5.7 Indoor Air Quality Assessment

Safety, Health, and Environmental Manual


These guidelines and the Indoor Air Quality Questionnaire (see chapter 7) address concerns about indoor air quality in your workplace.

5.7.1 Introduction

Complaints about indoor air quality (IAQ) range from simple complaints, such as the air smelling odd, to complex ones, such as the air quality causing illness and loss of work time. It may not be easy to identify a single reason for IAQ complaints because of the number and variety of possible sources, causes, and individual sensitivities.

Use these guidelines to help evaluate IAQ complaints, and develop an action plan to monitor and resolve them. Do not use the guidelines and questionnaire for diagnosing individual sensitivities and complaints; use them to help determine if the building is suffering from IAQ problems.

If you still cannot identify the source of IAQ problems after you have followed all the steps in this guideline, before taking other steps, contact the Risk Management Division at Church headquarters or your local safety and health representative for further instruction.

Use these guidelines to:

  • Log complaints.

  • Conduct a background assessment of the building.

  • Conduct a building walk-through inspection.

  • Assess the performance of heating, ventilating, and air-conditioning systems (HVAC).

  • Determine possible sources of IAQ problems.

  • Develop an action plan to address the likely sources of IAQ problems.

  • Keep building occupants informed about what action is being taken.

5.7.2 Log Complaints

Log each IAQ complaint using the Indoor Air Quality Questionnaire. Ask the person completing the form to be as specific as possible when answering each question. Review each form for the following:

  • Indoor environmental discomforts that have been reported

  • Signs or symptoms of health problems that have been reported

  • When the discomforts and symptoms began and how often they occurred

  • If the discomforts and symptoms continued outside the building

  • Dates and nature of recent episodes of poor air quality at the building

  • Comments that may help identify sources of IAQ problems

5.7.3 Conduct a Background Assessment

Gather as much of the following historical information as possible about the building:

  • Age of the building

  • Type of construction (masonry, wood frame, and so forth)

  • Types of carpets and other fabrics used in the building

  • Age and type of HVAC equipment

  • Recent renovations

  • Previously reported air quality problems

  • Quality and frequency of maintenance and custodial service

5.7.4 Conduct a Building Walk-Through

Walk through the building to get a good idea of any problems that may be present. When possible, interview people who have submitted air quality complaints to get a better understanding of the nature of complaints received.

Look at the following, and record all your findings:

  • Building layout and potential air-flow problems

  • Ventilation equipment for potential sources of chemical or microbiological contaminants

  • Storage places for cleaning materials, supplies, and equipment (note if and how the spaces are ventilated)

  • Outside air-intake locations and how close they are to possible sources of pollution, such as heating exhaust vents

  • Outside air dampers to see if they are open and operating

  • Storage closets that may contain chemical supplies, such as paints, glues, and so forth (note if containers are open and if and how spaces are ventilated)

  • Temperature levels inside and outside and, when environmental monitoring equipment is available in-house, carbon dioxide levels, humidity levels, and air movement

5.7.5 Assess HVAC System Performance

  • Look closely at HVAC equipment, including room air conditioners, to see if they are working properly.

  • Look for drain pans, heating and cooling coils, heat exchangers, and other sources of potential chemical or microbiological (fungus and mold) growth.

  • Review equipment maintenance schedules to see if areas of potential microbiological growth have been cleaned recently.

  • Record all findings.

5.7.6 Determine Possible Causes

Review the information gained from the background assessment, walk-through, and HVAC assessment. When possible, try to determine the sources of the IAQ problems and record all findings. Possible causes include:

  1. Inadequate Ventilation. When reviewing for inadequate ventilation, look for the following:

    • Closed dampers (intake, exhaust, manual, motorized, fire)

    • Blocked or clogged intake and exhaust vents

    • Blocked or clogged heating and air-conditioning vents

    • Not enough fresh outdoor air being brought into the building

    • Not enough inside air being ventilated to the outside

    • Poor air distribution within the building

    • Draftiness

    • Temperature and humidity differences within the building

    • Incorrect air filtration

    • Dirty filters

  2. Inside Contamination. When looking for contamination from inside the building, look for the following:

    • Air fresheners

    • Copy machine toner

    • Chemicals from other equipment

    • Stored cleaners and maintenance chemicals

    • Stored paints and glues

    • Stored lawn and garden chemicals

    • Incorrectly diluted cleaning agents

    • Insecticides, pesticides, and other chemical agents used in the building

    • Leaking heat exchangers

    • Loose and disconnected flues

    • Dry traps in floor drains

    • Broken sewer lines located below the slab and in crawl spaces

    • Fabrics and other finishing materials. Look for the following:

      • Recently installed carpet and wall coverings

      • Recently installed adhesives that are uncured or have been excessively applied

      • Recently installed material that is fibrous, odd smelling, and unfamiliar

      • Recently installed composite products (particle board, fiberboard, fiberglass panels, and so forth)

      • Recently installed paints, varnishes, and other finishes

      • Any of the former items, even if not recent installations, that might be contributing to IAQ problems

      • Any plans, specifications, submittals, and labels that might indicate the actual content of the products installed

  3. Outside Contamination. When looking for outside contamination sources, look for the following:

    • Airborne pollutants from on-site and off-site sources

    • Exhaust stacks too close to air-intake ducts

    • Air-intake ducts close to sources of automobile exhaust

    • Other sources of contaminants close to air-intake ducts

    • Pollen and allergy-causing plants near air intakes

    • Blocked and broken flues

    • Blocked air-intake grilles

  4. Microbiological Contamination. When looking for microbiological contamination, look for the following:

    • Standing water in the HVAC system or signs there has been standing water

    • Water damage to carpet and other furnishings

    • Other sources of leaking and standing water in the building

    • Accumulation of dust and dirt

5.7.7 Develop an Action Plan

After you have identified potential sources of indoor air contaminants, develop an action plan to contain or eliminate them, and then carry out the plan.

If the steps taken in your plan do not eliminate the sources of the contaminants and eliminate the air quality complaints, contact the Risk Management Division or your local area’s facilities management group or operations and maintenance (O&M) office for information and instructions.

5.7.8 Keep Building Occupants Informed

Keep those responsible for the building informed about complaints received and steps taken to correct IAQ problems. Ask them to help correct problems where appropriate.

Provide building occupants who have provided their names and addresses on the Indoor Air Quality Questionnaire with an acknowledgement of their responses and a brief description of the IAQ assessment findings and action plan. Keeping building occupants informed lets them know something has been done and invites them to help maintain the building’s air quality.