A Guide to Indoor Air Quality Standards for Office Buildings

Are you looking to improve the air your employees breathe? Ensuring excellent indoor air quality standards for office buildings isn't just about compliance; it's about creating healthier, more productive workspaces. Neglecting air quality can lead to significant health issues and decreased performance. Discover how to effectively meet and exceed these vital standards.

Understanding indoor air quality in office environments

How do we define indoor air quality in an office? Most often, it is through the measurement and monitoring of selected air pollutants and environmental parameters that affect the health, comfort, and productivity of people using the space. To determine the air quality in an office, specialized sensors are used, professional audits are carried out, or—sometimes—tests are performed independently.

Air quality sensors are electronic devices programmed to detect pollutants and environmental variables such as:

• carbon monoxide (CO),

• particulate matter (PM2.5 and PM10),

• volatile organic compounds (VOCs),

• formaldehyde,

• radon,

• carbon dioxide (CO₂),

• temperature,

• relative humidity.

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CO₂ concentration is a commonly used indicator of ventilation quality; a well-ventilated office maintains CO₂ levels below 800 ppm. Relative humidity should be kept below 60% to reduce the risk of mold growth and support user comfort, while temperature affects thermal comfort.

Professional IAQ (Indoor Air Quality) audits use air sampling, inspections of ventilation systems, and thermal comfort tests to comprehensively assess air quality in the office and recommend improvements. Some organizations implement centralized IAQ dashboards to collect and analyze real-time data, enabling predictive air quality management.

Why indoor air quality matters for health and productivity

Did you know that people spend around 90% of their time indoors, where air pollutants can often be 2-5 times higher than outdoors? Poor indoor air quality (IAQ) can have a significant impact on your health and wellbeing. Here’s how:

• Immediate symptoms: Exposure to poor IAQ can cause immediate symptoms such as eye, nose, and throat irritation; headaches; dizziness; fatigue; and respiratory problems such as asthma attacks.

• Long-term health effects: Prolonged exposure to poor IAQ has been linked to serious health conditions such as heart disease, lung cancer, and other respiratory diseases.

• Cognitive function: Studies have shown that poor air quality in offices can reduce adults’ cognitive performance, including their ability to focus, respond to tasks, and use verbal skills.

• Productivity: Workers tend to perform better in environments with lower levels of indoor pollutants and carbon dioxide. This is associated with fewer sick building symptoms and less absenteeism.

• Sick building syndrome: Poor IAQ can contribute to sick building syndrome – a condition where occupants of a building experience discomfort and illness symptoms that improve when they leave the building.

• Mortality rates: The World Health Organization estimates that millions of premature deaths each year are attributable to poor indoor air quality worldwide.

Main sources of indoor pollutants in office buildings

Common sources of indoor air pollution include:

• Building materials and furnishings such as pressed wood, carpets, upholstery, paints, and adhesives that release formaldehyde and other volatile organic compounds (VOCs).

• Office equipment such as printers, photocopiers, and other electronic devices that emit ozone and VOCs during operation.

• Chemicals in paints, adhesives, solvents, disinfectants, and cleaning agents that release harmful gases and particulates into the air.

• Biological contaminants such as mold and bacteria that can develop from moisture caused by leaks, high humidity or poor ventilation.

• Dust mites pollen animal dander can also be present particularly in carpeted or poorly cleaned areas

• Combustion sources such as indoor smoking vehicle emissions from underground parking garages combustion appliances can release carbon monoxide (CO) nitrogen dioxide (NO2) particulate matter (PM)

• Poorly maintained or designed ventilation systems which can either concentrate pollutants indoors or introduce outdoor pollutants

• Air fresheners pesticides used indoors which release chemical pollutants degrading air quality

Key parameters in indoor air quality standards

Indoor air quality (IAQ) standards typically focus on key parameters such as pollutant concentrations and factors that affect indoor air conditions within buildings.

The main pollutants commonly covered, often with specified limit values, are:

• particulate matter (PM2.5 and PM10),

• carbon dioxide (CO2),

• carbon monoxide (CO),

• nitrogen dioxide (NO2),

• sulfur dioxide (SO2),

• radon,

• ozone (O3),

• formaldehyde, and

• volatile organic compounds (VOCs).

Additional parameters of importance include:

• ventilation rates and air exchange,

• building characteristics, such as materials or furnishings, which can emit pollutants or absorb them;

• indoor temperature and humidity; and occupant activities.

A common distinction is that IAQ standards are mandatory limits set by regulatory authorities to protect occupational or public health – for example OSHA or national health agencies – whereas IAQ guidelines are generally voluntary health- or risk-based benchmarks intended to minimize or eliminate health risks at pollutant concentrations that may be achievable in practice.

The latest approaches emphasize real-time monitoring with sensors plus integration of monitoring data with building systems including HVAC to enable dynamic management of IAQ.

Overview of leading indoor air quality standards

Developed globally, leading indoor air quality (IAQ) standards are frameworks and guidelines intended to ensure that the air inside buildings is healthy and safe for occupants by addressing pollutants, ventilation, and other environmental factors.

ASHRAE Standard 62.1

ASHRAE Standard 62.1 is a widely recognized guideline that specifies minimum ventilation rates and related measures to achieve acceptable indoor air quality (IAQ) in non-residential buildings. The standard defines the minimum amount of outdoor air ventilation, as well as additional measures, required to provide indoor environments that are acceptable to occupants while minimizing health risks.

The standard applies to all indoor spaces intended for human occupancy, with some exceptions for certain special spaces explicitly excluded in the standard. It provides two main ventilation design approaches: a Prescriptive Approach, which specifies minimum outdoor airflow rates; and a Performance-Based Approach, which uses calculations of contaminant levels.

Some key requirements include:

• Minimum ventilation rates for various spaces such as offices

• Requirements for contaminant control measures

• Guidance on controlling moisture, odors, and other pollutants

ASHRAE Standard 62.1 is updated approximately every three years to incorporate the latest research and technologies. Many building codes and jurisdictions adopt ASHRAE 62.1 as a baseline standard.

EPA guidelines

When it comes to EPA guidelines for indoor air quality (IAQ) in office settings, the focus is on maintaining healthy air through proper ventilation, pollutant control, and monitoring key indicators. Here are some of the main points:

• The ventilation system should be designed and maintained to provide enough outdoor air to dilute indoor contaminants.

• Indoor temperature should generally be kept between 68°F and 79°F (20°C to 26°C).

• Carbon dioxide (CO2) levels are used as an indicator of ventilation effectiveness since CO2 builds up as people breathe out.

• It’s important to identify and minimize contamination of incoming (make-up) air from sources like vehicle exhaust or cooling towers.

• Employers should have designated personnel who understand HVAC systems so they can ensure ongoing maintenance and operation.

In fact, in cooperation with the EPA, ASHRAE provides a free, detailed guide for design and commissioning of IAQ systems that you might find useful.

WELL Building Standard

The WELL Building Standard sets limits for the most important indoor air pollutants, including particulate matter (PM2.5 and PM10), volatile organic compounds (VOCs), inorganic gases, and radon.

• The standard requires that PM2.5 concentrations be kept below 15 μg/m³ under normal conditions.

• For offices with ≥ 25 occupants, demand-controlled ventilation systems must maintain CO₂ concentrations below 800 ppm.

• High-quality filtration of outdoor supply air is required (e.g., carbon filters, media filters, etc.).

• The presence of radon must be monitored and controlled through engineering measures or regular testing.

• The use of sensors for continuous air quality monitoring is encouraged or required, enabling real-time data collection and management.

• Routine maintenance activities must use non-toxic and hypoallergenic cleaning agents.

LEED certification requirements

LEED certification requires:

• The use of building materials, furnishings, and finishes with low volatile organic compound (VOC) and formaldehyde emissions to minimize indoor pollutants.

• Conducting air sampling and testing prior to occupancy to quantify particulate matter (PM10 and PM2.5), carbon monoxide, ozone, formaldehyde, and VOCs.

• Flushing the building with outdoor air prior to occupancy to dilute contaminants.

• Ongoing management of indoor environmental quality per LEED requirements, including proper filtration (e.g., HEPA filters) and maintaining temperature/humidity controls.

• If pollutant levels surpass LEED limits, identifying the source and rectifying it; retesting as necessary before certification can be achieved.

The latest version of LEED (v5) places greater emphasis on indoor air quality by requiring more stringent testing protocols aimed at enhancing occupant health and productivity.

RESET Air Standard

The RESET Air Standard is an indoor air quality standard that requires ongoing real-time monitoring, analysis, and transparency. It mandates continuous monitoring of fine particulate matter (PM2.5), total volatile organic compounds (TVOCs), carbon dioxide (CO2), and in some cases, carbon monoxide (CO).

For commercial interiors, the standard applies to 80% of occupants in regularly occupied indoor spaces. Sensor data are uploaded to an online platform called the “Assessment Cloud” and shared with occupants to increase awareness.

The standard sets performance targets of PM2.5 below 35 µg/m³, TVOCs below 500 µg/m³, and CO2 below 1000 ppm. Temperature and humidity are also monitored continuously.

One unique aspect of RESET Air is the RESET Air Index which accounts for the cumulative impact of all pollutants together providing a more comprehensive measure of air quality.

Fitwel certification

Fitwel certification establishes standards to ensure healthier, safer, and more comfortable indoor environments. To that end, Fitwel requires buildings to monitor and maintain pollutant levels within specified healthy limits (e.g., PM2.5 below 12 µg/m³, CO2 below 1000 ppm) and relative humidity between 30% and 60%. Certified buildings must conduct IAQ assessments and implement protocols for continuous IAQ improvement.

Fitwel places particular emphasis on ventilation improvements such as demand-controlled ventilation or the provision of operable windows. It also encourages the use of HVAC systems that are both effective for IAQ and energy-efficient. The updated Fitwel standards place greater emphasis on documented indoor air quality policies and routine monitoring.

International schemes such as EEA and Hong Kong IAQ Certification

Programs designed to assess, promote and ensure good indoor air quality (IAQ) in office buildings and other public spaces. Notable international schemes include:

• Hong Kong's voluntary IAQ Certification Scheme: Launched in 2003, this scheme targets offices with mechanical ventilation and air conditioning (MVAC) systems. It uses two IAQ class levels as benchmarks – Excellent Class and Good Class. Certification is valid for 12 months, with a full IAQ check required every five years.

• European Environment Agency (EEA): While the EEA provides independent information on the environment, it does not operate a specific IAQ certification scheme. European countries tend to adopt various national or EU-level standards and use schemes such as LEED or WELL to demonstrate compliance with IAQ benchmarks.

Ventilation and filtration requirements

Office buildings should be provided with an outdoor air ventilation rate that is generally recommended to be between 5 and 15 cubic feet per minute (cfm) per person. These ventilation rate standards are primarily based on guidelines in ASHRAE Standard 62.1.

Buildings must supply either the ventilation rate calculated on the basis of floor area or the rate calculated on the basis of occupants – whichever of the two is larger. For spaces with higher occupant densities, demand-control ventilation is commonly required to adjust the quantity of outdoor air supplied according to actual occupancy.

Filtration is used to remove contaminants such as dust, pollen, and mold spores from the indoor air. It’s commonly recommended to use filters rated MERV 8 to MERV 13 for office environments in order to reduce airborne particulates. Filters with higher efficiency (MERV 13 or above) can capture smaller particles but may impose greater air resistance and therefore require HVAC systems designed to accommodate that resistance.

Monitoring indoor carbon dioxide (CO2) concentrations is a common method for assessing ventilation adequacy.

Monitoring and managing indoor air quality

How is indoor air quality (IAQ) in office buildings monitored and managed? Specialized air quality monitors and systems are used to detect pollutants and guide ventilation adjustments.

IAQ monitors measure key pollutants such as:

• carbon dioxide (CO2)

• volatile organic compounds (VOCs)

• radon

• particulate matter

• chemical pollutants

The latest IAQ monitors use smart sensors that continuously collect data and provide real-time feedback on a touchscreen or mobile app. Some sensors are installed inside HVAC ducts to measure air quality parameters within the ventilation system.

Sensors data is used to adjust HVAC operations, increasing fresh air intake or filtration when pollutant concentrations rise. IAQ management also involves routine testing, HVAC system maintenance, and remediation of pollution sources. Displaying IAQ information visibly increases occupant awareness and encourages behaviors that improve air quality.

Roles and responsibilities in maintaining air quality

Coordinated actions by building owners and managers, maintenance staff, and occupants and tenants are required for effective indoor air quality (IAQ) management in office buildings.

1. Building owners and managers are responsible for:

   • Developing and implementing an IAQ management plan that includes the design, operation, and maintenance of ventilation systems.

   • Establishing and enforcing policies to control pollutant sources such as smoking, renovation materials, or pest control products.

2. Maintenance staff are responsible for:

   • Performing routine cleaning to control dust and allergens.

   • Regularly inspecting and maintaining all components of the HVAC system.

   • Addressing building issues like leaks or floods promptly to prevent mold growth.

3. Occupants and tenants are responsible for:

   • Reporting any air quality concerns to building management and following workplace policies.

   • Positioning office furniture or equipment in a way that does not block airflow from ventilation systems.

   
   

Compliance strategies for office buildings

Recommended compliance strategies for indoor air quality (IAQ) management include:

1. Control pollutant sources, ensure adequate ventilation, monitor air quality, and manage building maintenance.

2. Maintain proper ventilation in line with standards from organizations like OSHA and ASHRAE.

3. Consistently monitor pollutants such as carbon dioxide (CO2), nitrogen dioxide (NO2), allergens, and microbial contaminants.

4. Create a written indoor air quality management plan that outlines responsible personnel, maintenance schedules, and procedures for handling occupant complaints.

5. Control pollution sources by using low-VOC materials and cleaning products and repairing water leaks promptly.

6. Address occupant complaints about symptoms related to air quality quickly to identify the root cause of issues.

7. Manage indoor temperature within recommended ranges (e.g., 68-76°F) and control CO2 buildup.

8. Avoid outdoor pollution intrusion by closing windows when outdoor air is poor and implementing smoking restrictions.

   
   

Responding to indoor air quality problems

Responding to IAQ (Indoor Air Quality) problems requires a comprehensive plan that includes monitoring, prevention, remediation, and maintenance of ventilation systems. Here are some key steps to take:

1. Continuously monitor air pollutants such as dust, allergens, cleaning chemicals, and carbon dioxide.

2. Ensure adequate airflow by maintaining HVAC systems to bring in fresh outdoor air and dilute indoor pollutants.

3. Install filters with appropriate MERV (Minimum Efficiency Reporting Value) ratings to capture airborne particles.

4. Control indoor humidity with humidifiers or dehumidifiers to prevent mold growth and reduce dust mite proliferation.

5. Inspect and repair roofs, walls, and foundations to prevent moisture intrusion or the entry of outdoor pollutants.

6. Educate and train employees on how to identify and report air quality concerns promptly.

7. Create an IAQ management plan for your facility; designate an IAQ Coordinator; follow best practices from EPA or OSHA guidelines

8. Limit use of harmful cleaning chemicals; minimize dust generation during renovations/remodeling

   
   

Tackling indoor air quality issues head-on will help you create healthier environments where everyone can breathe easier!