Salt, magnesium chloride and plant nutrients producer Compass Minerals announced this week that it is spending $45 million to purchase a majority equity stake in long-term fire retardant company FORTRESS North America following an earlier $5 million initial Series A investment.

FORTRESS manufactures the fire retardants using minerals supplied from Compass’ solar evaporation site on Great Salt Lake in Utah.

“Since we began working closely with the entrepreneurial Fortress team 18 months ago, we have been excited about the growth potential of their innovative products in what has historically been a stagnant and sole-sourced market,” Compass CEO and President Kevin S. Crutchfield said in a statement. “We believe the support, both financially, and operationally, will help accelerate that growth potential, and we anticipate Fortress’ high demand season will help to counter-balance the seasonality of our core deicing business.”

The company produces environmentally friendly and carbon neutral fire retardants based on magnesium chloride that are used to douse wildfires. FORTRESS North America has developed products for aerial drops and its FR-600 ground retardant has been added to the US Forest Service’s (USFS) Qualified Products List. Recent tests of FR-600 conducted by USFS indicated that product performs 20% to 30% better than ammonium phosphate products.

Compass said the transaction will enable FORTRESS to scale production its magnesium chloride-based retardants more quickly. The company is in the process of building several manufacturing facilities for powders and liquid concentrate products.

“Nothing about our alliance with Compass Minerals is happenstance,” said FORTRESS North America CEO Robert Burnham in the release. “The alignment of capabilities were crystal clear from our very first meeting, and taking this step now allows us to scale rapidly and effectively.”

The global market for fire retardants is expected to grow at a compound annual growth rate (CAGR) of 8% between 2021 and 2021, according to a recent forecast by Grand View Research.