Are the retardants used to fight wildfires a problem? [Louise]

HFC’s are used in fighting fires with fire extinguishers.

Scientists are concerned about the rise in HFC use because they are thousands of times more potent on a pound-per-pound basis than carbon dioxide (though in aggregate they contribute far less to climate change). New chemicals are being phased in to replace HFCs, though the process will take time.

Fire retardant chemicals found in the home: What are PBDEs? https://toxtown.nlm.nih.gov/text_version/chemicals.php?id=79#locationtable2

Polybrominated diphenyl ethers (PBDEs) are manufactured, flame-retardant chemicals that are used in many consumer products to make them difficult to burn. Products treated with PBDEs have been used in the home, businesses, and the transportation sector. PBDEs are members of a broader class of brominated chemicals used as flame retardants. PBDEs are considered to be persistent organic pollutants (POPs), a group of highly toxic chemicals that are persistent in the environment

Notes from Alan

On a quick search, this is the best I came up with: https://www.sgvtribune.com/2016/07/23/is-that-red-fire-retardant-dropped-from-planes-during-wildfires-safe-for-humans-and-the-environment/

Fire retardant is 85 percent water, 10 percent fertilizer and 5 percent minor ingredients such as colorants, anti-corrosive material, thickeners (clay or natural gum), stabilizers and bactericides, according to the USFS public affairs specialist Jennifer Jones.
Most agree that the chemical is not harmful — at least not to humans and other mammals — even though it can cause quite a mess. However, studies show it may be lethal to aquatic life in lakes, creeks or rivers and scientists more recently are concerned about lingering effects of retardant on trees and chaparral during the current drought, which has made scarce the cleansing rains that can wash the chemicals away.