The hazards of wildfires are well known, but smoke is a more likely and prevalent threat this time of year. The Lab’s Facilities and Environmental Health and Safety divisions have made several changes to help mitigate the adverse effects before and during smoke events.
Wildfire smoke is a complex mix of fine particulates, gases, and volatile organic compounds. Those fine inhalable particulates are the main threat, and even healthy people, or those at a distance, can feel sick from breathing smoke-filled air. The most common symptoms include irritation of the eyes, nose, and lungs, persistent coughing, wheezing, or difficulty breathing.
To better protect employees, the Lab last year implemented engineering and administrative controls that include boosting air filtering within facilities, improving systems and operational responses, and enhancing air quality monitoring in the area.
“Facilities is improving particulate filtration in building ventilation systems to remove wildfire smoke and create improved indoor air quality,” said Deputy Director for Operations Michael Brandt.
Many air conditioner filters use a rating known as Minimum Efficiency Rating Value or MERV. The higher the MERV rating, the better, and the long-term goal for the Lab is to upgrade all our air handling systems to MERV 13-rated filters or better.
Some Lab facilities have already received MERV 14-rated filters more commonly used in smoking lounge ventilation systems. These new filters are capable of capturing particles between 0.3 micros and 1.0 with 98 percent efficiency. Everyday dust, pollen, mold spores, car fumes, and smoke are no match for the MERV 14 filters. In hard-to-reach areas, portable HEPA air purifiers are being used for additional filtration.
Buildings set to receive the new MERV 14 filters are prioritized based on expected occupancy and the availability of filters that fit their ventilation systems.
“Facilities is working to confirm optimum operational efficiencies are being met, and that appropriate filter upgrades are purchased and installed during preventative maintenance,” said Dean Sedlachek, Engineering Department Head for the Facilities Division, adding that the pandemic increased demand for filters while at the same time disrupting production, further complicating the effort.
Filtering smoke has limitations. Foul air can bypass an air conditioning system by entering through building openings such as windows and doors. And the new filters can, in some cases, restrict airflow beyond what a system can handle, leading to unsafe pressurization in lab spaces or cooling and heating issues.
These issues are particularly prevalent in older buildings and form a challenge for the Lab’s move to modernize its air handling systems, which are already taxed by greater demands for cooling and hindered by COVID ventilation requirements that prohibit total air recirculation. It’s important to note that in August 2020, the Lab’s Ventilation Working Group reviewed the available literature and found a low risk of COVID-19 transmission through properly functioning filtered air conditioning systems.
Monitoring unsafe air quality conditions has become a frontline tool used to guide administrative controls. Currently, approximately 50 sensors are monitoring indoor and outdoor air quality across the Lab, helping identify poor-performing buildings and areas most at risk. Real-time sensor data can be viewed on purpleair.com, which displays air quality index (AQI) changes.
During a fire or smoke event, an AQI spiking toward 300 could lead to the Lab restricting operations and possibly sending people at the Lab’s sites home — a decision made by the chief operating officer.
Learn more about what you can do to help yourself and your loved ones ride out a smoke event. For more information, follow these links:
Wildfire Smoke and Air Quality Website
IAQ Working Group Position Paper
Ventilation Working Group Report
EHS Recommended Portable Air Purifiers
Bay Area Air Quality Management District
MERV Filter Rating Overview (EPA)
Purpleair AQI Monitoring Sensors