A construction company has been recently conducting blasting to remove boulders near our offices. One of our employees happened to walk through the edge of the plume from the blasting when he arrived for work in the morning. At the end of the day, more than eight hours later, we tested him for exposure to explosives. By placing the employee’s necktie in front of the DART we could easily detect nitroglycerin, as shown in Figure 1 (below). It was not necessary to take the tie off to perform the analysis.