Context: Pink retardants are being used to contain Los Angeles and Southern California wildfires, with thousands of gallons of it being dropped using the planes.
Relevance of the Topic: Prelims: Key facts about Pink Fire Retardant.
What is the pink fire retardant?
- Fire retardant is a mix of chemicals used to extinguish or slow down the spread of fires. There are different types of fire retardants but Phos-Chek (a brand of fire retardant) is the most common in the United States.
- Phos-Chek is a mix of water, fertilizer, and colour. Phos-Chek commonly contains two types of salt: diammonium phosphate ([NH4]2HPO4) and ammonium polyphosphate ((NH4PO3)n).
- Salts such as ammonium polyphosphate do not evaporate easily like water and stay for longer.
- The retardant is sprayed ahead of the fire to coat vegetation and prevent oxygen from allowing it to burn.
- The reaction between the retardant and cellulose (in plants) consumes heat energy from the approaching fire and produces non-flammable carbon material.
- Colour is usually added to the fire retardant to ensure that firefighters can see it against the landscape. This helps them create fire lines around the fire retardant, potentially saving lives and property.
What are the concerns?
- A 2024 US found that Phos-Chek is laden with toxic metals.
- Between 2009 and 2021, more than 400 tons of heavy metals were released into the environment from fire suppression.
- These toxic metals include chromium and cadmium which can cause cancer, and kidney and liver diseases in humans.
- Further, these metals can enter waterways (growing source of pollution for rivers and streams) and can kill aquatic life.
- The effectiveness of Phos-Chek also remains unclear. Aerial retardant is effective over a narrow range of conditions (dependent on slope, fuel type, terrain and weather). The windows of opportunity for these conditions are narrowing each year due to climate change.
Cause of the devastating wild fires
- Southern California (the site of the fires) has been experiencing drought conditions and has not seen significant rainfall for months.
- The dry conditions are aided by the Santa Ana winds (dry and hot winds common in the area) which most likely caused the wildfires.
- Further, climate change has contributed to an increase in the frequency, season length and burned area of wildfires.
Read more:Santa Ana winds drive Wildfire