When purchasing a new fume hood filtration system or perchloric acid wash-down sys-
tem or replacing older equipment, consider the replacement options outlined below.
Fume Hood Filtration System Replacement
For facilities that need a fume hood filtration system, consider installing a gas-phase
filtration system, such as activated carbon, that does not require water consump-
tion. Replacing an existing fume hood wet scrubber system with an adsorbent dry
filter system will eliminate water used to trap and contain hazardous substances.
Because these systems require a consistent check on contaminant concentrations
and maintenance of the adsorbent, these factors should be taken into account as an
alternative to fume hood wet scrubber systems. Particulate filtration might also be
considered, depending upon the type of contaminants present. Keep in mind the
contaminant and concentration that needs to be removed to ensure that the hazard
is fully abated.
Keep in mind that a wet scrubber is sometimes necessary for the handling of highly
toxic contaminants. Adsorbent dry filters should not be used if safety will be compro-
mised as a result.
Perchloric AcidWash-Down Retrofit or Replacement
For facilities requiring a perchloric acid wash-down system, consider a system with
automatic shut-off valves, which limit the amount of water used during the wash-
down process by controlling the duration of the wash-down cycle. Water savings will
be dependent upon the reduction in wash-down cycle length and the flow rate of
the wash-down sprayers.
Sufficient information is not available to estimate the savings potential associated
with these products.
East Bay Municipal Utility District. 2008.
WaterSmart Guidebook—A Water-Use Efficien-
cy Plan Review Guide for New Businesses
Hitchings, Dale T. September 1993-January 1994. “Fume Hood Scrubbers—Parts I, II,
Laboratory Building Design Update
Lab Manager Magazine
Fume Hood Homepage.
National Research Council,
Hitchings, Dale T.,
Fume Hood Filtration and Wash-Down Systems