Frequently Asked Questions
Q: What do I do if my hood alarm activates?
A: The alarm on the laboratory chemical hood notifies you that the hood is not performing as desired, which could lead to overexposure to chemicals. If the alarm triggers, take the following steps:
- Shut down your experiment
- Close the sash
- Call UNC Facilities Services immediately at 919-962-3456
If the alarm sounds due to a scheduled power outage and someone turns it off, post the hood as “Out of Service” (Appendix 17-A) until power is restored. Turn the alarm back on before conducting further work in the hood.
Q: Why does my alarm always go off when the laboratory door is open?
A: Please keep in mind that when doors are propped open, the airflow in the laboratory is affected and the hood may go into alarm. If you believe your alarm is too sensitive, notify EHS for a calibration assessment. Never tamper with the alarm by taping over openings.
Q: Can I use radioactive material in my laboratory hood?
A: The Radiation Safety Committee, appointed by the Chancellor, formulates radiation policies and procedures. Responsibility for carrying out these policies and procedures rests with the Radiation Safety Officer who directs the Radiation Safety Section of the Department of Environment, Health and Safety. Hoods must receive individual authorization by the Radiation Safety Section. EHS provides the radiation caution signs that indicate which hoods it has authorized for use with radioactive materials. Hoods must have this posting before you use radioactive materials in them.
Q: Can I do my virology/bacteriology work in my laboratory hood?
A: In general, virology and bacteria work shall not occur in a laboratory chemical hood. When working with cultures, use a biological safety cabinet. For information about biological safety cabinets at UNC, refer to Chapter 16: Biological Safety Cabinets.
Q: How do I make modifications to my existing hood or exhaust system?
A: Students, faculty, staff and Facilities Services personnel must not modify hoods by drilling, cutting or removing the hardware originally provided with the hoods. Such modifications are likely to degrade hood containment performance and result in hood leakage. Installing a standard latticework of “monkey” bars at the rear of the hood is an exception. The installer must follow the hood manufacturer’s recommendations when installing these support bars in the hood. EHS must review and approve in advance any other proposed hood modifications, and post-test following modification.
Do not add shelving to the hood, nor block the rear slots or front airfoil at any time. Ensure the sash and panels are in place before operating.