Table 16. Minimum treatment required to remove organic contaminants.
10 min/10 min 24 hr/10 min
24 hr/24 hr
dry (105C) 1
Hot wash, oven dry,
plus unspecified addi-
tional treatment needed4
"Cold wash" was room temperature water containing 1% detergent.
"Hot wash" was ~100C water containing 1% detergent.
1 Oven dry for 4 hours.
2 Rinsing was not sufficient to remove pesticides, but a room temperature wash was not
3 Only a hot detergent water wash and rinse was tested.
4 A hot detergent water wash, hot water rinse, and oven drying (~117C, 24 hr) removed
step (i.e., solvent rinsing) serves no useful pur-
taminated. For these materials, ease of decontam-
pose and thus could be eliminated from all
ination is a function of the analyte, the rigidity
and sorptive nature of the material, and the con-
The data from this study also indicate that
tact time for sorption and desorption.
washing is not necessary to remove VOCs and
Volatile organics are readily removed from
nitroaromatic compounds if the materials are
PVC test pieces that have been exposed to low
oven dried for four hours at 105C. We did not
ppm levels for up to 24 hours simply by washing
pursue testing the effectiveness of using only
with a hot detergent solution and rinsing with
oven drying for removing pesticides, because we
hot DI water. For more sorptive polymers, such as
felt that detergent washing was essential to
PTFE, additional oven drying is necessary for
effective decontamination. Apparently oven dry-
This study shows the importance of hot air
out of the polymer.
drying for decontaminating the more sorptive
Pesticides are readily removed from most
materials. While it would be a departure from
polymeric materials by using a hot detergent
currently used protocols, there are several ways
wash and hot water rinse. LDPE was found to be
that equipment could be heated in the field. A gas
the exception to this, and could not be adequately
oven or an electric oven with a generator could be
cleaned using this method if the exposure times
set up in the field. Another possibility would be
were 24 hours. This tubing material was also the
to place an oven in a small trailer or in any build-
most sorptive material tested. Washing followed
by oven drying did substantially improve remov-
haps even a hair dryer could be used. Our next
al of these contaminants. Again it appears that
study will examine this issue further.
oven drying speeds diffusion of the organic out of
There are two decontamination issues that
have not been explored at this time but should be
This study also showed that solvent rinsing
addressed at a later date: the effect of even longer
did not aid in the removal of VOCs from these
exposure times and the effect of exposure to
surfaces. While solvent rinsing did improve
either neat organic chemicals or to aqueous or-
removal of pesticides from LDPE slightly, oven
ganic solutions at very high concentrations.
drying was much more effective. These findings
Longer exposure times may be significant when
are important because this means that a consider-
decontaminating devices that have been left in a
ably cumbersome, expensive, and hazardous