Transcript Decontamination is - Brownfields Toolbox

Decontamination
Instructional Goal
• understand the purpose and
principles of decon
• see the potential for work-related
exposure during decon
• demonstrate decon principle is
the field
Decontamination is . . .
process of removing or
neutralizing contaminants
that have accumulated on
personnel and equipment
Why Decon?
• Protect personnel by reducing the
transfer of harmful materials into clean
areas;
• Helps prevent mixing of incompatible
chemicals;
• Protects the community by preventing
uncontrolled transportation of
contaminants from the site.
Decontamination Plan
• Establish methods and procedures
• Determine appropriate decon methods
• Determine number and layout of decon
stations
• Establish procedures to prevent
contamination of clean areas
• Determine decon equipment needed
• Establish methods for disposing of
clothing and equipment
S O Ps for
Decontamination
Minimize contact with waste
• Stay out of the contaminant
• Use remote sampling
• Protect equipment
• Wear disposable outer garments
• Use disposable equipment when possible
• Encase contaminant sources
S O Ps for Decontamination
Maximize Worker Protection
• Check PPE before use
• Proper dressout
procedures
• Training and retraining
Decontamination
Maximize Worker Protection
Fasten all fasteners
&
Seal all gaps
Levels of Contamination
• Surface - easy to detect and remove
• Permeation
– Contact time
– Concentration
– Temperature
– Size of molecules and pore space
– Physical state of waste
Key Questions
Is the decon method effective for
the specific substances
present?
Does the method itself pose any
health or safety hazards?
Decontamination Methods
Isolation-Dry Decon
Contaminants end up in the Bag
“Bag and Stash”
Hazardous
Waste
Decontamination Methods
Physical Removal
• Loose contaminants
• Adhering contaminants
– Solidification
– Rinsing
• Volatile Liquids
Decontamination Methods
Chemical Removal
•
•
•
•
Dissolving Contaminants
Surfactants
Neutralizers
Disinfection / Sterilization
Testing for Effectiveness
• Visual Observation
– Natural & UV Light
• Wipe Sampling
• Cleaning Solution Analysis
• Testing for Permeation
Health and Safety Hazards of
Decontamination
• Consider compatibility of decon
solutions or other decon
materials BEFORE use
• Consider the effect of the
decon method on decon
personnel and workers BEFORE
use
Decon Facility Design
• Depends on site-specific factors
• Provides an organized process to
reduce levels of contamination
• Flow patterns and separate stations
Decontamination
Disposal Methods
All equipment and
materials used for
decontamination
must be
decontaminated or
disposed of properly
Decontamination
Personal Protection
Decon workers stationed
closest to the Exclusion
Zone need more PPE than
decon workers stationed
near the Support Zone
Basic 6 - Step Decon Line
1) Equipment Drop
2) Gross Decon - wash / rinse boots &
gloves
3) Air Tank Change
4) Boots, gloves, & outer garment off
5) SCBA Facepiece Removal
6) Field Wash
EQUIPMENT
DROP
1
ENTER
HOT ZONE
SHOWER
STALL
Field wash 5 GAL
WITH
boots and PAIL
WASHWATER
CPC
3 Get full air tank
and return
Bag for
OR
Drop SCBA SCBA
2
RETURN
WITH
NEW AIR
TANK
SPARE
AIR
TANKS
Leave SCBA facepiece on
Bag
Drum for
Step into
55-85
bagged
bag and
gallon
CPC
CLEAN
peel CPC off
SIDE
and into bag
Tub for
Remove SCBA
5
SCBA
facepiece and
facepiece
inner gloves
4
DIRTY
SIDE
SUPPORT ZONE
6
Wash face
and hands
Tub with washwater
and towel
Decontamination
Emergency Decontamination
• Procedures must be
established
• Stabilize first or decon
first???
• Protect medical personnel
• Dispose of contaminated
stuff
Accident or Injury
Yes
Life-saving
Procedures
Required?
Contaminants Hazardous?
Yes
No
Grossly Decontaminate
or Cover
or Wrap
Contaminated Areas!
Decontaminate as
much as possible!
Further Medical
Attention or
Surveillance
Needed?
Yes
Transport to
Medical facility!
No
Perform Life-Saving
Procedures!
No
Additional
Emergency Care
Needed?
Yes
Report to
Safety Officer!