ISPM-15
The International Standard for Phytosanitary Measures, Publication #15 or ISPM 15 requirement is the guideline for regulating wood packaging material in international trade. This standard was developed to greatly reduce the Phytosanitary (insect) concerns related to growing global trade and significant spread of non-native pests through wood packaging material.
Neville designed and installed a custom, state of the art, 2.2 million BTU Heat Treating Oven, in order to continue to meet ISPM 15 requirements of core temperature of 135 degrees Fahrenheit for a minimum of 33 minutes.
Neville designed and installed a custom, state of the art, 2.2 million BTU Heat Treating Oven, in order to continue to meet ISPM 15 requirements of core temperature of 135 degrees Fahrenheit for a minimum of 33 minutes.
UNDERSTANDING THE DIFFERENCES BETWEEN MOLD AND LUMBER STAINING IN THE SHIPPING INDUSTRY
|
CAUSES OF MOLD GROWTH
Whether we like it not, mold is all around us. Mold spores are in the air and on the the surfaces surrounding us. When the perfect conditions come together, such as those during the summer months in the Northeast, mold spores bloom and flourish. During the months when high temperatures and humidity are prevalent, wooden products like pallets and crates become a natural food source and growth media for mold. Most hardwoods are processed while still being green (freshly cut) and have a high moisture content. These factors, combined with a lack of air circulation due to the stacking and confined storage methods for lumber and pallets results in the growth of mold on the products we produce. DETERRING MOLDS GROWTH Preventing mold growth, without chemicals, involves eliminating molds access to one or more of the four key growth factors. Moisture and poor ventilation are the two key factors that can be more easily influenced to achieve this. Keeping the moisture content of lumber at or below 20% will keep mold from blooming and growing. While it may not sound difficult to keep wood dry, there are many environmental factors that work against us. To start, the green hardwood used in the pallet making process is cut and milled with a moisture content greater than 30% and is typically stored and transported uncovered and exposed to the elements and free floating mold spores. This means the process of decreasing moisture content doesn't start until the pallet producer receives the lumber. The proper stacking and storage of lumber and finished products to allow good airflow and ventilation is the best way to allow lumber to dry naturally and achieve the desired moisture content of 20% or below. The use of fans to keep air moving and wick moisture from the surface of pallets is highly recommended. These practices, if maintained by the supplier and consumer, can help to achieve and maintain the required conditions to keep mold growth at bay. Unfortunately, for both the producer and consumer, this isn't where the issue of keeping pallets and lumber dry ends. The dryer the wood is, the more it tends to acts like a sponge. Excessive humidity in the air, rain, condensation in buildings and trailers, morning dew, and road spray while in transit are all common sources of moisture that can rewet dried wood and allow for mold to begin to grow. While we can mitigate some of these factors, others are unavoidable. COOPERATION IN PREVENTION The only way to limit or prevent the growth and spreading of mold on wooden pallets and crates is for all parties involved to be active in the process. Following the recommendations provided below will give all involved the best chance to avoid the negative effects mold creates.
|
HEAT TREATMENT TO MEET ISPM-15 STANDARDS
It is important to note that there is a common misconception in the industry that the heat treatment process will kill off mold and bacteria that are harmful to human health. The truth of the matter is that the process is designed to kill invasive species of insects and their larva/eggs. The temperature, time period, and ventilation style of a heat treat oven resembles that of a sauna more than a kiln. It tends to bring moisture to the surface of the wood, warm the wood, and draw the natural sugars in the wood to the surface. This, in effect, creates the ideal habitat for the growth of mold and bacteria, resulting in a bloom of spores that can contaminate all the products in the oven or transport trailer after the process has completed. So while heat treatment is necessary to meet export standards, it is not a viable solution to mold prevention and can often exacerbate the situation.
It is important to note that there is a common misconception in the industry that the heat treatment process will kill off mold and bacteria that are harmful to human health. The truth of the matter is that the process is designed to kill invasive species of insects and their larva/eggs. The temperature, time period, and ventilation style of a heat treat oven resembles that of a sauna more than a kiln. It tends to bring moisture to the surface of the wood, warm the wood, and draw the natural sugars in the wood to the surface. This, in effect, creates the ideal habitat for the growth of mold and bacteria, resulting in a bloom of spores that can contaminate all the products in the oven or transport trailer after the process has completed. So while heat treatment is necessary to meet export standards, it is not a viable solution to mold prevention and can often exacerbate the situation.
BLUE STAIN DISCOLORATIONIt is important to understand that not all discoloration on lumber is the result of mold that poses a risk to human health. Timber staining, such as Blue Stain, is an example of a type of naturally occuring fungus that grows in many species of hardwoods. Blue stain, which is typically blue to grey in color (but can be red, brown, black, and even yellow) is not detrimental to human health, nor does it effect the integrity of the lumber itself. While not always making for the most attractive of pallets, it poses no threat to you or your products when used. The ability to identify timber staining over mold can go a long way in avoiding unnecessary delays and keeping a positive relationship with your customers and suppliers.
|
IRON STAIN DISCOLORATIONLike blue stain, iron staining is not dangerous to human health nor damaging to the integrity of the lumber. Iron staining occurs when moisture bridges the gap between natural extracts in the wood and introduced metals such as fasteners, straps, brackets, and saw blades. The wetter the wood, the greater the chance of and the surface area covered by the iron stain. Oak, being one of the strongest and most readily available hardwoods for the pallet industry, is high in tannin extracts and therefore one of the more susceptible species to iron stain.
|
WEATHERED WOODWeathering (aka sun bleaching) occurs as a result of prolonged exposure to the sun and moisture. The UV rays, given off by the sun, change the color of most lumber to a greyish hue. While this is merely a cosmetic discoloration and has no ill effects on the stability or integrity of the lumber, it is important to note that pallets that are built with weathered boards or become weathered after being built will tend to have a rougher surface, as shown above, that freshly built pallets.
|
|
Neville Manufacturing, Distribution, and Services, Inc.
2320 Clinton Street Cheektowaga, NY 14224 |
|
