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.