• Unattended operations which may continue several hours, overnight, or even over several days shall be pre-approved, in writing by the lab supervisor or PI.

The presence of an unattended operation shall be posted on the lab door by means of the Unattended Operation Permit Form.

  •  Which identifies the person responsible for the unattended operation and his/her 24 hour contact information.  It shall also be posted at the operation by means of a second copy of the permit note attached to a fume hood sash or oven door.  Unattended Operation Permits are intended for use on processes that use or produce hazardous materials, require water jacket cooling devices, or could become hazardous in the event of an electrical outage, water outage or ventilation failure.  Permits are not required for biological incubations, plate rotators, or other low hazard processes, but should be used for those which are odorous.
  • Many unattended operations utilize water as the coolant in condensers and other equipment.  Use of tap water to cool unattended operations is discouraged.  Whenever possible, water cooled operations should utilize recirculating refrigerated water baths to conserve water and protect against floods.  However if this is not possible, the following guidance is provided:
    • A decrease or increase in tap water pressure can have serious consequences:  Lower pressure, typical in the early morning as water usage increases, can result in a slower flow and inadequate cooling.  Higher pressures can cause leaks, separation of connections and flooding.
    • When setting up unattended operations, regulate the water pressure automatically via the installation of a water pressure regulator.  The regulator must be protected by an appropriate filter to prevent clogging.  Monitor the water flow so that in the event of interruption, electricity and water supply can be turned off.  The latter is necessary because a break in a connection can result in flooding.  Position the monitor at some point after the water has passed through the apparatus and is on its way to the drain.
  • Operations should be designed to be safe, and plans should be made to avoid hazards in the event of a failure in power, water, gas or some other service.  Room lights should be left on and the Unattended Operation Permit Form should be posted on the room door.