It’s not
that bad. Look at the bottom of this page:
https://www.odysseymanufacturing.com/ultrachlor-bleachA few things here are worth noting. Highly pure bleach is more stable. And chlorate is undesirable and mildly toxic. You don’t want too much in your drinking water.
From experience, one should only buy bleach from stores with decent turnover. Bleach from the corner store may well be dead.
