What is the basis for categorizing tarps in fumigation?

The categorization of tarps in fumigation primarily revolves around their thickness in mils. The thickness of a tarp is critical because it directly affects the material's permeability and durability during a fumigation process. Tarps that are thicker generally offer better gas retention, which is vital for ensuring that the fumigant remains contained within the targeted area for an effective duration. This helps in maximizing the efficacy of the fumigation treatment, as it prevents gas escape, reducing the amount of fumigant required and improving safety protocols.

While the other factors mentioned—composition, cost, and color—may have relevance in specific contexts or preferences related to tarp selection, they do not primarily define the functionality and effectiveness of tarps in fumigation as thickness does.