Pellets are manufactured from grains or seeds, or from residues produced in the milling process.
After production, Pellets should be left for some time to cool prior to shipment, like Seed Cakes (Oil Cakes). If pellets are loaded at a high temperature or with an excessive moisture content, or are adversely influenced by climatic changes during the voyage, the cargo can overheat and/or sweat.
In certain circumstances, Pellets can emit carbon dioxide gas, with resulting danger to anyone entering cargo holds.
Certainly ships engaged to carry Expellers, Seed Cakes (Oil Cakes) or Pellets, should be fitted with a fire smothering system, such as a CO2 system, so as to control possible outbreaks of spontaneous combustion.