In June 2025, the Georgia Environmental Protection Division (EPD) updated their Toxic Air Pollutant (TAP) Modeling Limit for formaldehyde (annual average) from 1.1 ug/m3 to 0.0909 ug/m3, a 92% (or 12-fold) reduction. Per Georgia EPD’s guidance, any air permit application submitted after November 2024 that require plume dispersion modeling as part of the Toxic Impact Assessment (TIA) will need to comply with the new annual formaldehyde limit of 0.0909 ug/m3.
This reduction was the result of EPA’s Integrated Risk Information System (IRIS) Toxicological Review of Formaldehyde (Inhalation) conducted in August 2024. The Review concluded that formaldehyde is carcinogenic to humans through inhalation and updated the risk values for formaldehyde. Georgia EPD calculated the new TAP modeling limit for formaldehyde based on the updated risk values in EPA’s toxicological review.
This update has a significant impact on sawmills, because formaldehyde is emitted when drying pine lumber and combusting wood residuals. Any sawmill in Georgia that plans to increase their drying capacity, add a new kiln, add a new boiler, or make any modification that could potentially increase formaldehyde emissions will have to submit an air permit application and conduct a Toxic Impact Assessment. The TIA modeling must comply with the new annual formaldehyde limit to demonstrate that nearby residences are not exposed to formaldehyde at levels detrimental to their health.
With such a substantial decrease in the formaldehyde limit, passing the TIA modeling will be more challenging, especially if there are residential properties located close to the facility. Possible solutions to help comply with the limit include adding/modifying control equipment, alternative drying/production scenarios, and constructing the emission source further away from residences.
Lookout for our the next CTI Newsletter, which will take a deep dive into this topic and include a technology solution being deployed by CTI and CTI clients to potentially reduce the amount of fugitive emissions leaking from a continuous dry kiln, allowing for less formaldehyde emissions to be included in the Plume Dispersion Modeling required for some state air permits.
For more information on air permits and Toxic Impact Assessments, please contact us at (770) 263-6330 or cti@conversiontechnology.com.