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What is a Bowie-Dick test?

January 1st, 2014


Works for you because...

  1. Lower Cost per test
  2. Superior ink chemistry
    • A colour change to green indicates a Bowie-Dick Test PASS
    • If any purple colour remains in the centre, a FAIL is indicated
  3. Requires less storage space than other BD products
  4. Environmentally safe
  5. Permanent colour change
    • Can be used as a permanent record
    • Information recorded on the back


Bowie-Dick packs typically hold a volume of air that the sterilizer must remove. This volume of air is held in a matrix of porous material, typically cloth or porous paper. The penetration of steam into the pack is documented through the use of an indicator sheet placed in the middle of the pack. The indicator sheet changes color upon contact with steam. If air remains in the center of the pack, steam will be prevented from penetrating and therefore, the center of the indicator sheet will be unchanged in color, or less changed than the perimeter of the test sheet. Heat energy from the condensing steam contacts the indicator sheet as the steam penetrates the pack and causes the chemical reaction of the indicator ink to change color. In other words, the color change comes from the penetration of heat carried by the steam to the center of the pack. Most ink chemistries used in printing Bowie-Dick test sheets change color with heat energy from steam, not from the steam itself.