most dangerous jobs (either in terms of task or tools used)?
• Where are the most hazardous areas for eye safety?
• What type of eye protection is appropriate for these jobs or areas?
• Are other preventative measures available?

Start at the beginning

As with every safety program we discuss, prevention is the key. Look at your answers to the questions above and start by determining how you can eliminate eye hazards at your site. First, develop an eye safety strategy based on job hazard analysis. This should incorporate engineering solutions, administrative solutions and proper eye protection. Engineering controls are best and, ideally, implemented first. They include guards to prevent particles and splashes from being dispersed, hoods to capture dust particles and vapors and other such equipment. Administrative controls include setting up hazard areas as off-limits and locating passageways and thoroughfares away from active work areas. The last piece of the puzzle, proper eye protection, is the focus of this article. Keep reading to learn more on the basic types of eye protection and when to use them.

When should eye protection be worn?

"I didn't think I needed it!" That is the most common response by those unfortunate workers with eye injuries when asked why they were not wearing eye protection. One question we need to answer for our employees is: When do I need to wear eye protection? The simple answer: Any time there is a risk of something getting into the eyes. In general, this includes common laboratory tasks such as mixing, pouring, weighing out materials and similar jobs that create dust or particles or present a splash hazard. For specialty research, hazards vary depending on the task and technology employed and whether one is doing field investigations or working in the lab. Researchers can be exposed to vapors, sprays and powders, so keep eye protection in place when mixing or using chemicals and cleaning solutions, and when doing any job that can produce a splash. Do not overlook the less common operations such as lasers and radiation that pose special hazards. Finally, pay attention to common maintenance activities that may occur in the lab or facility such as welding, soldering, hammering, sawing, grinding and other such tasks.

In my experience with research laboratories we have identified a number of tasks where eye protection should be mandatory. These range from routine housekeeping duties to hazardous light sources to working with solvents and chemicals in analytical labs.

What type should I be using?

The major groups of eye protection are safety glasses, goggles and face shields. There is an optimum type of eye protection for each of the tasks listed above. First, suitable eye safety wear should bear the Z87 marking. This refers to meeting the American National Standards Institute (ANSI) testing criteria for safety eyewear³. Safety glasses (non-prescription) must withstand a -inch BB shot at 100 mph and an impact from a one pound pointed weight dropped from 4 inches above. The lenses must not break in either test to receive the Z87 mark. Prescription safety glasses must withstand the impact of a 2-inch steel ball dropped from 4 inches above, unless they have the Z87+ mark indicating they passed stricter tests. Most safety lenses are made of polycarbonate, a material much more impact-resistant than glass or plastic. Polycarbonate tends to crack when impacted, whereas glass and plastic will shatter into many small, sharp pieces.

By far the most common, safety glasses are used for impact hazards such as sawing, hammering, drilling and optical radiation from lasers and torch soldering. If flying particles are present then side protection should also be used. Older style safety glasses used side-shields whereas newer styles provide wrap-around designs.

Goggles are the next step up in protection, being stronger than safety glasses. If the particles are bigger, heavier or falling from above, goggles provide more impact resistance and complete coverage. Goggles are also used to guard against splash hazards like mixing or using chemicals and cleaning solutions. Many goggles are designed with venting to prevent fogging during use but these are not suitable against splashes or very fine dust. We tested a set recently where if you were splashed on the forehead the liquid was directed to the eyes by the vents, so be careful in your selection.

Face shields offer an extra level of protection. They provide higher impact resistance and protect the wearer's entire face, not just the eyes. However, they should always be used with either safety glasses or goggles as splashes, particles or chemicals can get around the shield and into the eyes. Also, it is a common tendency to lift face shields to check the work progress thus leaving the eyes unprotected if used alone. Face shields are typically used for work involving spraying and pressurized equipment.

Keep an eye out for safety

Vision is one of our most precious senses. Injuries can lead to long-term problems or permanent disability. With the cost and performance of today's safety eyewear, the risk for potential injury is a price not worth paying. Take the time now to ensure your employees are keeping safety in sight.

1. National Institute of Occupational Safety and Health (NIOSH) Eye Safety
2. Laboratory Safety Incidents: Chemical Exposures and Burns, American Industrial Hygiene Association, Fairfax, VA. February 2004.
3. American National Standards Institute (ANSI)