AJIC

314 APIC Guidelinethis guideline, entitled “Guideline for Handwashing and Hospital Environmental Control, 1985,”was published in .November1985.2 This latterguideline did not recommend chemical germicides that were formulated for use on medicalequipment or environmental surfaces in healthcare facilities. Rather, the revised CDC guidelinefocused on strategies for disinfection and sterilization of medical (equipment used in the healthcare setting.
The purpose of this revised Association forProfessionals in Infection Control and Epidemiology, Inc. (APIC) Guideline, which is an updatedversion of previous publications,3-6 is to assisthealth care professi~onals in their decisions involving the judicious selection and proper use ofspecific disinfectants. In the preparation of thisguideline, articles in the scientific literature wereused to augment the manufacturers’ label claimsbecause these claims were not consistently verifiables7 Disinfectant failures noted at variance tolabel claims may be caused by deficiencies in
7testing methods or by improperly conductedtests8 In addition, in-use testing has not beenincorporated into all Environmental ProtectionAgency (EPA) methods (e.g., Association of Official Analytical Chemists [AOAC] tuberculocidalactivity test), and fa:ilures have been demonstratedwhen some disinfectants are subjected to conditions, such as dilution, age, and presence oforganic matter, that challenge their antimicrobialactivity.g It should also be recognized that EPAregistration claims are based on microbicidalefficacy data submitted by manufacturers. TheEPA does not independently test disinfectantsbefore their registration, but in 1990 the EPAresumed postregistration testing of chemical sterilants to ensure that they satisfy their registeredlabel claims.
DEFINITIONS

For the purpose of this guideline, the followingdefinitions will be used:Sterilization is the complete elimination ordestruction of all forms of microbial life. It isaccomplished by either physical or chemicalprocesses. Steam under pressure, dry heat, lowtemperature sterilization processes (ethylene oxide [ETO] gas, plasma sterilization) and liquidchemicals are the principal sterilizing agentsused. The term sterilization is intended to conveyan absolute meaning, not a relative one.
Disinfection describes a process that eliminates

August 1996

BACTERIALSPORESBacillus subtilis4MYCOBACTERIAMycobacterium tuberculosisaNONLIPID OR SMALLVIRUSESpolio virus4FUNGITrichophyton spp.

VEGETATIVE BACTERIAPseudomonas aeruginosaStaphylococcus aureusJJ

LIPID OR MEDIUM-SIZED VIRUSESherpes simplex virushepatitis B virushuman immunodeficiency virusFig. 1. Descending order of resistance to germicidalchemicals. This hierarchy considers broad classifications ofmicrobial categories. It is considered a rough guide togeneral susceptibility of microorganisms to disinfectants.
Adapted from Favero MS, Bond WV Chemical disinfectionof medical and surgical materials. In: Block SS, ed.
Disinfection, sterilization and preservation. 4th ed. Philadelphia: Lea & Febiger, 1991:621.

many or all pathogenic microorganisms, with theexception of bacterial spores, from inanimateobjects. In health care settings, this is generallyaccomplished by the use of liquid chemicals or wetpasteurization. The efficacy of disinfection isaffected by a number of factors, each of which maynullify or limit the efficacy of the process. Some ofthe factors that have been shown to affect disinfection efficacy are the previous cleaning of theobject, the organic load on the object, the type(Fig. 1) and level of microbial contamination, theconcentration of and exposure time to the germicide, the physical configuration of the object (e.g.,crevices, hinges, lumens), and the temperatureand pH of the disinfection process. More extensiveconsideration of these and other factors that affectboth disinfection and sterilization may be found in6t lo-l3 Chemical disinfectantsseveral references. 3,can be classified by several schemes. This guideline uses the terminology used by the CDC’s“Guideline for Handwashing and Hospital Envi-