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Why Installed-Condition Testing Matters: A Closer Look at BSL 3 Exhaust Duct Air Valve Verification

January 26, 2026

Testing and verifying the performance of BSL‑3 containment exhaust systems is one of the most critical—and often least visible—components of commissioning. As organizations work to balance constructability, cost considerations, and compliance, it is essential to ensure that verification methods align fully with the intent of applicable standards.

Maintaining clarity around containment exhaust testing requirements is essential for any BSL‑3 project. The discussion surrounding the exhaust duct air valve has provided an opportunity to revisit the relevant standards and ensure that the verification approach accurately reflects installed‑condition performance expectations.

1. Compliance Is About the Installed System—Not Just Component Ratings

A common area of confusion in laboratory and containment design is the difference between component‑level ratings and installed‑system performance.

While manufacturer data or nominal pressure ratings for an exhaust air valve provide useful baseline information, they do not demonstrate compliance with the performance verification requirements of:

ANSI Z9.14 – Testing and Performance Verification of Laboratory Fume Hoods and Containment Systems
ASME N510 – Testing of Nuclear Air Cleaning Systems

Both standards require testing of the entire installed exhaust assembly, which includes:

The valve
Upstream and downstream ductwork
Field joints and couplings
Gaskets, sleeves, transitions, and associated connections

System leakage almost always occurs at field‑assembled interfaces rather than inside a factory‑tested component. That’s why only installed‑condition testing can confirm the containment integrity required for BSL‑3 operation.

2. Bench Testing Is Useful—But Not Sufficient for Acceptance

Bench tests can help validate a component’s general capability, and in some cases may even demonstrate performance above expected operating conditions (such as exceeding 4″ w.g.). However, these tests cannot replicate:

Real-world mechanical stresses on ductwork
Variations introduced during installation
Joint expansion and contraction
Multiple potential leakage pathways
Interaction with adjacent system components

As a result, bench testing alone cannot be used to demonstrate compliance with ANSI Z9.14 or ASME N510. Installed-condition testing is the only reliable method to verify that the complete exhaust system performs as required.

3. Commissioning Tests Required by Standards Are Not Optional

Project contracts may dictate who performs or pays for certain tests, but they do not change whether those tests are required.

For acceptance under ANSI Z9.14 and ASME N510, a BSL‑3 exhaust system must demonstrate:

Pressure integrity of the installed duct upstream of HEPA filtration
Acceptable leakage levels across all components and joints
Performance of the system as a cohesive, installed assembly

These commissioning tests remain mandatory regardless of how they are allocated contractually. Safety and compliance always take precedence.

4. The Correct Approach: Installed Duct Testing Based on ANSI Z9.14 Acceptance Criteria Requirements

After evaluating technical requirements and constructability constraints, the most appropriate and standards‑aligned testing method is clear:

✔ Conduct duct testing from the BSL-3 room through the air valve at 4″ w.g., under fully installed conditions.

This approach:

Meets the intent of ANSI Z9.14 for upstream containment exhausts
Verifies real‑world performance of the installed assembly
Avoids overreliance on bench test data
Provides defensible acceptance documentation
Ensures containment integrity for BSL‑3 operations

It is both a practical and technically rigorous solution.

Collaborative Solutions Drive Successful Commissioning

One of the most important aspects of any containment project is the ability of teams—engineering, construction, commissioning, and facility stakeholders—to work together toward solutions that uphold safety and regulatory integrity.

By focusing on installed‑condition performance, aligning with recognized standards, and maintaining open communication, we can ensure the containment exhaust system achieves the level of reliability and protection that BSL‑3 environments demand.

For more information or to discuss how these principles apply to your facility, contact World BioHazTec today to schedule a free consultation with our biosafety and biocontainment experts.

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What This Award Represents—and Why Biosafety Matters

By: Kerstin Haskell, MBA. President, World BioHazTec. I remember exactly where I was when I got the call. I was sitting in an airport, waiting for my flight home from Iceland after attending a conference in Germany. I was exhausted, jet-lagged, and only half paying attention to my phone when it rang. “Check your email!” said Carol Traum, our Executive Vice President. “Congratulations!” said Ted Traum, our Principal. “What are you talking about?” I asked. I was tired. “The award! You got it!” “Wait,” I said, suddenly more awake. “I’m going to meet the Governor?” That was the moment I learned I had been selected to receive the World Trade Center Institute Maryland International Business Leadership Award. It Started with a Conversation, Not a Campaign Like most meaningful recognition, this did not begin with a campaign or an application package. It started with a phone call from Brian Castleberry at the Maryland Department of Commerce—an exceptional partner who had helped bring Biosafety Day to Maryland the year before. He asked a few straightforward questions about our exports that year. “I’m putting you in for an award,” he said. “Oh, okay,” I replied, and rattled off some numbers. At the time, it didn’t feel momentous. In hindsight, it was one of those quiet inflection points that leadership careers are built on. Showing Up as a Team When the interview invitation arrived, the timing could not have been better. Dan Yoong, World BioHazTec’s Managing Director for Asia, the Middle East, and Africa, was already in the U.S. preparing for the ABSA International Conference. There was no question—Dan needed to be part of that interview. If we were being asked to speak about global impact, public health, and international collaboration, then he was a living example of that work. His wife joined us as well, as we were driving straight from the interview in Baltimore to Raleigh, North Carolina, for the conference. I will never forget that room—nearly fifteen people gathered around a conference table, introducing themselves. When it was Dan’s wife’s turn, she smiled and said, “I’m the boss of him,” pointing directly at Dan. The room immediately burst into laughter. Any nervousness disappeared. From there, we spoke openly and proudly about biosafety, engineering, partnership, and what it takes to build a company that crosses borders while remaining deeply rooted in Maryland. A Night That Felt Bigger Than One Person The awards ceremony at the M&T Bank Exchange was unforgettable. The room glowed with dramatic purple and blue hues, and for a moment, everything felt quietly surreal. Sitting to my left was my mentor, RADM Deborah Wilson, PhD, CBSP, RBP (ret.), with her husband, Tom, by her side. On my right was my husband, Jake. At our table were my parents, Ted and Carol Traum, long-time leaders and partners in World BioHazTec, alongside COO Juan Osorio and his wife Nathalie, and Lia Vizzotti, CEO of World BioHazTec Latin America. As I looked around the room, what struck me most was the scale. There were nearly 400 people in attendance—leaders from business, government, academia, and industry. Many of them had likely never heard the word biosafety before that evening. And yet, the work represented in that room—and far beyond it—depends on it. That realization stayed with me. Biosafety should not be a niche term known only to scientists and engineers. It should be recognized and embraced by C-suite executives, policymakers, investors, and institutional leaders as a foundational element of responsible innovation, public health preparedness, and economic resilience. If biosafety is invisible, it is vulnerable. If it is understood, it becomes integrated into decision-making at the highest levels. That sense of responsibility made the night feel larger than any single recognition. The People Who Brought Us Here That feeling deepened as women approached me throughout the evening—congratulating me, thanking me, and noting that I was the only woman among the six award recipients that year. Each time, I proudly introduced them to RADM Wilson and shared just how instrumental she has been in bringing so many of us together. From Ted’s early brainstorming sessions with RADM Wilson, to Juan Osorio—whom we met through colleagues in RADM Wilson’s orbit who recognized both his talent and the growing need for leadership in biocontainment engineering—to Lia Vizzotti, whom we met during a WHO-supported training session RADM Wilson helped organize, the throughline was RADM Wilson. She had an extraordinary ability to see what was needed and to connect people at exactly the right moment. We never forget that. Seeing Our Story on the Screen I will admit, I was nervous when the program began introducing each honoree and playing short videos about their work. I didn’t know what to expect when World BioHazTec appeared on the screen. You can watch the video here. What I saw was emotional, grounded, and deeply reflective of what our team has built over decades. When the video ended and I stood, the applause was immense—and humbling. A Conversation with the Governor When I met Governor Wes Moore, I thanked him for issuing Maryland’s Biosafety Day Proclamation—and, admittedly, asked whether we might be able to have another one. I asked him to connect me with his team so we could talk more about biosafety, its economic impact, and why Maryland is uniquely positioned as a global hub for high- and maximum-containment laboratories. We are a dense, interconnected community doing work that matters far beyond our borders. He was gracious, engaged, and genuinely curious. After confirming it was allowed, my husband stepped up to the stage. As we stood with Governor Wes Moore, he handed his phone to a woman nearby and asked, “Would you mind taking our picture?” I quickly interjected, “Jake, she is probably the CEO of some big company.” She laughed and replied, “Actually, I am the CEO of BWI Airport,” and graciously took our photo with the Governor. What This Award Represents This award is an honor—but more importantly, it is a responsibility. It reflects the collective work of World BioHazTec’s global team, the mentors who shaped us, the partners who trusted us, and Maryland’s leadership in biosafety and public health. The work continues, and we are proud to carry it forward—together. My hope is that leaders across industry, government, and policy will engage with biosafety not as a compliance obligation, but as a strategic responsibility that protects people, strengthens innovation, and safeguards our collective future.

Elevating Biocontainment Certification: World BioHazTec’s Engineering Approach

Ensuring the performance and safety of BSL-3 and ABSL-3 laboratories requires more than a checklist. It demands an engineering-based methodology that anticipates risk, verifies containment performance under both normal and abnormal operating conditions of critical laboratory systems, and delivers clear findings with actionable, technically sound recommendations to support facility leadership decision-making. At World BioHazTec, we have built our certification approach on that principle, combining deep technical rigor, licensed engineering oversight, and structured, decision-ready reporting. Expert-Led Certification, Not Technicians High-containment laboratories operate at a level of complexity where engineering judgment and field experience are critical. For that reason, we do not deploy technicians. Your facility is evaluated onsite by senior Subject Matter Experts (SMEs) who have assessed more than 200 biocontainment laboratories, contributed to biosafety guideline development, and presented internationally on certification practices and performance verification. This SME-led model ensures that subtle performance anomalies are accurately interpreted, risk assessments reflect operational realities, and recommendations are technically robust and strategically applicable to operations, maintenance, and Environmental Health and Safety (EHS) leadership. Engineered Assurance with PE Oversight World BioHazTec certification reports are reviewed and signed by a licensed Professional Engineer (PE). This provides technical authority, professional accountability, and regulatory defensibility to the findings and recommendations, giving stakeholders confidence that the report meets rigorous engineering standards. Comprehensive Methodology, Beyond the Baseline Baseline certification includes: Document review Interior inspection Differential pressure verification during normal/abnormal laboratory operation Verification of calibration of installed instrumentation Performance testing under normal operating conditions Performance testing under critical system failure scenarios Quantitative directional airflow verification Functional alarms confirmation World BioHazTec goes beyond the baseline by including: Exterior building inspection Thermal imaging Differential pressure trend analysis SME-led risk assessment Structured quality improvement recommendations Remote notification system verification One-year expert access Decision-Ready Reporting Our reports are structured to support executive and operational decision-making. Data related to pressures, airflow behavior, and alarm performance are presented alongside engineering interpretation, risk analysis, and clearly defined corrective and preventive actions. Fail-Forward: Proactive Failure Scenario Testing World BioHazTec conducts controlled failure scenario testing during laboratory operation to strengthen system reliability, not merely to record pass/fail results. Airflow behavior under upset conditions is thoroughly documented, with SME-led evaluations guiding risk-based corrective actions. Independence from BAS-Generated Graphs World BioHazTec does not rely solely on Building Automation System (BAS) trend graphs. BAS trend logs may be limited by server bandwidth restrictions or legacy system constraints, which can obscure or oversimplify critical airflow behavior or differential pressure relationships between areas, variables essential for containment integrity. Instead, we use certified and calibrated instruments to obtain independent measurements, ensuring that the data presented is precise, high-resolution, and fully representative of actual critical system performance. This approach provides engineering-grade documentation that stands independently of automation system limitations. Report Clarity and Usability Clear communication is essential in high-containment facilities, where decisions impact safety, operations, and long-term system reliability. Our reports are intentionally designed to be precise, structured, and easy to navigate. We focus on relevant information presented clearly and directly. We avoid excessive narrative, redundant data, and confusing diagrams. Each report follows a logical structure that directs the reader to key findings. Data is presented using clear photographs, defined graphs, and well-labeled diagrams that quickly identify what is functioning properly, what requires attention, and what actions are recommended. This clarity ensures documentation that is technically rigorous, practical, and ready for audits, internal reviews, and operational planning. Lifecycle Partnership, Not a One-Time Event High-containment environments evolve as equipment ages, operations change, and research requirements shift. Our one-year complimentary expert access ensures continued technical support beyond the certification visit. Why This Matters for BSL-3 / ABSL-3 Facilities A comprehensive certification approach provides: · Greater system reliability · Clear documentation for audits and regulatory compliance · Early identification of vulnerabilities · Trend analysis to support maintenance and upgrade planning · Stronger technical support for leadership decisions Beyond Compliance: The World BioHazTec Philosophy Compliance is the starting point. Our goal is engineered assurance, ensuring that the facility performs as intended, especially during off-normal events. Ready to learn more? Contact us for a free consultation.

Biocontainment Laboratory workers in a lab

Design Pitfalls in Biocontainment Laboratories: Lessons from Real Projects

Building a biocontainment laboratory—whether BSL-3, ABSL-3 or ACL-3, is a highly specialized process that requires careful planning and coordination. When design decisions are made without early input from Subject Matter Experts (SMEs), critical issues often surface late in the project, leading to costly changes and delays. Below are examples of common challenges identified during design reviews and commissioning phases. These illustrate why early integration of biosafety and engineering expertise is essential. Example 1: Missing Containment Features In one recent project, a design review uncovered a critical oversight. The Basis of Design (BOD)—the document outlining the institution’s requirements for the laboratory—specified that the facility would support research involving avian influenza. However, the design did not include provisions for a shower-out protocol or the necessary plumbing infrastructure to accommodate a future effluent decontamination system, both of which may be required by evolving regulations. This omission significantly limited the laboratory’s operational capabilities, restricting it to work with agents that do not require a shower-out process. Ultimately, substantial redesign was needed to bring the project back into alignment with the BOD and ensure long-term compliance and flexibility. Other issues included: In a BSL-3 setting, undefined personnel pathways and workflows create unclear boundary separations, increasing the risk of containment breaches, procedural confusion, and noncompliance biosafety requirements. Insufficient clearance for biosafety cabinets (BSCs) in isolation spaces. Doors swinging against intended airflow direction. Use of inappropriate sealing materials for penetrations. Inclusion of a fume hood for chemical work instead of a Class II Type B2 BSC. Incomplete risk assessment during early design phases. Insufficient attention to maintenance access and laboratory equipment placement. Structural limitations in the room envelope made it unable to safely tolerate deep negative pressure conditions. Impact: These oversights affected containment integrity and workflow efficiency, requiring structural changes late in the process. Example 2: Airflow and Equipment Integration During commissioning of a facility under construction, several design gaps were identified: A BOD change required upgrading the Class II BSC from Type A2 to Type B2, but the existing exhaust fan curves could not support the increased airflow demand. Lack of exhaust ducting over the autoclave chambers to manage heat and connecting to the BSL-3 exhaust ductwork. Freezer placement in a concentrated area not accounted for in the air distribution. Provision for decontaminating large equipment before removal. Autoclave bioseal ordered for the wrong side with the master control on the wrong side. Impact: These issues prolonged commissioning, delayed the project schedule, and resulted in substantial change-order claims. Example 3: HVAC and Containment Compliance In another case, evaluation of arthropod containment labs revealed: Omission of supply and/or exhaust air in anterooms. Misinterpretation of containment guidelines led to improper combining of BSL-2 and BSL-3 exhaust ductwork. Non-airtight ceiling access doors and introducing unaccounted infiltration affecting directional airflow. HVAC airflow reversals during failure testing created unacceptable containment risks. Impact: These deficiencies increased the risk of containment loss, with airflow reversals posing the greatest safety threat and pest intrusion creating major USDA compliance concerns. Top 6 Design Principles for Biocontainment Labs To avoid these pitfalls, consider these foundational principles during the earliest stages of design: 1.Define the Research Capabilities of the Laboratory Clearly defining laboratory intent in the Basis of Design is essential to ensure the facility is engineered to meet its functional, safety, and regulatory requirements. 2. Define Containment Boundaries Clearly Establishing primary, secondary, and tertiary barriers in relation to workflow early ensures the laboratory’s containment strategy is clear, coordinated, and integrated into the design from the start. This prevents costly redesigns, reduces construction risk, and supports reliable, compliant biocontainment performance. 3. Plan for Directional Airflow and Pressure Differentials Ensure airflow moves from clean to contaminated areas, with validated pressure relationships and redundancy in HVAC systems. 4. Integrate Equipment into Design Account for biosafety cabinets, autoclaves, and other critical equipment in spatial layouts and airflow calculations to ensure sufficient make-up air and proper cooling and heat-load dissipation. 5. Design for Maintenance and Decontamination Include provisions for safe removal and decontamination of large equipment and keep serviceable maintenance items outside of containment where possible. 6. Follow Risk-Based Guidelines and Standards Align with Biosafety in Microbiological and Biomedical Laboratories (BMBL), NIH Design Requirements Manual, WHO Laboratory Biosafety Manual and other relevant standards to ensure compliance and operational safety from the start. The Bottom Line Early engagement with World BioHazTec’s SMEs ensures: Compliance from the start with WHO, CDC, NIH, ANSI/ASSP Z9.14-2014 and other applicable guidelines. Cost savings by avoiding late-stage redesigns. Operational efficiency through risk-based design and redundancy planning. Don’t wait until commissioning to discover design flaws. Partner with World BioHazTec early and build a laboratory that meets the highest standards of safety and functionality. Ready to start your project right? Contact us for a free consultation.