Lou I do not remember if those are the exact ingredients we used, but I saw a friend get severely hurt by shaking it and thinking it would be funny to hold it in their hands and explode. We made a very very fast trip to the ER many years ago. He was very fortunate to not do more damage than he did! The drano actually burnt his skin pretty bad once it got inside the wounds if I remember correctly!
Pretty low if people are going around putting them in mailboxes!!!