Fire Inhibiting Sprays
Risk Reduction Category
Technology Description
Fire inhibiting sprays may be categorized as fire retardants or fire suppressants—the latter being considered short-term retardants. Fire suppressants, that may include gels based on superabsorbent polymers or perfluorinated surfactant-based foams, may be applied to an active fire. While the perfluorinated foams have been found very effective in suppressing fires these are considered toxic environmental contaminants. The gels lose effectiveness when the water evaporates—perhaps within an hour of application.[1]
According to the USDA, long-term retardants contain about 85% water with 10% fertilizer (typically ammonium phosphate fertilizers), along with 5% colorant, stabilizers, bactericides, corrosion inhibitors, and thickener (clay and natural gum). The colorants make the fire retardant visible both from the air (so that pilots can more accurately deliver subsequent drops) and from the ground (to help firefighters in positioning themselves).[2]
A Study from the 1970s found phosphate chemistry to be among the most effective according to three parameters involving effectiveness: fuel weight loss, amount of radiation emitted, and amount of residue after all combustion had ended as the fuel burned. The chemicals rated highest in effectiveness were monoammonium phosphate, diammonium phosphate, potassium carbonate, and phosphoric acid. Those showing high to moderate effectiveness were boric acid, ammonium pentaborate, and sodium tetraborate. [3]
Proprietary sprays intended for the protection of structures are also available.
Technical Readiness (Commercial Availability)
The following list of manufacturers is the product of an Internet search using a general description of the technology as the search term. Sometimes more than one variation on the search term is used. The objective is to identify the most demonstration-ready products available in the category. Toward assessing demonstration readiness, the manufacturer websites typically provide useful information such as writeups of successful use cases or field demonstrations, number of deployments, or other indicators. Where lack of information exists online, further inquiry is made by phone. Generally, one to three frontrunners emerge as being most ready for a field demonstration. Preference is given to manufacturers who sell to the United States, or, if emerging technology, those who have participated in US-based field demonstrations.
Perimeter Solutions: Phos-Chek (currently in use by the United States Forest Service (USFS) in their firefighting air tanker fleets.) Phos-Chek is a long-term fire-retardant employing water and fertilizer as described previously. Products are developed in compliance with NFPA FIREWISE USA® Guidelines
https://www.perimeter-solutions.com/en/
Barricade International: Barricade ® II liquid fire gel concentrate(LC): Barricade has been approved by the US Forest Service to be used in Single Engine Air Tankers (SEATs), helicopters using buckets and firefighters on the ground using fire engines. It is described as having negative impacts on the environment and is said to be easy to store, maintain and mix for aerial operations. Barricade provides a thermally protective coating intended to protect structures from burning due to fire conditions. This spray may be applied using a garden hose and may last 24 hours or longer according to the website.
https://firegel.com/wildfire-applications/
Sunseeker Enterprises, Inc.: doing business as Sun FireDefense: offers a patented spray for application to buildings, SPF3000 (patent #11441076). The coating may be applied to wood, polymers, metals, plastic, fiberglass, and fabrics. This coating technology, according to the patent, provides a layer of protection that expands, prevents oxygen from getting to the flames and then self-extinguishes. [4]
Implementations / Deployments
Phos-Chek has been used in firefighting air tanker fleets for over 55 years. A non-colored version is available for use in residential environments.
In California, on a four-mile stretch of Route 118 (between Ventura and Los Angeles County), PHOS-CHEK FORTIFY was applied before the 2019 fire season. While 37 fire starts were recorded for this location in 2018, none were recorded in 2019.[3]
Barricade appears to be intended for towns and homes in wildfire-prone areas. Its materials indicate that it has been used on wildfires from aircraft.
SPF3000 has been applied to homes in California to protect them against wildfires. In 2018, Corral Canyon, Malibu, one house treated with SPF3000 is said to have survived the Woolsey wildfire that destroyed neighboring homes. Likewise, in 2017, one house in Bel Air also treated with SPF 3000 is said to have survived the Skirball wildfire while other nearby houses did not
Innovations as of Mid 2023
From Perimeter Solutions: ground-based, or ground-applied fire retardants for wildfire prevention in high risk areas: PHOS-CHEK Fortify and PHOS-CHEK LC-95W. These may be found on the USDA Forest Service Qualified Products List (QPL). [3]
Potential Enrichment Work Opportunity
References
[1] PNAS site (Proceedings of the National Academy of Sciences of the United States of America) Wildfire prevention through prophylactic treatment of high-risk landscapes using viscoelastic retardant fluids. Anthony C. Yu, et al. https://www.pnas.org/doi/10.1073/pnas.1907855116#data-availability
[3] Perimeter Solutions https://www.perimeter-solutions.com/wp-content/uploads/2022/05/PERI1216_LTR_White_Paper_v4b.pdf
[4] Sun FireDefense website https://www.prnewswire.com/news-releases/us-patent-granted-to-sun-firedefense-for-wildfire-coating-technology-301635665.html