The concept of Chain of Contamination is simple enough that most people consider it almost self-evident when explained, yet it is the most difficult concept for most to grasp and understand. Simply stated, anything which touches something contaminated is itself contaminated.

The primary source of contamination in a body piercing environment is the blood of a client. Following Universal Precautions, we assume from the outset that blood is a source of infection. Since blood contamination does not have to be visible to be present, we make the simple assumption that anything which comes in contact with the site of a piercing has been contaminated. Thus gloves, needles, body jewelry, gauze, swabs, tools etc. all become secondary sources (reservoirs) of contamination. Anything touched by these objects are, in turn, reservoirs, and so on.