Stanford University

EH&S Campus Advisory – Smoke UPDATE 11/16

UPDATE: 11/16 2:09PM: Tomorrow’s Big Game at UC Berkeley has been rescheduled to Saturday, December 1, due to continuing poor air quality in the Bay Area. In addition, several athletic events scheduled to be held at Stanford today and over the weekend have been moved or canceled. More information is available at the athletics website.

UPDATE 11/15 09:40 PM: Classes for Friday 11/16/18 have been CANCELED. Please see for more information and details. For information regarding athletics, please visit the athletics website.

UPDATE 11/15 01:28 PM: We have received numerous questions, and we are providing information about steps you can take to limit your exposure, during this period of poor air quality.

The Dish and Matadero Trail have been closed for the remainder of Thursday, November 15th. Gates may remain closed on Saturday if air quality remains poor. Look for updates on The Dish website. In addition, Stanford Athletics is providing updates on its website regarding the status of scheduled athletic events.

Wildfires around the Butte County areas combined with recent weather conditions have resulted in wildfire smoke being experienced in the Bay Area.

At this time, all members of the campus community are encouraged to take the following common-sense steps to address their personal health and comfort:

  • Stay indoors as much as possible.
  • When indoors, keep windows and doors closed.
  • In vehicles, use air-recirculation mode.
  • Drink plenty of water to help minimize potential irritation.
  • When outdoors limit prolonged and heavy activity. Consider the difference between a short bike ride to class, and a long vigorous run.
    • Prolonged exertion: This means any outdoor activity that you’ll be doing intermittently for several hours and that makes you breathe slightly harder than normal. A good example of this is working in the yard for part of a day. When air quality is unhealthy, you can protect your health by reducing how much time you spend on this type of activity.
    • Heavy/Strenuous exertion: This means intense outdoor activities that cause you to breathe hard. When air quality is unhealthy, you can protect your health by reducing how much time you spend on this type of activity.
  • If you do need to be outside, monitor the air conditions and potentially shift activities to when the air quality has improved.
  • Remember you can use the Marguerite shuttles to get around campus, there are many routes available, check for more information.
  • If you have outdoor activities planned for this weekend, we encourage you to monitor the conditions and limit your exposure.
  • is an online resource where you can monitor current air quality conditions, and learn more information.
  • Consult with your healthcare provider if you experience smoke related health issues.
  • Given that the above precautions are taken, masks are not recommended at this time for healthy individuals. Using respirator masks can make it harder to breathe, which may worsen existing medical conditions. For sensitive populations, including those with lung or heart disease or who are chronically ill, we recommend consulting with their personal health care provider before using any mask. Further considerations regarding mask use can be found at:

For individuals who may experience smoke-related health issues, we recommend consulting with one’s primary healthcare provider.



  • Minimize outdoor activities and keep the children indoors as much as possible.  Parents who have specific health concerns should consult their child’s pediatrician for further advice.


  • Individuals experiencing smoke-related distress symptoms should contact Vaden Health Center for further consultation.


PIs/Supervisors should review their group’s work activities and apply the following best practices:

  • Postponing prolonged or strenuous outdoor work.
  • Avoiding building-to-building foot travel where possible by scheduling video/phone conferencing, etc.
  • Keeping an open workplace dialogue, ensuring any related concerns and questions are communicated.

Stanford University continues to monitor local air quality levels to assess the potential impact on personnel and operations.


N95 Masks – Safe Usage Considerations

EH&S continues to stress that the best way to prevent wildfire smoke inhalation is to remain indoors and limit strenuous outdoor activities as much as possible. If electing voluntary use of an N95 mask, users should heed the following considerations:

  • For sensitive individuals, including those with lung/ heart conditions, such as asthma, we recommend consulting with their personal health care provider before using any protective mask.
  • Users might be tempted to stay outdoors longer because they think they’re protected. Continue to limit outdoor activity, even while wearing an N95 mask.
  • As mask effectiveness strongly depends on face fit/seal. N95 users should be clean-shaven so no facial hair interferes with the seal.
  • N95 use FAQs provided by Cal/OSHA:

General Indoor Air Quality on Campus

Provided doors and windows are kept closed, air quality in buildings will be much better than outdoor conditions. How much better will vary depending on the rate at which air “leaks” into the building but is especially dependant on the quality of the air filters used in the ventilation system. For campus buildings, ventilation systems are typically equipped with high-efficiency air filters (MERV 13 rating) that provide at least 90% filtration efficiency of fine particulate matter as small as 1.0 micron in diameter. Typical applications for MERV 13 rated filters include hospitals/ healthcare and other environments that have a higher demand for air quality. To further maximize indoor air quality, campus ventilation systems have, where possible, implemented a smoke mitigation protocol which further reduces the infiltration of air pollutants/odors by minimizing the amount of outdoor air pulled into the building. Note that laboratory buildings continue to provide filtered 100% outdoor air.

Despite highly efficient building air filtration systems in place, smoke odors may still be noticeable indoors during large-scale regional wildfires.  Although some may experience varying levels of smoke-related irritation while indoors, building air filtration systems consistently allow for better air quality than found outdoors, and remain the best means for minimizing smoke exposure during extended periods.

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