When a drug is snorted, it comes into contact with the lining of the nasal cavity. The drug can cause the blood vessels to dilate and rupture, allowing tiny, even microscopic, amounts of blood to leak out onto the snorting device. If you reuse snorting equipment used by another person, blood from the previous person can enter your own bloodstream. When this blood is infected with Hep C, there is a risk of transmission. To prevent the spread of Hep C, people should use their own straws when snorting or else something that can be disposed of immediately. A pack of Post-it Notes can be a large supply of disposable, rollable straws. As people don’t often throw out money, using a bill is not necessarily safe. It may have passed through many hands—and many noses—before coming to the current user.