Workshop on Exotic Pests

International Measures for Solid Wood Packing Material

David McNamara & Göran Kroeker

Wood packing material in international trade
A very large proportion of all the commodities that are traded among countries is accompanied by packing wood. Probably as much as 70% of all cargoes transported internationally by plane, ship, rail, and road are supported in transit by wooden structures. These may be pallets, crates or boxes, dunnage, sawdust, or shavings. A very small proportion of cargo packing may be made from materials other than wood (e.g., plastic on metal), and some of the wooden packing (less than 5%) may be made of “processed” wood (e.g., chipboard, plywood, oriented strand board, and cardboard). The vast majority of packing material is made of solid wood.

Packing wood is usually inferior-quality timber and, as such, is likely to suffer from various imperfections such as growth abnormalities, physical damage, presence of bark, and (most importantly from the forest health point of view) wood pests and diseases. Processed wood is unlikely to contain forest pests, which are destroyed during the processing procedure. Therefore, this paper concerns only solid wood packing material (SWPM).

Phytosanitary risks from wood packing material
The world has become aware only in recent years of the risks of exotic forest pests being introduced with SWPM. In Europe, for example, those responsible for the protection of forests from exotic pests have feared the introduction of the pine wood nematode (PWN), Bursaphelenchus xylophilus (see http://www.uvm.edu/~dbergdah/pwn/pwn.html#A1.1), with imported wood from those parts of the world where the pest occurs (North America, Japan, China, Taiwan, and Republic of Korea). PWN is most likely to be introduced if the wood also contains its vector insects, long-horned beetles or Monochamus spp. Attention was focused originally on imports of all types of wood, but inspectors became increasingly aware during the last ten years that packing wood was far more frequently infested with beetles and nematodes than other types of imported wood. This could be seen by the frequency with which packing wood showed the typical grub holes caused by the larvae of long-horned beetles.

Jyrki Tomminen and his colleagues of the Plant Quarantine Service of Finland tested SWPM and found that 5% of all the tested packing wood from the United States, Canada, or China was infested with PWN. Considering the amount of packing wood that accompanies imports into a modern trading country like Finland, this percentage represents an enormous source of infection with a pest that could seriously damage one of the country’s major industries, forestry. Other European countries have also become so concerned by these risks that they have targeted SWPM for specific inspection. During 2000, 149 interceptions were made by just nine European countries. Of these interceptions were consignments that included SWPM infested with PWN and/or possible vectors in the family Cerambycidae. Multiply this by the number of countries importing daily from infested parts of the world and you can understand the magnitude of the risk. It is not too surprising to learn that when PWN was finally introduced into a European country, Portugal, in 1999, it was determined that the most probable pathway of introduction was with SWPM.

Another reason to focus attention on SWPM was the introduction of the Asian long-horned beetle, Anoplophora glabripennis, into the United States in the 1990s. Numerous interceptions of the insect on SWPM indicated that hardwood packing material from China is, by far, the major pathway for A. glabripennis. As the presence of this insect appears to be limited to the environs of New York and Chicago, U.S. authorities, in an attempt to stop further spread, were very keen to prevent any additional introductions from abroad. Other parts of the world with suitable climates and host trees for establishment of A. glabripennis are also justifiably concerned about the possible entry of the pest.

Phytosanitary measures to mitigate the risks
These two dramatic examples have convinced most people that it is justifiable to require all SWPM moving in international trade to be subject to some plant-health quality requirements such as inspection or treatment to eliminate possible infestation. Such requirements would, in fact, be unique in plant quarantine in that a particular type of article from all origins would be subject to the same measures. Normally, phytosanitary measures are applied only to commodities from identified origins when it is established that a particular quarantine pest occurs in those origins. Some people would argue that such “universal” requirements, for all SWPM from all sources, can not be justified because a large proportion of the SWPM would be coming from countries where no specific quarantine pests occur. Those countries would be obliged to apply unnecessary measures to their exports, thus adding additional cost to the commodities and, consequently, reducing their competitiveness on the world market. The prevailing opinion today is that, in this particular case, because, firstly, SWPM can be infested with a wide range of organisms in an enormous volume of trade and, secondly, because SWPM is reused so frequently by the importing country for its own exports that the origin of arriving SWPM is often unknown. There is good justification for imposing universal measures to block a particularly dangerous pathway for the dissemination of forest pests.

Several countries have already initiated phytosanitary measures against SWPM. For example, Finland, in reaction to the frequent finding of pine wood nematode and its vectors in SWPM, has imposed emergency requirements that SWPM from countries where PWN occurs should be accompanied by a phytosanitary certificate to confirm that the SWPM is:

free from bark and from insect grub holes greater than 3 mm and have a moisture content less than 20%;

or heat treated (56°C for 30 minutes);

or kiln dried to below 20% moisture;

or fumigated with an appropriate pesticide.

China has similar requirements, and the European Union has signalled to the World Trade Organization its intention to introduce emergency measures against PWN. In 1998, the three countries of the North American Plant Protection Organization (NAPPO) agreed on a regional standard, Wood Dunnage and other Wood Packing Materials (http://www.nappo.org/989-002_e.htm), but this has not yet been implemented in the regulations of these countries (see the paper by Ian McDonell). The United States imposes measures against SWPM from China, however, targeted specifically at the Asian long-horned beetle. These measures require official certification that SWPM has been heat treated, fumigated or treated with preservatives. Similar measures are applied by Australia and New Zealand.

International standard for wood packing material
With so much concern by countries around the world about the risks from SWPM, the Interim Commission on Phytosanitary Measures of the International Plant Protection Convention decided in 1999 that an expert group on wood packaging material should be established, as a high priority, to prepare an International Standard on Phytosanitary Measures (ISPM) on the subject. The working group, composed of phytosanitary experts and representatives of the packing, wood industry (including both authors of this paper), has now met twice and used, as a basis for its work, the regional standard of NAPPO. A draft ISPM is expected to be presented to the Interim Standards Committee in May 2001. After that, the draft standard will be sent to all FAO countries and regional plant protection organizations for their opinion of its content. It may also modified by the Interim Standards Committee before being approved as an international standard in April 2002 (see the paper by Robert Griffin in this session for information on the procedures of the IPPC standard-setting bodies). This would be the earliest date for approval, and it could possibly be delayed for another year, if agreement cannot be reached on all of its aspects. In fact, an agreement may be difficult to reach, since the provisional actions taken by individual countries have already led to some heated debates in international meetings.

It is, at this stage, impossible to predict exactly what the format and content of the ISPM will be, but it may contain the following elements:

PRA should be performed wherever possible on SWPM to evaluate the risks and to chose appropriate measures, but SWPM may need to be managed differently from other types of commodities because the origin is often not known. Therefore, universal measures may need to be applied in order to destroy all possible pests.

National plant protection organizations should recognize that certain types of packing material (processed or manufactured) carry no risk of dangerous pests.

National plant protection organizations may establish requirements for SWPM including visual inspection or treatment and/or a phytosanitary certificate. Because phytosanitary certification may be difficult operationally, however, alternative methods should be accepted.

Universal measures of treatment could be, for example, a heating/drying process or chemical-pressure impregnation, with an approved chemical preservative, or other effective methods.

For other identified quarantine pests, appropriate treatments could be (depending on the nature of the pest) removal of bark, fumigation, and/or inspection for signs or symptoms.

Whatever the content of the final ISPM, this is an international standard that is awaited eagerly in order to block a particularly dangerous pathway for the transport of exotic forest pests.