Four abbreviations, different processes
HT refers to conventional heat treatment, DH to dielectric heating, MB to methyl bromide fumigation and SF to sulphuryl fluoride fumigation. Recognition in the international standard does not mean that every method is available from a particular supplier or acceptable under every customer instruction. State a prescribed method explicitly in your enquiry.
Conventional heat versus dielectric heating
UK guidance describes conventional HT as 56°C for 30 continuous minutes throughout the wood, including its core. It describes a different schedule and dimensional conditions for dielectric heating. Those are controlled treatment processes, not instructions for buyers to reproduce with ordinary heating equipment. Purchase compliant packaging from an appropriate provider.
Fumigation is specialist work
The fumigants named by the codes require professional handling and applicable approvals. A buyer should focus on method acceptance, provider responsibility, marking and any destination conditions. Do not infer that an old fumigation code establishes suitability for food use, domestic reuse or a specific industrial environment.
A clear specification avoids substitution
If your customer writes “HT only”, pass that exact requirement on. If it asks for ISPM 15 compliance more generally, ask the supplier what treatment will actually be provided. Record the agreed answer with the product specification so a later substitution is reviewed. Contact the importer when a destination or customer requirement is ambiguous.
Sources & further reading
Forestry Commission: wood packaging material for import and export (opens in a new tab)References reviewed 7 October 2026. Confirm the current rules for your shipment with the relevant authority or freight adviser.