Direct contact with spray-on conformal coatings can be harmful to the skin. These coatings may contain chemicals that cause skin irritation, leading to redness, itching, and discomfort. In some cases, individuals may also experience allergic reactions, which causes more severe symptoms such as swelling, rashes, and difficulty breathing. Also, if these coatings are absorbed through the skin, they can enter the bloodstream. This can affect other organs or systems in the body and may lead to more serious health problems.