EPA Finalizes New PCWP NESHAP Standards for Wood Products Facilities

Key Takeaways

• The EPA finalized amendments to the PCWP NESHAP on July 6, 2026, adding emission standards for previously unregulated sources, new pollutant standards at already-regulated sources, and new work practice standards.
• Major-source wood products facilities are affected — including particleboard, MDF/HDF, OSB, hardboard, plywood and veneer plants, engineered wood products, and lumber kilns.
• Existing sources must comply by July 6, 2029; new sources must comply by July 6, 2026 (or upon startup).
• New requirements may mean process changes, expanded emission testing, added controls, and new monitoring and reporting.

As of July 6, 2026, the U.S. Environmental Protection Agency (EPA) has published the Final Rule amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for the Plywood and Composite Wood Products (PCWP) source category. The original PCWP NESHAP regulated organic hazardous air pollutant (HAP) emissions from certain types of wood product facility emission units, such as dryers and presses. The July 6th amendment sets emission standards for sources that were not previously regulated, sets emissions standards for several new pollutants for sources previously regulated, and implements work practice standards.

Who Must Comply?

The PCWP NESHAP applies to certain wood products facilities that are major sources of HAPs. Facilities most likely to be affected include major-source PCWP operations such as:

• Particleboard
• MDF/HDF
• Oriented strand board (OSB)
• Hardboard
• Plywood and veneer plants
• Engineered wood products
• Lumber kilns

Sources that commenced construction on or before May 18, 2023, are considered existing, and those that commenced construction after May 18, 2023, are considered new.

Key Updates to the PCWP NESHAP

New Standards for Dryers

• Additional work practice standards for all direct fired dryers.
• New numeric standards for emissions of filterable particulate matter, mercury, hydrochloric acid, polycyclic aromatic hydrocarbons, dioxins, and furans from direct-fired dryers. 
• Numeric standards compliance must be demonstrated by continuous monitoring and source testing every five years. 
• Numeric standards compliance can be achieved through production-based or concentration-based reporting.
• Biomass direct-fired dryers (i.e., green rotary) will have dioxin/furan limits. 
• Fiberboard mat dryers and hardboard press pre-dryers will have new emission limits at existing sources for acetaldehyde, acrolein, formaldehyde, methanol, phenol, and propionaldehyde.
• Dryers fired with wood or other fuels except natural gas have new HAP emission limits based on particulate matter as a surrogate.
• Work practice standards include annual tune-ups to reduce emissions during periods of stack bypasses during startup and shutdown periods.

New Standards for Resinated Material Operations 

Resinated Material Handling process units include resin tanks, plywood presses, engineered wood products presses and curing chambers, blenders, formers, finishing saws, finishing sanders, panel trim chippers, reconstituted wood products board coolers (at existing affected sources), hardboard humidifiers, and wastewater treatment operations. The recently finalized rule establishes work practice standards for these sources including:

• Use only a non-HAP resin or use a resin with a maximum true vapor pressure less than or equal to 5.2 kPa (0.75 psia) for resins stored in tanks >40,000 gallons and 13.1 kPa (1.9 psia) for resins stored in tanks <40,000 gallons or use a combination of resins meeting the first two options. A non-HAP resin is one that contains less than 0.1% by mass of formaldehyde and less than 1.0% by mass each of phenol, methanol, and methylene diphenyl diisocyanate (MDI).
• Pre-dried purchased process wood material must have a moisture content no greater than 30 weight percent, dry basis. On-site process wood material must be dried in a dryer located at the PCWP facility. This requirement does not apply to wet formers or on-site wastewater treatment operations.
• MDI Resin Operations: New emission limits and an expanded list of new and existing sources were established for operations using resins containing MDI, including reconstituted wood products presses, tube dryers, and miscellaneous coating operations.

New Standards for Atmospheric Refiners

• New emission limits were established at new and existing sources for acetaldehyde, acrolein, formaldehyde, methanol, phenol, and propionaldehyde.

New Standards for Kilns

• New work practices were established to limit over-drying, including burner tune-ups and operating under certain temperature and moisture conditions.

Other Miscellaneous Standards

• Work practice standards for log vats
• Work practice standards for stand-alone digesters and fiber washers
• Standards for mixed process streams

How Can Facilities Prepare?

• Sources with one or more mixed PCWP process streams (comingled emissions from multiple affected sources) that elect to comply using control systems must submit documentation demonstrating that the mixed process stream met the compliance option by August 6, 2026.
• Existing sources are required to comply with new emission standards by July 6, 2029.
• New sources are required to comply with new emission standards by July 6, 2026, or upon startup and are required to submit an Initial Notification no later than 120 calendar days after initial startup. 
• New sources demonstrating initial compliance that does not include a performance test must submit a Notification of Compliance Status within 30 days of completing the initial compliance demonstration.
• Performance tests must be performed within 180 days of startup, with a notification 60 days prior and results reported 60 days after.
• Lumber kilns choosing to develop a site-specific plan for work practices must submit the plan by January 6, 2028.

How Can MFA’s Air Quality Team Help? 

These rule amendments may result in the need for process modifications, upgraded work practices, substantially expanded emission testing, additional control devices, and monitoring and reporting changes. MFA can help you review and determine applicability of new requirements, identify gaps, prepare compliance strategies, assist in the submission of compliance notifications, and help develop site specific compliance plans. 

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