Beyond the Webinar: Expert Insights on Fume Hood Risk Mitigation

Coryne Casey, associate principal, ZGF

Coryne Casey, associate principal with ZGF, conducted an “Ask Me Anything” webinar in the Fume Hood Risk Mitigation Digital Conference. Coryne spoke to Lab Design News to share key webinar takeaways, unanswered questions, and her insights on future trends in lab design for fume hood safety.

“Ask Me Anything–Fume Hood Risk Mitigation with a Lab Design Expert,” as well as the other webinars in this digital conference, is available for free on demand viewing. Register now to access these videos.

Q: What were some of the most common concerns or misconceptions attendees had about fume hood safety and compliance during the AMA session?

A: A common theme of the audience’s questions was fume hood selection, including how the correct volumetric rates are determined and how to identify what applications need what containment conditions. It was a great opportunity to discuss how fume hoods are not a one-size-fits all selection, as well as who the responsible parties are in coming to the correct decisions.

I would imagine it is a common misconception that the design team (i.e., lab planners and engineers, most commonly) are responsible for determining the chemical hygiene plan for each project or client. Compliance and safe practices begin with input from someone who has boots on the ground when the research is active—in the form of the EHS or facilities teams.

Q: You addressed questions about automatic sash closures and ventilation regulations. Do you see any emerging trends in fume hood regulations that labs should be aware of?

A: The standards and regulations guidelines are doing their best to keep up with the various application and energy-saving solutions offered in the ever-changing market. The clearest trend in design across the board is meeting sustainability goals and reducing consumption, waste, and emissions in all building typologies.

From what I am seeing, we are at a turning point in systems designs; tasked with embracing the more efficient options even when it is a change to what has come before and what preconceived notions, we as the design team, may be challenged with. This is manifesting itself in some of these standards being codified in certain states—like the California State Energy Code requiring auto-sash closers. It’s extremely likely we will see more of the same being adopted in other states, or as generally accepted best practices.

Q: Energy efficiency versus safety is often a point of discussion in lab design. What are some of the best strategies for balancing these two priorities when selecting or upgrading fume hoods?

A: For any possible balanced solution, the first step is to identify the risks and applications that would apply to the hood(s). Without a risk assessment, the tendency would be to proceed with an abundance of caution, putting safety as the primary driver and landing on an inefficient design with oversized equipment and systems. Unless there is an engaged EHS team, there is not a strong opportunity to have a balanced design that meets both sustainability goals and safety requirements. With EHS as an integrated team member, the design team can convert their chemical hygiene plan into a mechanical design.

An engaged EHS/chemical hygiene officer can also be a champion for technologies that would promote safe use of the hoods while simultaneously minimizing over consumption of utilities. Most of the tools available require the facilities team and end users to be more aware of these features than the standard workhorse fume hood. More mechanical components mean more variables and more points of potential failure; the team tending to these hoods needs to be trained and proactive.

Q: During the webinar, the topic of ductless vs. ducted hoods came up. Could you elaborate on key considerations for labs deciding between these two options?

A: Ductless hoods fill very specific needs within certain labs; similarly to conventional fume hoods, selection begins with understanding the chemistry planned for each hood and what risks would need to be mitigated.

Benefits of ductless hoods include spatial convenience and a lack of building exhaust coordination—both are extremely valuable in tight spaces and renovations where we see a lot of parameters to work within. However, even with the advancements in filtration and safety features on the ductless hoods they cannot accommodate all chemicals and need to be fully vetted for each application. The best way to decide on the appropriate hood for each need would be to engage the chemical hygiene officer and the end user(s), and then reference the testing data, chemical lists for each hood, and the guideline standards available—namely NFPA 45—for acceptable use and planning.

Q: Many labs operate in older buildings with legacy systems. What are the biggest challenges you’ve seen in retrofitting fume hoods for compliance and performance improvements?

A: There are two challenges I find to be common when confronting the task of retrofitting labs and targeting performance improvements. The first is determining and working within the limited capacity of the existing system; the second is asking the researchers and facilities teams to adjust to a change in their operations.

Working with existing hoods during a renovation requires testing the volumetric rates (fpm and cfm) at all hoods, determining the capacity of the mechanical system, and then identifying the new intended usage. The size of the system and anticipated diversity of usage (e.g., hoods open at the same time) can inform the design team what is achievable for future lab needs, and sometimes that is not compatible with an optimistic program. It’s a matter of working backward before moving forward.

As high-performance hoods and smart technology options are used more broadly, it’s imperative that the users and facilities teams adapt with the systems. Some of the tools that ensure performance improvements come with the responsibility to have proactive maintenance schedules, stringent testing regimens, and additional training for proper use and safety protocols. When confronted with a resistance to change, it’s important for the design team to have an understanding of the ultimate benefits of these new features and systems as well as what solutions can help alleviate concerns.

Q: What role do lab users play in maintaining fume hood efficiency and safety, and what best practices should they follow daily?

A: Lab user safety begins with proper training. It’s crucial that the researchers understand how the hoods work, how the systems work, and how safety can be ensured. Best practices that should be common knowledge among all users would be:

• Work within the safe working zone inside the hood. This means six inches back from the front of the hood to allow uninterrupted airflow.

• Keep the sash opening at the correct operating height or lower. Lowering the sash to only be open as needed can further improve safety and efficiency.

• Close the sash when not in use. Auto-closing options are available to ensure this measure is taken.

• Do not store chemicals within hoods long term. Be sure to use appropriate chemical storage solutions, preferably nearby or below the hood to minimize travel distance between storage and the fume hood.

• Always use proper personal protective equipment when working in a lab.

Q: Were there any particularly surprising or insightful questions asked during the AMA that highlighted lesser-known fume hood risks or best practices?

A: Most of the questions were focused on how to make the correct fume hood selection; whether it be ducted vs. ductless, selecting the correct face velocity, or complying with new codes and regulations that might require certain options be provided.

There was one question, though, that mentioned a 40-year-old building with a mixture of existing and new fume hoods. The participant had asked how they could ensure that the hoods and mechanical systems were functioning to the standards as expected. During the AMA session, this question led to a conversation about testing hoods As Used (AU) to get a clear understanding of what was happening at the hoods and within the mechanical system after years of use.  

We also discussed the need to reassess hoods as researchers and applications change over time. In a building with any longevity, it is expected for the people and processes to have a higher turnover rate than the equipment; meaning it is important that the EHS team/chemical hygiene officer confirms that the existing fume hoods will mitigate any new risks as things change. This may seem like unnecessary red tape or a hurdle to getting research underway, but safety must be the primary goal.

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