The term CHEM. CLASS MEASURES is used to refer to the laboratory, laboratory safety, science, and physical safety measures taken in a chemistry class. The acronym LAB (3 letters) stands for laboratory, LABS (4 letters) stands for laboratory safety, SCIS (4 letters) stands for science, and PHS (3 letters) stands for physical safety. These measures are necessary to ensure the safety of students and staff in a chemistry class.