Designed for use with 6th grade middle schoolers, this lab contract could be used for science labs in roughly 4th - 8th grade. It lays out the safety expectations and responsibilities for students, as well as sets students up to work in teams with each member having specific responsibilities. There is a place for both the student and his/her parent or guardian to sign.
I go over this contract with my students at the beginning of every year in our first science lesson, and send it home to be re-read and signed by the students and their parents as their first homework assignment. It also, then, builds anticipation for science lab and their responsibilities that come with it.