EMD545b Lecture #5

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Nov 14, 2013 (3 years and 8 months ago)

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Controls in Biosafety I

EMD545b Lecture #5


Facility Design &

Engineering Controls



Facility Design Overview


Goals:


Separation of hazardous work from public
spaces (isolation of lab, prevent accidental
release)



Controlled airflow


product protection vs. personnel protection


combination of both?


negative pressure, air changes per hour

Facility Design Overview


Security/Life Safety Elements


fire rated doors


emergency lighting


Intrusion alarms (motion detectors, etc.)


restricted access (locks, keycard)


lock boxes, locked storage equipment


background checks on personnel

Facility Design Overview

Secondary Barriers


BSL1
-

BSL4 Laboratories


BSL1
-

basic lab


BSL2
-

basic lab + aerosol confinement


biosafety cabinet


BSL3
-

containment laboratory


2 door separation from building occupants


BSL4
-

maximum containment laboratory


separate building from general research population

Biosafety Level 1 Laboratory


Door


Sink


Easily cleaned work
surfaces


Impervious bench
tops


Sturdy furniture


Windows fitted with
fly screens

BSL2 Laboratory


BSL1 Lab plus:


lockable doors


chairs covered with non
-
fabric material


Biosafety cabinets installed as needed


eyewash available


negative airflow, non
-
recirculation
recommended


door closed when work is in progress


autoclave within facility

Signs and Labels


Biohazard warning labels on equipment

Biosafety Level 3


“The laboratory has special
engineering and design features.”










CDC/NIH BMBL, 5th Ed. 2007

BL3 Lab Design Elements


2 door entry (ante
-
room, airlock)


Solid easily cleanable surfaces (floor, walls,
ceiling)


Coved floors


Sealed penetrations


Lighting flush to ceiling


Hands
-
free sink near exit door


Eyewash/shower station


Pass through autoclave


Wash hands
after removing
PPE at the
hands
-
free sink

Eye/face wash: understand how to use, flush at
least weekly, and identify closest station outside the
BSL
-
3 lab (in event of release outside of
containment)

Signs and
Labels


BL3 Door Sign


agent name


entry requirements


emergency contact(s)


lab personnel


safety personnel


campus emergency
responders




BL3 Lab Design Elements


Negative airflow (into lab)


Most negative at rear of lab


> 12 air changes per hour


-
0.05”H20 pressure diff.


Dedicated exhaust fan


Exhaust/supply interlock


Exhaust velocity >3000 fpm, away from
intakes, people


Direct exhaust, no recirculation


BL3 Lab Design Elements


Airflow monitor, gauges


CO2/N2 feed from outside


Keycard, locked access


Doors open inward, self
-
closing


Access fixtures from outside space


Door sign at entry


Class II BSC


Canopy exhaust over BSC


Means of communication to areas outside lab


BSL
-
3 Lab Design

Supply Fan
-

interlocked with
Exhaust Fan, > 50 ft away from
exhaust

Exhaust stack velocity
> 3000 fpm, away
from air intake

Exhaust HEPA filter, in
accessible location for
testing, minimize
contaminated ductwork

-
0.05” to
-
0.1”
H20 pressure
diff. at each
door

BSL
-
3 Lab Design

Controlled
airflow into
the lab

Visible
airflow
indicator
at each
entry

12


15 Air
Changes per
Hour (constant
flow)

Exhaust > supply
by 15% or 100
CFM

Sealed
penetrations
(non
-
shrink
sealants)

Dedicated exhaust
fan, no
recirculation

Dedicated
supply fan
preferred

BSL
-
3 Lab Design

Positive seal
dampers on each
side of exhaust
filter

Positive seal
damper on supply
air duct(s)

Pass
through
auto
-
clave

Canopy/thimble
over biosafety
cabinet

Class II
Biosafety
cabinet

Centrifuge with
aerosol
containment

Audible &
visual airflow
alarms

BSL
-
3 Lab Design

Lighting flush with
ceiling with access
from outside
containment

Solid ceiling and
walls

Monolithic floor
with coved wall
base

Gases (CO2/N2)
piped into lab from
outside containment

Access
to repair
of
equip.
from
outer
area

Vacuum
system
HEPA
filtered

Benches
resistant to
chemicals
used

BSL
-
3 Lab Design

Emergency back
-
up power for fans
and equipment

Bag
-
in bag
-
out filter
housing

Ports pre/post exhaust
filter for HCHO
decon./sampling

Trained
personnel

Supply HEPA as
backflow prevention
BSL
-
3 AG, Canada
BSL
-
3

BSL
-
3 Lab Design

Automatic or
hands
-
free
sink near exit

Eye Wash and
Emergency
Shower

Backflow
prevention on
sink

Two
door
entry
from hall
corridor

Biohazard
door sign

Secure
keycard
access
door

Effluent Sterilization
Tank (BSL
-
3 AG/BSL
-
4)

BSL
-
3 Lab Design

Motion
detectors,
intrusion
alarms

Phone, fax


to outside

Potential for separate
clean and dirty change
anterooms w/
personnel shower

Fire sprinklers

Consideration of
back
-
up exhaust fan

Consideration of
back
-
up exhaust
HEPA

Locked boxes, locked
equipment (biosecurity)

BSL
-
3 Lab Design

Ducts under negative
pressure within the
building

Minimize length of
contaminated ductwork

Alarms to 24/7
Control Center

Contaminated ducts labeled
w/biohazard symbol

Sealed
windows if
present

Glass break
alarms

Anteroom
or airlock

Surface mounted
electrical outlets

BSL
-
3 Lab Design

Floors: heat seamed
vinyl or poured epoxy

Walls:
concrete
block,
cement
board, plastic

Wall finishings: enamel,
epoxy, acrylic latex

Ceilings: similar to
walls

Doors
open
inward,
& self
-
closing

Preparation Procedures


Entry
Procedures


Verify airflow


Enter ante room


Close outer door


Sign log book


Don PPE


Supplies


Enter laboratory

For work in a Biosafety Cabinet




solid
-
front or wrap
-
around gown




gloves (double
gloving)




face protection (face
shield or mask and
safety glasses
)

Use of a HEPA
-
filtered PAPR for additional
protection during high
-
risk research procedures

For work outside a Biosafety cabinet


solid
-
front or wrap
-
around gown or jump
suit


gloves (double gloving)


face protection (face
shield or mask and safety
glasses)


Respiratory protection if
aerosols are generated

Autoclave located
within BSL
-
3
Laboratory

All waste from BSL
-
3
lab must be
autoclaved prior to
disposal

Label autoclaved BSL
-
3
waste as “Pathological
Waste” for incineration

BL4 Lab
-

Max Containment


Containment Lab Planning Team


Project managers, engineers, architects,
electricians, HVAC, controls, safety, researchers,
USERS!


Formal program document of requirements


description of all proposed activities


#’s (personnel occupancy)


major equipment requirements


space allocation


general environmental control criteria


facility controls

Containment Lab Planning Team


Questions:


Specific single project?


Future changes, government regulations?


Flexibility in design?


Pathogenic microbes used?


Quarantine areas needed?


Animals? #’s? Species?


Treatment of liquid or air effluents?


Transitional areas needed?


Finishings, Services (water, vacuum, gas, air, etc.)


Commissioning/Verification

Communication



Local/state public health offices


Public affairs office


Biosafety Committee


Citizens (neighbors)


Toronto debacle


Winnipeg’s “accident”


CDC (in the shadow of Emory University)


The BU BSL4 Lab

Community Design Wish List


HEPA filtered exhaust air


Alarms & supply/exhaust interlock


Emergency back
-
up power (fan, biosafety
cabinets, freezers)


Effluent sterilization system


Pass through autoclave


Shower


Community Design Wish List


True airlock


Separate clean (entry) and dirty (exit)
anterooms


Glove boxes


Ducted or canopy connected biosafety
cabinets


Dunk tanks, pass through autoclaves, facility
sterilization system


Backflow prevention

Community Design Wish List


Trained architect/planners/builders


Trained research and safety staff


Initial and ongoing commissioning


Written facility policy manual


Emergency procedures known and practiced


Focus on eliminating community exposure


Not in my backyard!


Engineering Controls


Primary Barriers


Mechanical devices that minimize exposure


Must be applied before work practices and
personal protective equipment


Chemical Fume Hood


Room air drawn into
front opening


Direct ducted exhaust
to exterior of building
at roof level


100 fpm inflow
velocity


dilution of toxic,
flammable chemicals

Class I Biosafety Cabinet


HEPA
-
filtered fume
hood


Protects worker and
environment


No product protection


inflow velocity 75 fpm


Exhaust to room or
hard
-
ducted

Class II Type A1 Biosafety Cabinet


inflow velocity 100 fpm


70% air recirculation


Protection of worker,
product, and environment


Class II Type B2 BSC


Total exhaust BSC


Can use small quantities
of chemicals or
radioactive materials

HEPA
-
filtered Gloveboxes


Animal Care Containment


Cage dumping station


Confinement of
pathogenic waste,
allergens

Clean Bench
-

Horizontal Flow


Product protection
only


Air blown at operator
from across work area


Not for use with
potential biohazards,
cell culture work, or
allergens


Sharps


Percutaneous exposure risk



employ safe work practices


utilize safe sharp devices


Aerosol risk


work practices, containment equipment for confinement

Safe Sharps Devices


Sharps with Integrated Shields


Safer Products



Mylar wrapped glass
capillary tubes





Plastic Vacutainers

Other Engineering Controls


Animal Care & Use


microisolater cages, ventilated cage racks


ventilated cage racks


poles & collars (NHP’s)


squeeze
-
back cages


Spill
-
clean up


tongs, forceps, broom & dust pan, manila folder


paper towels, bench matting

Engineering Controls


Gasketed blenders, homogenizers


Cotton plugs, filters for flasks in shakers


filtered pipette tips


HEPA and hydrophobic vacuum line filters


Plastic pipettes


Gas burners w/ shield, microincinerator


Centrifuges


interlock, solid cover, safety buckets, O
-
rings


Transport Containers


Rigid Medical Waste Containers


For items that could
puncture a bag


Never allow to overfill

Reusable Sharps


Use tongs to handle


Place in disinfectant
bath


Use labeled leak
-
proof
container


15 minute decon prior
to handling


Clean and terminal
disinfection

Plastic for Sharps


Avoid glass pasteur
pipettes


Plastic transfer
pipettes


Plastic aspiration
pipettes


Other plastic products

Centrifuge Containment


Load/unload in BSC


Wait 2 minutes after
run to allow aerosols
to settle


Decontaminate
centrifuge and buckets
after each use

Mechanical Devices for Sharps


Keep hands away
from needles


Use mechanical
methods for removal


Only use if absolutely
required as part of a
process

Scalpel Removal Device


Confinement at Source


Vacuum System Protection


Medical Waste Receptacles


Biohazard bags and
boxes


Sharps containers