1.  Room air currents at the fume hood should not exceed 20% of the average face velocity to ensure fume hood containment.

_{Prudent Practices in the Laboratory 8.C}

_{Good Practice per Stanford University}

_{ANSI Z9.5-2003}

Z9.5-2003 allows air velocities up to 50 fpm, but lower room air velocities around hoods cause less interference with the operation of the hood. Make up air should be injected at low velocity through an opening with large dimensions to avoid creating jets of airflow. An alternative is to direct air towards a ceiling that will allow the air velocity to decrease by the time it approaches a hood.

2.  Make-up air should be introduced at opposite end of the laboratory room from the fume hood(s) and flow paths for room HVAC systems shall be kept away from hood locations, to the extent practical.

_{NFPA 99, Chapter 5-4.3.2}

_{NFPA 45, Chapter 6-3.4 and 6-9.1}

_{NIH Design Policy and Guidelines, Research Laboratory, 1996, D.7.7}

_{ANSI Z9.5-2003}

Air turbulence defeats the capability of hoods to contain and exhaust contaminated air.

3.  Make-up air shall be introduced in such a way that negative pressurization is maintained in all laboratory spaces and does not create a disruptive air pattern.

_{Good Practice per Stanford University}

4.  Cabinetry or other structures or equipment should not block or reduce effectiveness of supply or exhaust air.

_{Good Practice per Stanford University} 

5.  Supply system air should meet the technical requirements of the laboratory work and the requirements of the latest version of ASHRAE, Standard 62, Ventilation for Acceptable Indoor Air Quality.

_{Good Practice per Stanford University}