What is the flooring of a shipping container made of?

Usually, shipping container floors are one-inch marine plywood made from tropical hardwood such as Apitong or Keruing.
Some shipping container floorings also are made from bamboo, this bamboo makes the floors more strength and longer life.

Shipping container floors plywood treatment

Unfortunately, these kinds of hardwoods attract pests of all sorts. To prevent damage to the goods by the insects and other critters, the wooden floors are treated with pesticides.
In China, when floorings export, usually use fumigation the floorings to kill the pests.