Different standards apply to various uses. What is legal to sell for municipal use, bulk chlorine for example, may not be to sell for individual use, but you can sell it for disinfecting pool water, a different use. The same government that recommends using bleach in an emergency, won't allow it to be sold as a drinking water disinfectant. The law is an ass, as someone once pointed out.

It gets even sillier. If I somehow produce the exact same product as your approved product, I cannot get it approved to sell without conducting my own expensive testing and approval of the packaging (including the text on the package) and if the standard has gotten tougher since yours was approved, I have to pass the tougher standard, even if yours couldn't...and mine won't. There is little consistency and no logic. However, if I don't claim that it's a water disinfectant, I can sell it without the EPA's blessing. But, if someone at the EPA gets up on the wrong side of the bed one morning and goes after me, I could end up in deep doo doo if they determine I am marketing for such uses.

Don't even try to make sense of it...