I get bleach from E-Konomy Pool, they are NOT sealed. They reused the bottles. Many of the jugs have bleach crystalized on the side of them. So, yes, there are fumes.Bleach is factory sealed, so no fumes from unopened bleach. Opened bottles don't release fumes if they're properly capped. And yes, storing it indoors is the best thing to do.
Most all chlorine and muriatic acide jugs have vented caps. That bei g said, I keeps my chlorine in the laundry room and have never had a chlorine oder come from the bottles. There are presently 8 full jugs in there right now as I went to the pool supply yesterday to change out my refillable jugs - and zero odor.
Where are you that it gets hotter than Tucson? It's 120 farenheit here in the summer. Maybe if I wash the bleach bottles, since they are refillable and get bleach on the outside, crystallized and put them in a closed storage bin.I always keep a couple bottles in our laundry room. Never any smell. We get a whole lot hotter than you all.
Summer outdoor temperatures in our area will make your 10% LC 6% in a very short period of time.