Enzymatic cleaning chemistries are used throughout healthcare facilities to aid in the cleaning of medical instrumentation and devices. They are the workhorse products in both endoscopy and sterile processing/central services areas. Enzymatic cleaning products are used as a precursor, to help other detergents work properly. They are used as presoaks, during manual cleaning of delicate items and endoscopes, and as the first stage of most automated washer processing cycles. Because they are an important part of most cleaning processes in healthcare facilities, it is important to have a thorough understanding of enzymatic cleaner capabilities and limitations in order to use them effectively and assure productivity and safety. Enzyme cleaning products are made up of a variety of components, the most critical of which are the enzymes themselves. Enzymes are part of the class of compounds known as proteins. Proteins are large, naturally occurring molecules made up of amino acids with a very complex structure that drives their functionality. The structure allows the reactants (in this case soil and water) to be held in conformation close enough to each other to give the reaction a “push” on the molecular level. The enzymes are effective at very low concentrations and are not consumed during the process. Through the use of enzymes, reactions that would normally require an alkaline pH (hydrolysis, for instance) can take place rapidly at a neutral pH. This results in better compatibility with instrument component materials and thorough cleaning with minimal mechanical action (brushing, spraying or agitation, for example). There are several types of enzymes in enzymatic cleaning products. These include proteases, lipases, amylases and cellulases. Proteases break down proteins by hydrolysis of the peptide bonds between amino acids. Proteins tend to be very large and water insoluble molecules. Proteases take the large insoluble molecules and break them down into smaller more water soluble ones. Although proteases are specific to breaking bonds in proteins, the proteases used in enzymatic cleaners for the healthcare environment are non-specific – they cleave peptide bonds in a wide variety of protein soils such as blood, mucous, tissue and serum. Different types of proteases with complementary pH and temperature profiles can be combined to enhance their effectiveness over broader pH and temperature ranges. Lipases are the other enzymes that have a practical application in the healthcare environment. Lipases work by hydrolyzing
ester bonds in fats and oils such as adipose tissue and triglycerides. These fat and oil molecules are, in contrast to proteins, not very large but also tend to be insoluble in water. Amylases break down starch or carbohydrates, and cellulases, as their name implies, break down cellulose. Amylases and cellulases are typically included in household products such as powdered laundry detergents to break down gravy and grass stains on cloth, but are not typically needed in cleaning formulations for surgical instrumentation. Enzymatic cleaners help to set the stage for the next step in the process. By removing the first layer of soil from medical instruments, they reduce bioburden and help break down the proteins that adhere to surfaces. The right enzymes in the right formulation will result in a fast-acting product that literally lifts soil off instruments into the cleaning solution. The use of enzymatic cleaners helps make the next step in the cleaning process more effective, and allows for the use of neutral pH cleaners, which are much more compatible than alkaline chemistries for delicate instruments made with soft metals. Concern for our global environment is reflected in an increased emphasis on “green” products. Enzymes themselves are organic in nature, but enzymatic cleaners are formulated with a variety of ingredients. With their neutral pH and the ability of enzymes to be readily broken down as part of an effluent stream, enzymatic products are the perfect candidates for environmentally conscious facilities.