Indoor Environmental Quality

Understanding indoor pollution, indoor air quality (IAQ), and the overall indoor environmental quality (IEQ).

Download LEED v4 Solutions Guide


Ceiling materials with low emission levels, natural resistance to mold and microorganisms, and high acoustic comfort contribute to improved indoor environmental quality (IEQ). The health and wellness benefits of IEQ, including mitigating poor indoor air quality (IAQ), are recognized by LEED, WELL and other green building standards.

The first area of IEQ we are going to review is the importance of indoor air quality.

Indoor air quality (IAQ)

Indoor air quality is more commonly referred to by its abbreviation, IAQ. In LEED v4, the relevant category is called Indoor Environmental Quality (IEQ).

A key factor in IEQ is the use of low-emitting materials and acoustic treatments in interior spaces. High levels of contaminants and unwanted noise can lead to loss of concentration, bad odors, and irritation.

Children are often the most susceptible to pollutants emitted from building materials. This is because children breathe in more air and, as a result, are absorbing more chemicals that can be harmful to their growing bodies. Since most children spend most their year inside school buildings, these projects deserve extra attention for IAQ.

The U.S. Environmental Protection Agency found that up to half of the schools in America have problems linked to poor IAQ.1 This increases the risk of chronic allergies and asthma among children. Asthma is considered the #1 chronic childhood illness and the leading cause of absenteeism, with almost 14.7 million school days missed each year.2

Get more insight into achieving LEED v4.

Access our latest solution guide for the information you need on your next project.

What is indoor air pollution and how does it affect acceptable indoor air quality?

The definition of indoor air pollution broadly refers to physical, chemical or biological contaminants. The World Health Organization (WHO) calls air pollution “the invisible killer.” Research data shows nine out of 10 people worldwide breathe air containing high levels of pollution. The WHO estimates that around 7 million people die every year from exposure to fine particles in polluted air that penetrate deep into the lungs and cardiovascular system, causing diseases including stroke, heart disease, lung cancer, chronic obstructive pulmonary diseases and respiratory infections.3

Indoor air pollution plays a critical role when looking at the importance of indoor air quality (IAQ). The U.S. Environmental Protection Agency (EPA) states that IAQ: “refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. Understanding and controlling common pollutants indoors can help reduce your risk of indoor health concerns.”4

The U.S. Occupational Health and Safety Administration (OSHA) summarizes, “The qualities of good IAQ should include comfortable temperature and humidity, adequate supply of fresh outdoor air, and control of pollutants from inside and outside of the building.”5

IAQ is part of the larger picture for improving indoor environmental quality (IEQ) and health. Supporting health, indoor air quality, and environmental quality, our entire portfolio of stone wool products is GREENGUARD Gold Certified for low emissions.

Products that have achieved GREENGUARD Certification are scientifically proven to meet some of the world’s most rigorous, third-party chemical emissions standards – helping reduce indoor air pollution and the risk of chemical exposure while aiding in the creation of healthier indoor environments.

Enhanced indoor air quality strategies


What are the sources/ causes of indoor air pollution that lead to poor IAQ and IEQ?

The WHO’s indoor air quality guidelines note factors affecting indoor air quality can involve pesticides and biocides, carbon monoxide, carbon dioxide, radon, solvents, volatile organic compounds (VOCs), allergens, molds, asbestos and other particulate matter. Less obvious sources of indoor air pollution also are found in air fresheners, scented candles, cleaners, adhesives, paints, and treatments on fabrics, wood products, and building materials.6

‘The products that we use to build and furnish our indoor environments can have a significant impact on indoor air pollution levels,” per UL.7

In addition to increased health risks, the geographic location of a building will yield different concerns with indoor pollution. WHO’s research shows:

  • More developed industrialized countries are challenged to remove formaldehyde, insecticides, and phthalates from indoor air
  • Less industrialized areas’ must address pollution from fuels used for heating and cooking indoors
  • Agricultural areas have more issues with dust and organic particles
  • Urban dwellings have more mites, mold and fungal contaminants

Tobacco smoke, especially second-hand smoke, is among the few factors that affect indoor air quality in all settings.

Pollutants described by WHO can cause reactions ranging from headaches, nausea and eye strain to asthma, damage to the central nervous system and cancer.

Ventilation systems and IAQ

The risk of exposure for everyone can increase due to ventilation systems that are outdated, damaged or not optimized to the activities and occupants within the building. U.S. Green Building Council’s LEED v4 and it's rating system recognize this with credits for enhanced IAQ strategies to address mechanical and natural ventilation.8

With respect to ventilation and fresh air, WHO suggests a three-part approach to reduce indoor air pollution: 

  1. Eliminating and controlling the sources of pollution
  2. Diluting and removing pollutants through ventilation with outdoor air
  3. Cleaning the air with air filters and ionizers

Our ceiling tiles can be part of the first step in controlling and minimizing the risks associated with indoor pollution. All our stone wool acoustic ceiling products are certified by UL to GREENGUARD standards.9

In addition to our stone wool tiles, our Rockfon specialty metal ceiling products and Chicago Metallic® suspension systems have no reportable VOCs in the finished product.

Moisture, humidity, water, and IAQ

Along with being low-emitting, our stone wool ceiling panels also are mold resistant and water resistant without added biocides. The water-repellent material that provides no sustenance to microorganisms. These potentially harmful microbes, molds, and bacteria are of top concern for indoor air quality standards for hospitals, medical centers, senior care facilities, and children’s schools and daycares.

Legionnaires' disease is one bacterial disease commonly associated with water-based aerosols that have originated from warm water sources. OSHA estimated there are between 10,000 and 50,000 cases of Legionnaires' disease each year in the U.S., including in hospitals, hotels, and offices.10

“Many notable cases of IAQ problems have been associated with excessive moisture in building assemblies, particularly in the building envelope. Such a situation can lead to mold growth that can be difficult to fix without major renovation efforts and costs. Moisture problems arise for a variety of reasons, including roof leaks; rain penetration through leaky windows; envelope design and construction defects, such as low permeability wall coverings in hot and humid climates; and poor building pressure control. These problems are largely avoidable, but require an understanding of building moisture and attention to detail in envelope design and construction and in mechanical system selection, installation, and operation.”11

Rockfon offers a choice of water-resistant, durable ceiling solutions for interior spaces where high humidity and moisture are concerns; in hospitals and facilities where the sick, elderly or children are present; and in buildings where HVAC systems are not in continuous operation.

RockWorld imagery, The big picture, rock, stone, greenery

Sustainable Ceilings for Green Building Standards

Rockfon acoustical ceiling products are made from stone, nature's most abundant resource and meet industry-leading sustainability requirements.

See our sustainable ceiling testimonial

What should we know about how to measure, test and improve indoor air quality?

When measuring indoor air pollution and complying with IAQ standards, U.S. commercial building spaces typically follow ASHRAE 62.1, “Ventilation for Acceptable Indoor Air Quality.” 

The 2016 version includes a significant change with new requirements to the Indoor Air Quality Procedure. The updated procedure determines minimum ventilation rates be considering the combined effects of multiple contaminants on individual organ systems.12

There is no single test to find an IAQ problem and there currently are no OSHA indoor air quality standards, but it does provide guidelines about the most common IAQ workplace complaints.

  • "Employers are required to follow the General Duty Clause of the OSH Act, which requires them to provide workers with a safe workplace that does not have any known hazards that cause or are likely to cause death or serious injury."
  • "The OSH Act also requires employers to obey occupational safety and health standards created under it. Employers should be reasonably aware of the possible sources of poor air quality, and they should have the resources necessary to recognize and control workplace hazards. It is also their responsibility to inform employees of the immediate dangers that are present. Specific state and local regulations may apply.”
  • “Your employer should check measurements of temperature, humidity, and air flow. In addition, inspection and testing of the ventilation, heating and air conditioning systems (to make sure it is working according to specifications for building use and occupancy) should be performed."
  • "A building walk-through to check for odors and look for water damage, leaks, dirt or pest droppings may be helpful. Leaks need to be eliminated. Standing water in humidifiers, air conditioning units, on roofs and in boiler pans can become contaminated with bacteria or fungi and need to be eliminated, also. In some circumstances, specific testing for radon or for asbestos may be required as part of building occupancy.”
  • “You may also request a Health Hazard Evaluation (HHE) from the National Institute of Occupational Safety and Health (NIOSH). At no cost to employers or workers, NIOSH may investigate workplace health hazards in response to requests from employers, employees and their representatives, and federal agencies.”13

Prevention is preferred to intervention and remediation, and less costly. To improve IAQ and to ensure indoor environmental quality, begin with these goals as part of the design process. IEQ should be discussed in every step of your project’s development: from site planning and orientation, to operable windows that provide access to natural ventilation and HVAC equipment that is sized and zoned correctly, to regular maintenance of equipment and green cleaning practices.

Weekly Newsletter

Never miss a beat.

Register for our newsletter and stay up to date on the latest Rockfon® project profiles, industry insights, and product news.

Beyond IAQ to IEQ - optimizing the indoor experience and environmental quality

The air and environment inside the spaces where we learn, work, heal, eat, shop and play should not make us sick. Ideally, they should keep us healthy. In working toward this goal, more building owners and occupants are following LEED, WELL and other green building guidelines that embrace health and wellness for both people and the planet. Many of these guidelines and standards recognize the integrated significance of air quality, thermal comfort, visual comfort and auditory comfort on the indoor experience and environmental quality.

As designs trend toward higher ceilings and larger windows, this allows for more connection to the outdoor environment, as well as better use of natural light in the indoor environment. Remember also that hot air rises and with it, air pollutants and unwanted heat may be carried upward and properly vented. Higher ceilings support the creation of a cooler, cleaner, and more breathable area for the occupants to enjoy.

Our products enhance occupants’ health, wellness, and IEQ by contributing to their visual comforts, such as maximizing light reflectance and improving light diffusion to reduce glare and associated eye strain.

Occupants’ auditory comfort also is essential to their indoor experience and IEQ. Controlling noise from exterior sources, such as traffic or pedestrians, may be considered when designing the building. But such acoustic considerations often can be overlooked when choosing ventilation, heating, cooling, illumination and electronic equipment, or privacy and concentration needed within the building’s walls.

Our sound-absorbing ceiling tiles, Island® Wall Systems, and Plenum Barrier Board help you optimize acoustics to manage background sound pollution, improve speech intelligibility and maintain confidential conversations.

When people experience greater comfort and more control over their environment, they are less stressed and irritable, take fewer sick days, are more accurate and productive, and ultimately, can make a more positive impact in their work and in their communities.

Weekly Newsletter

Never miss a beat.

Register for our newsletter and stay up to date on the latest Rockfon® project profiles, industry insights, and product news.

Optimize your project's indoor environment.

Find the right products to create an optimal occupant experience.

Other product benefits