EPA Draws Link Between Low-Dose Formaldehyde Exposure and Cancer

Published 06/23/2022
By Christian Weeks
Clean air and save in offices with enVerid HLR technology

In April, the U.S. Environmental Protection Agency released an updated draft risk assessment for formaldehyde, the leading gaseous contaminant in offices, schools, retail spaces, and residential buildings. The EPA draft risk assessment links long-term, low-dose inhalation of the common chemical to a range of health effects including nasal cancers, myeloid leukemia, and various non-cancer health outcomes such as sensory irritation, respiratory problems, reproductive and developmental toxicity, and nervous system effects.

Also in April, ASHRAE published Addendum aa to Standard 62.1-2019, Ventilation and Acceptable Indoor Air Quality. Addendum aa lists 14 design compounds and design limits to achieve acceptable IAQ. Formaldehyde is on the Addendum aa list (see Table 6-5) with a Design Limit of 33 µg/m3, which is equivalent to 27 parts per billion (ppb).

enVerid has run thousands of IAQ calculations based on the design compounds listed in Addendum aa, and formaldehyde is almost always the “long pole in the tent” when optimizing ventilation rates using ASHRAE’s IAQ Procedure. This is why we are excited that the EPA is updating its draft risk assessment for formaldehyde.

How prevalent is formaldehyde in commercial buildings?

Formaldehyde is used in many products found indoors including carpeting, flooring, furniture, foam insulation, paints, wood glue, adhesives, and personal care products, all of which contribute to widespread human exposures indoors. Contrary to popular belief, formaldehyde emissions from building materials are not exclusive to newly constructed or furnished buildings. Studies of air pollutants in homes, schools and offices, and retail stores show that formaldehyde, at concentrations typically found indoors in existing buildings, is a leading gaseous contaminant.

WELL Building points HVAC Load ReductionAdditionally, minimum ventilation rates based on the Ventilation Rate Procedure (VRP) are not always adequate to maintain formaldehyde at safe levels. For example, a 2012 study on ventilation and IAQ in retail stores with ventilation rates designed using the VRP found that 12 out of 14 retail stores had formaldehyde levels above the CA Office of Environmental Health Hazard Assessment (OEHHA) threshold levels, and 6 out of 14 retail stores had formaldehyde levels above the established NIOSH/FEMA threshold levels. Similarly, a 2013 study on the effect of ventilation on chronic health risks in schools and offices found that doubling the ventilation rates did not lead to formaldehyde concentrations below the CA Office of Environmental Health Hazard Assessment (OEHHA) threshold levels.

Why should we worry about formaldehyde levels?  

The EPA’s updated risk assessment associates potentially adverse health effects with lifetime doses even lower than those identified by the EPA in its 2010 draft assessment. If the nasopharyngeal cancer and myeloid leukemia risks are combined, the cancer risk could be 3.5 times higher than the current value.[1] We expect that these findings will lead to more stringent health-based limits for formaldehyde in future standards to protect workers, children, consumers, and frontline communities exposed to formaldehyde in ambient outdoor air.

What are safe formaldehyde levels?

The answer to this question depends on who you ask, but the indoor limit ranges from 7 ppb to 27 ppb. We recommend keeping formaldehyde levels as low as possible and at least below 27 ppb.

Standard/Guideline/Recommendation Limit (ppb)
ASHRAE 62.1-2019 Addendum aa
ASHRAE 189.1- 2014
LEED (Pilot Credit – EQPC124)
WELL (v2, A05)

Is it possible to measure formaldehyde levels in buildings?

Formaldehyde, at the low concentrations found in most buildings, can be measured very accurately by taking air samples according to an industry standard test method (e.g., ISO 16000-3 and EPA TO-11) and sending the sample to a lab for analysis. One can also take real-time measurements over a short period of time (typically 30-40 days at typical formaldehyde levels) using sensors with a detachable consumable colorimetric cartridge that measures formaldehyde levels down to 10 ppb. Firms like UL and Enthalpy Analytical can test for formaldehyde levels and process samples collected by building personnel for a cost of $700-$1,600 depending on the number of contaminants and locations tested.

How can I ensure safe formaldehyde levels in my building?

There are three ways to ensure safe formaldehyde levels in buildings: source control, source removal, and dilution. Combining all three strategies using the IAQ Procedure will almost always deliver the most effective and energy efficient result for commercial buildings.

Source control can be done by using low-emitting materials in your building. For example, a simulation study for a medium office found that using low-emitting formaldehyde material decreased daily average formaldehyde concentrations by 81% compared to using typical-emitting formaldehyde material. LEED’s Low-Emitting Materials credit includes an emissions evaluation framework that can be used to identify low formaldehyde emitting materials.

While source control is an effective starting point, it will not eliminate the presence of formaldehyde. This is where source removal and dilution become necessary. Designers often use the VRP to comply with outside air ventilation requirements to maintain acceptable IAQ. In offices, school buildings, and retail spaces with typical emission rates of formaldehyde, the VRP results in formaldehyde levels of 10-40 ppb, but in some cases the levels may be higher as we saw with the retail example earlier.

The best approach is to combine all three strategies, including formaldehyde removal solutions, with the IAQP to design to specific, ideally more stringent, formaldehyde levels. This is the most direct way to ensure desired formaldehyde levels are maintained without increasing energy costs by over ventilating buildings. Our Sorbent Ventilation TechnologyTM (SVT) available in standalone enVerid HLR modules and in Daikin Applied airside systems has been shown to be very effective at removing formaldehyde from buildings.

Figure 1 illustrates the advantage of combing removal with outside air ventilation using the IAQP compared to only relying on outside air ventilation based on the VRP. Compared to the VRP, the IAQP solution represents a 76% reduction in outside air ventilation to reach the same formaldehyde concentration target of 27 ppb. If we set a more stringent enhanced IAQ target of 16 ppb, we get an 41% reduction in outside air ventilation with the IAQP.

Using the IAQP to reduce formaldehyde concentrations
Figure 1: Achieving target formaldehyde concentrations using the VRP and IAQP

To learn more about how to use the IAQP with SVT, read our blog post How to Use the IAQP: A Streamlined Approach Based on the New ASHRAE 62.1 User’s Manual and Addendum aa.


Contact enVerid to learn more about how to design and operate buildings with low formaldehyde levels.


[1]The draft assessment concludes that 1 microgram of formaldehyde in a cubic meter of air increases the number of myeloid leukemia cases by roughly 3.5 in 100,000 people, more than three times the cancer risk in the assessment now in use. The EPA currently regulates formaldehyde using an outdated set of calculations, finalized in 1991, based on the risk of nasopharyngeal cancer. If the nasopharyngeal cancer and myeloid leukemia risks are combined, the cancer risk could be 3.5 times higher than the current value.

Christian Weeks

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