Niagara A-B foam concentration for wildland/grass fires?

• A. 0.1%
• B. 0.1-0.5%
• C. 0.5%
• D. 1.0%

Answer: (B)

Foam concentration for wildland and grass fires with Niagara A-B is kept in a low-to-mid range to maximize wetting and film formation on lighter fuels. The recommended range is 0.1% to 0.5%. This provides enough foam to create a protective blanket and reduce surface tension so water can penetrate grasses and brush, helping to cool the fuel and slow flame spread. Going below 0.1% risks insufficient wetting and film formation, while going above 0.5% wastes concentrate and can hinder water delivery or handling in rough terrain. In practice, you tune within this range based on fuel load, wind, and available water, with roughly 0.2% common for typical grass fires and up to 0.5% for denser fuels. For mixing, 0.1% means 1 part concentrate to 1000 parts water, and 0.5% means 5 parts concentrate to 1000 parts water.