Indoor Air Quality - Q&A

General Information

  • Indoor air quality (IAQ) refers to the quality of air in non-industrial workplaces, such as office buildings, governmental institutions, libraries, malls and schools.
  • IAQ can be a problem when any of the following occur:
    • There is inadequate fresh air ventilation for the building.
    • Painting or other remodeling is performed nearby or in the building.
    • There is a furnace malfunction.
    • Outdoor pollutants enter the building through improper location of fresh air intakes.
    • Water leaks or condensation result in mold or other microorganisms forming either inside the building or in the heating and ventilation system.

What to expect from DOSH

  • Although the Division of Occupational Health (DOSH) receives many inquiries from employees and employers about the air quality in non-industrial buildings, the only DOSH requirements associated with IAQ are:
    • Prohibition of smoking in offices, found in the Safety and Health Core Rules, WAC 296-800-240 (1.28 MB PDF).
    • Protection from exposures to specific chemicals at levels typically seen in an industrial setting, found in Respiratory Hazards, WAC 296-841.
  • In most cases, DOSH will not conduct an onsite investigation related to IAQ because:
    • Experience in indoor air monitoring has shown that concentrations of chemicals in non-industrial settings rarely exceed current DOSH permissible exposure limits.
    • Mold and mold spores are everywhere. Mold growth can present a health concern, but DOSH has no specific requirements about levels of mold or mold spore contamination.
  • In some cases, DOSH may conduct an onsite investigation if:
    • Employees have ongoing or physician-diagnosed symptoms consistent with IAQ problems.
    • Employees suffer heat stress, or heat stress is a possibility.
    • Evidence exists of employee exposure to conditions such as:
      • A known chemical.
      • Gross mold contamination.
      • Other exposure to disease-causing microorganism.
  • DOSH responds to employer and employee concerns in different ways. The following table, DOSH Response to IAQ Concerns, shows what services DOSH provides regarding IAQ:
DOSH Response to IAQ Concerns
If DOSH receives: Then DOSH provides these services:
An employer concern
  • Information packets.
  • Recommendations for private IAQ consultants.
  • Recommendations to contact a qualified HVAC consultant.
    See Private IAQ Consulting Companies for a partial list of HVAC consultants.
  • A no-fee confidential onsite consultation, if requested, to evaluate such things as:
    • Gross mold contamination.
    • Fresh air ventilation.
    • Chemical exposure under certain conditions.
    • Infectious microorganisms, if suspected.
  • Find out more about the DOSH Consultation Program and how to request a no-charge, confidential consultation.
An employee concern
  • A letter sent to the employer asking them to investigate the situation.
  • An onsite inspection may result if a concern involves exposures such as:
    • Carbon monoxide.
    • High levels of chemicals.
    • Life-threatening infectious agents like legionella or histoplasma.
    • Visible mold contamination.
  • If the employer does not respond to a DOSH letter requesting they investigate an IAQ situation, then DOSH may do an on-site inspection.

NOTE: Complaint forms can be found at Alleged Safety Or Health Hazards (DOSH Complaint Form).


Suggestions for specific IAQ concerns

Expand/collapse all

  • Expand/collapse Asbestos

    If you have IAQ concerns about asbestos, the following information might be helpful:
      Asbestos is a carcinogen and employees can be exposed if asbestos is disturbed, for example while removing sheet vinyl and flooring tiles.
      "Popcorn" ceilings, insulation, pipes, heaters, and other old building materials may contain asbestos.
      Before beginning your construction or remodeling project, you are required to determine if materials contain asbestos.

    Also see:
      Construction or remodeling in this document.
      Asbestos, Tremolite, Anthophyllite, and Actinolite, WAC 296-62, Part I-1 (388 MB PDF).

  • Expand/collapse Carbon monoxide/exhaust

    If you have IAQ concerns about carbon monoxide or auto exhaust, the following information might be helpful.

    IAQ problems can result from carbon monoxide or irritants such oxides of nitrogen from internal combustion engine exhaust. The following are some examples where this can occur:
      Temporary equipment, such as generators, heaters, compressors, or propane fork lifts. These need to be sited outside or well ventilated.
      Misplaced air intakes, for example next to a loading dock.
     Auto exhaust coming in from a loading dock, or an open door or window.

  • Expand/collapse Carpets

    If you have IAQ concerns about carpet or carpet adhesive, the following information might be helpful:
      While some new carpets can smell strongly after installation, they usually don’t emit gases or vapors that exceed permissible exposure limits (PELs).
      Request material safety data sheets (MSDS) for chemicals or glues being used to evaluate potential hazards and take action to decrease or eliminate employee exposures.
      Some sensitive people may be temporarily affected by the odors.
      Generally, the odors diminish within a few days or weeks. If time allows, the carpet can be installed several days prior to occupancy and maximum fresh air ventilation can be provided to reduce odors when employees occupy the building or room.
      Low-odor carpets can also be purchased from some manufacturers.
      For more information related to indoor air quality, carpets, and carpet adhesives, see the Carpet and Rug Institute Web page (

  • Expand/collapse Chemical smells or strong odors

    If you have IAQ concerns about chemical smells or strong odors, the following information might be helpful:
      Request material safety data sheets, if available, to determine potential hazards so you can eliminate or decrease employee exposures.
     If an employer requests assistance from a DOSH consultant, the consultant may recommend actions to control employee exposures.
      In some instances, a building owner directly in control of activities in the building may be required to control exposures to building occupants.
      Employees can express concerns to:
    - Their employer.
    - The manager of the business generating the contaminants.
    - The building manager or owner.
      If a company or building owner is notified and doesn’t take action, the local air pollution authority can be contacted and asked to investigate.
      If an employee files a complaint with DOSH, both their business and adjacent businesses may be inspected. Either or both may be required to control employee exposures.
      If permissible exposure limits (PELs) are not exceeded, DOSH cannot compel an employer, adjacent business, building owner, or manager to stop or change their activities.
    Reference: See Table 3 in Chapter 296-841 WAC, Respiratory Hazards, for more information about exposure limits for air contaminants.

  • Expand/collapse Construction or remodeling

    If you have IAQ concerns related to construction or remodeling, the following information might be helpful:

      Construction or remodeling inside a building occupied by office workers can sometimes cause significant amounts of dust, noise, and chemicals.
      Occasionally, remodeling and construction can expose office workers to levels of contaminants above their permissible exposure limits (PELs), found in Respiratory Hazards, WAC 296-841. In these cases, DOSH may do the following:
    - Investigate if asked by management or if an employee complains.
    - Require measures to reduce employee exposures.
      Remodeling should be isolated from office workers with temporary barriers as much as possible.
      In some cases, exhaust ventilation will be needed in the construction area to remove dust or chemical vapors.
      Remodeling and construction can be done after hours or on weekends.
     Request material safety data sheets for materials, chemicals, or glues being used and take necessary actions to decrease or eliminate employee exposure.
    Also see:
    - Asbestos.
    - Hot tar roofing.
    - Paint.

  • Expand/collapse Copy machines

    If you have IAQ concerns related to copy machines, the following information might be helpful:
      Copy machines can produce irritating dusts, ozone, or chemicals, though generally not over the permissible exposure limits (PELs).
      Provide adequate ventilation.

  • Expand/collapse Hot tar roofing

    If you have IAQ concerns related to hot tar roofing, the following information might be helpful:
      While hot tar operations can be smelly and even cause adverse symptoms in some people, the permissible exposure limits (PELs) are rarely exceeded in offices or workplaces inside the building. However, because fresh air intakes are often on the roof or downwind of the tarring operation, the odors and fumes can be drawn into the building and affect sensitive individuals.
      Consider the following strategies:
    - Do tarring operations during non-business hours.
    - Temporarily alter the fresh air intakes so they still provide adequate ventilation but draw from somewhere else. For example, temporarily extend the intakes past the hot tar area.
    - Request a material safety data sheet from the roofing company and review for hazards, following personal protection recommendations.
     If a company or building owner fails to take action, you can call the local air pollution authority and ask them to investigate.

  • Expand/collapse Mold

    If you have IAQ concerns related to mold, the following information might be helpful:

     Tackle visible mold contamination by having qualified personnel do one of the following:
    - Remove contaminated porous material such as rugs, ceiling tiles, or sheetrock.
    - Thoroughly clean contaminated hard surfaces such as ductwork and cooling towers.
    - Identify and remove, or block, the pathway between the mold source and building occupants.
    - Fix ongoing sources of water, for example roof leaks or leaking pipes, to prevent reoccurrences of contamination.

      Make sure all investigation and cleanup operations are conducted so that investigators, cleanup personnel, and building occupants are not exposed to contaminated material. This may require one or more of the following:
    - Using Personal Protective Equipment (PPE) such as: gloves, tyvek, coveralls, or respirators during removal.
    - Conducting removal work when the building is not occupied and the HVAC system is shut down.
    - Isolating the work from building occupants.
    - Providing additional local ventilation for cleanup activities.

      Review of the WISHA Regional Directive (WRD) 10.10 at Indoor Air Quality (242 KB PDF).
      Request an onsite investigation. For example, if there is:
    - Extensive water damage to a building.
    - Gross mold contamination.
    - Reports of adverse health effects associated with mold exposure.

  • Expand/collapse Paint

    If you have IAQ concerns related to paint, the following information might be helpful:

     Old paint may have heavy metals such as lead or cadmium, and during construction or remodeling employees can be exposed to these components over the permissible exposure limit (PEL).
    You can get the material safety data sheets (MDSD) or have paint chips analyzed at a laboratory for metals.
     For specific requirements for lead in construction, go to Lead In Construction Training Kit.
      Using flammable paint may expose employees to chemicals at concentrations over the PEL. Flammable hazards must also be considered.
    Also see:
    - Remodeling or construction on a building.

  • Expand/collapse Schools

    If you have IAQ concerns related to schools, the following information might be helpful:

      DOSH requirements apply to all school employees, including teachers.
      DOSH doesn’t have jurisdiction over students.

  • Expand/collapse Smoking

    If you have IAQ concerns related to smokoing, the following information might be helpful:

      DOSH has specific regulations in WAC 296-800-240 (1.28 MB PDF), Environmental Tobacco Smoke in the Office, prohibiting smoking in offices or office buildings, except in specially ventilated rooms.
     DOSH has no regulations that limit or prohibit smoking in other workplaces.

  • Expand/collapse Temperatures (hot/cold)

    If you have IAQ concerns related to temperatures, the following information might be helpful:

      DOSH does not specifically regulate temperatures in workplaces. The effects of temperature depend on many variables including individual susceptibility. A DOSH inspector may investigate the workplace in the following situations:
    - Heat exhaustion or heat stroke has occurred.
    - Conditions exist that increase the likelihood or possibility of heat stress, such as:

      • Sustained temperatures above 90° F.
      • Employees wearing personal protective equipment.
      • Employees are dehydrated or physically active on the job.
      • Employees are exposed to cold temperatures below freezing.

      Heat stress measurements can be taken with special instruments.

Other Resources for IAQ

For information and guidance about IAQ, see the following resources:

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