Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Toxic

These tablets work great, but I find they are way too toxic in terms of the airborn chemicals they release. I started having symptoms almost right away. I've tried them twice -- several years apart -- but I still get bad symptoms. I'm actually quite sorry, because it's nice to feel that the toilet is always sanitary and that the bathroom has no germs. But, I can't deal with the side effects of these tablets.