Last time I looked at this issue they were not EPA approved and were therefore not legal. My understanding is that you cannot sell any product for disinfecting water for human consumption unless it is EPA approved for those purposes. It is treated the same as any pesticide, even if the pests can only be seen under a microscope. That has never stopped folks from doing it and being very careful about what they claim. It also doesn't mean they don't have other certifications from the EPA. Given that the current EPA test includes Crypto, the regular chlorine tabs like these wouldn't pass. It is a murky quagmire of an issue that I avoid by using the chlorine dioxide tabs now distributed by three different companies: Katadyn, Potable Aqua and McNett. They work on Crypto and are EPA approved. . Down side is they are lots more expensive and the packaging isn't as compact and a 3-year shelf life. <shrug> You pays your money and takes your pick.

If the company believes otherwise, ask them for proof and a complete explanation.