Your question can be answered a couple of different ways, so without knowing your concerns let me try and go back to basics…

Unlike a lot of other fruits and vegetables that go on trees or above the ground, any spraying in the field will not normally come in contact directly with the potato or its exterior skin. It grows underground and is not exposed to air until harvested. As to the term “chemical” do you mean fertilizers or pesticides or sprout inhibitors? All fall under the terminology. Without conventional or organic enhancements to the crop, the yields will be affected negatively, the plants or potatoes could be subject to disease or the potatoes will sprout after a few weeks or a couple of months.

There are very strict guidelines on when and how any of this is applied. The overall consideration is that no residue that is considered of a harmful level be detectable via sampling and that the food supply is safe for human consumption.