Indoor Air Quality

Factors Affecting I.A.Q.

Many factors affect indoor air quality (IAQ) and occupant comfort - including less obvious issues such as ergonomics (light levels, staff work practices, seating and process arrangements, etc.), and outdoor air pollutants (surrounding industry or other activities can produce contaminants with the potential to migrate indoors). Facilities Management can explore various contributing factors. Typically, initial investigations include an assessment of basic indoor air quality parameters:

  • Carbon Dioxide (CO 2) - a by-product of human respiration and therefore provides an indicator of whether sufficient fresh air (outside air) is being introduced into a building space.
  • Carbon Monoxide (CO) - a colorless, odorless gas. CO is a by-product of incomplete combustion and potential indoor air quality contaminant from outdoor sources or indoor equipment emissions (e.g., combustion furnace).
  • Temperature - because it affects occupant comfort and perception. There is no well defined guidance or universally accepted standard on a proper indoor temperature and much controversy regarding what constitutes optimal indoor temperature and humidity. Generally, for workers typically clothed, temperatures should be maintained between 73 degrees ( º) Fahrenheit (F) and 79 º F in the summer months and between 68 º F to 75 º F during the winter months. However, these temperatures are affected by the relative humidity (which in most all cases should be maintained below 70%). The District adopted energy conservation measures on June 26, 1997 and revised these on April 15, 1999, that specify classroom temperature limits “to maintain an environment conducive to the educational mission of the district . . .” of “ . . . no higher than 70 degrees in elementary schools during the heating season and no lower than 76 degrees during the cooling season.”
  • Humidity - a state of moisture in the air and is typically measured as relative humidity (RH) - the amount of moisture in a given volume of air compared to the amount that volume is capable of holding, expressed as a percentage. Excessively high or very low RH can produce discomfort. Debate continues concerning the optimal levels of humidity. In general, the RH recommended for indoor environments by varying organizations ranges from 30-60%. High RH reduces the body’s ability to lose heat and may also promote the growth of mold and mildew. Low RH causes discomfort from drying nose and throat mucous membranes and skin. Humidification units that add moisture to conditioned air are not recommended because of the risks of microbial growth in improperly maintained humidification systems.

Visual inspections are always part of intial IAQ investigations, but other parameters may be explored and occupant interviews will be conducted as well.

If you suspect that you have an indoor air problem, call Facilities Management (303) 982-2247 to initiate a work request, or call Environmental Services directly with questions and concerns (303) 982-2349.

What You Can Do

  • Maintain your classrooms and work areas clean and free of clutter.
  • Eliminate sources of moisture and quickly report leaks and flooding.
  • Don't use excessive amounts of water when shampooing carpets and ensure good extraction. Use fans to help ensure adequate drying.
  • Pets can harbor allergens. If you maintain small caged pets in the classroom, ensure that bedding is changed frequently. (note that reptiles carry salmonia so ensure hands are washed after each handling).
  • Minimize use of chemical products and ensure appropriate storage - especially for volatile compounds (e.g., flammable liquids). Use safer alternatives whenever possible. Use volatile chemicals only in places with very good ventilation, outdoors or in areas with exhaust systems or fume hoods.
  • Equipment such as copy machines, laminating machines, printing presses, kilns, etc. have emissions that pose potential occupant health risks. Ensure that you operate equipment in appropriate areas and that all combustion equipment has appropriate exhaust/vent systems.
  • Plants help your indoor environment, but can also present hazards for some people with specific allergies. Potted plants provide soil media ideal for bacteria and mold growth. Remove these or ensure that they are not over-watered. Remove standing water trays. Check occasionally for pest infestations.
  • Do not use humidifiers in classrooms. If use in offices is necessary  ensure unit is well maintained, water is changed daily, and unit interior is cleaned at least weekly.
  • Pay attention to storage areas in classrooms and offices. Ensure these areas are cleaned at least once per year. Go through storage and remove chemicals and products you do not have a use for within the year. Remove clays, pastes, markers, paints, cleaning products, potting soil, fertilizers, etc. that you do not plan to use in the year. Avoid storage of these types of materials in classrooms. If storage within the classroom is neccessary, ensure that materials are containerized or placed in closable cabinets.
  • Store food in closed containers and remove unwanted products frequently.
  • Report pest infestations quickly. Ensure that a Facility Manager or Facilities Management personnel are informed rather than attempting to resolve the problem yourself with pesticides. 


Radon – a colorless, odorless, toxic gas formed during the decomposition of uranium. This radioactive gas occurs naturally and is found in soils and granite. A known carcinogen, radon has the potential to cause or contribute to the occurrence of lung cancer through indoor exposures related to area soils, building materials and well water sources.

Jeffco has conducted one or more radon sampling at all schools. Radon levels are not anticipated to rise. Therefore, re-screening is not typically conducted. New schools or newly renovated sections of schools may not have undergone initial sampling yet. Where levels are at or above the the EPA’s recommended action level of 4 pico curies (pCi) of radon per liter of air (pCi/l), radon mitgation equipment is installed. To get information about a specific school, contact Environmental Services at (303) 982-2349.  


The best way to control mold is to control moisture. Visual inspections and odors are good indicators of whether you have mold growth in an area. Typically, in minor situations, mold presents a concern only for those with compromised immune systems, asthma, or mold allergies. However, moisture and mold growth should be controlled. If you suspect you have a mold problem or have experienced water damage/flooding, contact Facilities Management at 982-2247 to initiate a work request, or call Environmental Services directly at 982-2349 with questions. Quick abatement of water and moisture sources is key to preventing mold. Don't wait to report leaking, flooding or signs of moisture.

Mold Information Sheet (Colorado Department of Public Health & Environment) 

Brief Guide to Mold in the Workplace (Occupational Safety and Health Agency)

At Home: Protect Yourself From Mold (Centers for Disease Control) 

Helpful Links

Indoor Air Quality in Schools (Environmental Protection Agency) 

Indoor Air Quality Tools for Schools

This web-based resource contains recommendations and tools to help communities and design professionals integrate good indoor air quality practices into the design, construction, renovation, and operation and maintenance of K-12 school facilities. Practical, cost-effective actions ranging from walk-off entry mats to advanced ventilation systems can reduce contaminants in schools and help protect the health of children and staff.

Managing Asthma in Schools (Environmental Protection Agency)

Mold Information - (Environmental Protection Agency)