PHPR 2011Sep DHS AllHazardsReceiptFacilityBestPracticesGuidelines

7/24/2019 PHPR 2011Sep DHS AllHazardsReceiptFacilityBestPracticesGuidelines

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All Hazards Receipt Facility

Best Practices GuidelinesA Tiered Approach

September 2011

UNCLASSIFIED//FOR PUBLIC RELEASE



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A Tiered Approach

September 2011

All Hazards Receipt FacilityBest Practices Guidelines




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All Hazards Receipt Facility Best Practices Guidei



Prepared by:

The U.S. Army Edgewood Chemical Biological Center (ECBC)

Submitted to:

Donald A. Bansleben, Ph.D.

Science and Technology Directorate (S&T)

U.S. Department of Homeland Security (DHS)

Division: Chemical and Biological Defense Division

Thrust: Chemical

Program: Chemical Attack Resiliency

Project: Fixed Laboratory Response Capability

Performer: ECBC

Appropriation Year: FY09

Budget Authority: No Year R&D

Program Manager: Donald A. Bansleben, Ph.D.

Lead Support Staff: Erik Lucas, Ph.D.; Neal W. Cole

Modification to HSHQDC-06-X-00503


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All Hazards Receipt Facility Best Practices Guide



Disclaimer

This document was prepared for the Science and Technology Directorate of the U.S. Department of

Homeland Security (DHS) under Interagency Agreement HSHQDC-06-X-00503. This document ispresented here in its final version. The contents of this document do not necessarily reflect the views

of the U.S. Department of Homeland Security or any other parts of the U.S. Government, nor do DHS

or any other parts of the U.S. Government endorse the purchase or sale of any commercial products or

services. Peer review comments should be submitted to the DHS program manager below.

Donald A. Bansleben, Ph.D.

Science and Technology Directorate

U.S. Department of Homeland Security

245 Murray Lane

S&T CBD Stop 0201

Washington, DC 20528-0201

202-254-6146

Email: [email protected]


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All Hazards Receipt Facility Best Practices Guidev



TableofConten

ts

TABLE OF CONTENTS

Disclaimer .....................................................................................................................................................iii

TABLE OF CONTENTS ................................................................................................................................... iv

TABLE OF FIGURES ....................................................................................................................................... vi

1.0 Introduction ...........................................................................................................................................1

1.1 Scope and Application .......................................................................................................................1

1.2 AHRF Effectiveness ............................................................................................................................2

1.2.1 Containment ............................................................................................................................2

1.2.2 Assurance .................................................................................................................................2

1.2.3 Training ...................................................................................................................................3

1.3 Assumptions ......................................................................................................................................4

2.0 Lessons Learned ......................................................................................................................................5

3.0 Tiered Approach .....................................................................................................................................8

3.1 Tier 1 Description ..............................................................................................................................8

3.2 Tier 2 Description ............................................................................................................................11

3.3 Tier 3 Description ............................................................................................................................14

3.4 Summary .........................................................................................................................................18

4.0 Equipment, Design, & Operational Considerations ............................................................................19

4.1 CBR Filtration ..................................................................................................................................19

4.2 Capabilities and Limitations of Carbon Adsorbers ...........................................................................20

4.3 Glovebox Considerations .................................................................................................................21

4.4 Class II BSCs and Fume Hoods ........................................................................................................24

4.5 Testing of CBR Containment & Filtration Systems ............................................................................27

4.5.1 Leak & Performance Testing ...................................................................................................27

4.5.2 Monthly Inspection ...............................................................................................................28

4.6 Filter Service Life & Replacement Considerations ............................................................................29

4.6.1 Carbon Adsorber Service Life .................................................................................................29

4.6.2 Carbon Adsorber Replacement Considerations ......................................................................294.6.3 HEPA Service Life & Replacement Considerations .................................................................. 30

4.7 Design considerations for building decontamination ......................................................................31

4.7.1 Retention of CBR Agents Released into a Building ................................................................. 31

4.7.2 Design objectives to facilitate decontamination .....................................................................31


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5.0 AHRF Prototype Documentation .........................................................................................................33

5.1 Introduction ....................................................................................................................................33

5.2 Features of the AHRF Prototype .......................................................................................................36

5.2.1 AHRF Layout ..........................................................................................................................36

5.2.2 Sample Movement & Primary Containment ...........................................................................37

5.2.3 Anteroom & Main Entrance....................................................................................................385.2.4 Change Room ........................................................................................................................38

5.2.5 BSL-2 Area .............................................................................................................................38

5.2.6 Bleaching Station ...................................................................................................................38

5.2.7 BSL-3 Area .............................................................................................................................39

5.2.8 HVAC/Filtration Room ..........................................................................................................41

5.2.9 Utility Room .........................................................................................................................41

5.2.10 Airflow Through the AHRF (HVAC Systems) ........................................................................41

5.2.11 Color Coding & Labeling .....................................................................................................42

5.2.12 Electronic & Computer Systems ...........................................................................................42

5.2.13 Security Cameras & Closed Circuit TV System ......................................................................42

5.2.14 Intercom System ..................................................................................................................43

5.2.15 Fire Alarm & Smoke Detectors .............................................................................................43

5.2.16 Electrical Power Systems & UPS ...........................................................................................43

5.2.17 Water ...................................................................................................................................44

5.2.18 AHRF Entrances, Exits & Interior Doors ...............................................................................45

5.2.19 Mobile Platform Considerations ..........................................................................................45

Appendix A List of CBR Materials ...........................................................................................................47

Glossary ......................................................................................................................................................48

Bibliography ...............................................................................................................................................51


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All Hazards Receipt Facility Best Practices Guidevi



TABLE OF FIGURES

Figure 1. AHRF Prototype Floor Plan. ............................................................................................................. 8

Figure 2. Photograph of the AHRF Prototype Exterior. ................................................................................... 9

Figure 3. Photograph of the Class III and Class II A2 Biosafety Cabinets in the AHRF Prototype. ................... 9

Figure 4. Photograph of the Receiving Laboratory (BSL-2) in the AHRF Prototype........................................9

Figure 5. Overview of the AHRF Protocol (Tier 1). ...................................................................................... 10

Figure 6. Example Glovebox & Floor Plan for a Tier 2 AHRF. .......................................................................11


Figure 8. Range of Glovebox Types for Tier 3. ..............................................................................................14


Figure 10. Example Filter Unit for AHRF Applications. ................................................................................20

Figure 11. Class III BSC (Glovebox) as Illustrated in the BMBL. ................................................................... 22

Figure 12. Interior Design Concept of the AHRF Prototype..........................................................................36

Figure 13. Photograph of a Bleaching Station. .............................................................................................39

TableofFigur

es


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1.0 Introduct ion

1.1 Scope and Appl ication

The U.S. Department of Homeland Security (DHS), U.S. Environmental

Protection Agency (USEPA), U.S. Department of Defense (DoD), Federal

Bureau of Investigation (FBI), and the Association of Public Health

Laboratories (APHL) have combined efforts to develop, construct, and

implement All Hazards Receipt Facilities (AHRFs) for screening samples

of unknown and potentially hazardous character prior to laboratory analysis.

The effort was initiated in response to requests from state and federal agencies,

particularly public health and environmental laboratories, to help protect

laboratory facilities and staff.

The first two AHRFs are in operation at the Wadsworth Center, a public

health laboratory of the New York State Department of Health, and the

USEPA New England Regional Laboratory in Chelmsford, MA (EPA Region

1). Valuable information has been obtained through these AHRF prototypeoperations as described in this report.1In addition, an AHRF protocol

was developed and published by the DHS and EPA in September 2008

(publication DHS/S&T-PUB-08-0001, EPA/600/R-08/105). This protocol

is directed at screening unknown samples for chemical, radiochemical, and

explosive hazards prior to laboratory analysis. A supplement to the protocol

was recently completed and published in December 2010 (publication

EPA/600/R-10/155).

With the AHRF protocols detailed in other documents, the scope of this

document is to describe the facility and equipment design principles in

such a way that others may apply these principles using a graded approachin keeping with the organizations available funding. To this end, a tiered

approach is suggested to encourage laboratories to adopt an AHRF capability

and implement AHRF protocols.

The Wadsworth Center, with funding provided by DHS, has developed and

implemented a training program on the use/maintenance of an AHRF and on

the application of the screening protocol.

Implementation of the guidance provided in this document should reflect the capabilities and

goals of the particular implementing entity at a given location. Applicable laws, regulations, and

guidance must be considered in addition to the guidance provided in this document.

The scope of this document

is to describe All Hazards

Receipt Facility (AHRF) des

principles in such a way

that others may apply these

principles at various levels o

facility investment. A tiered

approach is proposed to ena

laboratories to adopt an AH

capability and implement A

protocols.

1 The purpose of presenting detailed information about the AHRF prototype design in section 5 of this guide is

not to make it the standard but to allow others to understand the design considerations and choices made so

that the reader can apply what is appropriate for their laboratory. This prototype design includes containment

and engineering controls that are defined in this document as a tier 1 AHRF capability.


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All Hazards Receipt Facility Best Practices Guide2



1.2 AHRF Effect iveness

1.2.1 Containment

Effective containment of potentially harmful substances and materials is one

of the fundamental design principles of the AHRF.2This principle is well

established in the Biosafety in Microbiological and Biomedical Laboratories(BMBL)document, as well as its counterpart chemical agent safety and radiological

safety programs. To paraphrase the BMBL, the term containment is used in

describing safe methods, facilities, and equipment for managing hazardous

agents in the laboratory environment where they are being handled or

maintained. The purpose of containment is to reduce or eliminate exposure

of laboratory workers, other persons, and the outside environment to

potentially hazardous agents.

The effective use of gloveboxes, fume hoods, filtration systems, and

air handlers fall within this definition of containment. These topics are

discussed in detail in this guide.

It is important to keep in mind that containment measures for the AHRF

should provide adequate protection for the safe handling of samples that

might contain hazardous biological, chemical, radiological, or explosive

material. A mixed threat is also possible. Measures that provide protection

against a single threat category are therefore inadequate when used alone for an

all-hazards application.

1.2.2 Assurance

The AHRF and its protocols should provide both quality assurance and

safety assurance. These matters are generally handled by different partsof a laboratory operation, but are both important to AHRF operation.

Quality assurance is needed to meet the standards necessary for scientific

and evidentiary acceptance of the results obtained by the AHRF as well as

the condition and authenticity of samples forwarded to a confirmatory

laboratory or otherwise preserved for evidentiary purpose. Safety assurance

is required for protection of people, laboratory, and the environment.

Implementation of proper qualification and selection standards for AHRF

staff and periodic proficiency testing to ensure that those standards are

maintained are important elements of the assurance program. Similarly,

proper design of the facility, installation of appropriate engineering

controls, effective procedures and training of personnel, and performance

testing of safety equipment such as gloveboxes, fume hoods, filtration

AHRFEffectivene

ss

CONTAINMENT, ASSURANCE

& TRAINING as described

in this section are the three

key elements to AHRF

effectiveness and safety.

2 This design principle is reflected in the three primary reference documents for this guide, which are: Biosafety

in Microbiological and Biomedical Laboratories (BMBL), Fifth Edition, February 2007; Army Pamphlet 385-

61 Toxic Chemical Agent Safety Standards, 17 December 2008; and Unified Facilities Criteria (UFC) 4-024-01

Security Engineering: Procedures for Designing Airborne Chemical, Biological, and Radiological Protection for

Buildings, 10 June 2008. Website URLs for these documents are provided in Section 4.0.


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systems, air barriers, and the like will provide assurance that effective

systems are available and operating as intended.

In addition to maintaining proper safety and environmental standards, the

AHRF and its protocols should maintain chain of custody consistent with

evidentiary requirements, not cross-contaminate, adulterate or otherwise

compromise the sample, and preserve an adequate amount of sample

for confirmatory testing and evidentiary purposes. The local FBI WMD

Coordinator, laboratory director, and appropriate local authorities should

be consulted on the development and implementation of these practices.

1.2.3 Train ing

Laboratory staff as well as facility/engineering support personnel should

be properly trained in their respective AHRF functions to ensure safe and

effective AHRF operations. This training should reflect the specific concerns

and operating environment for each organization that undertakes an AHRF

capability.

The Wadsworth Center has been tasked by DHS to develop hands-on training

that leverages the availability of an AHRF prototype at the Wadsworth Center

as well as the experience gained by Wadsworth Center personnel in AHRF

practices. Additional information about Wadsworth Center conferences and

workshops is available at http://www.wadsworth.org/conferences/index.htm .

Two of the course descriptions follow.

Course 1: All Hazards Response Training for Laboratory Personnel

This hands-on training program will concentrate on the All Hazard

approach to identifying unknown threat substances and will follow

the established DHS/EPA All Hazard Receipt Facility testing algorithms.

An integrated approach will be taken in order to tie in chemical,

biological, radiological, and explosive hazards. Emphasis will be placed

on appropriate containment requirements, testing options, and workflow

considerations as well as key characteristics of hazardous agents. Public

health laboratories will benefit from this training as they begin to explore

the necessity of melding existing lab testing with an all hazard screening

approach. The final days of this course will include testing of unknowns

according to the DHS/EPA algorithm available on the APHL website.

Course 2: All Hazards Receipt Facility Training for Engineering and Support Personnel

This course will focus on training facilities staff and engineers on

the state-of-the-art AHRF air handling, security, liquid handling, and

biosafety systems. Staff will be trained in the routine maintenance and

upkeep of these highly specialized units and will gain an understanding

of the requirements for their annual certification. Emphasis will be placed

on critical considerations needed for the integration of a stand-alone

Training, and the awareness

created through training, is

vital part of any AHRF oper

regardless of the level of fac

investment, even for those

laboratories that do not inte

to receive all-hazards or mix

threat samples.


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All Hazard Receipt Facility or as a retro-fit space within an existing

laboratory structure. The extensive experience gained by the Facility

and Engineering staff at the Wadsworth Center during the integration

of the AHRF into the Public Health Laboratory will be shared with

attendees in order to facilitate their experience with such a complex

project. This course will include both operational and didactic

components.

Additional courses and training material are available from other sources.

For example, the National Select Agents Registry (NSAR) is an important

information source as it oversees activities involving possession of

biological agents and toxins that have the potential to pose a severe threat to

public, animal or plant health, or to animal or plant products. The various

Select Agent Regulations and other useful information on biohazards are

available from the NSAR website at http://www.selectagents.gov/ .

1.3 Assumptions

It is assumed that the information contained in this guide will be reviewedand applied by a multidisciplinary team working under the guidance of a

laboratory director.3The team should include expertise across the following

disciplines: laboratory building design, occupational safety and health, and

forensic science laboratory practices.

The AHRF Protocol (publication DHS/S&T-PUB-08-0001,

EPA/600/R-08/105 of September 2008) contains additional assumptions

regarding AHRF staff and laboratory procedures.

AHRFEffectivene

ss

3 The term laboratory director as used here refers to the person serving in the position with ultimate authority

and responsibility for the day-to-day operation of the organization in which the AHRF resides. This is not

intended to refer to the team leader who is likely to be one of the subject matter experts who leads the team

and reports to the laboratory director.


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2.0 Lessons Learned

A summary of the findings obtained to date through this AHRF Best Practices

project follows. These findings are based on site visits to the two AHRF

prototype operations and numerous discussions with AHRF subject

matter experts.2.1. AHRF prototypes are serving a useful function at the Wadsworth Center

and EPA Region 1 laboratories in demonstrating the utility of a specially

designed facility and protocol for screening samples of unknown and

potentially hazardous character prior to laboratory analysis (Detailed

design specifications of the AHRF prototypes are provided in Section 5).

The overall design of the AHRF in terms of floor plan, sample flow, and

work space is advantageous, especially given the design constraint of a

mobile platform.

2.2. The dual-sided feature of the glovebox was noted as useful in allowing

two people to work simultaneously, therefore increasing efficiency andproductivity.

2.3. One lesson learned in this project is that mobility of the AHRF is not

particularly important in applications where the AHRF serves to protect

a particular fixed-site laboratory and therefore is unlikely to be moved

within its service life. An AHRF capability integrated into a permanent,

fixed-site building would provide benefits of reduced energy and

maintenance costs and enhanced dual-use.

2.4. It was noted that the capability provided by the AHRF to safely produce

subsamples, and, in some cases, dilute dissolved solutions, which can

then be brought into the laboratory for further analysis is a key function

of the AHRF.

2.5. As a receipt facility used in conjunction with a laboratory, the AHRF was

intentionally designed without a GC-MS or other advanced laboratory

analysis instruments. However, some of the current designs for AHRF

suites to be built in new laboratories, as well as the design of mobile

laboratories such as those used by the National Guard Civil Support

Teams, include a GC-MS. In addition to unknown sample analysis, the

GC-MS (or another analytical instrument) could be used to monitor

ASZM-TEDA filter performance. If more advanced laboratory analysis

instruments are added to the AHRF, it is important to consider theadditional design requirements that these systems may introduce.

For example, the addition of a GC-MS to analyze chemical warfare

agent (CWA) would require venting of the instrument to the AHRF

engineering controls or dedicated ASZM-TEDA filters to prevent

operator exposure to CWAs.

To safely produce subsampl

and, in some cases, dilute

dissolved solutions, which c

then be brought into the m

laboratory for further analy

a key function of the AHRF.

Mobility of the AHRF is not

particularly important in

applications where it serves

protect a particular fixed-sit

laboratory and therefore is

unlikely to be moved within

service life.


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2.6. The AHRF prototypes have 16x16 interlocking, double-door

air-locks. In practice, samples are often delivered in coolers as the

transport container with both primary and secondary containers

within the cooler. Many of these coolers are too large to fit within

the air-lock and also too tall for the fixed shelf of the bleaching

station/fume hood. Subject matter experts (SMEs) disagree on how

to handle this operational consideration. One option is to makethe air-lock opening larger; a second option is to limit the size

of the transport container; a third option is to open the transport

container outside of the AHRF provided that this does not result in an

unacceptable level of risk to personnel (e.g., the sample is contained

inside an air-tight primary container, and perhaps a secondary

container, within the cooler). All of these options present their own

benefits and risks. Ultimately, the selection of a mitigation strategy for

this operational consideration must be informed by a risk assessment

performed by the laboratory staff and safety professionals.

2.7. It was noted that dual use of the AHRF is important. At Wadsworth,this is currently being done through utilization of the AHRF for

training and proficiency testing. At EPA Region 1, it was noted that

a future AHRF capability could be integrated into the laboratorys

normal sample receipt area. As such, sample flow into the laboratory

could be directed through one path for high-hazard samples

(the AHRF side) and another path for all other samples

(the normal sample processing side).

2.8. The notion of a tiered approach was discussed and received

widespread approval in concept. Further details of such an approach

are presented in section 3 of this guide. The rationale of this approach

is to enable a level of AHRF capability at reduced costs, perhaps as

an interim step until the next laboratory construction or renovation

project in a given area, or as a permanent measure that adequately fits

the needs of a given laboratory.

2.9. Best practices and the adoption of local standard operating procedures

(SOPs), including testing and maintenance schedules appropriate for

a given AHRF, and local hazard analysis are needed in addition to the

Biosafety in Microbiological and Biomedical Laboratories (BMBL)

and other standards. Existing national standards do not fully cover the

AHRF application, and AHRF usage and environmental factors will vary

from laboratory to laboratory. Further guidance on filter inspection,

testing, and replacement schedules are factors that need to be

addressed as experience is gained in AHRF operation. Such experience

will provide valuable data for refining SOPs, equipment selection, and

filter inspection, testing, and replacement schedules.

Current best practices in

designing AHRF exhaust air

systems (CBR filtration) call

for the utilization of two

High Efficiency Particulate

Air (HEPA) filters in series

with two ASZM-TEDA filters

as discussed in Sections 4.1

and 4.2.

LessonsLearn

ed


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2.10. Current best practices in designing AHRF exhaust air systems

encompass filtration of chemical, biological, and radiological hazards

(CBR filtration) and recommend the utilization of two HEPA filters

in series with two ASZM-TEDA filters. The ASZM-TEDA filters should

each have a minimum dwell time of 0.25 seconds with a sample port

provided between the ASZM-TEDA filters for periodic performancemonitoring. These design specifications were built into the AHRF

prototype and are discussed in detail in Sections 4.1 and 4.2 of this

guide.4

2.11. The capabilities and limitations of ASZM-TEDA filters are discussed in

Section 4.2. Other filtration materials and exhaust system components

are under development and can be leveraged by the AHRF community

in the future with some retrofitting. In retrofitting an exhaust system

for the AHRF prototype, consideration should be given to the

installation of an exhaust stack. The retrofitting of any exhaust system

should be accomplished in a way that preserves proper air flows and

pressure differentials.

2.12. An interagency effort led by the National Institute for Occupational

Safety and Health (NIOSH) has resulted in the recent creation of

respirator standards for use in atmospheres that contain chemical,

biological, radiological, and nuclear (CBRN) respiratory hazards. These

respirators are generally better suited for an all hazards environment

and therefore recommended for AHRF operators to have on hand in case

of a spill, equipment failure, or an emergency. Information about the

CBRN Respirator standards and a list of NIOSH-certified respirators are

available at http://www.cdc.gov/niosh/npptl/topics/respirators/cbrnapproved/apr/.

National Institute for

Occupational Safety and

Health (NIOSH) approved

respirators for use in

atmospheres that contain

chemical, biological,radiological, and nuclear

(CBRN) respiratory hazards

are recommended for AHRF

staff to have on hand in case

of a spill, equipment failure

or an emergency.

4 Sample ports were built into the glovebox filtration system for the AHRF prototype. The current

recommendation in this draft guide is to include sample ports in all newly constructed or refurbished filtration

systems within the AHRF.


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3.0 Tiered Approach

A suggested definition for each of the three AHRF capability tiers is

provided below and summarized in Table 1. All three tiers require training

and assurance programs as described in Section 1. These suggested

definitions are intended for discussion among the AHRF community.

Comments should be provided to the DHS program manager forconsideration in any future revision of this guide. While the current

material in this chapter emphasizes safety considerations associated with

AHRF tiers, operational impacts such as decreased throughput, increased

sample transfers between stations, increased decontamination burdens,

limitations of sample types/sizes, and the like should be considered so that

an informed cost-benefit analysis can be performed when selecting the

tier appropriate for a facility. As more quantitative information becomes

available, such data can be added to this best practices guide.

3.1 Tier 1 Description

Tier 1 can be defined as the full AHRF capability as embodied in the

AHRF prototype or equivalent. It need not involve a mobile platform.

A preferred approach for some laboratories is to incorporate these

capabilities into a permanent building. The tier 1 capability as suggested

here, however, does require a dedicated facility in the form of a separate

building, isolated suite, or mobile/modular facility to provide separation

from other laboratory functions. In this way, a minimal number of people

are exposed to the risk of a hazardous sample and robust containment and

engineering controls are provided to mitigate any hazard within the AHRF.

TieredApproa

ch

Tier 1 can be defined as

the full AHRF capability as

embodied in the prototype or

equivalent. It need not involve

a mobile platform but does

provide separation from other

laboratory operations and has

both primary and secondary

containment systems.

Figure 1. AHRF Prototype Floor Plan.


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As illustrated in Figure 1, the prototype design includes both BSL-3 and BSL-2 areas, a stainless steel Class

III biosafety cabinet (BSC)/glovebox, a second Class II A2 BSC connected to the glovebox, a fume hood or

bleaching station, and two HVAC systems. Figure 2 shows the exterior of the completed AHRF prototype.

It should be noted that the Class III glovebox and Class II A2 BSC in the BSL-3 area of the AHRF are

equipped with CBR filtration (Figure 3). This is also true of the bleaching station/fume hood (Figure

4) and BSL-2/3 areas of the AHRF prototype. Thus, primary containment is provided by the cabinets

and fume hoods, along with any additional containment (e.g., sample containers) used within this

equipment, while an additional level of secondary containment is provided by the facility itself.

Figure 2. Photograph of the AHRF Prototype Exterior.

Figure 3. Photograph of the Class III and Class II A2

Biosafety Cabinets in the AHRF Prototype.

Figure 4. Photograph of the Receiving Laboratory

(BSL-2) in the AHRF Prototype.

The AHRF protocol (publication DHS/S&T-PUB-08-0001, EPA/600/R-08/105) contains four major

operational steps: Sample Receipt and Transport Container Screen, Secondary Containment and Primary

Sample Container Screen, Sample Screen, and Document Results. In a tier 1 facility, the AHRF protocol can

be executed as developed without modification due to facility limitations. Figure 5 provides an overview of

the AHRF protocol as implemented in a tier 1 facility.

The cost to replicate the AHRF prototype as it is described in Section 5, or to create an equivalent tier 1

capability in an existing building, is estimated between $1M and $2M.


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TieredApproa

ch

Figure 5. Overview of the AHRF Protocol (Tier 1).


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Tier 2 can be defined as a dedicated room for AHRF operations which is

isolated from general laboratory air flow and is equipped with a stainless

steel Class III glovebox and a fume hood, both with proper CBR filtration.

Figure 6 illustrates one possible layout for a tier 2 facility.

Unlike tier 1, a single room is allocated to AHRF operations with the roomexhaust isolated from the HVAC return-air for the rest of the building. Supply

air is provided by the building HVAC system, and air is exhausted from the

room through the fume hood and glovebox. While room air intake to the fume

hood and glovebox will exit through CBR filters, some room air could possibly

exit the room into other parts of the building during a failure of the fume

hood and glovebox exhaust system. This is mitigated by minimizing leaks in

walls and ceilings and maintaining a negative room pressure. Construction of

air-lock access to the room will aid in maintaining proper negative pressure.

In addition, it is recommended that a bioseal damper be installed on the room

supply duct as an automatic check valve to ensure that contaminated air cannot

be backdrafted through the ducts in the event of an exhaust system failure.

Care needs to be exercised when balancing the supply air into the room.

This is necessary to avoid turbulence near the fume hood, as well as to

maintain proper negative pressure in the room.

Tier 2 can be defined as a

dedicated room for AHRF

operations which is isolated

from general laboratory air

flow and is equipped with a

stainless steel Class III glove

and a fume hood, both with

proper chemical, biological

radiological (CBR) filtration

Figure 6. Example Glovebox & Floor Plan for a Tier 2 AHRF.

Isolation from the HVAC return-air for the rest of the building is importantto mitigate the risk of exposing people in other parts of the building. Also,

such isolation mitigates the risk of interrupting other laboratory operations,

which otherwise could be adversely impacted should decontamination

beyond the tier 2 space be required.

The AHRF protocol can be performed in its entirety in a tier 2 facility

(Figure 7); however, minor adjustments must be made to how the protocol

is carried out because tier 2 lacks the Class II A2 BSC found in tier 1.


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TieredApproa

ch

Sample Receipt and Transport Container Screen is performed outside of

primary containment as described in the protocol and, therefore, could be

performed within a tier 2 facility as presented here. This could, for example,

be performed on the lab bench illustrated in Figure 6 provided that a

tier 2 AHRF is deemed acceptable to the implementing organization.

Secondary Containment and Primary Sample Container Screen is performedinside the bleaching station/fume hood. Again, this can be performed

within a tier 2 AHRF as a fume hood with CBR filtration is available.

Sample Screen is performed primarily in the glovebox, which poses no

problems for the tier 2 capability given that it includes a stainless steel

Class III glovebox with proper CBR filtration. The thermal susceptibility

test for explosives can be performed in the fume hood of the tier 2

facility as it will also have proper CBR filtration and air-flow face velocity to

mitigate risk.

Document Results calls for the resulting sub-sample and primary sample to

be prepared for delivery to the designated laboratory(ies) and/or samplingauthority and kept in the biosafety cabinet to await transfer. In a tier 2

facility, these packaged samples can be placed in the fume hood to await

transfer. Depending on the level of activity, storage space could become

insufficient and/or impede use of the fume hood to process new samples.

A significant difference between the tier 1 and tier 2 facilities is the

presence (or absence) of interconnected engineering controls. In tier

1 facilities, the engineering controls are connected through a series of

interlocked air-locks. This allows samples to remain under engineering

controls at all times. This will not necessarily be the case for all tier 2

facilities, particularly those that re-purpose existing engineering controlsto build an AHRF capability. In cases where the engineering controls are

not connected by interlocked air-locks (as shown in Figure 6), there

is an increased risk of accidental release and exposure to the operator.

Appropriate containment will be needed to move samples between the

fume hood and glovebox, and procedures for decontamination, packaging,

and monitoring of sample containers described in the AHRF protocol

will have to be strictly followed to ensure operator safety. In addition, the

movement of samples will increase the time required to process samples

and negatively impact sample throughput.

Basic CBR materials needed for AHRF applications include detectors,decontamination materials, and Personal Protective Equipment (PPE)

(A list of such items is provided in the Appendix). The investment needed

for a tier 2 capability as described above is therefore limited to the purchase

of a stainless steel glovebox and CBR filtration system with retrofitting to

an existing fume hood plus basic CBR materials. The initial investment

cost of a tier 2 capability is estimated in the range of $100K to $250K

depending largely on the type of glovebox purchased and the extent of

room modifications needed.


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Tier 3 can be defined as a portable glovebox having proper CBR filtration

used in a room which is isolated from building air flow and traffic when

needed for an AHRF operation. As such, it can be considered an improvised

AHRF capability using the lowest cost and minimal number of components

deemed acceptable to a given laboratory. For obvious reasons, this poses agreater risk to the people within the tier 3 room, others that are nearby, and

the environment. Nonetheless, this tier 3 capability provides a CBR primary

containment capability that may be lacking in even an otherwise high-

containment facility such as a BSL-3 or BSL-4 laboratory or comparable

environmental laboratory.

As with tier 2, the risk resulting from the limited equipment investment

of tier 3 can be mitigated to a certain extent through proper training of

staff in the handling of samples, use of PPE, detectors and decontamination

procedures. In addition, through training and awareness, procedures can be

implemented at a tier 3 operation to redirect higher risk samples to a tier 1or 2 facility as opposed to accepting them at the tier 3 facility.

The equipment investment for tier 3 as defined here is limited to the

purchase of a portable glovebox having a CBR filtration system and basic

CBR materials (A list of CBR materials is provided in the Appendix). The

glovebox can be made of stainless steel or thermoplastic such as acrylic.

Figure 8 shows two potential glovebox configurations that could be

used in a tier 3 facility. The use of soft glovebags, while cost-effective, is

not recommended. Since the primary sample container is opened in the

glovebox, it represents the area of highest potential contamination within

the AHRF. In addition, the AHRF protocol makes use of an exposed heating

element and several pieces of equipment with sharp edges, which could

puncture the glovebag and break containment. A loss of containment due to

accidental puncture of a soft glovebag would present a risk of exposure to

the operator that far outweighs the cost savings.

TieredApproa

ch

Tier 3 can be defined as a

portable glovebox havingproper CBR filtration used

in a room which is isolated

from building air flow

and traffic when needed

for an AHRF operation.

The use of soft glovebags,

while cost-effective, is not

recommended.

Figure 8. Range of Glovebox Types for Tier 3.


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The majority of the AHRF protocol can be performed in a tier 3 facility

(Figure 9). Adjustments must be made to how the protocol is carried out

because tier 3 lacks both a fume hood and a BSC. In addition, the thermal

susceptibility test for explosives must be eliminated due to safety concerns

as described in the Sample Screen section below.

Sample Receipt and Transport Container Screenis performed outside of primary

containment as described in the protocol and, therefore, could be performed

within a tier 3 facility. This could, for example, be performed on a lab bench

provided that a tier 3 AHRF is deemed acceptable to the implementing

organization.

Secondary Containment and Primary Sample Container Screenis performed inside the

bleaching station/fume hood in tier 1 and 2 facilities. Within a tier 3 facility,

all of this screening would be performed within the glovebox. This could

present challenges to the operator if the secondary containment is too large

to fit in the air-lock or takes up too much usable space inside the glovebox.

Unpackaging the primary sample container inside the glovebox means that alarge amount of solid waste will be generated in a potentially contaminated

area; this waste will have to be decontaminated and removed from the

glovebox frequently to prevent clutter.

Sample Screen is performed primarily in the glovebox, which poses no problems

for the tier 3 capability given that it includes a stainless steel or thermoplastic

Class III glovebox with proper CBR filtration. The thermal susceptibility test

for explosives must be eliminated in tier 3 testing. This test requires the use

of an open flame, which is not recommended in a glovebox. Normally, the

elimination of this test would represent a significant reduction in capability

for tier 3 facilities. However, the AHRF protocol includes a colorimetricscreen for explosives that is used on the primary sample container. While

the colorimetric test does not offer the full-range of detection capability

and level of detail provided by the thermal susceptibility test, it could be

used by the AHRF operators to screen the sample directly thereby mitigating

loss of the thermal susceptibility test for explosives. In addition, since all

of the AHRF protocol testing must be performed in the glovebox, this may

require operators to move screening equipment into and out of the glovebox

frequently to avoid clutter.

Document Results calls for the resulting sub-sample and primary sample to

be prepared for delivery to the designated laboratory(ies) and/or sampling

authority and kept in the biosafety cabinet to await transfer. In a tier 3 facility,

these packaged samples can remain in the glovebox to await transfer if there

is room. Depending on the level of activity, storage space could become

insufficient and/or impede use of the glovebox to process new samples. If

supported by a risk assessment performed by the laboratory, packaged samples

could be removed from the glovebox and stored appropriately to await transfer.


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Since both the Secondary Containment and Primary Sample Container Screenand

Sample Screensteps must be performed in the glovebox, managing working

space is the greatest challenge for operators in a tier 3 facility. Accumulation

of waste and equipment in the glovebox could lead to spills or other

accidents. Frequent movement of waste and equipment out of the glovebox

could lead to breach of containment and an increased risk of exposure to

the operator. A robust risk assessment must be performed to understandthe operational limitations and potential hazards. In addition to the greater

risk presented when using a tier 3 facility, the movement of waste and

equipment and the resulting clutter will increase the time required to

process samples and negatively impact sample throughput.

Basic CBR materials needed for AHRF applications include detectors,

decontamination materials, and Personal Protective Equipment (PPE)

(A list of such items is provided in the Appendix). The investment needed

for a tier 3 capability as described above is therefore limited to the purchase

of a stainless steel or thermoplastic glovebox and CBR filtration system plus

basic CBR materials. The initial investment cost of a tier 3 capabilityis estimated at less than $100K.

TieredApproa

ch


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3.4 Summary

Table 1 briefly describes each of the tiers detailed in Sections 3.1 through

3.3, along with the associated costs, benefits, and risks. It is important

to emphasize that all three tiers must be supported by robust operator

training, careful risk assessment processes, and assurance programs as

described in Section 1.

TieredApproa

ch

Tier Description Estimated Cost Benefit/Risk

1 Full AHRF capability as embodied

in the prototype or equivalent, i.e.,

a dedicated facility in the form of a

separate building, isolated suite, or

mobile/modular facility. Includes

BSL-3 and BSL-2 areas, a stainless steel

Class III glovebox, a second Class II

A2 BSC connected to the glovebox,

a fume hood or bleaching station,

and dedicated HVAC system(s) with

proper CBR filtration.

Between $1M and

$2M to replicate the

AHRF prototype as

it is described in

Section 5, or to create

an equivalent tier 1

capability in an existing

building.

Minimizes risk to AHRF

staff and practically

eliminates the risk to other

laboratory personnel and

operations by isolating

the AHRF function.

Utilizes both primary and

secondary containment

equipment plus separation

distance.

2 A dedicated room for AHRF

operations which is isolated from

general laboratory air flow and is

equipped with a stainless steel Class

III glovebox and a fume hood, both

with proper CBR filtration.

Room exhaust is isolated from the

HVAC return-air for the rest of the

building. Supply air is provided by

the building HVAC system, and air is

exhausted from the room through the

fume hood and glovebox equipped

with CBR filtration.

Between $100K and

250K depending

on the type of

glovebox purchased

and the extent of

room modifications

performed. Cost

includes CBR filtration

equipment, handheld

detectors, PPE, and

decon kits.

Provides a level of

protection to AHRF

staff similar to tier 1 via

primary containment but

to a lesser extent given the

fume hood and glovebox

may be separate. Some risk

to other personnel and

operations remain as AHRF

room air could exit into

other parts of the building

and there is little or no

separation distance.

3 An improvised AHRF capability using

the lowest cost and minimal numberof components deemed acceptable

to a given laboratory. E.g., a portable

glovebox having proper CBR filtration

used in a room which is isolated from

building air flow and traffic only

when needed for an AHRF operation.

Less than $100K with

an acrylic gloveboxhaving CBR filtration

and a minimal set of

handheld detectors,

PPE, and decon kits.

Poses a greater risk to

AHRF staff, others nearby,and the environment

compared to tiers 1-2, but

provides a CBR primary

containment capability

that may be lacking in

even an otherwise high-

containment facility.

Table 1. Summary of Suggested Tier Definitions with Associated Costs and Benefit/Risk Aspects.


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4.0 Equipment, Design, & Operational

Considerations

This section borrows heavily from three U.S. Government documents with

editing and arrangement of the source material to fit the AHRF application.

The source documents are:

a. Biosafety in Microbiological and Biomedical Laboratories (BMBL),Fifth Edition, February 2007, available athttp://www.cdc.gov/OD/ohs/biosfty/bmbl5/bmbl5toc.htm

b. Army Pamphlet 385-61 Toxic Chemical Agent Safety Standards,17 December 2008, available at www.armypubs.army.mil/epubs/pdf/p385_61.pdf

c. Unified Facilities Criteria (UFC) 4-024-01 Security Engineering:Procedures for Designing Airborne Chemical, Biological, andRadiological Protection for Buildings, 10 June 2008,available at https://pdc.usace.army.mil/forums/ufc/4-024-01

Quotation marks and footnotes to identify the specific quoted material and

source document are omitted as these markings would be a distraction to most

readers. The URL for each source document is provided above so that readers

can easily obtain the source material if desired.

The National Select Agents Registry (NSAR) is an additional information

source as it oversees activities involving possession of biological agents and

toxins that have the potential to pose a severe threat to public, animal or plant

health, or to animal or plant products. The various Select Agent Regulations

and other useful information on biohazards are available from the NSAR

website at http://www.selectagents.gov/.

4.1 CBR Filt ration

It is important to emphasize that all three of the AHRF tier definitions in

Section 3 call for CBR filtration. That topic is explored in this section.

CBR filtration in an AHRF application must provide an effective level

of protection against the release of airborne chemical, biological, and

radiological agents. In tier 1 facilities, such as the prototypes in use at the

Wadsworth Center and EPA Region 1, CBR filtration is provided for the air

streams exiting both the primary containment equipment (Class III glovebox,

Class II A2 BSC, and fume hood) as well as the room air. That is, both the

containment equipment exhaust air and the exhaust air from the interiorof the AHRF are passed through CBR filtration systems before exiting to

the outside environment. Significant and continuous air streams are pulled

through the respective filtration systems in order to maintain a specified

pressure differential between containment and surrounding area. This pressure

differential provides greater assurance that hazardous materials stay within the

containment boundaries.


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Current best practices for filtration systems used in an AHRF application

based on the combined guidance of the BMBL and Army Pamphlet 385-61

call for two HEPA filters with a minimum efficiency reporting value of

MERV 17 in series with two impregnated carbon adsorbers that meet

ASZM-TEDA standards (See Section 4.2 on capabilities and limitations of

carbon adsorbers). A pre-filter is sometimes used upstream of the first HEPA

filter to collect large dust particles and extend the life of the HEPA filters.Pressure gauges are useful in monitoring HEPA loading. Additionally, a

sample port is strongly recommended between the first and second carbon

adsorbers to permit periodic monitoring of CBR filtration performance.

4.2 Capabili ties and Limitations of Carbon

Adsorbers

The carbon adsorbers used in an AHRF application must provide the

capability to remove a broad spectrum of chemical vapors and gases from

an air stream. Carbon adsorbers consist of a packed bed of impregnated,

activated carbon granules. The carbon adsorber employs two different

processes to remove chemicals from the air stream: physical adsorption

and chemical reaction. The ASZM-TEDA filters (U.S. military gradecarbon adsorbers) recommended in this Best Practices Guide employ

activated carbon, impregnated with copper, silver, zinc, molybdenum, and

triethlyenediamine. ASZM-TEDA filters are proven effective in removing

chemical warfare agents (CWAs) and certain toxic industrial chemicals

(TICs) under expected operating conditions. Expected operating conditions

include chemical concentration, air stream temperature and humidity, and

the residence time in the filter. Residence time, also referred to as dwell

time, is the time taken by the air to pass through the carbon adsorber. It is

CBR

Filtration

This filter unit design is based

on the combined guidance of

Biosafety in Microbiological

and Biomedical Laboratories

(BMBL) and Army Pamphlet

385-61. The combination

of HEPA and ASZM-TEDA

filters is needed to provide

protection against airborne

chemical, biological, and

radiological agents.

Figure 10. Example Filter Unit for AHRF Applications.


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therefore dependent on the flow rate of the air stream and the volume of the

adsorber bed. This relationship is described by the following equation:

adsorber volume

flow rate

In this equation, residence time is measured in seconds, adsorber volumeis measured in cubic feet (ft3), and flow rate is measured in cubic feet per

minute (cfm).

The above information is critical to AHRF designers, but it is also important

to operators of an AHRF. For example, an increase in the flow rate of a filter

system will increase the pressure differential between containment and

surrounding area (a good result that could be used to compensate for leaking

gaskets and the like), but will decrease the residence time within the adsorber

(a detrimental outcome for adsorber performance). Similarly, cost savings

achieved through reducing adsorber volume should be avoided if it would

reduce the residence time beyond acceptable limits. The ASZM-TEDA adsorbermaterial is specified and tested based upon a minimum residence time of 0.25

second. An equal, or preferably longer, residence time is therefore required to

ensure adequate filtration for AHRF operations.

It is also important to note that there is no single adsorber material available

that removes all potentially harmful chemical vapors and gases. To ensure

adequate protection, it may be necessary to add a filtration element to the

filter assembly illustrated in Figure 5 to remove specific TICs that are

considered a threat agent to a given laboratory or that become known threat

agents in the future. On the other hand, the dilution that results from large

air flows through the filtration and exhaust system serves to mitigate this risk.Laboratory exhaust stacks designed to provide large dilution factors

are commercially available and recommended for consideration in future

AHRF designs.

4.3 Glovebox Considerations

The BMBL 5th Edition and Army Pamphlet 385-61 both contain important

information about glovebox design and performance considerations applicable

to AHRF applications. Material from these two references is provided below

with minor editing for incorporation into this document.

The Class III BSC (glovebox) is illustrated in Figure 11. This enclosure was

originally designed for work with highly infectious microbiological agents

and provides maximum protection for the environment and the worker. It is

gas-tight (no leak greater than 1x10-7 cc/sec of 1% sulfur hexafluoride,

SF6, or helium at 3 inches pressure Water Gauge, or equivalent).

It is important to note that

no single adsorber material

including ASZM-TEDA, rem

all potentially harmful chem

vapors and gases. Also, that

residence time and therefor

flow rate are key factors tha

effect adsorber performance

5 The BMBL references the use of a dunk tank or autoclave for this purpose. An autoclave is not suitable for AHRF

applications where subsequent assay for biological material is performed and the custom fumehood/decon

station as used in the AHRF prototype is preferred over a dunk tank.

x 60residence time =


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Access for passage of materials into the Class III BSC (glovebox) as designed

for the AHRF prototypes is through a fumehood/decon station, which

can be decontaminated between uses. Reversing the access process allows

materials to be removed from the Class III BSC safely. 5

Both supply and exhaust air are HEPA filtered on a Class III BSC (glovebox).

In accordance with BMBL, exhaust air must pass through two HEPA filters,

or a HEPA filter and an air incinerator, before discharge to the outdoors

(see Sections 4.1-4.2 for AHRF recommendations). Airflow is maintained

by a dedicated, independent exhaust system exterior to the cabinet, which

keeps the cabinet under negative pressure (minimum of 0.5 inches ofpressure Water Gauge).

Long, heavy-duty rubber gloves are attached in a gas-tight manner to ports

in the cabinet and allow direct manipulation of the materials isolated inside.

Although these gloves restrict movement, they prevent the users direct

contact with the hazardous materials thereby maximizing personal safety.

Use of a dual-sided glovebox with glove ports and viewing plates on facing

Figure 11. Class III BSC (Glovebox) as Illustrated in the BMBL.

Glovebox components:

A. Glo ve po rt s wi th O-ring fo r at tach ing ar m- leng th gl ove s to ca binet

B. Sash

C. Exhaust HEPA filter (include ASZM-TEDA for AHRF applications per Sections 4.1-4.2)

D. Supply HEPA filter

E. Double-ended autoclave or pass-through box

Note: Rapid transport containers, which are mountable to the glovebox via a bayonet-type

connection, are commercially available and can prove useful in AHRF applications.

Note: For an AHRF application, both HEPA and ASZM-TEDA carbon adsorber filters are

required for effective CBR filtration. (See Sections 4.1-4.2.)

Glov

eboxConsideratio

ns


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sides of the glovebox has proven advantageous in AHRF prototype operations.

The dual-sided glovebox enables accommodatation of multiple-operator

sample manipulations and the ability for increased decontamination efficacy

with enhanced access.

Depending on the design of the cabinet, the supply HEPA filter provides

particulate-free, albeit somewhat turbulent, airflow within the work

environment. Laminar air-flow is not a characteristic of a Class III cabinet.

Several Class III BSCs can be joined together in a line to provide a larger

work area. Such cabinet lines are custom-built; the equipment installed in

the cabinet line (e.g., refrigerators, small elevators, shelves) is generally

custom-built as well.

Pressure within gloveboxes will be a minimum of 1/4 inch of water gaugebelow that of surrounding areas (note that the BMBL calls for 1/2 inch, which

is therefore recommended for AHRF applications).

Makeup air or inert gas should be allowed into the glovebox to prevent

stagnation and buildup of agent concentrations. The makeup sources will be

protected by filters, backflow dampers, or other means (Note the BMBL calls

for HEPA filtration of makeup air).

Procedures should be used to avoid breaking containment when a glovebox

is in operation; however, should a temporary opening into a glovebox occur,

the design must maintain an inward flow of at least 90 linear feet per minute

(LFPM) if agent is contained in the glovebox.

If a glovebox has large or permanent open areas, it should be considered a

ventilation hood and subject to criteria in Section 4.4.

The AHRF prototypes were not designed to handle gas bombs, canisters, or

gas cylinders that are under pressure, and the AHRF protocol directs operators

to obtain expert assistance in removing such items from the AHRF, if samples

containing these items are received. However, if a toxic agent operation

requires handling a pressurized vessel within the glovebox, a local risk

assessment should be performed to ensure the operation can be conducted

safely. The risk assessment must take into account the maximum crediblepressure release from the vessel and determine if the glovebox is capable

of handling such a release. When conducting such operations, the glovebox

should be leak-tested prior to each operation.

Glovebox and fume hood

performance specifications

must take into account the a

hazards mission of the AHR

Most venders sell these prod

for either biological or chem

safety; few address both unl

specifically asked to do so.

While the above glovebox considerations are from the BMBL 5th Edition, the following

information is from Army Pamphlet 385-61. Both are applicable to AHRF applications.


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4.4 Class II BSCs and Fume Hoods

As with glovebox considerations, the BMBL 5th Edition and Army

Pamphlet 385-61 both contain important information about Class II BSCs

and fume hoods as applicable to AHRF applications. Material from these

two references is provided below with minor editing for incorporation

into this document.

Per the BMBL 5th Edition, flammable chemicals should not be used in

standard Class II, Type A1 or A2 cabinets since vapor buildup inside the

cabinet presents a fire hazard. The electrical systems of standard Class II

BSCs are not spark-proof. Therefore, three options are available: a chemical

concentration approaching the lower explosive limits of the compound can

be prohibited (difficult to ensure this in an all-hazard or unknown threat

sample), a special-order Class II BSC having the appropriate spark-proof

electrical system and exhaust filtration system can be used, or a chemical

fume hood with the appropriate exhaust filtration system can be used.

Recommendations from the former Office of Research Safety of the

National Cancer Institute (NCI) stated that work involving the use of

chemical carcinogens for in vitro procedures can be performed in a

Class II cabinet which meets the following parameters: 1) exhaust

airflow is sufficient to provide a minimum inward velocity of 100 LFPM

at the face opening of the cabinet; 2) contaminated air plenums under

positive pressure are leak-tight; and 3) cabinet air is discharged to the

outdoors. National Sanitation Foundation (NSF)/ANSI 49 2002 currently

recommends that biologically-contaminated ducts and plenums of

Class II, Type A2 and B cabinets be maintained under negative air pressure,

or surrounded by negative pressure ducts and plenums and be exhausted

to the outdoors. This approach of maintaining negative air pressure is

recommended for AHRF applications.

Volatile radionuclides such as 125 I should not be used within Class II,

Type A1 BSCs; or an A2 BSC unless the exhaust air is discharged out of

doors and appropriate additional filtration techniques are used (See

Section 4.1-4.2). When using nonvolatile radionuclides inside a BSC, the

same hazards exist as if working with radioactive materials on the bench

top. Work that has the potential for splatter or creation of aerosols can be

done within the BSC. Radiologic monitoring must be performed. A straight,

vertical (not sloping) beta shield may be used inside the BSC to provide

worker protection. A sloping shield can disrupt the air curtain and increasethe possibility of contaminated air being released from the cabinet.

A radiation safety professional should be contacted for specific guidance.

As previously noted, standard

biosafety cabinets are notdesigned for an all-hazards

application and therefore

must be purchased as special-

order items or retrofitted for

all-hazards applications.

ClassIIBS

CsandFumeHoo

ds

While the above Class II BSC considerations are from the BMBL 5th Edition, the following

information is from Army Pamphlet 385-61. Both are applicable to AHRF applications.


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(1) A laboratory hood in which agent operations are conducted will providean average face velocity of 100 plus-or minus 20 LFPM through theworking opening. A traverse of one measurement per square foot(approximately) should be used to compute the average face velocity.No single point velocity may deviate from the average face velocity bymore than 20 percent.

(2) Laboratory hoods in which agent operations are conducted will bechallenged with test aerosols (visible smoke) with the sash in themaximum open position. No visible smoke will escape from thehood while the sash is slowly closed to as much as the operational

set up will allow and then slowly raised to the fully opened position.

(3) Laboratory chemical hoods will be tested and verified under the

following conditions:

(a) When installed and at least annually (within a 12-month period)thereafter.

(b) When substantive changes have occurred to the hood or hood

operating environment, such as

1. When the ventilation system has undergone repairs or changesthat may affect the airflow rate or patterns;

2. When the hood operating environment (for example, supplyair distribution patterns and volume, lab/furniture geometry)has changed such that it may decrease the performance ofthe hood;

3. When there have been changes in hood setup (that coulddecrease hood performance), hood face velocity controltype, set point, range, and response time; and

4. When there have been changes in exhaust system static

pressure, control range and response time.

(4) Sash stops may be used to define the maximum sash position opening.

(5) Hoods used only for storage of double-contained agents (no operations)are not subject to upper limits on airflow when the hood sash is loweredand locked for security.

(6) Previously existing (pre-1984) laboratory hoods designed and approvedat 150 plus-or-minus 30 LFPM may continue to be used until they can bemodified to the above criteria, provided containment is verified by smoke

tests or other appropriate methods.(7) When existing hoods are replaced in a room or a facility, the ability of

the ventilation system to maintain the room or facility at a negativepressure should be verified. Adjustment or renovation to the systemmay be required. Consult with the supporting industrial hygienist for

design guidelines.

(8) When ventilation hood exhaust systems contain filters that have beenused for agent operations, the ventilation system must maintain an inward

Fume hoods for an AHRFshould maintain an average

face velocity of 100 linear f

per minute (LFPM) through

the working opening, plus-

minus 20 LFPM with the sa

set at a proper working heig

This needs to be verified at

annually and when changes

have occurred to the hood o

operating environment.


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airflow through the hood even when the working area of the hoodno longer contains agent or agent-contaminated material. In this case,no minimum face velocities are required; however, inward flow will

be verified by smoke tests or other visual means. If the filter system is

isolated from the hood (for example, back-flow dampers, and blind

hinges), this subparagraph does not apply, though visible indicators

that show the positioning of dampers (open/closed/partly closed)should be provided at the work station.

(9) The design exhaust volume of the hood should provide excessinitial capacity.

(10) New hood installations should make maximum use of proventechnologies such as bypass construction, multiple baffles, and otherenhancements to provide optimal containment of chemical agentvapors and mists. The U.S. Army Public Health Command (USAPHC),Industrial Hygiene Program, APG, MD 210105403 is a good sourceof information for assistance in laboratory hood construction criteria,concept development, and design review services.

(11) Effluent air from laboratory hood systems must not containconcentrations of agent in excess of the Short Term Exposure Limit(STEL) concentration. If the quantity of agent being used or the typeof operation is such that this amount may be discharged into theatmosphere, the discharge of the ventilation system must be equippedwith chemical-type filters or other air treatment systems to reduce the

agent in the effluent to an acceptable level.

(12) Existing hood ventilation systems will be equipped with an audiblealarm device that will give a warning should the ventilation systemfail because of power failure, mechanical malfunction, or if the averageface velocity falls below 80 LFPM. For new construction, hoods will be

provided with both visible and audible alarm devices. Visible alarmswill be located so that they can be readily seen by personnel whileworking at the exhaust hood. For storage hoods, the visual alarmshould be visible from outside the room containing the hood. Alarmsshould be periodically function tested at a minimum every 6 months.

(13) Each laboratory room will have a means of assessing approximatehood face velocity prior to beginning operations each day. A hangingvane velometer is considered sufficiently accurate.

(14) No agent or agent-contaminated equipment will be allowed within20 centimeters (8 inches) of the hood face unless a hazard analysisdemonstrates that worker safety will not be compromised. The20-cm (8-in) zone should be designated by paint or tape.

AHRF exhaust systems should

maintain an inward airflow

through the fume hood and

glovebox even when not in

use because the filters will

likely contain contaminants.The minimum face velocity

is not applicable to sleep

mode. Lower flow rates

during sleep mode will save

energy and filter life.

ClassIIBS

CsandFumeHoo

ds


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4.5 Testing of CBR Containment and

Filtration Systems

4.5.1 Leak & Performance Testing

The CBR containment and filtration systems for an AHRF applicationshould be subjected to in-place leak and performance tests to ensure

adequate performance. Some leaks are not apparent in regular operations

even with careful monitoring of pressure gauges. For example, a leak past

the filter-to-housing seals would seriously compromise CBR filtration

performance given that some air would bypass the filter media, but this

type of leak would not be readily apparent from pressure gauge readings.

Leak testing is recommended upon initial installation of any AHRF

equipment and at least annually thereafter.

The BMBL 5th Edition contains the following guidance for HEPA filter leak

and performance testing: This test is performed to determine the integrity of

supply and exhaust HEPA filters, filter housing, and filter mounting frames

while the cabinet is operated at the nominal set point velocities. An aerosol in

the form of generated particulates of dioctylphthalate (DOP) or an accepted

alternative [e.g., poly(alpha-olefin), di(2-ethylhexyl) sebecate, polyethylene

glycol, and medical grade light mineral oil] is required for leak-testing HEPA

filters and their seals. The aerosol is generated on the intake side of the filter

and particles passing through the filter or around the seal are measured with

a photometer on the discharge side. This test is suitable for ascertaining the

integrity of all HEPA filters.

After testing, adjusting, and balancing individual components of an AHRF,

the system as a whole should be tested to ensure that all componentsperform as integral parts of the system and that pressures, temperatures,

and conditions are met and evenly controlled throughout the AHRF.

Corrections and adjustments should be made as necessary to produce

the conditions indicated or specified. An HVAC engineer experienced

with laboratory CBR containment and filtration systems should conduct

capacity tests and general operating tests to demonstrate that the entire

system is functioning according to specifications. It is recommended that a

CBR containment and filtration system engineer be present to observe the

performance testing, or perform separate certification or performance

testing, to verify that all CBR safety requirements are met.

As noted in Section 4.1, pressure gauges within the filter train are useful

in monitoring HEPA loading. Additionally, a sample port is strongly

recommended between the first and second carbon adsorbers to permit

periodic monitoring of CBR filtration performance. Periodic monitoring

can mitigate the risk of breakthrough and provide valuable data for

monitoring the remaining service life of the first carbon adsorber.

In-place leak and performan

tests should assess both

HEPA and ASZM-TEDA filter

performance. The two types

of filters require different

testing protocols.


36/63




Commercial filter housing systems are designed to meet applicable codes

and performance testing. Testing includes a housing leak test, pressure test,

and airflow capacity test. The filter housing (with inlet and outlet bubble-

tight dampers installed) must be tested in situ by pressure decay testing

in accordance with ASME N510. In addition to the filter housing, supply

ductwork and exhaust ductwork needs to be tested in situ by pressure

decay testing in accordance with ASME N510. Rate of air leakage forthese tests may not exceed 0.1% duct volume/min at 1000 Pa (4 wg)

minimum test pressure.

UFC 4-024-01provides the following guidance for filter bank in-place

testing: After installation, all ColPro (collective protection) filtration systems

should be in-place tested for leaks using a mechanical test method. This

test is used to evaluate the overall performance of the filtration system by

injecting a challenge agent upstream of the filter bank and measuring the

challenge agent concentration upstream and downstream of the filters.

The testing should occur in accordance with applicable sections of ASME

N510. The use of an independent testing agency is recommended. Thetesting agency should be certified in accordance with ASME NQA-1 or an

approved equal. The HEPA filtration system housing and HEPA filter aerosol

penetration should be less than 0.01 percent for the polydisperse aerosol

challenge specified in ASME N510. The carbon adsorber system housing and

carbon adsorber should be challenged with decafluoropentane (HFC-4310)

or an approved equal, with the downstream concentration not to exceed 0.1

percent of the upstream concentration.

4.5.2 Monthly Inspection

In addition to daily checks of differential pressure gauges, the AHRF

components and systems should be inspected at least once each month by

AHRF staff to ensure that they are operating as designed and are in good

operating condition. Continuously operated systems should be monitored

monthly to ensure that they are operating properly. Monthly inspections

and monitoring should include, at a minimum, verification that the

design pressure differentials and air flows are met for all containment

systems (glovebox, Class II BSC, fume hood, AHRF rooms). In addition,

the following should be checked: the pressure drop across the pre-filters

(if used) and HEPA filters; the damper operation; the heating and cooling

equipment; the protective area envelope

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