Wood Packaging Heat Treatment: A Green Barrier for International Trade

In global trade, wood packaging materials such as wooden crates, pallets and dunnage are widely used because they are strong and low in cost. Untreated wood packaging, however, may carry pests and diseases and threaten the ecological environment and agricultural safety of the importing country. International quarantine standards have therefore been established, and heat treatment has become an important compliance technology as an efficient and environmentally friendly method.

The core principle is to inactivate harmful organisms such as longhorn beetles, nematodes and fungi in the timber by high temperature. Under ISPM 15, the wood must be heated under specified conditions: the core temperature of the timber must reach 56 °C or above and be held for at least 30 minutes; environmental humidity must be controlled during treatment to avoid cracking or carbonisation; and heat must penetrate the interior of the timber evenly without dead corners.

Process. First, pre-treatment preparation: the timber is sorted, cut and assembled, bark is removed because it easily harbours pests, and traceable batch information is marked. Second, the heating stage: the wood packaging is placed in a dedicated heat treatment chamber and heated by thermal oil, electricity or gas, with temperature and humidity sensors and an automatic control system ensuring that the target is reached precisely. Third, continuous monitoring and recording: the internal temperature of the timber is monitored in real time and a treatment report including time and temperature curve is generated for later certification.

Advantages. Compared with chemical fumigation such as methyl bromide, heat treatment leaves no toxic residue and reduces harm to the environment and operators, in line with the global trend towards green supply chains. The treatment cycle is short, usually six to twenty-four hours, and the IPPC-recognised HT mark is accepted by most countries. Treated timber loses little strength and can be reused, lowering long-term packaging costs.

Application and compliance. The treatment applies to wood packaging for exported machinery, electronic products and agricultural products. Besides ISPM 15, the European Union, the United States and China all recognise heat treatment as an official quarantine measure. Companies should choose a treatment organisation authorised by customs or the Asia and Pacific Plant Protection Commission so that the process is traceable.