Hazmat suit

# Overview
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." More generally, hazmat suits may provide protection from:
- Chemical agents - through the use of appropriate barrier materials like teflon, heavy PVC or rubber and tyvek
- 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 via air hoses.
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.

## Ratings

### In the United States
Hazmat suits are considered to be Level A, B or C protective clothing.
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 protection also exists, but does not include a 'hazmat suit', as it only requires specific work clothing and eye 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 fluid. These suits do not protect gainst 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.

## 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.

# In fiction

## In movies
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.

## In television
Hazmat suits are a favourite prop for MacGyver in MacGyver, which he wears when performing rescues in nuclear reactors.
They are also frequently used in the science fiction television series Stargate SG-1 and its counterpart, Stargate Atlantis, in order to avoid alien pathogens.
Employees of the Charles Montgomery Burns-owned Springfield Nuclear Power Plant, on the television show The Simpsons, are often shown wearing Hazmat suits.
In season 17 of Law and Order in the episode 'Over Hear' doctors are seen wearing hazmat suits due to the poison Ricin.
Hazmat suits are often seen in the TV series 24. They were used in Day 2 to deal with a radiation leak, in Day 3 during a biological threat, in Day 5 to deal with nerve gas, and in Day 6 after a nuclear bomb was detonated.

## In video games
Gordon Freeman, the main protagonist of Half Life and Half Life 2 is famous for wearing his Hazardous Environment Suit (HEV Suit) throughout the game. This might however be more correctly tagged as an NBC suit (the military equivalent of a hazmat suit) and also functions as body- and power armour.
The first-person shooter Doom features the 'Radiation Shielding Suit' which, while it lasts, renders the player immune to damage normally incurred from walking over toxic waste and lava.
An advanced, disposable hazmat suit appears in the game Deus Ex, and can be used to temporarily ward off toxins and poisons when entering hazardous environments. In the game 007: Nightfire, during the mission 'Chain Reaction' in which James Bond infiltrates a nuclear power plant, enemies in the plant are seen wearing level A and B suits, although Bond himself does not wear a suit.
In the game S.T.A.L.K.E.R., hazmat suits are almost essential to traversing the landscapes closer to the Chernobyl power plant. Early on the player gains access to civilian-grade hazmat suits, which offer little protection against conventional harm from bullets and wild animals. Armoured military-grade suits, and combat armour with some hazmat elements (such as a sealed helmet and air supply) become available later on.
H.U.N.K., a character in Resident Evil 4 wears a black Class A Hazmat suit. He is generally agreed to be the most mysterious character in the game, and his face has never been shown in gameplay.
The main characters in Area 51 also wear hazmat suits to protect themselves from infection from an alien disease.