Indoor Air Quality

I.  Purpose/Scope

  • PURPOSE: The purpose of the Indoor Air Quality (IAQ) management program is to provide a proactive and systematic approach to identify and remove/control sources of indoor air pollution in ordert to provide a healthy environment for the University’s employees, students and visitors.  This program describes the tools, techniques, communications and protocols followed by the University for maintaining optimal Indoor Air Quality and promptly responding to building occupants’ concerns regarding IAQ.
  • SCOPE:  This program applies to all California State University, Northridge owned and maintained buildings. 

II.  Definitions

  • ASHRAE:  American Society of Heating, Refrigerating and Air-Conditioning Engineers.  A society with a purpose of advancing the art and science of heating, ventilation, air conditioning and refrigeration for the public’s benefit through research, standards writing, continuing education and publications.
  • Air Handling Unit:  Equipment that includes a blower or fan, heating and/or cooling coils, and related equipment such as controls, condensate drain pans, and air filters; does not include duct work, registers or grilles, or boilers and chillers.
  • Allergen:  A substance capable of causing an allergic reaction because of an individual’s sensitivity to that substance.
  • Cubic Feet per Minute (CFM):  The amount of air, in cubic feet, that flows through a given space in one minute.  1 CFM equals approximately 2 liters per second (l/s).
  • Carbon Monoxide (CO): is a colorless and odorless gas. It results from the incomplete oxidation of carbon in combustion processes.
  • Carbon Dioxide (CO2): is a colorless, odorless product of carbon combustion.
  • Carcinogen: A substance that can cause or contribute to cancer.
  • Conditioned Air:  Air that has been heated, cooled, humidified or dehumidified to maintain an interior space within the “comfort zone.”
  • Comfort Zone:  The University standard for employee comfort level (zone) for the indicated conditions are:
    • Temperature: 68°F to 78°F (maintained in air conditioned spaces only).
    • Humidity: 30% to 60% (where controllable), Summer 20% - 60%, Winter 40% - 60%.
    • Carbon Dioxide: (CO2) ASHRAE no more than 700 parts/million (ppm) above ambient outside levels, (Cal/OSHA standard is 5000 ppm)
    • Carbon Monoxide: (CO) below 9 ppm in classroom; below 25 ppm in garages (Cal/OSHA PEL is 25 ppm)
  • EH&S:  Environmental Health & Safety Department
  • ETS:  Environmental Tobacco Smoke is tobacco smoke in the ambient atmosphere composed of side-stream smoke and exhaled mainstream smoke; or exposure to second hand smoke.
  • Hazardous Waste:  By-products of society that can pose a substantial or potential hazard to human health or the environment when improperly managed. They have at least one of four characteristics: they are ignitable, corrosive, reactive, or toxic.
  • HVAC:  Heating, Ventilation and Air-Conditioning system
  • IAQ:  Indoor Air Quality
  • Indoor Air Pollutant:  Particles, dust, fibers, mists, bio-aerosols, gases and vapors, in air.
  • SDS:  (Safety Data Sheet) Product safety and handling information supplied by the product manufacturer.  It is a requirement of the OSHA Hazard Communication Standard that a copy of a chemical's SDS be made available to any person working with or around a hazardous material.
  • Outdoor Supply Air:  Air brought into a building from the outdoors (often through the ventilation system) that has not been previously circulated through the system.
  • PEL:  Permissible Exposure Level for a hazardous material.
  • Preventative Maintenance:  Regular and systematic inspection, cleaning, and adjustment of worn parts, materials, and systems. Preventive maintenance helps to prevent parts, material and system failure by ensuring that parts, materials and systems are in good working order.
  • PPM:  Physical Plant Management Department.
  • Sources:  Sources of indoor air pollutants. Indoor air pollutants can originate within the building or be drawn in from outdoors. Common sources include people, room furnishings such as carpeting, photocopiers, art supplies, etc.
  • Ventilation:  The process of supplying and removing air by natural or mechanical means to and from any space. Such air may or may not be conditioned.
  • Zone: The occupied space or group of spaces within a building which has its heating or cooling controlled by a single thermostat. 

III.  Responsibilities

  • Building Occupants:  University building occupants are expected to maintain the area they occupy in a clean and healthful state.  This means that occupants should:
    • Properly dispose of unused food and drink, and the associated containers
    • Comply with the University’s no smoking policy (Policy No. 350-60).
    • Clean-up or report leaking or spilled liquids
    • Report inadequate ventilation and persistent offensive odors
    • Avoid bringing air pollutants indoors
  • EH&S:  The Environmental Health & Safety Department is responsible for:
    • Developing and maintaining the IAQ Management Program.
    • Providing information and guidance to all employees concerning IAQ issues.
    • Taking the lead in response to all IAQ concerns (See Figure 1).
    • Investigating all reported Indoor Air Quality concerns and if necessary, making recommendations for improvement.
    • Directing any HVAC system issues to Physical Plant Management as necessary.
    • Maintaining records of employee IAQ concerns and corrective actions.
    • Keeping a history of IAQ issues for each campus building for future reference.
    • Communicating the status of investigations and corrective action to all concerned.
  • PPM:  The Physical Plant Management Department is responsible for:
    • Operating and maintaining all building HVAC systems using qualified staff:
    • Conducting inspections and maintenance of HVAC systems.
    • Notifying EH&S of any occupant IAQ concerns or potential projects impacting IAQ.
    • Maintaining records of design, installation, inspection, testing, balancing, water treatment, preventative maintenance, repair, replacement and adjustments of HVAC systems.
  • Facilities Planning, Design, and Construction:  The Facilities Planning, Design and Construction Department is responsible for:
    • Conducting plan reviews concerning design of new and retrofitted HVAC system.
    • Ensuring all new and remodeled facilities are provided with adequate ventilation based on Uniform Building Code requirements.
    • Notifying EH&S and specific campus areas and department managers of projects which may impact IAQ.

IV.  IAQ Management Controls

Several factors are known to contribute to poor air quality. These include poor housekeeping and maintenance, inadequate air flow, filtration or ventilation; poor planning or coordination of activities; and sometimes just a lack of understanding or concern. 

 The health, comfort, and learning environment of students and staff are important aspects of CSUN’s mission.  PPM and EH&S have developed a proactive IAQ Management Plan that will help monitor and improve the quality of air in our buildings. The goals of this IAQ Management Plan are to:
  • Reduce the levels of indoor air pollutants through preventive measures such as routine maintenance activities, periodic building evaluations and inspections, and IAQ-specific policies.
  • Provide and maintain adequate airflow by repairing and maintaining ventilation equipment, which will promote a comfortable and healthy learning and working environment.
  • Develop and maintain effective control of indoor and outdoor air pollutions sources.
  • Respond to IAQ-related concerns and problems in a prompt and thorough manner, and effectively communicate the progress of investigations and their resolution to all interested parties.
  • Involve concerned employees in all phases of an IAQ investigation including the results of the investigation and any planned corrective action.

The following IAQ management control measures are designed to prevent problems by focusing on prevention in the areas indicated.


Maintaining properly functioning HVAC systems is key to providing consistently good air quality.  PPM’s Mechanical Services Section, which maintains the heating and air conditioning of campus buildings, conducts the following activities to assure the supply of clean indoor air.

  • Annual Service:
    • Heating coils/cooling coils inspection.
    • Chiller system seasonal maintenance.
    • Heating system seasonal inspection.
  • Semi-Annual Service:
    • Filter changes for air handling units.
  • Quarterly Service:
    • Filter changes.
    • Check belt tension.
    • Supply fan inspection.
  • As Needed Service
    • Outdoor air intake inspection.
    • Exhaust air outlet testing.
    • HVAC ductwork inspection/cleaning.
    • HVAC controls calibration.
    • Filter changes.
    • Heating coils/cooling coils cleaning.
    • Supply fan cleaning.
    • Chiller system seasonal maintenance.
    • Heating system seasonal maintenance.


  • Entrances are the only areas where dirt can be stopped before entering a building, and therefore, are perhaps the most critical areas.  Two items are used to help stop dirt from entering buildings at entrances: dirt and moisture mats and waste receptacles.

Food Areas:

  • Food and beverage residual can attract pests, insects and rodents which in turn can harbor allergens and transmit infectious airborne diseases. Therefore, Physical Plant Management cleans common areas daily and uses liners in all waste receptacles to trap moisture and ease cleaning.  Employees are responsible for cleaning up after themselves, especially within individual department kitchen areas, before residues may become attractive to pests, insects and rodents and before residues can be tracked into other areas of the building.  In addition, employees should take precautions when food is left in desks or in lobby areas (i.e. use zip-lock bags, place leftovers in refrigerator, etc.).
  • Restrooms/Locker Rooms:
    • Restrooms receive more routine cleaning than any other areas.  PPM routinely cleans these areas for hygiene purposes and the potential of IAQ problems. 
  • Classrooms/Laboratories:
    • Clean floors and chalkboards (if used) are priorities in classrooms.  If chalkboards are utilized, the dust may become a nuisance and therefore routine cleaning is conducted. Floor cleaning is conducted because tracked in dirt can be a source of contaminants.
  • Offices:
    • In offices the emphasis is on floor care, dusting and waste removal.
  • Student Health Center:
    • Daily mopping and disinfecting of the floors and other surfaces must occur in these areas.


Please refer to the University Smoke-and Tobacco-Free Policy on Smoking located in the University’s Polices & Procedures.


  • Waste materials produced on campus create the potential for adverse safety, health and environmental issues, including poor air quality.  The control of the production, storage, use and disposal of waste materials is essential for good indoor and outdoor air quality.
  • The University is engaged in developing and implementing waste management programs for hazardous waste materials, medical waste, construction waste, general waste and waste water throughout the campus.  These waste control programs are on-going and continuously updated as changes to technology and Federal/State and County requirements occur.  The specifics of any waste control program are available from EH&S.
  • Renovation, remodeling and construction activities have the potential for causing IAQ problems.  Proper planning is important to minimize future problems.  If possible, these types of activities should occur when the building is not occupied.  The contractor must make safety data sheets (SDSs) available when employees may be exposed to relevant hazardous chemicals.
  • To ensure the health and safety of personnel and students, CSUN will adhere to the following when it reconfigures or changes the use of space within a building:
  • After construction and prior to use, test the air quality of space that has been modified to ensure that the quality of the air is within accepted guidelines for humidity, temperature, carbon dioxide and carbon monoxide.
  • For the space to be used for personnel and/or students, test results must fall within accepted guidelines for each element tested.
  • Student Housing:
    • The harboring, feeding or possessing of any animal in or around the residence halls is not allowed. With certain exceptions, no “visiting” pets are allowed in student rooms or residence hall lobbies.  See:  Student Housing Rules and Regulations.
    • General Animal Control Policy.
    • No animals shall be permitted inside University facilities with the exception of those authorized by the responsible administrative Dean, Department Chairperson or Director for the specific needs of instructional program, or those animals that are certified service animals for persons with disabilities. All animals on University property must be properly restrained at all times and are prohibited from running at large on the campus. It is the responsibility of the owner to clean up animal excrement on University property as well as to ensure the actions/behavior of the animal does not cause harm to individuals or University property. Service animals must be licensed in accordance with county regulations, wear a vaccination tag and be on a leash. 
V.  IAQ Concern Resolution

The greatest challenge posed by IAQ concerns is that the reported symptoms and health complaints are generally diverse and usually not suggestive of any particular medical diagnosis or readily associated with a causative agent. Typically, physical symptoms include headaches, unusual fatigue, itching or burning eyes, skin irritation, nasal congestion, dry or irritated throats, and other respiratory irritations. The workplace environment is frequently implicated because workers report that their symptoms diminish or cease once they leave the workplace. In such cases, however, it is often difficult to ascertain causation and/or substantiate a complaint.

Strategies for investigating indoor air quality problems can be very straightforward in that relevant information is gathered and conclusions are drawn based on findings.  In the absence of specific contaminant sources or obvious ventilation problems, EH&S will try to analyze the scope of the problem and systematically identify or eliminate elements which are specifically associated with IAQ episodes. It should be noted that an overwhelming majority of investigations of campus ventilation systems reveal that they are well maintained and operating properly. 

When the occupant believes the cause of physical symptoms is the quality of the indoor air, the following typical procedure will be followed by EH&S (the scope may vary depending on findings).  A more specific response can be found in Section 10.0, Figure 1, in the form of a flow chart.


  • Meeting:  an EH&S staff person will meet with someone familiar with the problem, usually the affected person(s) or a supervisor, to identify the specific concern.
  • Walk-through:  an initial walk-through will be conducted by EH&S to possibly identify immediately correctable causes or to develop a plan for conducting a more thorough investigation.
  • Scope:  strategies/hypotheses are developed to evaluate suspected problems.
  • Initial Sampling:  a preliminary IAQ sample may be conducted.  An instrument will be used that measures temperature, relative humidity, carbon dioxide and carbon monoxide.  Additional monitoring equipment may be used depending on the known activities in the area.
  • Temperature:  CSU Executive Order No. 917, Policy Statement on Energy Conservation and Utilities Management for California State University and Energy Consumption Reduction Goal for 2004/2005 Compared to 1999/2000, state that energy resources on CSU facilities will be between 68° F to 78° F.  ASHRAE recommended ranges of 73° F to 79° F during the winter months and 69 to 75 during summer months will be evaluated.
  • Relative Humidity:  levels can affect the release rate of many indoor contaminants, their concentrations in the air, and the potential growth of microbial organisms. In ASHRAE 55-1981, an acceptable range of humidity is 20 to 60%.
  • Carbon Dioxide:  is used as an indicator to evaluate the performance of ventilation systems. Ordinary outside air in urban areas normally contains about 300 to 500 parts per million (ppm). ASHRAE standard 62-2001 (Ventilation for Acceptable Indoor Air Quality) recommends that CO2 levels not exceed 700 ppm above outdoor ambient levels.  OSHA limits carbon dioxide concentration in the workplace to 5,000 ppm for prolonged periods, and 35,000 ppm for 15 minutes.
  • Carbon Monoxide:   indoor levels of CO are generally similar to levels found in the air outside of the occupied building. The current regulatory permissible exposure limit (PEL) as set by Cal/OSHA is 25 ppm.
  • Involve Other Departments:  EH&S will call upon Physical Plant Management, Facilities Planning, Design & Construction, the Student Health Center and Risk Management for expertise.
  • Evaluate Findings:  conditions and measured/monitoring results are compared to criteria established through standards, codes, guidelines and good practices.
  • Identify Solutions:  the need for corrective actions and controls is identified, and solutions are recommended.
  • Correction:  controls and recommendations are implemented as necessary.
  • Follow-Up:  findings and results are communicated to concerned parties.

Investigations will not be initiated over issues of comfort, and such issues normally will not result in a walk-through or follow-up. 

 VI.  References & Resources

  • California Code of Regulations Title 8, Sections 332.2, 332.3, 3203, 3362, 5141, 5142, 5143, 5155 & 14004.
  • Recommendations from the Environmental Protection Agency (EPA): Tools For Schools.
  • IAQ Building Education & Assessment Model (I-BEAM); Building Air Quality: A Guide for Building Owners and Facility Managers; Building Air Quality Action Plan.

Other references can be found at:

VII.  Administering Agency

State of California, Division of Occupational Safety and Health (Cal-OSHA)

VIII.  Record Keeping

Physical Plant Management measured/monitoring results are compared to criteria established through standards, codes, guidelines and good practices

Revision Record





Original Program

April 2003


Update program details and format

November 2009


Update program and move to web one

January 2014


General revisions

June 2016


I. Purpose/Scope, II. Definitions, III Responsibilities, HVAC Maintenance, Building Cleaning Services, Waste Management, Renovation/Remodeling and New Construction, Overview, EH&S Response format update.

VI. References & Resources link updates

June 2018


General revisions and link updates

October 2022

Problem Solution Flowchart