HAZMAT Suits – Levels of Protection
March 5, 2020
From health care workers to emergency responders in the event of a chemical or biological incident, HAZMAT suits could mean the difference between life and death. Historically, for every weapon created, a piece of armor was designed to shield against it. For swords it was the chainmail, and for noxious chemicals we have the HAZMAT suit. In fact, the use of HAZMAT suits dates back to the 14th century when it was used as a means of protection against the bubonic plague.
In the modern times workers engaged in hazardous waste operations and staff at nuclear power plants, use HAZMAT suits on a day-to-day basis to protect themselves against hazardous contaminants. More recently, health care workers involved in the treatment of patients infected with the Ebola virus and Coronavirus have made use of these suits as a safeguard against airborne hazards.
What is a HAZMAT Suit?
The U.S. Department of Homeland Security defines a hazmat suit as “an overall garment worn to protect people from hazardous materials or substances, including chemicals, biological agents, or radioactive materials.”
There are four levels of HAZMAT protection as designated by the EPA, ranging from level A (most protective) to level D (least protective). The ensemble must be tailored to the specific situation and hazardous material encountered. The bottom line – the level of protection assigned for a particular situation must adequately protect the wearer from the anticipated physical, chemical, and biological hazards.
Level A protection is required when the greatest potential for exposure to hazards exists. This level provides the highest available level of respiratory, skin, and eye protection from solid, liquid, and gaseous chemicals.
This ensemble is used when the hazards have been identified to pose a high level of threat to the skin, eyes, and respiratory system. For example, operations that are conducted in poorly ventilated areas and confined spaces require the use of level A protection.
Level A ensemble includes positive pressure, full facepiece self-contained breathing apparatus (SCBA), or positive pressure supplied-air respirator with escape SCBA, totally encapsulated chemical- and vapor-protective suit, inner chemical-resistant gloves, chemical-resistant safety boots, and two-way radio communication system. In-suit cooling system, outer gloves, and hard hat are optional elements of this ensemble that are used based on the unique requirements of each situation.
Level B protection is needed under circumstances that require the highest level of respiratory protection, but a lower level of skin protection is needed. This ensemble provides the same level of respiratory protection as Level A, but less skin protection. Level B provides liquid splash protection but does not safeguard against chemicals and vapors.
This ensemble is used when chemicals have been identified and the primary hazards associated with site entry are in contact with liquids but not vapors.
Level B ensemble includes positive pressure, full facepiece SCBA or positive pressure supplied-air respirator with escape SCBA, liquid splash-protective suit, inner chemical-resistant gloves, chemical-resistant safety boots, two-way radio communication system, and hard hat. The cooling system and outer gloves are optional elements of this ensemble.
Level C protection is required when the concentration and type of airborne contaminants have been identified and the criteria for using air-purifying respirators are met. This level provides the same level of skin protection as Level B (i.e. liquid splash protection but no chemical or vapor protection), but a lower level of respiratory protection. Level C ensembles are used when contact with contaminants on-site will not affect the skin.
Level C ensemble includes a full-facepiece, air-purifying, canister-equipped respirator, chemical resistant gloves and safety boots, two-way communication system, and hard hat. Face-shield and escape SCBA are optional elements of this ensemble.
Most hazardous material sites are characterized by contaminants below OSHA’s permissible exposure limits (PELs). This makes level C ensemble the most commonly used type of protection for cleanup and response efforts at such sites. However, level C HAZMAT suits are only suitable for atmospheres that contain at least 19.5% oxygen. Such ensembles are not acceptable for chemical emergency response.
Level D protection is a simple work uniform affording minimal protection. This level of protection is used when the atmosphere contains no known hazard and work functions preclude splashes, immersion, the potential for inhalation, or direct contact with hazardous levels of chemicals.
Level D ensemble requires no respiratory protection and only minimal skin protection. The ensemble includes coveralls, safety boots/shoes, and safety glasses or chemical splash goggles. Gloves, escape SCBA, and face-shield are optional elements of this ensemble.
Level D HAZMAT suits are only suitable for atmospheres that contain at least 19.5% oxygen. Such ensembles are not acceptable for chemical emergency response.
A Final Note
While the above are some generic guidelines for typical equipment to be used in certain circumstances, other combinations of protective equipment may be used based on specific site characteristics. The type of equipment and level of protection must be periodically reevaluated as site conditions change or when the job duties of workers change.