Export Wood Packaging

Wood Packaging


NELMA is pleased to provide extensive inspection services to companies that require IPPC ISPM 15 certification, verification, and stamping of wood packaging used in export shipments. Wood packaging materials (WPM) are defined as shipping units constructed completely or partially of solid wood materials such as pallets, skids, boxes, crates, reels, etc., in addition to individual pieces utilized for blocking, bracing, and dunnage for securing the shipment while in transport.


IPPC ISPM 15 is the acronym for International Plant Protection Convention, International Standard for Phytosanitary Measures No. 15. The International Plant Protection Convention (IPPC) is an international plant health agreement, established in 1952, that aims to protect cultivated and wild plants by preventing the introduction and spread of pests. The Convention extends beyond the protection of cultivated plants to the protection of natural flora and plant products, which includes hardwood and softwood forests. It covers vehicles, aircraft, vessels, containers, storage places, soil and other objects or materials that can harbor or spread pests.

More than 175 countries are signatories to IPPC, which has developed a total of 34 ISPMs to date. ISPM 15, titled, Regulation of Wood Packaging Material in International Trade, was adopted by more than 150 countries at the International Plant Protection Convention in March 2002. Each country was then allowed to choose a future date for actual implementation and enforcement. This particular standard was developed as a means to greatly reduce the phytosanitary concerns related to growing global trade and the significant spread of pests through solid wood packaging materials.

Numerous examples exist around the world of environmental and economic harm associated with the introduction of a non-native invasive species to a country, traced back to non-heat treated or non-fumigated wood packaging materials used in shipping. As the leading global consumer market, the U.S. unfortunately has numerous examples of invasive pests introduced into the country over the years, such as the Asian Longhorned Beetle, the Emerald Ash Borer, and the Dutch Elm Disease. Most all can be traced back to shipments received where the non-heat treated solid wood packaging materials contained these forest destructive pests.


Currently, three types of treatments for WPM items are approved in ISPM 15:

  • Heat treatment (HT), and
  • Fumigation with methyl bromide (MB)
  • Fumigation with Sulphuryl Fluoride (SF)  -new in 2018
  • Dielectric Heating (DH) – Microwave or radio waves)

These treatments must be applied to all solid wood components of the wood packaging materials, both hardwood and softwood species of wood. Solid components generally mean the lumber, timbers, or smaller items produced from lumber or timbers. Heat Treatment requires that each solid wood component must be heated to a minimum of 56 degrees C (133 degrees F) for 30 minutes at the core of each piece. Composite wood products such as plywood, particleboard, oriented strand board (OSB), flakeboard, and veneer are exempt from this standard due to the fact that high temperatures are used in their manufacturing process. Preservatively-treated (pressure-treated) wood does not meet the Standard unless the wood was heat-treated and stamped HT prior to preservative treatment.

Since NELMA’s Inspection Services concentrate solely upon the Heat Treatment (HT) aspect of meeting the IPPC ISPM 15 Standard, the following information will cover only the HT compliance process. Additional information on Dielectric Heating (DH) may be found by reviewing/downloading the Dielectric Heating Quick Guide.


There are three primary categories of businesses involved with the export of goods that require certification, verification, and stamping capabilities from an accredited agency to meet the requirements of ISPM 15:

  • Heat Treatment Facility – a facility that has a chamber or kiln designed to (a) heat treat solid wood materials to be used in the construction of wood packaging for export, such as lumber, timbers, or components, and/or (b) to heat treat finished wood packaging units such as pallets, skids, boxes, crates or reels.
  • Wood Packaging Facility – a facility that purchases heat-treated and HT-stamped lumber/timbers or components and produces finished pallets, skids, crates, or custom packaging either for sale or for their own company’s use in exporting goods.
  • Facilities that Re-manufacture Heat Treated Lumber – a facility that purchases full-size heat-treated and HT stamped lumber/timbers and re-manufacturers the material into components and re-stamps the output HT for resale to another wood packaging facility or supplier.

A company may be involved and certified in a combination of any or all of these three categories as well.


The following example defines the basic process that a company designated as a Wood Packaging Facility would follow when certified by an agency accredited to provide compliance and verification inspections, such as NELMA:

Step 1: The facility purchases heat treated lumber or components, with EACH piece required to be stamped with an “HT” mark, an ALSC-accredited agency logo, and facilty/mill number/name. The HT mark signifies that the material has met the minimum temperature/time requirements of the Standard and was verified by an agency accredited under the ALSC program. Typically only one “HT” mark will be ink-stamped on each piece on the face of the material or ends, most commonly incorporated within a grade stamp but may be separate. A “KD HT” mark may be included within the lumber/timber grade mark which indicates that the item was not only heat treated, but dried to a moisture content of 19% or less.

Step 2: As a certified WPM facility, the “HT”-stamped lumber/timbers may then be cut to any size for use in manufacturing the finished wood packaging item without regard to having an “HT” mark on each cut piece. The finished pallet, skid, crate, or box would then be stamped on a minimum of two opposite sides with the certified facility’s “IPPC” stamp. This registered stamp that is issued by the agency for use only by and at the facility incorporates the International IPPC logo, the facility’s unique number, and the certifying agency’s logo. This signifies to custom agents in export countries that the wood packaging meets IPPC’s ISPM 15 Standard and is part of the US’s verification program.

A Heat Treatment (HT) facility would have a hot box, oven, or conventional dry kiln capable of meeting or exceeding the temperature/time requirements of the Standard, certified by the accredited agency. This facility may either heat-treat completed WPM units and/or lumber/timbers and components for use in WPM manufacturing. For heat-treated finished units, the facility would apply the “IPPC” stamp issued by the agency. For lumber/timbers/components for sale to a WPM manufacturer, the facility would apply their agency issued HT stamp on EACH piece.

A Re-Manufacturing  facility would purchase “HT” or “KD HT” stamped lumber/timbers, then re-manufacture the material into components to be sold to a producer of wood packaging finished items, such as pallets, skids, crates, or boxes. In this scenario, the re-manufacturer would be required to re-stamp EACH component with their agency issued “HT” stamp on EACH piece.

Facilities in every category must maintain detailed records and documents to maintain compliance with ISPM 15, as required by the accredited agency.


Founded in 1933, NELMA has a proud history as a non-profit lumber trade association that has been involved with providing lumber grading quality control and compliance inspections for decades. As one of the original agencies that became certified to provide WPM inspections in 2001, NELMA has acquired a vast knowledge of the ISPM 15 Standard based on 20+ years of field experience with our certified-WPM facilities. It’s this knowledge exchange that NELMA’s customers can rely upon to meet their every-day export packaging compliance needs. Our signature service includes:

  • An experienced and knowledgeable staff, both in the field and within the headquarters office,
  • You speak with an informed person when contacting NELMA – not a machine!
  • A toll-free 800 number to call NELMA at any time,
  • Vigilant monitoring of potential illegal counterfeit stamping issues and swift legal action
  • A reference summary of the very latest implementation and enforcement information, by country, and accessible online via password 24/7 (or print/mailed copy by request)
  • Automatic email newsflash alerts regarding changes/revisions within the global implementation of the International Standard, and
  • A flat fee service, no hidden costs or add-ons. 

In addition, NELMA has a long-standing relationship with the American Lumber Standard Committee (ALSC), the accrediting body that administers the U.S. IPPC ISPM 15 Compliance Program on behalf of the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA APHIS). NELMA’s active participation with ALSC as a lumber grading and wood packaging inspection agency provides WPM facilities with a direct voice in the compliance process.


Check out the “Quick Reference Links” box above for access to additional program details and reference documents. The linked items include complete details of NELMA’s certification program for the various types of operations within the NELMA Facility Certification Program and Compliance Procedures for Heat Treatment (HT) and Wood Packaging Materials (WPM) publication (Also available in Latin American Spanish), and a full list of countries that require IPPC ISPM 15 compliant wood packaging materials to enter their ports.

Please contact us by phone at 207-829-6901 or email us at info@nelma.org with any questions that you may have about the program or to inquire about our fee schedule. To apply for HT and/or WPM inspection services from NELMA, you may download an application form (link provided above), complete the requested information, and return via fax (207-829-4293) or email (info@nelma.org).

In addition, the NELMA staff is available upon request to present the details of the IPPC ISPM 15 International Wood Packaging Standard and the NELMA Inspection Program to company personnel as a valuable service to potential customers or industry groups…just call us to schedule!