chaosmagnet... there is an inhalation danger if the compound is finely powdered, and splash danger when in solution in addition to the danger from the gaseous chlorine that might be generated...small amounts of water to a large volume of calcium hypochlorite could pose an oxidizing reaction...good ventilation naturally...I would hate for a well meaning individual that does not normally handle pool chemicals to be injured...my hope was that a person that already stored HTH would also have a chlorine test kit, to see if my calculations were in the target range

take care