In the context of the fight against dramatic fires in Los Angeles (USA) These days some neighborhoods, land and even vehicles have appeared stained with a peculiar red-pink dust, a substance spilled from seaplanes that, mixed with water, contributes to slowing down the flow. flame spread.
This chemical compound called retardant It helps the water poured to smother the flames take longer to evaporate and causes the combustion process to slow down when it reaches the flame front, as the firefighter from the fire department explained to EFE today. Forest Fire Reinforcement Brigades (Brif) Spanish Carlos Martín.
In general in forestry fighting, water evaporates “very quickly” due to the intense heat when fight a fire and even more so in the conditions in which they are working these days in Los Angeles, with circumstances of “drought, wind and low relative air humidity.”
The unloading from a helicopter fire protection can be between 1,000 and 1,500 liters on average a bush on fire, pBut in just “five minutes it can evaporate” due to the high temperatures without even touching the surface of the soil or the vegetation, the expert has warned.
What type of retardants exist?
A firefighter installs a hose while battling the Palisades Fire in Mandeville Canyon, Saturday, Jan. 11, 2025, in Los Angeles. (AP Photo/Eric Thayer)
On the one hand, there are short-term retardants, which would be foaming agents, such as foams, which increase the insulating surface between fuel and heat and fire.
On the other hand, there are long-lasting compounds, which leave a red trace whose color intensity could vary depending on the amount of mixture water and concentration levels.
These are chemical compounds, especially “phosphate salts, phosphates and polyphosphates, to which are added another series of additives that can be contaminants and even affect the land they reach.”
The retardants They also include an agent anti-corrosionto prevent the tanker of the aerial means that transport them from rusting.
Why the color?
An air tanker drops retardant while fighting the Eaton Fire Monday, Jan. 13, 2025, in Altadena, Calif. (AP Photo/Ty ONeil)
He red color is provided by a dye, included on purpose, for promote visualization of the substance which, although it tends to disappear over time, is very useful in environments such as forests to clearly mark the area where it has been retardant applied.
According to Martín, the compound, in addition to slowing down the evaporation of the water poured by seaplanes in the fight against fires, leaves a layer of polyphosphates on the surface it reaches and contributes to making combustion “much more difficult for the flame front.” “.
Are retardants used in fires in Spain?
As in other countries, in In Spain it is common to use retardants in fires to suffocate them and to “consolidate a perimeter” in case there could be a possible future reactivation and no defense line could have been made, or in very inaccessible areas.
Retardants in these cases help a lot fire control and when it comes to marking the area where the emergency services have been acting; As the brand looks, the color is visualized from above in the seaplane and helps to know the actions of the companions in the fight against the fires.
