Teaching lab safety is an essential job skill for middle school science teachers. Students have to be told what to do, and, more importantly, what not to do. I usually teach lab safety in one large lesson at the beginning of the year and require students to pass a quiz in order to participate in the first lab. Here are the lab safety resources that I use in my middle school science classroom.
SlideShow
When I teach safety in middle school science, I want a slide show that specifies the rules while I talk about them. I usually tell stories about each rule. They like the story about the time a student broke a graduated cylinder and didn’t tell me about it and the custodian needed stitches when he accidentally “found” their hidden broken glassware. Another favorite story is about the time a student spilled acid on the lab table and didn’t report it. Within a few minutes, it had dripped off the table onto the leg of their lab partner where the acid ate through their pants (I know, I didn’t think that would really happen either) and left a burn mark on their leg for a few weeks. A third favorite is the time students were fooling around in the hall before school and one boy got perfume sprayed in his eyes, resulting in the one and only time I’ve had to use the eye wash. 
Practice
Just hearing my stories and watching my slide show isn’t enough for students to master the lab safety rules. Every year, I try to do something different for a practice session. Last year, when pixel art was all the rage, I did a pixel art worksheet. This year, I’m going to do a digital escape room that uses a Google form as its base. Directions to create your own digital escape room using Google Sites can be found here.
Assess
Before my students can participate in a lab, they must demonstrate mastery. Since every student is highly motivated to participate in the lab (it helps when the first lab is a fun one like the Ice Cream Lab), I usually get pretty high compliance. To make it easier on myself, I give the students a self-grading quiz on Google forms and allow them to retake it as many times as necessary to get 100. Steps to creating your own self-grading quiz can be found here.
How about you? How are you going to teach safety this year?