The original test pack was developed in England by Dr. J. Bowie and Mr. J. Dick and was first published in the 'Lancet' journal in 1963. Since that time, the 'Bowie-Dick' type test pack has been widely used and is recognized as a valuable means of monitoring the air removal efficiency of pre-vacuum and vacuum pressure pulse Steam sterilizers. The original test consisted of 29-36 huckaback type towels, each folded and stacked to a height of 10 -11 inches. A sheet of paper with chemical indicator tape (applied in the pattern of a St. Andrew's cross) was placed in the center of the towel stack. The towel stack was then placed inside a metal dressing casket or equivalent container.
Due to the lack of available materials originally specified for the Bowie-Dick type test pack, alternate configurations evolved in the 1970's. 100% cotton surgical towels were substituted for the huckaback towels; pre-printed chemical indicator sheets replaced the St. Andrews' cross pattern of indicator tape; muslin, and eventually non-woven surgical wrap material replaced the metal casket.
AAMI Standardized Test Pack
The substitutions of these various materials created chaos, so an attempt to standardize the Bowie-Dick test was undertaken by AAMI (Association for the Advancement of Medical Instrumentation). The first standardized description of a Bowie-Dick type test pack appeared in 1980 in AAMI's Good Hospital Practices: Steam Sterilization and Sterility Assurance document.
The AAMI document was updated in 1988 and Section 6.7 Prevacuum Sterilizer Residual Air Test goes into great detail describing the testing frequency (daily), construction (towels folded 9" x 10" x 12" freshly laundered - not ironed, with an indicator sheet or tape in the center, single wrapped), pack placement in the sterilizer (empty chamber, over the drain), test procedure (3.5 minutes at 273F) and acceptance criteria (uniform color change).
Disposable Test Packs
The early 1980's brought the first single-use, disposable Bowie-Dick test pack. This was a significant development in that for the first time, a convenient, yet reproducible test pack could be used, which was also less expensive. This innovation eliminated the cost of securing huckaback type towels, the time-consuming task of laundering the towels between tests (remembering not to iron them), the labor involved in pack assembly, and the storage space needed for the towel test packs.
The Lantor Cube- Reusable Test Pack
Responding to environmental and economic needs, SPSmedical has introduced the industry's first and only FDA cleared for market, reusable Bowie-Dick test pack. The Lantor Cube is approved for 25 uses and is specially designed to reduce waste, space and cost over single-use test packs. Each Lantor Cube comes with 25 consecutively numbered indicator test sheets for the user to replace prior to each test. Simple and easy to use, a metal clamp holds the Lantor Cube together and is provided at no cost after the product is purchased through the local or national Dealer of choice.