International Standards for Phytosanitary Measures No. 15 is an international phytosanitary measure developed by the International Plant Protection Convention (IPPC). The IPPC requires all wood with a thickness of more than 6mm that is used during shipments between different countries to be treated. The objective is to prevent the spread of diseases and insects (with all the negative consequences for local ecosystems and plants). ISPM 15 states that all wooden materials such as pallets, cases, etc. must undergo heat treatment, and be stamped and branded with a valid mark known as a wheat stamp.