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I believe it is. It mentions the EPA approval they have
I've used a lot of enzyme products over the years including The Natural and SpaPerfect. I love them myself. You just have to make sure you use them sparingly and with Dichlor or Bromine as a supplemental sanitizer. I'm sure this works in a similar manor...keeps hot tub from clouding, free of chlorine smell and oxidizes leftover lotions, etc. Good luck!