Methylisothiazolinone is one of the things my wife is allergic to. It is in nearly every shampoo and clothes detergent.Just read up on the Provanto and I wouldn't use it for my grow. Stick to dish soap or iso/water would be my advice.
Provanto has two ingredients on the data sheet:
"Methylisothiazolinone is moderately to highly acutely toxic in oral, dermal, eye irritation, dermal irritation, and inhalation acute toxicity studies."
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and
Deltamethrin, which is a form of pyrethrin.
"Pyrethrins kill insects on contact. But these chemicals hurt more than insects. Pyrethrins can also be harmful to humans, especially in cannabis products designed for smoking, because these chemicals can be easily absorbed through the lungs."
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It's used as a preservative.