and water solution. Diluted down to the 3 to 1 mix it is not harmful at all. Ammonia is used in several cleaning products from glass cleaners to counter top wipes and is far safer to use in a spray than bleach. On the container it gives you several ways to use the ammonia to clean, and all of them are listed as to how it should be diluted for each type of cleaning you need. Of course as with any chemical, you need to use it carefully, and not if you are allergic to that chemical. I'm sure if a train car of bleach spilled, Hazmat would also be called in. It's standard procedure for all chemical spills.