The latest version and content of the ANSI/AIHA Z9.5 standard has been completed, voted on and
was approved. It is now in the process of being properly formatted to ANSI requirements and
should be published in the first quarter of 2012.The new language of what should be named the
Z9.5-2012 standard is similar to the 2003 standard but provides some additional clarification
language beyond what the 2003 standard stated as noted below:
Section 2.1.2 - Laboratory (Room) Ventilation Rate (2012)
Requirements:
The specific room ventilation rate shall be established or agreed upon by the owner or his
or her designee.
Recommendations:
Ventilation is a tool for controlling exposure. Contaminants should be controlled at the
source. Potential sources should be identified and exposure control devices should be
specified as appropriate to control emissions at the source. (See sections 3 and 4) All
sources and assumptions should be clearly defined and documented.
An air exchange rate (air changes per hour) cannot be specified that will meet all
conditions. Furthermore, air changes per hour is not the appropriate concept for designing
contaminant control systems.
Excessive airflow with no demonstrable safety benefit other than meeting an arbitrary air
change rate can waste considerable energy.