According to 10 Tanker, their planes dropped nearly 450,000 gallons of fire retardant while responding in the Los Angeles area. The fire retardant consists of: 85% water; 10% salts; ...

The DC 10 is the largest air tanker in the world, holding 9,400 gallons of fire retardant and two and a half hours worth of fuel, all coming extremely close to the Earth's surface in the firefight.