Abstract: A ring element (10) attaches to a length of tubing (12) to prevent contamination at a site (24) through which a portion of the length of tubing (12) extends. A resilient material having a first end (14) and a second end (16) is provided capable of mating to form a hollow, cylindrical shell (10). An electrically conductive material is provided on a surface of the resilient material. In a preferred embodiment, the conductive material includes silver. The ring element (10) may be placed on a tube (12) to prevent contamination at a site (24) through which a tube (12) is secured. The ring element (10) is connected to the tube (12) at the site (24) of injection of the tube (12) wherein the ring element (10) is capable of removal without removal of the tube (12) from the site (24). The ring element (10) is particularly adaptable for a transfer set connectable to a peritoneal cavity and insertable at a site (24) for, for example, peritoneal dialysis.