Pistachio nuts can spontaneously combust when shipped in large batches. The nut's high oil content and low water content mean that large batches can self-heat to the point where they catch on fire. Pistachios also absorb oxygen and put out carbon dioxide, so they can be a health hazard when they are in large amounts in enclosed areas, such as in cargo ships or delivery trucks. This is why pistachio nuts have to be shipped under very careful conditions and must be regularly monitored for temperature during the shipping process.
More facts about pistachios and spontaneous combustion:
- Pistachios aren't the only food that can spontaneously combust. Walnuts, sunflower seeds, apricot kernels, flaxseed and cashews can also self-heat and spontaneously combust under the right circumstances.
- Iran produces the most pistachios of any country in the world: more than 423 million pounds (about 192 million kg) of pistachios a year. The United States produces the next most, followed by Turkey, Syria and China.
- Other things that can spontaneously combust in large amounts include haystacks, coal, cotton and even piles of manure.
Just because one thing combusts for one reason doesn't mean that all things combust for the same reason. The author never said that haystacks, etc combust for the same high-oil-low-water reason as the nuts and seeds.
The anon poster's explanation may be correct for some foods, perhaps, but the primary cause of auto combustion is reactions of the organic materials with oxygen. As oxidation continues, the material heats up, and will heat up faster with high surface areas. This is why oil on steel wool or linseed oil on cloth rags are potentially dangerous.
Eventually, the heat of oxidation exceeds the combustion point for the material, and a fire will occur.
They don't combust because they're dry and have high oil content - all these things combust when they get wet/damp and and get a mold in them. The mold grows and produces heat. Eventually the whole lot can heat up and catch fire. How do you explain haystacks, cotton, coal and manure if relying on high oil, low water for explanation?
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