Lab Ventilation-Summary When Expect Because The interior building and non-laboratory areas should be To feel air moving at a slightly positive pressure. Air should enter through the Entering the slightly towards the ventilation supply system. This filters and conditions the building outdoors as the air to keep pollutants, dust, humidity, radon, etc. from door is opened building up within the building envelope. To see all Propped doors waste energy and severely impact system laboratory doors performance and security. are shut To smell no These are generally indicative of problems and should be offensive odors reported unless a benign cause is obvious. In hallways, To feel offices or temperature and Temperature and relative humidity is normally 70F +/- 5F other non- humidity at and 55% +/- 5%, respectively. laboratory comfortable levels areas To see no condensation forming on indoor Indoor condensation should not occur and may cause surfaces (tiles on mold growth, damage to building materials, or other drop ceilings are indoor air quality problems. not stained, water is not pooling on sills, etc.) That flow indicators show Low flow alarms and indicators are required on all newer normal operation, fume hood installations. without alarms or Using fume instabilities hoods The hood is in good This is critical to safety and repairs must be done before working order with subsequent use. Sashes should never require much more sashes clear, clean than 5 lbs force to operate. and operate easily, That the work area This will minimize the potential for turbulence, mishaps, is unobstructed and cross contamination. and clean To see a label This label states the flow rate at that maximum height and showing the indicates that overall hood performance was adequate maximum working when inspected. Fume hoods are routinely tested on an height and testing annual schedule. is current Transient smells and other faulty conditions can be To find that hood indicative of problems. Simple indicators such as a light flow is proper tissue held or taped to the sash bottom (should be pulled during use inward slightly and steadily) can be used for easy confirmation. Horizontal sliding sashes and vertical sliding sashes should That sashes are be positioned to create a barrier in front of the user's face adjusted properly and be closed to the maximum degree possible for during use protection. Combination sashes require the vertical sliders to be shut before being lifted horizontally. That chemical operations are not Unattended operations should be avoided, but if required left unattended or they must be engineered to provide automatic override have appropriate and shutdown controls to prevent fires or pre-approved explosions. Periodic surveillance must also be scheduled. controls Potential The fume hood air flow which offers protections is fragile turbulence causing and susceptible to disturbances. Personnel walking by, events are opening of nearby doors, or similar situations can create minimized turbulence and vortices. All hood sashes are This provides maximum containment, maintains better lab closed air quality, and minimizes energy waste. Exiting laboratories All unused laboratory This will minimizes heat loads and energy use as well as equipment that can reduce the potential for fires. be turned off without ill effects is secured (ovens, hot plates, stirrers, etc.) All storage cabinets and chemical This will help minimize fugitive emissions, protect the containers are laboratory air quality, and ensure product integrity. tightly closed and labeled The laboratory This will help protect the contents, save energy, and allow lights are turned energy saving measures such as system setbacks to be off and it is locked effectively utilized. when unoccupied .