When it comes to indoor air quality in homes, formaldehyde stands out as the single most important aldehyde to measure and control. It is the most common, most studied, and most strictly regulated aldehyde in indoor environments — and for good reason. Even at low levels, it can cause health symptoms, and long-term exposure is linked to serious health risks.
While other aldehydes like glutaraldehyde may also be present, especially from certain mold-resistant paints where it is used as an additive, formaldehyde typically dominates both concentration and health impact in home air testing results.
It’s also important to understand that many aldehydes — including formaldehyde — are produced when indoor ozone reacts with common household materials such as furniture finishes, paints, coatings, and caulking. This means aldehyde contamination can continue to occur over time even without new construction or renovations.
Formaldehyde is one of the most significant chemical hazards found in residential indoor air.
As outlined in our
blog on the EPA’s new reference concentration for formaldehyde
,
recent evaluations indicate that health risks occur at much lower concentrations than many older standards suggest.
The U.S. Agency for Toxic Substances and Disease Registry (ATSDR) recommends limiting
chronic residential exposure to formaldehyde to 8 ppb.
By contrast, the OSHA workplace limit (PEL) is 500 ppb.
The ATSDR value reflects that formaldehyde is a
proven human carcinogen (IARC Group 1),
while the OSHA limit is oriented toward short-term irritation in industrial settings and does not incorporate cancer risk for homes.
Because people spend most of their time indoors, residential exposure can be continuous. Detecting very low concentrations is essential for protecting health and guiding remediation.
Our formaldehyde measurement products can quantify formaldehyde down to an
LOQ of 6 ppb using a 24-hour diffusive monitor,
providing the sensitivity needed to compare against health-based guidelines like the ATSDR’s 8 ppb recommendation.
The Hazard of Formaldehyde in the Home
Major Sources in Homes
Health-Based Guidance vs. Workplace Limits
Why Sensitive, Low-Level Testing Matters
Ozone is a powerful oxidizing agent that can react with many materials found in homes—furniture finishes, paints, coatings, caulking, and flooring—to generate a variety of aldehydes.
This process can occur gradually over time or be accelerated by high ozone levels.
Because ozone-driven chemical reactions can continue to generate aldehydes long after initial exposure, homes with chronic or repeated ozone infiltration may have persistent air quality issues.
Testing for a range of aldehydes is essential when ozone sources are present.
Aldehydes from Ozone Damage
Common Aldehydes Formed by Ozone Reactions
Sources of Indoor Ozone
Glutaraldehyde is a highly effective biocidal compound used in some interior and exterior paints to prevent the growth of mold, mildew, and algae on painted surfaces.
When incorporated into paint formulations, it provides long-lasting microbial protection, making it particularly attractive for use in damp or humid environments such as bathrooms, basements, kitchens, and coastal homes.
While its mold- and mildew-resistant properties are valuable, glutaraldehyde in indoor air can be a potent irritant for some individuals.
Even at low concentrations, it may cause eye, nose, and throat irritation, headaches, or respiratory discomfort.
People with asthma, chemical sensitivities, or other respiratory conditions may be more likely to experience symptoms.
For homeowners and indoor air quality professionals, awareness of glutaraldehyde’s presence is important when investigating unexplained irritation symptoms following a painting project.
If glutaraldehyde-containing paint is used indoors, proper ventilation during application and curing is essential, and post-application air testing can help ensure levels are within safe limits.
Glutaraldehyde in Paint
