What you need to know about proximity suits
Proximity firefighting ensembles are not just for aircraft firefighting, and not all suits have the same level of protection
Specialized clothing designed to protect workers from high levels of radiant heat have been around since the 1930s. Those first suits, developed to industrial workers, used asbestos fabric as the protective layer.
Asbestos has long since been replaced by increasingly high-tech fibers such as vacuum-deposited aluminized materials that reflect the high radiant loads produced by a fire.
When most firefighters hear the term "proximity suit," they envision the protective ensemble used by firefighters assigned to Aircraft Rescue Fire Fighting.
But this specialized ensemble is not just for ARFF; proximity clothing is designed to protect a firefighter from any fire producing high levels of radiant heat. In addition to aircraft fires, bulk flammable liquids, gasses and metals commonly produce high levels of radiant heat — as well as convective and conductive heat.
NFPA 1971 covers protective ensembles for proximity firefighting; it says proximity firefighting is typically exterior operations. Proximity firefighting differ from entry firefighting in that the ensemble is not designed for firefighters to enter into flames, but rather to protect from high levels of radiant and conductive heat for a short period of time — for example, the time to approach and close a fuel valve or affect a rescue from a plane crash.
Improper use of proximity suits may result in personal injury or death. Improper use includes, but is not limited to improper selection, use without adequate training, disregard of the warnings and instructions supplied with the suits and failure to inspect and maintain the suits.
There are three basic types of aluminized suits.
- Approach suit used for work in the general area of high temperatures such as steel mills and smelting facilities. Maximum ambient heat protection is about 200°F (93 °C).
- Proximity suit used for ARFF. Maximum ambient heat protection is about 500°F (260 °C).
- Entry suit used for entry into extreme heat and situations requiring protection from total flame engulfment. Most commonly made of Zetex or Vermiculite and not aluminized. Maximum ambient heat protection is about 2,000°F (1,093 °C)) for short duration and prolonged radiant heat up to 1,500°F (816 °C)
Complete proximity protection for ARFF requires aluminized hood or helmet cover with neck shroud, aluminized jacket and pants with vapor-barrier insulated liner, aluminized lined gloves, aluminized ARFF boots, and aluminized covers for SCBA bottles or suits that cover the air pack.
There are three primary materials used in proximity ensembles: aluminized glass, Nomex and Rayon.
Aluminized glass combines the reflectivity of an aluminized outer surface with glass fabric. Glass fabric neither burns nor supports combustion, and offers a combination of properties from high strength to fire resistance. It is a stable material that will not stretch or shrink, even after exposure to extremely high or low temperatures.
Aluminized Nomex combines an aluminized outer surface with Nomex, an inherently flame resistant material of aramid fiber by DuPont. Though considered expensive, it is very durable.
Aluminized Rayon combines an aluminized outer surface with Rayon, which provides excellent insulation. It is a permanently flame resistant material, which has been chemically treated to give it its flame resistant qualities.
Proximity suits are designed for exterior rescue operations and other fire situations where there are hazards and people operating in excessive temperature within the manufacturer's recommended operating range.
The outer layer of these aluminized ensembles help to reflect more than 90 percent of the radiant heat thereby helping the rescuer prolong their stay near a fire.
Modern Apparels' fire proximity suit is made of 16-ounce imported aluminized glass fiber fabric with dual mirror having 90 percent reflection of heat as an outer layer and with a woolen fabric lining. An additional vapor-barrier layer is also used for higher temperature.
Fyrepel's 700 and 705 Series proximity suits are designed for performing maintenance and repairs in high-heat areas. Fyrepel's multi-layer construction includes a vapor barrier and an outer layer composed of high-temperature aluminized glass. The 700 Series suit comes with a hood with gold reflective face shield, coat, pants, mitts and boots.
Globe's RSX ensembles use a reflective aluminized film for radiant heat resistance that is laminated to a knit PBI blend for the outer shell. Globe Cairns proximity gear is available with a choice of moisture barriers and thermal liners as well as a variety of custom options.
Fire entry suits
Modern Apparels' fire entry suit is offered in various layers, weighs 48 pounds and can provide protection for temperatures about 2,000°F. It consists of coat with long sleeves, double storm fly front and pouch to carry cylinder for breathing apparatus. In order to provide thermal protection to the eyes, the fiberglass helmet has tempered glasses and two gold plated lenses. The mittens and boots are constructed using ZetexPlus fabric.
Newtex's 2000 and 3000 Series suits are worn in preparation for possible fire eruption or for stand-by operations should a rescue or evasive action require passage through a fire zone. The suits have eight layers of insulation, a fully insulated hood, mitts, boots and soles.
The 2000 Series' ZetexPlus outer shell protects against temperatures of about 2,000°F (1,093°C). The 3000 Series aluminized Z-Flex outer shell protects against high radiant heat of about 3,000°F (1,650°C).
Globe says its Proximity 14-inch pull-on is the world's first leather proximity boot. It uses the same cushioned and contoured sole, athletic footwear construction, and custom fit system as Globe's Supreme structural boots. The boot meets the radiant heat requirements of NFPA 1971 for both proximity and structural ensembles.
Remember, for firefighting operations, proximity and fire entry ensembles are not designed for entry firefighting operations. They are designed to provide a level of protection that may be consistent with the tactical requirements of the incident. Just as with any of our other firefighting tools, there is a right time and a right place for the proximity ensemble.