Operating Instructions

Laboratory Room Controller Owner's Manual
5-2 Siemens Building Technologies, Inc.
Periodic Verification of Safe Laboratory Ventilation
When operating in a laboratory environment, it is important to purchase and commission a
safe laboratory system. However, that system by itself is not enough. A Chemical Hygiene
Plan should be in place that includes maintaining the system and verifying that it operates
safely. Your Industrial Hygienist should suggest the interval based upon ANSI Z9.5, which
recommends verifying pressurization regularly in intervals from one week to six months,
depending on the hazard involved. All openings to surrounding spaces must be inspected
and you must physically verify the direction of airflow. This applies even when continuous
monitoring equipment is used. Periodic inspection complements continuous monitoring
equipment. Monitoring equipment monitors the laboratory all day every day, providing much
more thorough verification than is possible with inspections, however, inspection keeps the
monitoring equipment reliable.
To be thorough, the inspection must include a full range of combinations of airflows, high and
low hood exhaust, and high and low general exhaust. For most laboratories, a visual
indication is the most cost effective. Test procedures should include recording the physical
indicator you use, along with the value the LRC reports for the flow difference (VOL
DIFFRNC). In this way, it is possible to record the controller’s assessment of pressurization
and obtain an independent, physical confirmation. The test records should also indicate all
the airflows in and out of the room as a way of documenting the test conditions.
Similarly, ANSI Z9.5 recommends inspection and verification of all ventilation system
components. In addition to visual inspections, this may include verifying airflow readings
against a recently calibrated device. Figure 5-2 is an example of the kind of document that
helps maintain a safe working environment. Your local Siemens Building Technologies, Inc.
office is qualified to carry out this service with documented procedures and documented
results.