This document discusses laboratory fume hoods and acid dilution. It describes the functions and components of fume hoods, including maintaining negative pressure to contain fumes and recommended face velocities. It also explains principles such as baffles and airfoils that optimize airflow. Regular testing and maintenance of fume hoods is important to ensure safe operation. When diluting acids, the document recommends adding acid to water slowly while stirring to control temperature rise and avoid spattering. Safety precautions should always be followed.