Where can I find an ALS-free toothpaste?

My dentist told me that the chemical Ammonium Lauryl Sulfate (ALS), a surfactant found in toothpaste, is possibly implicated as a cause of canker sores, which I get frequently. Toothpaste labels don’t list the “inactive” ingredients, so I don’t know what’s in my toothpaste. Other than home remedies like baking soda, does anyone know of a commercially marketed toothpaste that is explicitly ALS-free? Preferably something that can be had at the supermarket. I don’t like hunting around for health food stores.