Methods of training to detect powdered explosive-detection training aids

A method of training a mammal to detect a powdered explosive-detection training aid, which method comprises:

• placing a packaged powdered explosive-detection training aid in a training area, wherein the packaged training aid comprises:
• first and second opposing flexible sheets with the powdered explosive-detection training aid therebetween, the opposing flexible sheets being heat sealed along a periphery thereof,
• wherein a melting point of the first opposing flexible sheet is substantially the same as a melting point of the second opposing flexible sheet,
• wherein at least a portion of the first opposing flexible sheet is a semipermeable material,
• wherein the semipermeable material is permeable to a vapor emitted from the powdered explosive-detection training aid,
• wherein the semipermeable material is impermeable to liquid water and particulate matter from the powdered explosive-detection training aid,
• wherein the second opposing flexible sheet is impermeable to the powdered explosive-detection training aid vapor;
• and
• conditioning the mammal to detect the vapors permeating from the packaged powdered explosive-detection training aid, thereby training the mammal to detect the powdered explosive-detection training aid.