Mechanical vacuum pumps used in laboratories pose common hazards. Ensure that pumps have belt guards in place during operation and that service cords and switches are free from defects. Do not place pumps in an enclosed, unventilated cabinet and do not operate pumps near containers of flammable chemicals. If your pump uses oil, place a pan under it to catch oil drips. Used pump oil must be disposed as hazardous waste. Conduct all vacuum operations behind a table shield or in a fume hood and always wear safety glasses.