Although occupational exposure limits are sought to establish health-based
standards, they do not always give a sufficient basis for planning an indoo
r air climate that is good and comfortable for the occupants in industrial
work rooms. This paper considers methodologies by which the desired level,
i.e., target level, of air quality in industrial settings can be defined, t
aking into account feasibility issues. Risk assessment based on health crit
eria is compared with risk-assessment based on "Best Available Technology"
(BAT). Because health-based risk estimates at low concentration regions are
rather inaccurate, the technology-based approach is emphasized. The techno
logical approach is based on information on the prevailing concentrations i
n industrial work environments and the benchmark air quality attained with
the best achievable technology. The prevailing contaminant concentrations a
re obtained from a contaminant exposure databank, and the benchmark air qua
lity by field measurements in industrial work rooms equipped with advanced
ventilation and production technology. As an example, the target level asse
ssment has been applied to formaldehyde, total inorganic dust and hexavalen
t chromium, which are common contaminants in work room air.