Table 1.
Process | Level of Microbial Inactivation | Method | Examples (with Processing Times) | Health Care Application (Examples) |
---|---|---|---|---|
Sterilizationa | Destroys all microorganisms, including bacterial spores | High temperature | Steam (∼40 min), dry heat (1–6 h depending on temperature) | Heat-tolerant critical (surgical instruments) and semicritical patient-care items |
Low temperature | Ethylene oxide gas (∼15 h), HP gas plasma (28–52 min), HP and ozone (46 min), HP vapor (55 min) | Heat-sensitive critical and semicritical patient-care items | ||
Liquid immersion | Chemical sterilantsb: >2% glut (∼10 h); 1.12% glut with 1.93% phenol (12 h); 7.35% HP with 0.23% PA (3 h); 8.3% HP with 7.0% PA (5 h); 7.5% HP (6 h); 1.0% HP with 0.08% PA (8 h); ≥0.2% PA (12 min at 50°C–56°C) | Heat-sensitive critical and semicritical patient-care items that can be immersed | ||
HLD | Destroys all microorganisms except some bacterial spores | Heat automated | Pasteurization (65°C–77°C, 30 min) | Heat-sensitive semicritical items (eg, respiratory therapy equipment) |
Liquid immersion | Chemical sterilants/HLDsb: >2% glut (20–90 min at 20°C–25°C); >2% glut (5 min at 35.0°C–37.8°C); 0.55% OPA (12 min at 20°C); 1.12% glut with 1.93% phenol (20 min at 25°C); 7.35% HP with 0.23% PA (15 min at 20°C); 7.5% HP (30 min at 20°C); 1.0% HP with 0.08% PA (25 min); 400–450 ppm chlorine (10 min at 20°C); 2.0% HP (8 min at 20°C); 3.4% glut with 26% isopropanol (10 min at 20°C) | Heat-sensitive semicritical items (eg, GI endoscopes, bronchoscopes, endocavitary probes) | ||
Low-level disinfection | Destroys vegetative bacteria and some fungi and viruses but not mycobacteria or spores | Liquid contact | EPA-registered hospital disinfectant with no tuberculocidal claim (eg, chlorine-based products, phenolics, improved HP, HP plus PA, quaternary ammonium compounds, exposure times at least 1 min) or 70%–90% alcohol | Noncritical patient care item (blood pressure cuff) or surface (bedside table) with no visible blood |
Abbreviations: EPA, Environmental Protection Agency; glut, glutaraldehyde; HLD, high-level disinfection; HP, hydrogen peroxide; OPA, ortho-phthalaldehyde; PA, peracetic acid; ppm, parts per million.
Prions (such as Creutzfeldt-Jakob disease) exhibit an unusual resistance to conventional chemical and physical decontamination methods and are not readily inactivated by conventional sterilization procedures.17
Consult the FDA-cleared package insert for information about the cleared contact time and temperature, and see reference18 for discussion why greater than 2% glutaraldehyde products are used at a reduced exposure time (2% glutaraldehyde at 20 minutes, 20°C). Increasing the temperature using an automated endoscope reprocesser (AER) will reduce the contact time (eg, ortho-phthalaldehyde 12 minutes at 20°C but 5 minutes at 25°C in AER). Exposure temperatures for some of the aforementioned high-level disinfectants varies from 20°C to 25°C; check FDA-cleared temperature conditions.19 Tubing must be completely filled for high-level disinfection and liquid chemical sterilization. Material compatibility should be investigated when appropriate (eg, hydrogen peroxide [HP] and HP with peracetic acid will cause functional damage to endoscopes). Intermediate-level disinfectants destroy vegetative bacteria, mycobacteria, most viruses, and most fungi but not spores and may include chlorine-based products, phenolics, and improved HP. Intermediate-level disinfectants are not included in Table 1 as there as there is no device or surface for which intermediate-level disinfection is specifically recommended over low-level disinfection.