I have started student teaching science in middle school and next week we start chemistry. I am working on my lessons which are based on a given curriculum and chemicals we have already purchased as a school district. So I see that we are precipitating lead iodide using a lead nitrate solution which the teachers prepare and am thinking I have to find something that says we shouldn't be doing that.  I will have to check the disposal laws in New Jersey. We do it in a test tube, and use about 40 test tubes . Anyway, I will do the research and check the SDS that comes with it, etc. I know it's a carcinogen.

What I was wondering is if you knew off the top of your head any easily obtainable guidelines that recommend against using it in K-12 labs.