Dried blood represents the greatest challenge to cleaning surgical instruments. To meet this challenge, ASTM International Committee D12 on Soaps and Other Detergents has developed a new standard, D 7225, Guide for Blood Cleaning Efficiency of Detergents and Washer-Disinfectors. The new guide is under the jurisdiction of Subcommittee D12.16 on Hard Surface Cleaning.

Water-soluble components of blood are easily rendered insoluble when exposed to heat, chemical solutions, or time at room temperature. The water insoluble components of blood are the coagulating agents. These proteins bind quite readily to the surfaces of surgical instruments, making them difficult to remove even with the aid of chemical-cleaning agents. Instruments contaminated with blood represent a significant threat for contamination to healthcare workers and patients.

Healthcare facilities typically employ the use of automated instrument washers. These devices combine mechanical action along with chemical cleaning agents in a staged cycle designed to thoroughly clean surgical instruments, including areas of instruments which are not easy observed (for example, box locks). To function properly, these machines must perform at targeted mechanical efficiency and deliver the correct chemical-cleaning agents at the correct temperature, at the correct dosage for the correct period of time. Failure to meet these parameters will lead to a less than optimal cleaning process.

ASTM D 7225 suggests related methods for challenging the removal of standardized test soil as a result of mechanical or chemical action, or both, by the tested detergents or washer-disinfectors, or both. One method involves the use of a stainless steel coupon with dried blood soil held in a plastic holder. When followed, this method provides the user with a qualitative evaluation of cleaning efficiency. Another method utilizes a peroxidase reaction with hemoglobin to test for residual blood soil on presumptively cleaned surfaces.

ASTM International standards are available for purchase from Customer Service (phone: 610/832-9585; https://www.astm.org/contact/) or at www.astm.org.
For further technical information, contact Ralph J. Basile, Healthmark Industries Co., Saint Clair Shore, Mich. (phone: 800/521-6224; ralphjb@usa.net). Committee D12 will meet Oct. 25-26, at the October Committee Week in Atlanta, Ga. For membership or meeting details, contact Diane Rehiel (phone: 610/832-9717; drehiel@astm.org).

Release #7407