Methods for improving the resistance of fumigant sorption in produce containers made from expandable polystyrene particles in a fumigation process, and related produce containers. An embodiment involves pre-expanding the expandable polystyrene particles to form pre-expanded particles; applying a coating comprised of a chemical selected from the group consisting of mineral oil, polyethylene wax, ethylene vinyl alcohol copolymer, and polyethylene glycol to the pre-expanded particles and in amount of 0.05 to 5.0 parts per hundred; and forming the container from the pre-expanded particles. A further embodiment involves applying the chemical coating to the expandable particles; pre-expanding the expandable polystyrene particles to form pre-expanded particles; and forming the containers from the pre-expanded particles. Other methods involve increasing the cell size of the expandable particles used to form the produce container.