January, 2023 – Tahlia
Shipping pallets are a popular source of free or cheap wood for DIY projects. However, if you’ve looked into doing a project that re-uses pallets, you’ve probably come across the warnings about chemical treatments and questioned if they are the best option.
In this article I’ll go through the background of why and how pallets are chemical treated, what to look out for when choosing a pallet for an upcycle project and alternative sources of recycled timber.
The wood that pallets are made from can host fungi, bacteria and pests so there are standards in place to prevent the spread of new pests into our ecosystem. The international regulations on the treatment of wood packaging are set by the International Plant Protection Convention (IPCC).
The current recommended sterilization method for treating wood pallets is with heat treatment. This involves warming the core temperature of the wood up to 50-60 degrees for a minimum of 30 minutes to kill any pests before the pallets are used for transporting goods.
Heat treatment is done in a chamber in the form of :
Methyl bromide is the chemical that everyone’s talking about when it comes to reusing pallets. It doesn’t have any color or smell but is toxic to humans. Direct inhalation is fatal. At high concentrations, methyl bromide causes eye and respiratory irritation. While using second hand pallets doesn’t expose us to high concentrations of methyl bromide it definitely made me re-think my pallet bed project!
Methyl Bromide was commonly used in the past to fumigate pallet wood however it’s less often used now. The international regulator (IPCC) recommends heat treatment over methyl bromide treatment because of its ozone depleting properties. However, the standard still accepts the use of methyl bromide in countries where alternative treatments aren’t available or suitable.
The Montreal Protocol (1992) was intended to phase out the use of methyl bromide by 2005 in developed Countries but unfortunately, this hasn’t been achieved. Methyl bromide is still used for fumigating soils, sterilization of wood, grains, cereal and fruit. We still use this chemical in Australia to treat soil for strawberry runner production and on perishable food.
Wood pallets are fumigated in a sealed container (such as a gas-tight shipping container) for up to 24 hours to achieve a final minimum concentration of 24g/m3. Fumigators must meet strict requirements under Australian regulations. The occupational health standards set the safe exposure limit to 5ppm (19mg/m3) max for up to 8 hours in one day for no adverse health effects.
Above: Methyl bromide fumigation in a shipping container. Ref: Methyl bromide use in Australia Health.vic.gov.au
Sulfur fluoride is also colorless and odorless, it’s an accepted form of fumigation of wood pallets imported to Australia. Sulfur fluoride is used in the US to fumigate whole houses to kill insects and rodents. The safe concentration before people can re-enter their home is 1ppm measured by an air monitoring device.
The fumigation of wood pallets is done over 24- 48 hours in a concealed chamber and is only used on wood less than 20cm thick at its smallest width.
If the pallet has been used for international transport it will have the IPCC mark which includes the treatment type, look for the letters MB, SF and HT.
The marking should include the IPPC symbol, a country code, the treatment code and the treatment provider code.
The stamp below is the format suggested by the IPCC. The mark can be in different layouts but in contains:
If the pallet doesn’t have the IPCC marking it’s likely been produced for local transport. If the business selling or giving away the pallets knows the name of the manufacturer you may be able to find the manufacturing company listed on the Australian Wood Packaging Certification Scheme (AWPCS) Register. This lists pallet manufacturers and treatment providers including the type of treatment the company is certified for (heat or fumigation).
I haven’t found the official regulations on interstate standards but it’s commonly assumed that plain pine pallets manufactured for local use are untreated. If you know the details on this please get in touch, we’d love to hear from you!
While a heat treated pallet might not have a chemical treatment when it was manufactured, we need to consider what that pallet has been used for transporting. Wood pallets can be used to transport chemicals or be exposed to mold making them unsafe to use for indoor pallet furniture.
Some alternatives to pallet wood are wood off cuts, seconds or recycled timber. Businesses like Among the Trees in NSW are making recycled timber more accessible and even running competitions on creations made from wood offcuts.
Speak with your local hardware store about what happens with their off-cuts and seconds. I had a lovely chat with my local Bunnings tradie lady who gave me the full run down!
Waste wood products that we can buy at heavily discounted prices ($1-$5):
