Environmental Health and Safety

Microwave Safety

Microwave ovens can be valuable tools in the laboratory, but it is imperative to recognize the presence of additional hazards that are not typically present when using the microwave in the home. These hazards include rapid vaporization, superheating, ignition of flammable vapors/materials, pressure buildup in sealed containers, exposure to microwave radiation from a faulty unit, electrical shock, and burns from improperly handling heated material.

NEVER USE A LABORATORY MICROWAVE TO HEAT FOOD OR DRINK FOR CONSUMPTION

Checking the following exterior elements regularly ensures that some of these hazards associated with microwave ovens are kept to a minimum:

  1. Exterior Structure: Is the exterior structure intact? Has the unit has not been damaged or modified? Pay careful attention to seals as broken or burnt seals can be an indicator of microwave leakage.
  2. Electrical: Is the unit is grounded using a properly rated three-pin plug and connected directly to a wall outlet? Use of power strips or extension cords is prohibited.
  3. Ventilation: Is the area surrounding the unit clear, allowing for proper ventilation?

For safe operation:

  1. Follow all directions from the manufacturer for safe usage.
  2. Do not modify or defeat interlocks.
  3. Use unsealed non-metal vessels. This is the prevent arcing and explosion.
  4. Monitor the microwave while in operation especially when preforming the procedure for the first time or in a different unit. Material can react unexpectedly and power may differ between units.
  5. Do not overfill containers. No more than 2/3 full is recommended.
  6. Use proper safety equipment such as thermal gloves to remove heated items from the unit. In some cases, such as heating large quantities of materials, wearing a face shield is advised.
  7. Microwaving hazardous/flammable materials or agar may require specialized equipment or procedures.