Regulation of wood packaging material in international trade - Annex 1 of ISPM 15

Approved treatments related to wood packaging material

Approved treatments can be applied to units of wood packaging material or to pieces of wood from which wood packaging material is to be made.
Use of debarked wood
Regardless of the type of processing used, the wood packaging material must be made of debarked wood. According to this standard, any number of visually isolated and clearly distinguishable small areas of the bark can remain if they:

• have a width of less than 3 cm (regardless of their length), or
• they have a width of more than 3 cm with a total surface area of one separate section of the bark of less than 50 square centimeters.

When treated with methyl bromide, bark removal should be carried out before processing, since the presence of bark on the wood may affect the effectiveness of processing. During heat treatment, bark removal can be carried out both before and after treatment. If the size limit is specified for a certain type of heat treatment (for example, dielectric heating), the entire crust must be taken into account when measuring.

To achieve the required processing parameters, various energy sources or processes for its production can be used. For example, conventional drying in superheated steam,chamber drying,chemical impregnation under pressurewith thermal exposure and dielectric heating (microwave, in the field of high frequency currents) can be considered thermal treatments, provided that they comply with all the parameters of heat treatment specified in this standard.
NPPOthe necessary measures should be taken to ensure that the handlers monitor the processing temperature in the place that is the coldest, that is, in the place in the wood that takes the longest time to reach the set temperature, so that the set temperature is maintained during processing in the entire batch of processed wood. The location of the coldest point of the wood may vary depending on the energy source or the process used, the moisture content and the initial temperature distribution in the wood.

When using dielectric heating, the coldest part of the wood during processing is usually the surface. In some situations (for example, dielectric heating of large-sized frozen wood before it is thawed), the coldest part of the wood may be the core.

When using chamber heat treatment technology, the fundamental requirement is to achieve a minimum temperature of 56 °C continuously for at least 30 minutes throughout the entire thickness of the wood (including the core).

This temperature can be measured by placing temperature sensors in the core of the wood. In addition, when using drying chambers or chambers for other thermal treatments, treatment modes can be developed based on a series of test treatments, during which the main temperature of the wood is measured in various places in the heat treatment chamber and correlated with the air temperature in the chamber, taking into account the moisture content in the wood and other essential parameters (such as the type and thickness of wood, air flow intensity and humidity). A series of tests should demonstrate that the minimum temperature is 56C is maintained continuously for at least 30 minutes throughout the entire thickness of the wood.

Treatment modes must be specified or approved by the NPPO.
Handlers must be approved by the NPPO. The NPPO should consider the following factors, compliance with which may be required in order for the thermal chambers to meet the processing requirements.

• The heat treatment chambers are sealed and have good thermal insulation, including insulation on the floor.
• The thermal chambers are designed in such a way that the air flow can circulate around and inside the stack of wood.Wood The wood being processed is positioned in the chamber in such a way as to provide sufficient airflow around and inside the wood stack.
• If necessary, air deflectors and inter-row gaskets inside the stack are used to ensure optimal air flow in the thermal chamber.
• During processing, fans are used to circulate air, and the airflow from these fans is sufficient to maintain the temperature inside the wood at a given level for the required time.
• The coldest place in the chamber is determined at each loading, and that is where the temperature sensors are located: either in the wood or in the chamber.
• If the processing is monitored by the readings of temperature sensors placed in the wood, it is recommended to use at least two sensors. These temperature sensors should allow you to measure the temperature of the core of the wood. The use of multiple temperature sensors ensures that any temperature sensor failure is detected during the processing process. Temperature sensors are inserted into the core of the wood at a distance of at least 30 cm from the edge. For shorter boards or pallet checkers, temperature sensors are also placed in a piece of wood of the largest size in such a way as to provide temperature measurement in the core. All holes drilled in the wood to accommodate temperature sensors must be sealed with an appropriate material to prevent interference with temperature measurement related to convection or thermal conductivity. Particular attention should be paid to external influences on the wood, such as nails or metal inserts, which can lead to incorrect measurement.
• If the processing mode is based on monitoring the air temperature in the chamber and is used for processing various types of wood (for example, depending on the breed and size), the type, moisture content and thickness of the treated wood must be taken into account in the mode. In accordance with the processing mode, it is recommended to use at least two temperature sensors to monitor the air temperature in the chamber when processing wooden containers.
• If the air flow in the chamber changes regularly during processing, a larger number of temperature sensors may be needed to account for a possible change in the coldest place in the chamber.
• Temperature sensors and data recording equipment are calibrated in accordance with the manufacturer's instructions with a frequency set by the NPPO.

When using dielectric heating (for example, microwave), a wood packaging material consisting of wood not exceeding 20 cm4 when measured by the smallest dimension, or a stack must be heated to reach a minimum temperature of 60 °C continuously for 1 minute over the entire thickness of the wood (including the surface). The set temperature must be reached within 30 minutes after the start of processing.5.
Treatment modes must be specified or approved by the NPPO.
Handlers must be approved by the NPPO. The NPPOs should consider the following factors, compliance with which may be required in order for the dielectric heating chambers to meet the processing requirements.

• Regardless of whether the dielectric heating treatment is carried out as a periodic process or as a continuous (conveyor) process, the course of processing is monitored in the wood, where the temperature is most likely to be the coldest (usually on the surface) to ensure that the set temperature is maintained. When measuring temperature, it is recommended to use at least two temperature sensors to ensure that any temperature sensor errors are detected.
• The handler initially confirms that the temperature of the wood reaches or exceeds 60C continuously for 1 minute over the entire thickness of the wood (including its surface).
• For wood with a thickness of more than 5 cm, dielectric heating with a frequency of 2.45 GHz should be provided by two-way heaters or several waveguides to distribute microwave energy and ensure uniformity of heating.
• Temperature sensors and data recording equipment are calibrated in accordance with the manufacturer's instructions with a frequency set by the NPPO.
• For audit purposes, handlers store heat treatment and calibration data for a period of time determined by the NPPO.

The NPPO is encouraged to promote the use of alternative treatments approved in this standard. The use of methyl bromide should be carried out taking into account the CPM recommendation to replace or reduce the use of methyl bromide as a phytosanitary measure (CPM, 2008).

Wood packaging material consisting of pieces of wood exceeding 20 cm. when measured by the smallest dimension, should not be treated with methyl bromide.
Fumigationwood packaging material with methyl bromide should be carried out in accordance with the scheme specified or approved by the NPPO and allowing to achieve the minimum sum of the products of concentration for a time of 7 (KV) within 24 hours at the temperature and with the final residual concentration, which are indicated in Table 1. This KV value should be reached throughout the entire thickness of the wood, including its core, although concentrations are measured in the surrounding atmosphere. The minimum temperature of the wood and its surrounding atmosphere should be at least 10 C, and the minimum exposure time should be at least 24 hours. Gas concentration monitoring should be carried out 2, 4 and 24 hours after the start of treatment. In the case of a longer exposure time and a weaker concentration, additional measurements of the gas concentration should be recorded at the end of fumigation.
If the KV is not reached after 24 hours, corrective actions should be taken to ensure that the KV is reached; for example, start processing again or extend the processing time by a maximum of 2 hours without additional addition of methyl bromide to achieve the required KV.

Handlers must be approved by the NPPO. The NPPO should consider the following factors, compliance with which may be required in order for methyl bromide fumigation to meet the processing requirements.

• During the gas distribution phase during fumigation, fans are used in accordance with the established procedure to ensure uniform penetration; they should be placed in such a way as to ensure rapid and efficient distribution of the fumigant throughout the fumigated room (preferably during the first hour of application).
• Fumigated rooms should not be loaded by more than 80% of their volume.
• Fumigated rooms should be well sealed and, as far as possible, gas-tight. If it is necessary to carry out fumigation under the film, the latter must be made of gas-tight material and securely sealed at the seams and at floor level.
• The floor at the fumigation site must be impermeable to the fumigant; if it is permeable, a gas-tight coating is laid on it.
• It is recommended to use methyl bromide through an evaporator ("hot gassing") to completely vaporize the fumigant when it enters the fumigated room.
• Methyl bromide treatment of wood packaging material exceeding 20 cm. when measured by the smallest dimension, should not be carried out. For this reason, a separator for stacks of wood packaging material may be needed to ensure the required circulation and penetration of methyl bromide.
• The concentration of methyl bromide in the air is always measured at the place furthest from the gas inlet, as well as in other places throughout the room (for example, in the front lower part, in the central middle part, and the rear upper part), to confirm the achievement of uniform gas distribution. The start of processing is counted when a uniform distribution is achieved.
• When calculating the dosage of methyl bromide, it is necessary to take into account the availability of compensation for any gas mixtures (for example, 2% chloropicrin) to ensure that the total amount of methyl bromide used meets the required dosage standards.
• The initial dosage norms and procedures for handling the drug after treatment should take into account the possibility of absorption of methyl bromide by the treated wood packaging material or objects used with it (for example, polystyrene boxes).
• To calculate the dose of methyl bromide, the measured or expected temperature of the product or ambient air is used immediately before or during processing (the one that is lower).
• The wood packaging material to be fumigated must not be wrapped or covered with materials impervious to fumigant.
• Temperature and gas concentration sensors, as well as data recording equipment, are calibrated in accordance with the manufacturer's instructions with a frequency determined by the NPPO.
• For audit purposes, handlers store data on methyl bromide treatments and calibrations for a period of time determined by the NPPO.

As new technical information becomes available, existing treatments may be reviewed and modified, and alternative treatments or new treatment schemes for wood packaging material may be approved by the CPM. If a new treatment or a revised treatment scheme is approved for wood packaging material and is included in this ISPM, then the material already processed according to the conditions of the previously approved treatment and/or scheme does not need to be re-processed or re-labeled.