What's that red stuff coming down from the sky?

A dual purpose: fire retardant suppresses fire, encourages growth

Everyone saw the pictures.

On Oct. 14, the Santa Rosa Police Department shared photos of Cal Fire’s Supertanker 747 dumping neon red fire retardant upon the raging Tubbs, Nuns and Atlas fires.

“To give you a better idea of the resources Cal Fire is using to keep the Nuns Fire out of Santa Rosa, here are some more photos one of our officers took of the air attack operations today in the area of Highway 12 between Los Alamos Road and Pythian Road,” Santa Rosa PD wrote on Facebook.

The photos were awesome, especially to a community that was in the midst of a natural disaster and economic and emotional crisis that sprang seemingly out of nowhere in the middle of the night Oct. 9.

Through the course of the week following the initial outbreak, Cal Fire’s Supertanker 747 dropped retardant down on the raging fires, working in tandem with the thousands of firefighters who came from around the state, country and world to fight the deadliest fires in California history.

The aviation program, supported by airtankers and helicopters, dropped more than 2 million gallons of fire retardant upon Santa Rosa and surrounding areas — a record amount in California state history.

The massive amount has left locals wondering whether the land where the retardant landed is safe.

According to county official Jennifer Larocque, the retardant serves a dual purpose: putting out fire while also encouraging eventual regrowth.

“Eighty-five percent of the retardant is water, 10 percent is fertilizer and 5 percent is other stuff, like color,” Larocque said. “Nothing is harmful. It’s all met specific safety standards established by the state.”

Current retardant is made from inorganic fertilizers, with the active component being ammonium sulfate.

The agent is called Phoschek. According to the manufacturer, Phoschek has been used to fight wildland fires since 1962. The United States Department of Agriculture reports that a year later, mass manufacturers began making fertilizer-based retardants after more than 30 years of reliance on air fighting battalions. Fire retardant works by cooling and coating fuels, robbing fire of oxygen. As such, it slows the rate of fuel combustion with inorganic salts, which change how the fire burns. It is typically applied to advancing fire.

“They are the safest, most effective and environmentally friendly products available,” the manufacturing website reads.

Nevertheless, residents who have farms would be wise to wash off crops susceptible to the retardant or, if they are concerned about the effects of fertilizer, to avoid harvesting or eating crops altogether, Larocque said.

As for the growing season next tear, farmers, vintners and cultivators alike should not experience drastic changes in their seasons.

“The fertilizer helps with regrowth.” Zlarocque said.

The ammonia salt causes the remaining solution to adhere to vegetation and other surfaces, making it an effective solution for fighting fire and encouraging future growth, according to the USDA.

amie@sonomawest.com, Amie Windsor Staff writer. “What's That Red Stuff Coming down from the Sky?” Sonoma West Publishers, 3 Nov. 2017, www.sonomawest.com/the_healdsburg_tribune/news/a-dual-purpose-fire-retardant-suppresses-fire-encourages-growth/article_a111665c-be8d-11e7-ac1b-7b2cdf853433.html.