Clearing the Air on Indoor Air Quality Testing
Indoor air quality testing is the process of measuring and analyzing air pollutants in homes, offices, and other indoor environments to identify potential health hazards. Since we spend approximately 90% of our time indoors, the quality of the air we breathe significantly impacts our health and wellbeing.
Quick Guide to Indoor Air Quality Testing
| Testing Type | What It Detects | When to Test |
| VOC Testing | Chemicals from paints, furnishings, cleaning products, other chemicals | After renovations, new furniture, new carpet |
| Mold Testing | Mold spores, species, mycotoxins | Visible mold, musty odors, after water damage |
| Radon Testing | Radioactive gas from soil | When buying/selling home, basement renovations |
| Particulate Matter | Dust, allergens, smoke particles | Respiratory symptoms, poor ventilation |
| Carbon Monoxide | Colorless, odorless gas | Near fuel-burning appliances, annually |
Poor indoor air quality can lead to immediate symptoms like headaches, fatigue, and respiratory irritation, or long-term health issues including asthma, heart disease, and even cancer in cases of prolonged exposure to certain pollutants.
Unlike outdoor pollution, which is regularly monitored and regulated, indoor air pollutants can be 2-5 times higher than outdoor levels—and occasionally more than 100 times higher—yet receive far less attention.
The average person takes 12-16 breaths per minute, meaning we inhale approximately 15,000 liters of air daily. With each breath potentially containing harmful pollutants, testing is essential to identifying problems that often remain invisible until health issues emerge.
Omega Environmental Services has decades of experience in the environmental consulting industry, where indoor air quality testing has been a cornerstone of our work to protect building occupants from unseen hazards and facilitate regulatory compliance across commercial, residential, and industrial properties. Our Industrial Hygienists are highly skilled, certified, and ready to test indoor air quality in any work environment.
Indoor Air Quality Testing: What, Why, and When
Indoor air quality testing helps us measure what’s floating around in the air we breathe inside our homes and workplaces. As buildings have become more energy-efficient and cleaner through innovations like building sealing, they’ve also become better at trapping pollutants inside buildings with us.
Jeffrey Siegel, a civil engineering professor at the University of Toronto and an indoor air quality expert says, “The reason we do indoor air measurement is often to confirm a problem that we know exists, rather than to find some new problem.” Testing usually happens when we suspect something’s wrong—not as a routine check-up like we might do for our own health.
Defining Indoor Air Quality and Key Pollutants
Indoor air quality (IAQ) is all about how the air inside affects your health, comfort, and ability to function well. Think of it as the “wellness check” for a working or living space.
Pollutants Impacting Indoor Air Quality
- Volatile Organic Compounds (VOCs) are gases released from countless everyday items—fresh paint, new furniture, cleaning products, even that air freshener you just sprayed. While some just cause temporary headaches or irritation, others can contribute to serious health issues with long-term exposure.
- Mold and microbial contaminants love damp spaces and can trigger everything from sneezing fits to serious respiratory symptoms including asthma attacks. That musty smell in your basement? It might be telling you something important about your air quality.
- Radon silently seeps up through foundation cracks from the soil below. You can’t see, smell, or taste this radioactive gas, but it’s the second leading cause of lung cancer in America. Only testing can reveal its presence.
- Carbon monoxide (CO) earns its nickname as the “silent killer” because this odorless, colorless gas from malfunctioning furnaces or other fuel-burning appliances can be lethal before you know it’s there.
- Particulate Matter (PM2.5 or less and PM10.0 or less) consists of tiny particles smaller than 10 micrometers; small enough to cause respiratory irritation and exacerbate existing lung disease like asthma. PM2.5 micrometers or less is hazardous—so small they can bypass your body’s natural defenses, travel deep into your lungs, and even enter your bloodstream.
- Temperature and humidity do more than affect your comfort—they create conditions that either promote or discourage pollutants. High humidity, for instance, creates a paradise for mold growth.
The Health Effects of Poor IAQ
Poor indoor air quality impacts human health in both immediate and long-term ways.
Workers first might notice itchy eyes, scratchy throats, headaches, dizziness, or unusual fatigue. These symptoms often disappear when they leave the building—a classic sign of what experts call “sick building syndrome.”
Over extended periods of time, the exposure to poor quality air can cause serious illness. Respiratory diseases, heart problems, and even certain cancers have been linked to long-term exposure to indoor air pollutants.
The EPA consistently ranks indoor air pollution among the top five environmental health risks due its high exposure rate, higher pollutant concentrations, and number of potential sources.
And recent statistics about environmental health risks from national and global and national health agencies, such as the EPA and World Health Organization, tell us a sobering story:
Asthma affects 26 million Americans, including approximately 5 million children—and indoor air pollutants can trigger attacks.
Radon claims about 21,000 lives annually in the U.S. through lung cancer—deaths that could be prevented with IAQ testing and mitigation.
The EPA estimates that 50% of homes and 85% of commercial buildings show signs of water damage that could lead to mold growth.
Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. Studies have found levels average 2 to 5 times higher indoors, and during activities like paint stripping, levels can be 1,000 times outdoor levels.
When to Test Indoor Air Quality: Triggers and Recommended Frequency
While there’s no universal schedule for indoor air quality testing, certain situations should prompt you to check your air:
- After renovations or new construction, when fresh paint, new flooring, and building materials are actively releasing chemicals into your air. That “new house smell” isn’t always a positive.
- When buying or selling property; many property sellers now include IAQ testing (especially for radon) as part of their home inspection process.
- Following water damage or flooding, because moisture can trigger mold growth in as little as 24-48 hours, potentially creating a biological hazard source behind walls or under floors.
- When people feel sick in your building but better when they leave; this pattern often points to indoor air problems that testing can identify.
- Seasonal changes can affect your indoor air quality too. Radon levels, for instance, often rise in winter when homes are sealed tight against the cold.
- After nearby disasters like wildfires or chemical spills that might have introduced new pollutants into your environment.
- When repurposing spaces—turning that basement into a bedroom? Radon testing becomes particularly important when people will spend sleeping hours in below-grade spaces.
At Omega Environmental Services, we typically recommend annual baseline testing for commercial properties, with more frequent monitoring for sensitive environments like healthcare facilities, schools, and buildings with previous air quality issues. For homeowners, radon testing every two years and general IAQ assessments after significant home changes provide good protection.
Preventing and managing indoor air quality issues starts with knowing what’s actually in your air—and only indoor air quality testing can give you that crucial information.
How Indoor Air Quality Tests Are Performed—and What They Detect
There are several types of Indoor air quality testing, and the type you use depends on what you’re trying to accomplish: Are you trying to improve overall indoor air quality? Or manage air pollutants causing adverse health effects on people? A targeted goal will help determine what type of testing method to use.
| Testing Method | What It Measures | Accuracy | Best For |
| Air Quality Monitors | PM2.5, CO2, VOCs, temperature, humidity | Moderate | Initial screening, ongoing monitoring |
| Professional Spot Testing | Specific pollutants at a point in time | High | Confirming suspected issues |
| Professional Continuous Monitoring | Multiple pollutants over time | Very High | Comprehensive assessment, pattern identification |
| Laboratory Analysis | Precise identification of specific contaminants | Highest | Detailed contaminant identification |
Step-by-Step Indoor Air Quality Testing Process
IAQ Assessment
The first step in indoor air quality testing is an initial assessment where the environmental professional talks with the people who use the space. This investigative work is crucial because signs of building related illness or sick building syndrome can be vague and understated. Something as simple as headaches might be the first clue to a problem with indoor air quality.
Visual Inspection
Next comes the visual inspection where we look for the obvious and not-so-obvious—water stains on ceilings, condensation on windows, visible mold, or musty or acrid smells.
Then the environmental partner would inspect the HVAC system for possible contributors to air pollutants such as poor maintenance, which is often the culprit behind many indoor air quality issues.
Environmental Measurements
For environmental measurements, baseline readings of temperature, humidity, O2, CO, CO2, and air flow are taken. High CO2 levels, for instance, often mean a space isn’t getting enough outside air—like being stuck in a stuffy conference room after lunch.
Targeted Sampling
Based on what is found, we move to targeted sampling—collecting air samples for mold spores, VOCs, or particulates, taking surface samples where needed, and sometimes even sampling building materials.
Lab Analysis
These samples head to accredited labs for laboratory analysis using EPA-approved methods—no shortcuts here. After getting results, the environmental partner handles data interpretation, comparing findings to relevant guidelines.
IAQ Report
You’ll receive a comprehensive report with clear explanations and specific recommendations. If the consultant finds problems, they will provide remediation guidance custom to your situation. In the case of mold and moisture issues, they can conduct post-remediation verification to measure IAQ and determine if pollutant levels have decreased.
Pollutants Detected: VOCs, Mold, Radon, Particulate Matter, Carbon Monoxide
Different pollutants require different detection approaches.
VOC Testing
For VOC testing, an environmental professional can use several methods depending on the situation. They might use passive samplers that collect chemicals over time, or active sampling with pumps that draw air through collection media. For immediate readings, photoionization detectors (PIDs) help screen in real-time. The most detailed analysis happens in the lab using gas chromatography/mass spectrometry—which is a fancy way of saying “we can identify exactly what chemical compounds are present and in what amounts.”
When it comes to formaldehyde—particularly concerning VOC found in many building materials—they use specialized badges or collection methods designed specifically for this compound.
Mold Testing
Mold testing, which can happen in concurrence with IAQ testing, involves several approaches. The mold experts often use spore trap air sampling to capture what’s floating around in the air we breathe. For visible mold, they’ll take surface samples using tape lifts or swabs. Sometimes they need to take actual pieces of material (bulk sampling) when the situation calls for it. If they need to identify specific mold species, they’ll use viable (culturable) sampling.
Radon Testing
Radon Testing requires patience since this radioactive gas needs time to be measured accurately. A hazardous materials expert uses short-term tests (2-7 days) with charcoal canisters or electret ion chambers for initial screening. For more definitive results, long-term testing (90+ days) using alpha track detectors gives a better picture of your actual exposure. Experts can deploy continuous monitoring for real-time data when needed.
Particulate Matter
For Particulate Matter, an environmental partner uses optical particle counters with laser technology to count and size floating particles. Gravimetric sampling helps with detailed analysis, while real-time monitors keep track of PM2.5 and PM10 levels as they change throughout the day.
Carbon Monoxide
Carbon Monoxide is the silent killer that demands immediate attention in an IAQ assessment. Experts use electronic sensors that provide immediate readings, dosimeters for personal exposure assessment, and continuous monitoring devices when long-term tracking is necessary.
Low-Cost Indoor Air Quality Testing Devices vs Professional Labs
Those colorful air quality monitors at the electronics store look tempting, don’t they? They certainly have their place, but it’s important to understand their limitations.
According to the EPA, “A low-cost air pollution monitor is a device that uses one or more sensors and other components to detect, monitor and report on specific air pollutants like particulate matter (PM) or carbon dioxide and/or environmental factors such as temperature and humidity.”
These consumer devices can have some real benefits. They provide continuous monitoring so you can see how indoor air quality changes throughout the day.
Consumer monitors have lower accuracy and precision, limited calibration capabilities, detect fewer pollutants, lack standardized performance criteria, and don’t come with professional interpretation of the results.
While more expensive, professional indoor air quality testing brings significant advantages: calibrated, high-precision instruments (often worth $10,000+), comprehensive pollutant detection, accredited laboratory analysis, expert interpretation of what the numbers actually mean for your health, custom remediation recommendations, and compliance with regulatory standards.
At Omega Environmental Services, we often recommend a hybrid approach: start with professional comprehensive testing to identify specific issues and establish a baseline, then use consumer-grade monitors for ongoing awareness and early warning of new problems.
Regulations, Guidelines, and Current Limitations
One of the most confusing aspects of indoor air quality testing is the web of agency regulations to navigate during a project. Unlike outdoor air – which has to be managed under EPA regulations in certain industries like manufacturing – indoor air exists in a regulatory gray area.
The EPA has established an action level for radon (4 pCi/L) but only offers guidelines for other pollutants. OSHA regulates workplace exposures under the General Duty Clause. ASHRAE Standard 62.1 provides ventilation guidelines and general guidelines for indoor temperature and relative humidity that many buildings follow. Adding to the complexity, individual states may have their own requirements, particularly for schools and public buildings.
The EPA states that “there is no single test to find an indoor air quality (IAQ) problem.” This is why comprehensive assessment is important.
Current testing has several limitations worth noting. Many tests provide only a snapshot rather than continuous data, while pollutant levels can change dramatically throughout the day depending on the circumstances. Variables like weather, building/space occupancy, activities, and ventilation all affect IAQ monitoring results, which can make interpretation complex. There are also interpretation challenges in translating numerical results into actual health implications. Cost remains a barrier for many, leading to reliance on limited testing. And emerging contaminants from new building materials and products continuously introduce novel chemicals that standard testing might miss.
Despite these challenges, IAQ testing accuracy is advancing rapidly with new sensor technologies and standardized methodologies, bringing an increased awareness of how important indoor air quality is to our health and wellbeing.
What’s Your Indoor Air Quality Action Plan?
Indoor air quality testing isn’t just about finding problems—it’s about creating spaces where people can truly thrive. Throughout this guide, we’ve seen how the air inside our buildings directly affects our health, mood, and productivity every single day.
At Omega Environmental Services, we take a proactive approach to indoor air. With our team spread across Southern California and nationwide, our certified industrial hygienists work with diverse clients who all share one common concern: the air their people breathe. From general contractors managing complex renovations to school administrators responsible for hundreds of lives, we provide the necessary expertise to facilitate healthier environments.
Let an Expert Like Omega Guide You
Based on our years in the field, here’s what works for cleaner indoor air:
- Start with a professional assessment to understand what you’re actually dealing with. Many of our clients are surprised by what we find—both good and bad! This baseline testing gives you the facts you need to make smart decisions.
- When test results come back, don’t panic. Instead, prioritize. Some issues need immediate attention (like lifted carbon monoxide), while others can be part of a longer-term plan. Our reports always highlight what needs your attention first.
- The most effective approach? Address pollution at its source. This might mean replacing that old gas stove, fixing water leaks before mold takes hold, or switching to less toxic cleaning products. As one of our industrial hygienists likes to say, “Why filter what you can simply remove?”
- Good ventilation remains your best friend. Many buildings we test have perfectly good HVAC systems that simply aren’t bringing in enough fresh air. Sometimes the fix is as simple as adjusting settings or cleaning ductwork.
- Consider upgrading your filtration—especially if you’re in an urban area or wildfire zone. Today’s high-efficiency filters can capture particles far smaller than standard filters, making a noticeable difference in air quality.
- Don’t just test once and forget it. The smartest building managers combine occasional professional testing with continuous monitoring using quality sensors. This approach catches problems early while controlling costs.
- Share what you learn with everyone in your building. When people understand how their actions affect air quality, they become partners in maintaining it. Simple changes in behavior—like not idling vehicles near air intakes—can make a big difference.
- Document everything. Keep records of all testing, remediation work, and improvements. This history becomes invaluable when troubleshooting future issues or demonstrating your commitment to health and safety.
More Indoor Air Quality Resources for Decision-Makers
For facility and building managers looking to implement a comprehensive approach, we’ve created an in-depth guide: Indoor Air Quality Management for Building and Facilities Managers.
The air we breathe indoors shouldn’t be left to chance or guesswork. With proper indoor air quality testing and thoughtful improvements, every building can become a place that supports wellbeing—not undermines it.
Ready to breathe easier? Learn more about our indoor air quality testing services across Southern California and nationwide on our Indoor Air Quality services page.
