I purchased a gallon of the 35% and told the nutritionist who sold it to me that I was going to take it on the plane back to my home. She explained immediately that I'd better not do that! It will explode! This was 3 or 4 years ago -- she said that I might be arrested if I try to take the stuff on the plane with me. That's why we have to pay 'hazardous shipping' charges.
I use the 35% food grade h2o2 in my bath, to brush my teeth [diluted to 2%], I keep my toothbrush in a well of it, also in the kitchen. . . well, you get the point.