Not sure why people ignore this simple fact that there is a big difference between Ammonium Alum and Potassium Alum.
RazoRock Alum deodorant spray ingredients list:
Ingredients: Purified Water, Potassium Alum (Mineral Salts), Certified Organic Aloe Barbadensis (Aloe Vera) Extract.
You have no issues with this deodorant because it is made with Potassium Alum.
Good to know thanks! I always hated chemistry.