So far this year California has dropped 15 million gallons of fire retardant on burning forests and hillsides across the state. But here’s the thing: No one really knows what it’s made of — or its full environmental impact. The ingredients are protected as trade secrets under federal law, but they’re affecting plants and animals and humans. …It’s considered a vital firefighting tool, but this year California has dropped a new record amount, that’s double what it was three years ago. So, with the increase in drops, what are the repercussions on the environment? …Because their main active ingredient is ammonia… it’s been found that these retardants become a powerful fertilizer for plants in the aftermath of fires. This is true for invasive non-native plants in particular.