Phos-Chek is a brand of long-term [1] fire retardants, class A foams, and gels manufactured by Perimeter Solutions, headquartered in Clayton, Missouri, United States. [2] [3]
Phos-Chek is a brand of long-term [1] fire retardants, class A foams, and gels manufactured by Perimeter Solutions, headquartered in Clayton, Missouri, United States. [2] [3]
Phos-Chek fire retardants are manufactured as dry powders or as concentrated liquids and diluted with water prior to use. [4] The retardant is applied ahead of wildfires to homes [5] [6] and vegetation by ground crews and aerial firefighting units, either fixed-wing or rotary-wing aircraft. [7] As of 2022, Phos-Chek LC-95A is the most used fire retardant in the world. [8]
Phos-Chek is produced in several colors, including red, uncolored, and fugitive. The colored retardant gradually fades to an earth-tone when exposed to sunlight. [9] The red color aids aircrews in targeting drops of retardant. [10]
Some of the main components of Phos-Chek retardants include ammonium polyphosphate, diammonium phosphate, diammonium sulfate, monoammonium phosphate, attapulgus clay, guar gum (or a derivative of guar gum), and trade secret performance additives. [10] [11] Fire retardants are manufactured as several different formulations with varying proportions of the above components. [12]
Concerns have been raised that Phos-Chek harms fish and aquatic life; and that it causes long-term effects on soils, insects, and microbiology. [13] A group based in Oregon called Forest Service Employees for Environmental Ethics sued the U.S. Forest Service, claiming the service violated the Clean Water Act by spraying Phos-Chek without assessing the product's harmful effects on waterways. In 2023, a Montana judge agreed that the USFS was violating the Clean Water Act, but declined to prohibit the agency from using Phos-Chek, instead requiring the USFS to apply for a permit from the EPA, but permitting USFS to continue using the product in the meantime. [14]
The phosphate and sulfate salts act as fire retardants and prevent combustion of cellulosic materials. Phosphate can also act as a fertilizer once the fire danger has passed. Guar gum and clay are thickening agents to prevent dispersal of the retardant after it is dropped from the plane. Other ingredients include corrosion inhibitors and flow conditioners. [15] Phos-Chek and other retardants based on ammonium phosphate may cause algae blooms in bodies of water when washed downstream and may increase the growth of invasive plant species. [8]
Phos-Chek WD-881 is a mixture of anionic surfactants, foam stabilizers, and solvents including hexylene glycol. As a fire-fighting foam, it is used as a short-term fire suppressant. [16]
The first Phos-Chek retardant product was available in 1962, and was the first phosphate-based fire retardant approved by the United States Forest Service. The Phos-Chek brand belonged to the Monsanto Company until 1998, when ownership was transferred to Solutia Inc. In 2000, Astaris LLC acquired the Phos-Chek name. In November 2005, Astaris LLC was acquired by Israel Chemicals Ltd. (ICL), [17] and the Phos-Chek brand was renamed "PHOS-CHEK Fire Safety Group" and assigned to the Performance Products division of ICL (ICL PPLP). [18] In 2018, private investment firm SK Capital acquired the Fire Safety and Oil Additives businesses of ICL and renamed it Perimeter Solutions, and the PHOS-CHEK brand was acquired with the business. [19]
The Airbase Service Center, located in Post Falls, Idaho supports all bulk bases (equipment and product support to agency operated bases), SEAT bases (equipment and product support for Single Engine Air Tanker Bases), and Portable Base Operations (mobile rotor and fixed-wing bases). Various equipment maintenance and base rebuilds are performed from this location. Fabrication of liquid concentrate tanks, batch mixers, Hopper Units, and various other equipment is performed from this location. [20]
Guar gum, also called guaran, is a galactomannan polysaccharide extracted from guar beans that has thickening and stabilizing properties useful in food, feed, and industrial applications. The guar seeds are mechanically dehusked, hydrated, milled and screened according to application. It is typically produced as a free-flowing, off-white powder.
Flame retardants are a diverse group of chemicals that are added to manufactured materials, such as plastics and textiles, and surface finishes and coatings. Flame retardants are activated by the presence of an ignition source and prevent or slow the further development of flames by a variety of different physical and chemical mechanisms. They may be added as a copolymer during the polymerisation process, or later added to the polymer at a moulding or extrusion process or applied as a topical finish. Mineral flame retardants are typically additive, while organohalogen and organophosphorus compounds can be either reactive or additive.
A helicopter bucket or helibucket is a specialized bucket suspended on a cable carried by a helicopter to deliver water for aerial firefighting. The design of the buckets allows the helicopter to hover over a water source—such as a lake, river, pond, or tank—and lower the bucket into the water to refill it. This allows the helicopter crew to operate the bucket in remote locations without the need to return to a permanent operating base, reducing the time between successive drops.
In organic chemistry, organophosphates are a class of organophosphorus compounds with the general structure O=P(OR)3, a central phosphate molecule with alkyl or aromatic substituents. They can be considered as esters of phosphoric acid. Organophosphates are best known for their use as pesticides.
Aerial firefighting, also known as waterbombing, is the use of aircraft and other aerial resources to combat wildfires. The types of aircraft used include fixed-wing aircraft and helicopters. Smokejumpers and rappellers are also classified as aerial firefighters, delivered to the fire by parachute from a variety of fixed-wing aircraft, or rappelling from helicopters. Chemicals used to fight fires may include water, water enhancers such as foams and gels, and specially formulated fire retardants such as Phos-Chek.
This glossary of wildfire terms is a list of definitions of terms and concepts relevant to wildfires and wildland firefighting. Except where noted, terms have largely been sourced from a 1998 Fireline Handbook transcribed for a Conflict 21 counter-terrorism studies website by the Air National Guard.
Diammonium phosphate (DAP; IUPAC name diammonium hydrogen phosphate; chemical formula (NH4)2(HPO4)) is one of a series of water-soluble ammonium phosphate salts that can be produced when ammonia reacts with phosphoric acid.
Tributyl phosphate, known commonly as TBP, is an organophosphorus compound with the chemical formula (CH3CH2CH2CH2O)3PO. This colourless, odorless liquid finds some applications as an extractant and a plasticizer. It is an ester of phosphoric acid with n-butanol.
A fire retardant is a substance that is used to slow down or stop the spread of fire or reduce its intensity. This is commonly accomplished by chemical reactions that reduce the flammability of fuels or delay their combustion. Fire retardants may also cool the fuel through physical action or endothermic chemical reactions. Fire retardants are available as powder, to be mixed with water, as fire-fighting foams and fire-retardant gels. Fire retardants are also available as coatings or sprays to be applied to an object.
Firefighting foam is a foam used for fire suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, thus achieving suppression of the combustion. Firefighting foam was invented by the Moldovan engineer and chemist Aleksandr Loran in 1902.
ICL Group Ltd. is a multi-national manufacturing concern that develops, produces and markets fertilizers, metals and other special-purpose chemical products. ICL serves primarily three markets: agriculture, food and engineered materials. ICL produces approximately a third of the world's bromine, and is the world's sixth-largest potash producer. It is a manufacturer of specialty fertilizers and specialty phosphates, flame retardants and water treatment solutions.
The DC-10 Air Tanker is a series of American wide-body jet air tankers, which have been in service as an aerial firefighting unit since 2006. The aircraft, operated by the joint technical venture 10 Tanker Air Carrier, are converted wide-body McDonnell Douglas DC-10-30 passenger jetliners, and are primarily used to fight wildfires, typically in rural areas. The turbofan-powered aircraft carry up to 9,400 US gallons of water or fire retardant in an exterior belly-mounted tank, the contents of which can be released in eight seconds. Four air tankers are currently in operation, all DC-10-30 aircraft, with the call-signs Tanker 910, 911, 912 and 914. The original Tanker 910, a DC-10-10, was retired in 2014.
Monoammonium phosphate, ABC Dry Chemical, ABC Powder, tri-class, or multi-purpose dry chemical is a dry chemical extinguishing agent used on class A, class B, and class C fires. It uses a specially fluidized and siliconized monoammonium phosphate powder. ABC dry chemical is usually a mix of monoammonium phosphate and ammonium sulfate, the former being the active component. The mix between the two agents is usually 40–60%, 60–40%, or 90–10% depending on local standards worldwide. The USGS uses a similar mixture, called Phos Chek G75F.
Fire-retardant gels are superabsorbent polymer slurries with a "consistency almost like petroleum jelly." Fire-retardant gels can also be slurries that are composed of a combination of water, starch, and clay. Used as fire retardants, they can be used for structure protection and in direct-attack applications against wildfires.
The Modular Airborne FireFighting System (MAFFS) is a self-contained unit used for aerial firefighting that can be loaded onto both military cargo transport Lockheed C-130 Hercules and Embraer C-390 Millennium, which then allows the aircraft to be used as an air tanker against wildfires. This allows the U.S. Forest Service (USFS) to use military aircraft from the Air National Guard and Air Force Reserve to serve as an emergency backup resource to the civilian air tanker fleet.
In 2002, two large airtankers – a Lockheed C-130 Hercules and a Consolidated PB4Y-2 Privateer – crashed about a month apart while performing aerial firefighting operations. These crashes prompted a review of the maintenance and use of the entire U.S. large airtanker fleet. Ultimately, the whole fleet was grounded, dramatically reducing the resources available to fight major wildfires. Both aircraft were owned by Hawkins & Powers Aviation of Greybull, Wyoming and operated under contract to the United States Forest Service (USFS). The crashes occurred in one of the worst fire seasons in the last half century, one in which 73,000 fires burned 7.2 million acres (29,000 km2) of land.
Mark Rey is an American former timber industry lobbyist and administrator, who served as Undersecretary for natural resources and agriculture in the federal government of the United States in the Bush administration. He was sworn in as the undersecretary for natural resources and environment by the Agriculture Secretary, Ann M. Veneman on 2 October 2001. His responsibility was to monitor the U.S. Department of Agriculture’s Forest Service and Natural Resource Conservation Service.
The 747 Supertanker is a retired aerial firefighting airtanker derived from various Boeing 747 models. The aircraft is rated to carry up to 19,600 US gallons (74,000 L) of fire retardant or water. It is the largest aerial firefighting aircraft in the world.
On August 18, 1937, a lightning strike started the Blackwater Fire in Shoshone National Forest, approximately 35 miles (56 km) west of Cody, Wyoming, United States. Fifteen firefighters were killed by the forest fire when a dry weather front caused the winds to suddenly increase and change direction. The fire quickly spread into dense forest, creating spot fires that trapped some of the firefighters in a firestorm. Nine firefighters died during the fire and six more died shortly thereafter from severe burns and respiratory complications. Another 38 firefighters were injured. The fire killed more professional wildland firefighters in the U.S. than any other in the 103 years between the Great Fire of 1910 and the Yarnell Hill Fire in 2013.
The Washburn Fire was a wildfire that burned in Yosemite National Park near the Mariposa Grove of giant sequoias. The fire was reported on July 7, 2022, in the lower Mariposa Grove area near the Washburn trail, for which the fire is named. The fire quickly attracted national attention due in part to the role the Mariposa Grove played in the establishment of Yosemite National Park and the National Park Service.
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