What is true regarding tarping in fumigation regarding thickness?

When assessing the relationship between tarping in fumigation and thickness, it's important to recognize that the effectiveness of a tarp is significantly influenced by its permeability. The permeability of the material determines how easily the fumigant can pass through it. Thicker tarps generally have lower permeability, providing a better seal that minimizes fumigant loss and ensures a more effective treatment. Therefore, the thickness of the tarp is not independent of permeability, as thicker tarps tend to have a reduced permeability, enhancing the overall effectiveness of the fumigation process.

In this context, the other options relate to factors that do not accurately represent the role of tarp thickness in fumigation. The idea that it depends on density does not correctly capture the relationship between thickness and permeability, as density does not directly dictate how well the tarp functions in retaining fumigants. Suggesting that it should always be doubled implies a one-size-fits-all approach, which does not account for the specific conditions and requirements of each fumigation situation. Lastly, the notion that tarp thickness is based on the chemical used overlooks the fundamental principle that permeability plays a key role across differing chemicals and conditions.