My husband and I have both used the crystal stone deodorant for decades, actually my adult son uses it also. My son and I have not had any problems at all. We love the crystal stone. My husband is just now, after literally decades of using it, beginning to complain of severe itching in his armpits, some rash too. But, what is so weird is, why after all this time would he just now begin to experience this? Is it possible that different brands or different companies produce crystal stone deodorants with different salt mineral contents? Could the answer be just to try different brands of crystal stones?