Bacon

I was driving to work the other week when i stopped at a service station to grab a bite to eat. I got a bacon sandwich which was pretty good.
After i had eaten the sandwich i looked at it's ingredients and noticed POTASSIUM NITRATE.

My first thought was" thats weed killer " so i looked it up and it still is.
It is also used in fireworks and some types of rocket fuel.

I googled POTASSIUM NITRATE hazards and got this as the top page.

http://www.jtbaker.com/msds/englishhtml/P5950.htm

If you can add anything it will be welcome.