Somewhere between 1 an 5% sodium hypochlorite, the exact amount a trade secret, according to to safety data sheet (https://www.thecloroxcompany.com/wp-content/uploads/cloroxsplashlessregularbleach.pdf). So the not for sanitation/disinfection might be because it's hard to dilute to desired strength (since you're starting from an unknown strength), and using the normal bleach ratios will produce a too-weak mix; it's also possible it's because the lye in it will cause the pH to be too high (>8) for sanitation use (see, e.g., http://ucfoodsafety.ucdavis.edu/files/26437.pdf)