Odin Gel is the original NGP product developed in 2011. Certified for potable fresh water tanks. No need for scaffolding, rotating devices or heavy industrial equipment. Spray on Odin Gel, let the formula work and wash off with water. Odin Gel will kill 99.9% of the bacteria and efficiently remove any legionella and bio-film. HOCNF certified, non-toxic and non-flammable.