Armed with a proper understanding of chemical exposure risks and available safety solutions, engineers can be confident in selecting the best personal protective equipment to provide reliable barriers to workplace hazards
There is a tendency to think about personal protective equipment (PPE) in the workplace in the abstract — as a requirement to be checked off, rather than a critical component of worker safety and often the last line of defense. Most organizations care deeply about safety, of course, but their understanding of PPE — especially PPE designed to protect against chemical exposure — can be limited.
That is a problem, because different chemicals react differently to different PPE materials, and even today, there are examples of well-meaning companies that provide the wrong PPE to workers handling various types of dangerous chemicals. Just last year, there was an incident in which a manufacturer discovered a gap in its PPE program only when workers suffered adverse effects, believed to be because of exposure to chemicals in the workplace. It was a costly mistake, resulting in significant fines from the Occupational Safety and Health Administration (OSHA; Washington, D.C.; www.osha.gov) and an overhaul of the company’s PPE program and other related safety and occupational hygiene protocols.
This type of situation is not unusual, and it is easy to understand why. There are anywhere from 25,000 to 84,000 chemicals in use in the U.S. today, and this wide range is indicative of the difficulty the industry faces in tracking and cataloguing chemicals that are in active use. Imagine the challenge facing employers — they know they need chemicals with certain properties to produce their products, but the universe of chemicals is vast, changing every day, and those chemicals have diverse properties and present different risks in the workplace. Although the challenge to select the proper chemical PPE is daunting, it is certainly not impossible. This article provides some guidelines to help in the selection of PPE for chemical processing facilities.
Where to begin
There are some basic questions employers should ask when putting together a chemical PPE plan as part of their hazard risk assessment program, with the answers providing a reliable roadmap to optimal safety for their workers.
What are the chemical hazards?This seems simple, but it is far from it. Many work environments have multiple individual chemicals and combinations of chemicals (mixtures), and PPE providing protection from one chemical may not protect from others (Figure 1). Certain PPE materials provide effective protection against specific chemicals. Table 1 provides some common examples, but employers should consult with a manufacturer before choosing any PPE. Having a thorough inventory of chemicals that are present in a workplace is critical to ensuring appropriate risk assessments are in place, with appropriate worker-exposure prevention measures in place, including PPE. From there, it is important that any potential cross-exposure for multitasking employees is understood and accounted for in the PPE plan. Maybe that means different types of PPE, or maybe it changes the way workers approach various tasks, but the goal is to avoid unexpected exposure for workers who believe they are protected.
It is critical to remember that there is no single product that will protect a worker against all types of chemical hazards. Safety managers must therefore be experts in their work environments and provide the appropriate PPE for every given situation. Sometimes, the appropriate PPE can consist of multiple pieces of equipment, such as protective clothing, facemasks, gloves, boots and so on (Figure 2). Proper protection may also demand additional performance requirements, especially where there are secondary hazards, such as heat and flames, or explosive atmospheres to consider. It is not uncommon to see workers in complex chemical environments utilizing multi-hazard or multi-risk PPE to ensure they are protected against all hazards.
What are the physical hazards and needs of the working environment?It is easy to get lost in the complexity of chemical protection, but the reality is the risks to workers are not limited to chemical exposure. What are the threats for abrasion, exposure to heat and flame or extreme temperatures, or tears or punctures to protective clothing? Even a perfectly matched chemical protective suit is ineffective if it has a hole in it. There are solutions for multiple hazards — sometimes all-in-one PPE solutions, other times layered protection. The first step is understanding all the risks.
How are the workers exposed to the chemical? This is an important and often overlooked consideration. PPE selection can be different depending on whether the chemical is in liquid, particulate or gaseous form, and if the potential exposure is brief or extended. Exposure to saturating liquid spray for example, versus a light splash, presents a different challenge for PPE and therefore must be considered as part of the risk assessment
Next to the nature of the chemical, exposure time is one of the greatest determinants of appropriate protection. When assessing the effectiveness of PPE as it relates to exposure time, it is important to understand its performance in terms of chemical penetration and permeation. Penetration is the movement of large and likely visible quantities of chemical through a PPE material and can occur by movement of the chemical through a hole or a faulty seam, for example. Permeation is the process by which very small and likely invisible quantities of chemical pass through the protective material on a molecular level (typically in microgram quantities). It can be measured as a benchmark relative to other PPE in terms of permeation rate (how fast the chemical passes through the PPE material) and normalized breakthrough time (the time taken to reach a specified permeation rate, enabling different test laboratories to test to the same threshold).