Washington University in St. Louis faculty, staff, students and visitors should have a clean, healthy environment in which to work, study, live and perform various activities. Poor air quality can affect a person’s comfort, health, and productivity. EH&S, along with Facilities Services, work together to ensure the indoor air quality meets optimal standards set by Ashrea, CDC, EPA and industry best practices.

The purpose of the Indoor Air Quality (IAQ) program is to provide and maintain healthy and comfortable environments. A key part of the program is responding to and resolving concerns of building occupants about problems in their work environment. EH&S or Facilities generally will respond to and evaluate IAQ concerns. First, we determine if the issue is an emergency and, if so, take immediate action to protect the occupants.

How to report an air quality concern?
  • For temperature control, water intrusion, mold or natural gas odors please call building Facilities
    • Danforth Campus: 314-935-5544
    • Medical School Campus (FISC): 314-362-3100
  • For on-going issues or any other air quality concerns contact EH&S (during business hours) 314-362-6816
    • After hours or for emergency please call: Danforth Campus (WUPD): 314-935-5555
    • Medical School Campus (Protective Services): 314-362-4357

Nuisance Odors

If work-related contaminants are not above OSHA’s permissible exposure limit (PEL) or action level they are considered nuisance level. Although these odors may be bothersome to some people they are not considered hazardous to one’s health.


Spoiled food tends to be a common source of office nuisance odors. Forgotten food odors tend to be localized in a room and remain fairly constant over the course of a day (as opposed to a dry plumbing trap which can vary greatly in intensity over short periods of time). Before you contact EHS please search your area by looking in drawers, behind furniture, and in waste baskets. Dispose of odorous or rotten food in an outdoor trash container.

Definitions – According to OSHA

Action Level – means a concentration designated in 29 CFR part 1910 for a specific substance, calculated as an eight (8)-hour time-weighted average, which initiates certain required activities such as exposure monitoring and medical surveillance.

Permissible Exposure Limit (PEL) – The permissible exposure limit (PEL) is a legal limit in the United States for exposure of an employee to a chemical substance or physical agent. PELs are established by the Occupational Safety and Health Administration (OSHA).

Sewer Gas

Sewer gas is a mixture of inorganic gasses that contain hydrogen sulfide (H₂S), ammonia, carbon dioxide, methane, nitrogen and hydrogen. Sewer gas tends to have a strong odor of rotten eggs but can sometimes be described as a chemical or solvent odor. Exposure to sewer gas may cause irritation to the eyes and respiratory system. It can also cause apnea, coma, convulsions; dizziness, headache, weakness, irritability, insomnia and an upset stomach.


Sewer gas may be noticed around bathrooms and sink and floor drains and is usually caused from dry plumbing traps (the U-shaped pipe under the sink). Dry sink and floor traps are very common in labs. The smell can come and go and be very strong at times. The negative ventilation pressure in a laboratory is more likely to draw up odors from a drain. Other causes of sewer gas odors can be blocked vents or damaged drain lines.


  • To prevent sewer gas odors run sinks often and pour ½ gallon of water down floor drains monthly.
  • Do not block or cover up sinks or place equipment over floor drains.
  • If you notice a sewer gas odor try running water in a sink or pouring water into a floor drain. If this does not resolve the issue then please contact EH&S or facilities.

Other Building Odor Causes

  • Odors entering building air intakes are distributed via the mechanical ventilation system. The smell will be apparent in many rooms or an entire floor or wing of a building. Common odors include exhaust from a vehicle idling nearby, or from work being performed on or near the building’s air intakes or inside the air handler rooms.
  • Ask drivers parked near your building’s fresh air intake to turn off their engines. If it’s a recurring problem, contact the building manager or EH&S.
  • Maintenance or construction work may introduce odors from machines, equipment or chemicals that can be distributed by the ventilation system. Notify EH&S if you suspect a work practices is affecting the indoor air quality.
  • Primer, paint and new furnishings odors can be localized or distributed via the mechanical ventilation system. Campus projects use low-odor materials in most cases, but trace odors may still be detected by the nose after work is completed, and may take some time to dissipate. Maximize air circulation with continuous HVAC operation, opening windows, or running fans until odors are satisfactory.
  • Tobacco smoke from cigarettes, cigars, and other tobacco products occasionally waft into indoor spaces. Until the University becomes a smoke- free workplace on January 1, 2014, outdoor smokers should be at least 25-feet away from doors, windows and air-intakes. EH&S and University Health Services can assist with building signage and communication regarding smoking.

If your efforts to identify or control the odor are insufficient, contact Building Facilities or EH&S for assistance.

Dust and Humidity

Ultrafine Particulates

Ultrafine particles, also known as dust, are particles with a diameter of less than .1 micrometers. Size distinction is important as particle size reflects in part the penetration potential into the respiratory tract. Some particles are too big for us to breathe in altogether. Others, respirable particles (particles less than 5 micrometers) we breathe in are natural filtered out by our bodies and are not considered damaging. However, ultrafine particles have the ability to deposit deep into the lungs and prolonged exposure to high concentrations of them has the potential to cause health issues. Typically here at Washington University we see particulate levels significantly lower than this.

It is important to understand that we are exposed to ultrafine particles every day and our greatest exposure rate comes from being outdoors. For example, a driver on a busy highway traveling near or behind diesel vehicles can be exposed to concentrations of >100,000 particles/cubic centmeter (pt/cm3). Studies have shown that prolonged exposure to levels higher than 150,000 pt/cm3 can cause upper respiratory symptoms such as headache, nasal/sinus congestion and rhinitis.


About Mold–

Molds are fungi that are naturally occurring outdoors and may be found indoors as well. Mold needs nutrients, moisture, and favorable temperatures to grow and thrive. Building materials such as wood, paper, fabrics, and some synthetic products (e.g. paint, adhesives) are good food sources for mold. The moisture needed for mold growth can be provided in a couple of ways: either by a direct water source (e.g. water leak in building); or high levels of relative humidity (above 65%). Molds grow best in temperatures between 40F to 100F.

Mold can affect people in different ways. Mold may have little to no effect on some and others may be hypersensitive and a small amount could cause them to display symptoms of mold exposure. Some common mold exposure symptoms include the following: itchy/watery eyes, sneezing, runny nose, headache, wheezing.   Currently, there is no regulatory standard for mold.

FYI: The mold level target is likely never zero except in special applications such as medical and drug facilities which operate in a “clean room” environment where no stray particles are permitted. Mold is a natural ingredient in outdoor air most of the time.


In recent years, increased concern has arisen about exposure to specific molds that produce substances called mycotoxins. Health effects related to mycotoxins are generally related to ingestion of large quantities of fungal-contaminated material. No conclusive evidence exists of a link between indoor exposure to airborne mycotoxin and human illness. Many molds can potentially produce toxins given the right conditions. Some molds that produce mycotoxins are commonly found in moisture-damaged buildings; research related to the importance of these findings is ongoing. Although the potential for health problems is an important reason to prevent or minimize indoor mold growth and to remediate any indoor mold contamination, evidence is inadequate to support recommendations for greater urgency of remediation in cases where mycotoxin-producing fungi have been isolated.                  Source: CDC.gov

Should we test for mold?

CDC does not recommend mold testing. The health effects of mold can be different from person-to-person so you cannot rely on sampling and culturing to know if you might become sick. No matter what type of mold is present, it should be removed. Also, there are no set standards for what is and is not an acceptable quantity of mold indoors. The best thing you can do is to remove the mold and work to prevent future mold growth.

Scented candles, wax and oil use
Construction Standards

Painting and other Volatile Organic Compounds (VOC) use


Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. VOCs are emitted by a wide array of products numbering in the thousands.

Organic chemicals are widely used as ingredients in household products. Paints, varnishes and wax all contain organic solvents, as do many cleaning, disinfecting, cosmetic, degreasing and hobby products. Fuels are made up of organic chemicals. All of these products can release organic compounds while you are using them, and, to some degree, when they are stored.

VOC Sources

  • Paints, paint strippers and other solvents
  • Wood preservatives
  • Aerosol sprays
  • Cleansers and disinfectants
  • Moth repellents and air fresheners
  • Stored fuels and automotive products
  • Hobby supplies
  • Pesticide
  • Building materials and furnishings
  • Office equipment such as copiers and printers, correction fluids and carbonless copy paper
  • Graphics and craft materials including glues and adhesives, permanent markers and photographic solutions.

Health Effects

Health effects may include:

  • eye, nose and throat irritation
  • conjunctival irritation
  • headache
  • allergic skin reaction
  • dyspnea
  • declines in serum cholinesterase levels
  • nausea
  • emesis
  • epistaxis
  • fatigue
  • dizziness

Steps to Reduce Exposure

  • Increase ventilation when using products that emit VOCs.
  • Meet or exceed any label precautions.
  • Do not store opened containers of unused paints and similar materials.
  • Formaldehyde, one of the best known VOCs, is one of the few indoor air pollutants that can be readily measured.
  • Identify, and if possible, remove the source.
  • If not possible to remove, reduce exposure by using a sealant on all exposed surfaces of paneling and other furnishings.
  • Use integrated pest management techniques to reduce the need for pesticides.
  • Use products according to manufacturer’s directions.
  • Make sure you provide plenty of fresh air when using these products.
  • Throw away unused or little-used containers safely; buy in quantities that you will use soon.
  • Never mix household care products unless directed on the label.

Follow label instructions carefully.

Potentially hazardous products often have warnings aimed at reducing exposure of the user. For example, if a label says to use the product in a well-ventilated area, go outdoors or in areas equipped with an exhaust fan to use it. Otherwise, open up windows to provide the maximum amount of outdoor air possible.

Throw away partially full containers of old or unneeded chemicals safely.

Because gases can leak even from closed containers, this single step could help lower concentrations of organic chemicals in your home. (Be sure that materials you decide to keep are stored not only in a well-ventilated area but are also safely out of reach of children.) Do not simply toss these unwanted products in the garbage can. Find out if your local government or any organization in your community sponsors special days for the collection of toxic household wastes. If such days are available, use them to dispose of the unwanted containers safely. If no such collection days are available, think about organizing one.

Buy limited quantities.

If you use products only occasionally or seasonally, such as paints, paint strippers and kerosene for space heaters or gasoline for lawn mowers, buy only as much as you will use right away.

Keep exposure to emissions from products containing methylene chloride to a minimum.

Consumer products that contain methylene chloride include paint strippers, adhesive removers and aerosol spray paints. Methylene chloride is known to cause cancer in animals. Also, methylene chloride is converted to carbon monoxide in the body and can cause symptoms associated with exposure to carbon monoxide. Carefully read the labels containing health hazard information and cautions on the proper use of these products. Use products that contain methylene chloride outdoors when possible; use indoors only if the area is well ventilated.

Keep exposure to benzene to a minimum.

Benzene is a known human carcinogen. The main indoor sources of this chemical are:

  • environmental tobacco smoke
  • stored fuels
  • paint supplies
  • automobile emissions in attached garages

Actions that will reduce benzene exposure include:

  • eliminating smoking
  • providing for maximum ventilation during painting
  • discarding paint supplies and special fuels that will not be used immediately


CDC Indoor Environmental Quality

ASHRAE Position Document on Indoor Carbon Dioxide

ASHRAE Technical FAQ

Mold Course

MERV Filter Ratings