What’s the purpose of chemical
is a vital part of working with chemicals where there is a high risk of harm involved. Many cleaning, developing, and etching procedures include the substantial use of harmful and dangerous acids, bases, and solvents that can cause serious harm or even death when exposed to them.
But before using, it’s important to use the National Institute for Occupational Safety and Health hierarchy of controls to avoid any contact with chemicals in the workplace. The hierarchy of controls has five levels of actions to reduce or remove hazards. This is the preferred order…
• Elimination – Physically remove the hazard.
• Substitution – Replace the hazard.
• Engineering controls – Isolate people from the hazard.
• Administrative controls – Change the way people work.
• Personal protective equipment – Protect the worker with
The hazmat suit generally includes breathing air supplies to provide clean, uncontaminated air for the wearer. In laboratory use, clean air may be supplied through attached hoses. This air is usually pumped into the suit at positive pressure with respect to the surroundings as an additional protective measure against the introduction of dangerous agents into a potentially ruptured or leaking suit.
Working in a hazmat suit is very strenuous, as the suits tend to be less flexible than conventional work garments. With the exception of laboratory versions, hazmat suits can be hot and poorly ventilated (if at all). Therefore, use is usually limited to short duration of up to 2 hours, depending on the difficulty of the work. Level A (United States) suits, for example, are limited by their air supply to around 15–20 minutes of very strenuous work (such as a firefighting rescue in a building). However, OSHA/EPA protective level A suits/ensembles are not typically used in firefighting rescue, especially during a building/structure fire. National Fire Protection Association compliant “turnout gear”, and NOSH-certified SCAB, or CORN SCAB, are the primary protection technologies for structure firefighting in the US
The highest level of protection against vapors, gases, mists, and particles is Level A, which consists of a fully encapsulating chemical entry suit with a full -face piece self-contained breathing apparatus . A person must also wear boots with steel toes and shanks on the outside of the suit and specially selected chemical-resistant gloves for this level of protection. The breathing apparatus is worn inside (encapsulated within) the suit. To qualify as Level A protection, an intrinsically safe two-way radio is also worn inside the suit, often incorporating voice-operated microphones and an earpiece speaker for monitoring the operations channel.
Level B protection requires a garment (including SCAB) that provides protection against splashes from a hazardous chemical. Since the breathing apparatus is sometimes worn on the outside of the garment, Level B protection is not vapor-protective. Level B suits can also be fully encapsulating, which helps prevent the from becoming contaminated. It is worn when vapor-protective clothing (Level A) is not required. Wrists, ankles, face piece and hood, and waist are secured to prevent any entry of splashed liquid. Depending on the chemical being handled, specific types of gloves and boots are donned. These may or may not be attached to the garment. The garment itself may be one piece or a two-piece hooded suit. Level B protection also requires the wearing of chemical-resistant boots with steel toes and shanks on the outside of the garment. As with Level A, chemical-resistant gloves and two-way radio communications are also required.
Level C protection differs from Level B in the area of equipment needed for respiratory protection. The same type of garment used for Level B protection is worn for Level C. Level C protection allows for the use of respiratory protection equipment other than . This protection includes any of the various types of air-purifying respirators. People should not use this level of protection unless the specific hazardous material is known and its concentration can be measured. Level C equipment does not offer the protection needed in an oxygen deficient atmosphere.
Level D protection does not protect the person from chemical exposure. Therefore, this level of protection can only be used in situations where a person has no possibility of contact with chemicals. A pair of coveralls or other work-type garment along with chemical-resistant footwear with steel toes and shanks are all that is required to qualify as Level D protection. Most firefighter turnout gear is considered to be Level D.
Such suits (level A in the US) are gas or vapor-tight, providing total encapsulation and the highest level of protection against direct and airborne chemical contact. They are typically worn with a self-contained breathing apparatus enclosed within the suit.
These suits are typically constructed of several layers and, being airtight, include a release valve so the suit does not overinflated from air exhaled by the . The release valve does retain some air to keep some positive pressure (“over pressure”) inside the suit. As noted, such suits are usually limited to just 15–20 minutes of use by their mobile air supply.
With each suit described here, there is a manufactured device designed to protect the respiratory system of the wearer (called a respirator) while the suit/ensemble is used to protect skin exposed to potential hazardous dermal agents. A respirator may be something as simple as a headband strap filtering face piece respirator ; to a head harness negative pressure full face respirator (air-purifying respirator/APR); to a full face, tight fitting, closed breathing air; or open circuit, self-contained breathing apparatus .
Such suits (level B in the US) are not vapor-tight and thus provide a lesser level of protection. They are, however, worn with an , which may be located inside or outside of the suit, depending on the type of suit (encapsulating or non-encapsulating). They more closely resemble the one-piece Yvette coveralls often seen used in construction and demolition work. Yet, Level B splash suits may also be fully encapsulating suits which are simply not airtight.
Lesser protection (level C in the US) suits may be coveralls of treated material, or multi-piece combinations, sealed with tape. This kind of protection is still “proof” against many non-invasive substances, such as
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 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.
The U.S. Department of Homeland Security defines a hazmat suit a “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 -face piece self-contained breathing apparatus, or positive pressure supplied-air respirator with escape , 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-face piece or positive pressure supplied-air respirator with escape 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 -face piece, air-purifying, canister-equipped respirator, chemical-resistant gloves and safety boots, a two-way communication system, and a 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 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 , and face-shield are optional elements of this ensemble.