Hazmat suit

A hazmat suit is a garment worn as protection from hazardous materials or substances. A Hazmat suit is generally combined with breathing apparatus or protection and may be used by firefighters, emergency personnel responding to toxic spills, researchers, or specialists cleaning up contaminated facilities. It is sometimes confused with or referred to as an NBC (Nuclear, Biological, Chemical) suit, which is a military version intended to be usable in combat.

Capabilities

Overview

The United States 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." [" [http://books.google.com/books?id=jSLDhP0lFZgC&pg=PR26&vq=hazmat&dq=%22hazmat+suit%22&lr=&as_brr=3&source=gbs_search_s&sig=URgL5YATamddpMWpRBZ1MldRJvM#PPA215,M1 Dictionary of Homeland Security and Defense, The (excerpt via Google Books)] " - O'Leary, Margaret R.; iUniverse, Inc., 2006, Page 215] More generally, hazmat suits may provide protection from:

*Chemical agents - through the use of appropriate barrier materials like teflon, heavy PVC or rubber and tyvekFact|date=September 2007
*Nuclear agents - possibly through radiation shielding in the lining, but more importantly by preventing direct contact with or inhalation of radioactive particles or gas
*Biological agents - through fully sealed systems (often at overpressure to prevent contamination even if the suit is damaged)
*Fire/high temperatures - usually by a combination of insulating and reflective materials which reduce or retard the effects

Hazmat suits generally include breathing air supplies to provide clean, uncontaminated air for the wearer. In laboratory use, the external air may be provided through air hoses drawing from a "clean" location. This supplied air is usually provided at positive pressure with respect to the surroundings as an additional protective measure.

Working in a hazmat suit is very strenuous, as the suits tend to be less flexible than conventional work garments, and are hot and poorly ventilated (if at all). Therefore use is usually limited to short durations of up to 2 hours, depending on the difficulty of the work. Level A (United States) suits for example are limited to around 15-20 minutes of very strenous work (such as a firefighting rescue in a building) by their air supply.

However, typically OSHA/EPA protective level A suits/ensembles are not used in firefighting rescue, especially during a building/structure fire. National Fire Protection Association (NFPA) compliant turnout gear and NIOSH-certified SCBA or CBRN SCBA are the primary protection technologies for structural firefighting in the US.

Ratings

In the United States

Hazmat suits are considered to be Level A, B or C protective clothing. [ [http://www.sccfd.org/clothing_hazmat.html Protective Clothing - Hazmat Gear] (from the Santa Clara County Fire Department's website)]

*Level A suits are vapor-tight, providing total encapsulation and a high level of protection against direct and airborne chemical contact. They are typically worn with a self-contained breathing apparatus (SCBA) enclosed within the suit.

*Level B suits are not vapor-tight and thus provide a lesser level of protection. Level B suits are worn with an SCBA, which may be inside or outside of the suit, depending on the type of suit (encapsulating or non-encapsulating).

*Level C includes coveralls or splash suits providing a lesser level of protection than Level B and are typically worn with a respirator or gas mask only.

*Level D also exists, but does not constitute a 'hazmat suit', requiring only specific work clothing and eye (splash) protection.

Types

Hazmat suits come basically in two variations: splash protection and gastight suits. As the name implies the splash protection suits are designed to prevent the wearer from coming into contact with a liquid. These suits do not protect against gasses or dust. Gastight suits protect the wearer from basically any outside influence apart from heat and radiation.

Gas / vapor protection

Such suits (Level A in the US) are gas or vapor-tight, providing total encapsulation and a high level of protection against direct and airborne chemical contact. They are typically worn with a self-contained breathing apparatus (SCBA) enclosed within the suit.

These suits are typically constructed of several layers and, being airtight, include a release valve so the suit does not overinflate from exhaled air from the SCBA. The valve does retain some air to keep overpressure inside the suit. As noted, such suits are usually limited to around 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 while the suit/ensemble is used to protect the skin exposed to potential or actual dermal hazardous agents. That device is a respirator and it may be something as simple as a headband strap filtering facepiece respirator (FFR), to a headharness negative pressure fullface respirator (Air-Purifying Respirator (APR)), to a full face, tight fitting, breathing air closed or open circuit self-contained breathing apparatus (CC-SCBA or SCBA).

Splash protection

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 SCBA, which may be located inside or outside of the suit, depending on the type of suit (encapsulating or non-encapsulating). They more closely resemble one-piece Tyvek coveralls used in construction, but 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 anthrax." [http://www.enquirer.com/editions/2001/11/19/loc_hazmat_training.html Hazmat training reveals dangers] " - "The Cincinnati Enquirer", Monday 19 November 2001]

In fiction

Hazmat suits have long been an important device in fiction, especially science fiction, to accentuate the lethality of environments. Common dramatic situations usually involve a suit failure leading to rapid death in films such as "The Andromeda Strain" or "Outbreak". Plot resolutions usually make the removal of a suit a pivotal moment, signifying the end of the threat.

The anonymity provided by hazmat suits has often been used to accentuate sinister motives, the scientists in "E.T." are a good example of this, as are the farcical squad of hazmat encased characters in the animation "Monsters Inc.".

ee also

* Bunker gear
* Demron
* Fire proximity suit
* NBC suit, military equivalent
* Suitport

References