Compare and contrast the various types of Personal Protective Equipment (PPE) and how the selection of PPE is determined based on specific chemical hazards.

Personal Protective Equipment (PPE) is a critical component of a chemical safety program, providing a barrier between workers and hazardous chemicals, thereby minimizing the risk of injury or illness. PPE comes in various forms, each designed to protect different parts of the body and mitigate different types of hazards. The selection of appropriate PPE is not a one-size-fits-all approach; it is determined by a thorough assessment of the specific chemical hazards involved.

Eye and face protection is crucial when working with chemicals that could cause splashes or sprays that can potentially damage the eyes or face. Safety glasses are the most basic form of eye protection and provide impact protection, preventing debris and particulates from entering the eyes. For chemicals that could cause splashes, safety goggles offer a more secure seal around the eyes, preventing liquids or fumes from coming into contact with the eyes, and provide better protection overall than safety glasses. In situations with a higher risk of splashes or with irritating or corrosive substances, a face shield should be used in conjunction with safety glasses or goggles as an additional layer of protection, covering the whole face from droplets, sprays, and other flying hazards. For example, when handling a corrosive acid like sulfuric acid, workers should wear chemical goggles and a face shield in addition to other PPE like gloves, as a splash could cause serious damage to both the eyes and face. Regular glasses will not suffice as eye protection in hazardous chemical work.

Respiratory protection is essential when handling chemicals that pose inhalation hazards, such as volatile compounds, gases, vapors, or airborne particulates. Respirators are chosen based on the type and concentration of the hazardous substance and the surrounding environment. Air-purifying respirators (APRs) use filters or cartridges to remove contaminants from the air and are suitable for situations where the concentration of contaminants is within certain limits, the environment is oxygen-rich and the contaminants are known. There are also specific cartridge and filter types that are designed to protect from different chemical types and should be selected appropriately. For example, organic vapor cartridges will not protect from acid gases and vice versa. Air-supplying respirators (ASRs), such as self-contained breathing apparatus (SCBA), are used in more hazardous situations, such as in situations that are immediately dangerous to life or health (IDLH) or in environments where oxygen levels are deficient. They provide a breathable air supply from a portable source. A proper fit test must always be completed and the correct cartridges/filters must be selected for the specific chemicals present. When working with a highly toxic gas, workers should use a full-face respirator with the correct cartridges or even an SCBA if the hazard requires, along with appropriate skin protection.

Hand protection involves the use of gloves, and glove selection is often very specific to chemical hazards. Glove materials such as nitrile, latex, neoprene, and butyl rubber each offer different levels of protection and resistance to various chemicals. Nitrile gloves are a common choice for general chemical handling, offering good protection against many solvents and acids, as well as puncture resistance, but do not provide ideal protection against some organic solvents. Latex gloves are good for general purposes but may cause allergic reactions and offer poor resistance to chemical exposure, and are not appropriate for most work with chemicals. Neoprene gloves offer good protection against a wide range of acids, bases, and alcohols, and butyl rubber gloves provide excellent resistance to many chemicals, especially against ketones and esters. The selection depends on the specific chemicals being handled and the duration of exposure. For example, when working with a solvent like acetone, nitrile gloves are not suitable and butyl rubber gloves must be chosen, while working with weak acids may only require nitrile gloves. The selection chart must be consulted to determine the correct glove type. It’s also essential to check glove degradation, permeation, and breakthrough times before working with chemicals and to replace the gloves regularly.

Body protection such as chemical-resistant suits, aprons, and lab coats are used to protect the skin and clothing from chemical spills, splashes, and contamination. The material of these items must be selected based on the hazards they are designed to protect against. Chemical-resistant suits or coveralls provide full-body protection for extensive chemical handling, or in situations with a higher risk of contamination, and can be made from materials like Tyvek, or other specific chemical resistant materials. Chemical aprons provide a lower level of body protection, typically for the front of the body only, to protect from splashes and spills. A lab coat can offer a minimal amount of protection, such as protecting from spills, or contaminated particulates but is not adequate for working with concentrated, hazardous chemicals. For example, if handling a concentrated, corrosive acid in large quantities, workers should wear a chemical-resistant suit over other clothing, and proper respiratory, and eye protection along with the correct gloves.

Foot protection is crucial in chemical handling facilities to avoid injuries from chemical spills, drops, or punctures. Chemical-resistant safety shoes or boots with steel toes and soles provide the appropriate protection from the hazards. The materials must be selected to be resistant to the chemicals that are handled in the facility. For instance, when working with corrosive chemicals, chemical-resistant boots should be worn to prevent skin exposure from accidental spills or splashes.

The selection of PPE is a systematic process based on a hierarchy of controls. The first step is identifying the specific hazards by referring to the SDS and other resources. The next step is to implement engineering and administrative controls to reduce the risk. If these controls do not fully eliminate the risk, then PPE is chosen as the next level of mitigation. It is imperative to review the SDS of each chemical to determine all the possible hazards to the human body. A risk assessment must then be completed, which takes into consideration the hazards of each chemical being handled, the quantities being used, the exposure routes, and the tasks being carried out. PPE must be specifically selected based on this information, and workers must always be properly trained on the proper use, and limitations of all PPE they are required to use.

In summary, PPE should be chosen as a last line of defense, after all other means of mitigating hazards are implemented. It is critical to select the appropriate PPE based on the specific chemical hazards present, and this must be done using the SDS, a complete risk assessment of the workplace and all chemicals being handled, along with a complete understanding of all chemical hazards. It is not a one size fits all approach. The correct PPE, used correctly, is critical to protecting workers from exposure to hazardous chemicals and preventing injuries and illness.