Advancing Laboratory Safety: The Evolution Towards Dynamic Air Quality Control
Switching from traditional air changes per hour to a data-driven, demand-based air quality control enhances safety, reduces costs and improves efficiency in laboratories.
Environmental Health & Safety (EH&S) has traditionally relied on a fixed air changes per hour (ACH) approach to ensure safety in laboratory and research settings. Unfortunately, this method necessitated continuous high air flow rates, leading to significant expenses and carbon emissions. Despite its appearance of safety, this approach lacked insight into actual events within these spaces, the functionality of ventilation systems and the actual ACH being delivered.
As stakeholders aim for efficiency gains toward achieving net zero, there has been a gradual reduction in fixed ACH rates, a phenomenon known as "ACH creep." This trend has sparked inquiries into the minimum safe ACH rate, raising concerns over safety. Fortunately, an alternative approach based on dynamically controlling ACH rates through accurate real-time air quality measurements has emerged, offering cost and carbon emissions reduction while enhancing safety. Let’s elucidate the differences between prescriptive and manual approaches to lab safety through a data-driven, actively managed lab EH&S program. Below are highlights of insights and empirical data from over a decade of operational and safety results across various organizations.
Historical Lab Management Practices
Historically, laboratories were designed with 10 to 12 air changes per hour (ACH) to prioritize safety. While this seemed to ensure a safe environment, safety events remained a risk, leaving EH&S personnel predominantly in a reactive mode of operation. Despite its efficacy in ventilating spaces, maintaining 10 to 12 ACH incurred exorbitant environmental and operational costs. Studies suggested that 8 ACH was sufficient for effective ventilation, prompting clients to lower ACH rates to cut costs, with some even opting for 6 ACH. However, EH&S still lacked the necessary data to verify indoor air quality and gain insights into lab safety practices. This approach, while operationally feasible, did not yield cost savings and still posed safety risks. The reality is that most unsafe exposures cannot be seen instantaneously without the use of calibrated and accurate testing devices, which won’t be deployed without a compelling reason.
Shortcomings of Prescriptive ACH Approaches
Hindsight reveals that, while the prescriptive approach seemed convenient, it often led to either excessive energy consumption or inadequate ventilation. Data analysis indicates that the exact appropriate ACH was rarely achieved, leading to wasted energy and emissions. An analysis of data from various clients' lab buildings shows that rooms only required higher ACH to address events 2.3 percent of the time.
It's essential to understand the term "events," which encompasses various unsafe conditions beyond spills, including systemic, operational and episodic events. Addressing these events requires a more nuanced approach to safety management.
Lab Management Practices and Lab Banding
Mitigating risk involves developing more effective training methods and conducting better inspections of lab HVAC systems by EH&S teams. However, relying solely on lab banding, a static approach, is insufficient as it lacks real-time feedback to monitor and address events effectively.
Strategies to mitigate risk are developing more effective training methods and conducting better and more frequent inspections of lab HVAC systems and manual testing by EH&S teams. Think of this as the “brute force approach.” The idea is that if a lab establishes strict rules, conducts more training and ensures that all rules are being followed—and if nothing changes—a lab can achieve best-in-class safety. This approach identifies rooms with certain risk levels and then prescribes ACH levels for that room, the use of only certain chemicals and in specified quantities, etc. It also assumes that all experiments are done in containment hoods and that those hoods are properly working. This, of course, assumes that the lab operates under ideal conditions and incurs no episodic events. While lab banding had been around even before lowering ACH rates came into vogue—it is supported by ASHRAE and some EH&S consulting firms—it is still a “static” approach that relies on system and operational episodes being quickly diagnosed and mitigated.
Most importantly, it lacks any detection of episodic events. Banding is a logical approach for designing and qualifying room usage—in other words, to set a baseline for expected operating conditions—the lack of “real-time” feedback means that, by itself, banding is not an effective means of monitoring events and capturing insights to prevent future events and to react in real-time to provide safer operating conditions. To manage a banding program, organizations rely on human oversight reviews, which only capture a few hours of the 8,736 annual hours of operation. In perspective, that could be 0.2 percent of the total operating time.
Room safety rating and training for researchers on safe lab practices and protocols for specific spaces is absolutely part of best practice lab safety programs, but there is now strong evidence that using a demand-based control approach coupled with banding is the best approach for measuring and dynamically managing ventilation rates to optimize safety, energy savings and decarbonization.
DBC and A Data-Driven Approach
Demand-based control (DBC) for research spaces, coupled with data analytics, has proven effective in enhancing safety and efficiency. DBC adjusts ACH rates based on real-time data, enabling proactive identification and correction of various events.
The University of California (UC) Irvine has implemented DBC in nearly 1,500 research spaces, in conjunction with its SmartLabs program. UC Irvine attributes its significantly improved safety record, compared to other institutions in the UC school system, to the adoption of DBC. Transitioning from a reactive approach—where responses are triggered by incidents or complaints—to a proactive system of continuous, real-time safety enhancement, hinges on the availability of real-time measurement and intelligent insights across all research spaces, a concept often referred to as the “data layer.” While DBC is not a one-size-fits-all solution, it is the integration of this data layer and feedback loop that empowers EH&S teams to proactively manage various system, operational and episodic events occurring across all UC research institutions.
DBC instills confidence among EH&S personnel, facility managers and occupants by ensuring optimal airflow precisely when and where it's needed, unlike the rigid prescriptions of traditional approaches. When an event occurs within a room, DBC ramps up the ACH to typically double the baseline rate, such as from 8-to-16 ACH or 6-to-12 ACH. This added layer of safety is crucial and cannot be achieved through a banding-only strategy.
Moreover, it's essential to acknowledge that many clients implement lower airflow rates during nighttime or when labs are unoccupied to enhance cost savings. However, it's worth noting that using occupancy sensors to adjust lab ACH rates poses genuine risks, especially if someone enters a room that had been unoccupied. Nevertheless, occupancy sensors can contribute valuable data regarding lab occupancy and set higher temperature dead bands during daytime settings.
In contrast, a DBC system operates round the clock, adjusting ACH rates based on a room's air quality both during daytime and nighttime conditions, thereby ensuring continuous safety measures are in place.
Let’s explore this new toolset for EH&S closer. Using two of the most commonly used analytics of the DBC data platform, it’s easy to identify rooms that perform below expectations for a significant percentage of time compared to the baseline ACH. This analysis helps end users to quickly focus on rooms where the most persistent events occur and provides insights about what is causing them. For example, elevated TVOC levels, as measured by a PID (Photo Ionization Detector) sensor, might be causing ACH to go higher or if the airflow might be driven higher by thermal load requirements rather than the DBC system. These adjustments are the responsibility of energy and facility management teams rather than EH&S.
It’s clear that these tools can provide quick paybacks in energy efficiency, time and operational efficiency. Where they really excel is adding a layer of safety that didn’t previously exist and wouldn’t exist with a banding-only, prescriptive ACH approach.
EH&S teams may be fearful that the DBC program may create more work for them. However, end users who work closely with the data analytics platform may find the platform useful because it offers insight into issues before they become big problems or it shows that the lab’s system is working as it should so intervention is not needed.
Events happen in labs often and randomly by room, floor and building. When working properly, airflow ramps up to clean or purge the room and then ramps back down.
The integration of DBC control with an information management system has demonstrated itself as a more sustainable and secure method for managing and up-keeping research spaces over several years. When assessing the costs and advantages of implementing such a system, DBC fulfills two pivotal criteria. First, it enhances safety by facilitating continuous learning and the adoption of best safety practices. It notably enhances the capacity of EH&S teams to proactively recognize and address various types of events instead of merely reacting to them after they occur. Second, projects including DBC often yield paybacks in less than three years while delivering the ancillary benefits.
When considering the aggregate value derived from improved safety, operational efficiencies, carbon footprint reduction and additional benefits, the return on investment often proves to be infinite. This approach should be evaluated for all laboratories, given its undeniable advantages in both economic and safety aspects.