Decontamination and Cleaning
Cleaning is the single most important step in instrument reprocessing. Blood, tissue, and biofilm form a physical shield that sterilant cannot penetrate, so an item that is not clean cannot be reliably sterilized no matter how perfect the cycle. This chapter covers point-of-use treatment and transport, the engineering controls that define the decontamination area, personal protective equipment, manual and mechanical cleaning methods, water quality and chemistry, and the verification testing that proves the process is still working.
Point of Use and Transport
Reprocessing begins in the procedural area, not in the decontamination room. Immediately after use, gross soil is removed and the instruments are kept moist so that blood and tissue do not dry into serrations, box locks, and lumens. Dried soil is exponentially harder to remove and is the leading cause of instruments arriving in decontamination with baked-on debris. Moisture is maintained with a damp towel, a pre-treatment foam or spray, or another moisture-retention product used per the manufacturer instructions. Saline must never be used, because chloride ions destroy the passive chromium oxide layer that protects stainless steel and produce pitting, staining, and eventual instrument failure. Instruments should be transported promptly and processed as soon as possible; when a delay is unavoidable, a pre-treatment product buys time. Transport itself is regulated by OSHA. Contaminated items travel in closed or covered, leak-proof containers or carts that are labeled with a biohazard symbol or color coded so that anyone who encounters them knows the contents are infectious. Sharps must never be loose in a tray, and any found should be moved with forceps into a puncture-resistant container and the practice reported back to the procedural area.
The Decontamination Environment
The decontamination area is a deliberately engineered space. It is held at negative pressure relative to adjacent areas so that aerosols and chemical vapors generated during cleaning are drawn out and exhausted rather than migrating into the clean workroom or sterile storage. It receives a minimum of 10 air exchanges per hour to dilute contaminants. Temperature is kept at roughly 60 to 65 degrees F (16 to 18 degrees C), which is cooler than the rest of the department because staff work in full impervious protective attire and heat stress is a real risk. Relative humidity is held at approximately 30 to 60 percent across all work areas, low enough to discourage microbial growth and high enough to limit static and protect packaging materials elsewhere in the department. Underlying all of this is the principle of unidirectional workflow. Items move in one direction only: soiled receiving, then decontamination, then clean assembly and packaging, then sterilization, then sterile storage. Soiled and clean areas are physically separated, sterilizers are loaded from the clean side, and staff who move from decontamination to the clean workroom remove all protective attire and perform hand hygiene first. Time separation on a shared corridor is not a substitute for physical separation.
Personal Protective Equipment and Worker Safety
OSHA's Bloodborne Pathogens standard requires the employer to provide, at no cost to the employee, personal protective equipment that prevents blood or other potentially infectious material from reaching skin, mucous membranes, or street clothes. In decontamination this means a fluid-resistant or impervious gown or jumpsuit, heavy general-purpose utility gloves rather than thin exam gloves, a face mask combined with eye protection or a full face shield whenever splashing is anticipated, hair covering, and dedicated shoes or shoe covers. Personal eyeglasses do not count as eye protection because they lack side and splash shielding. Standard precautions apply, meaning every item arriving in decontamination is handled as if it were infectious regardless of what is known about the patient. Eating, drinking, smoking, applying cosmetics, handling contact lenses, and storing food or drink are prohibited in any area where occupational exposure is reasonably anticipated, including a covered cup on a shelf above the sink. Protective attire is removed in the decontamination area before leaving, and hand hygiene follows immediately.
Manual and Mechanical Cleaning
Manual cleaning is done in a three-sink configuration: wash, intermediate rinse, and final rinse, so that detergent and loosened soil are not carried forward. The critical technique point is that instruments and brushes stay fully submerged beneath the water surface while brushing, which contains splash and prevents contaminated aerosols. Water temperature must stay below approximately 140 degrees F (60 degrees C), because heat coagulates protein and effectively bakes blood onto the instrument, and because enzymatic detergents lose activity outside their labeled temperature range. Lumens require a brush of the correct diameter and length so that the bristles actually contact the channel wall along its full length, followed by thorough flushing. Ultrasonic cleaners work by cavitation: high-frequency sound waves create microscopic bubbles that implode against instrument surfaces and dislodge fine soil from crevices and box locks. Fresh solution must be degassed before use, because dissolved air absorbs the sound energy and prevents effective cavitation. The lid stays closed during operation to contain aerosols, and dissimilar metals are not mixed in the same bath because ion migration causes electrolytic corrosion and plating transfer. Washer-disinfectors combine spray impingement, detergent, and an elevated-temperature rinse, often 180 degrees F or higher, that provides thermal disinfection so items can be safely handled in the clean workroom. Thermal disinfection is not sterilization; critical devices still require terminal sterilization.
Water Quality, Chemistry, and Cleaning Verification
Water is the most heavily used chemical in the department and its quality directly affects outcomes. Utility water is the general-purpose supply used for flushing, washing, and initial rinsing. Critical water has been extensively treated by processes such as reverse osmosis or deionization to remove minerals, ions, and endotoxins, and it is what should be used for the final rinse so that residues are not deposited on devices destined for sterile tissue contact. Hard water leaves a chalky mineral film, and the durable fix is treating the water supply rather than adjusting detergent. Detergent selection follows the device manufacturer instructions, but as a general rule neutral pH products between about 6 and 8 are the safest for the widest range of instrument materials. Strongly alkaline products cut heavy soil but attack aluminum and certain finishes, and acidic products are used for mineral scale and rust deposits. Enzymatic cleaners contain protease for protein, lipase for fat, and amylase for starch, and they clean but never disinfect or sterilize. Finally, the process must be proven to still work. Cleaning verification test devices containing a standardized soil are run through mechanical washers at least weekly, and preferably each day the washer is used, to confirm that spray arms, pumps, and chemical delivery are still performing. Waiting for the operating room to complain about visible soil is reactive and allows contaminated devices to reach patients.
Last updated: July 2026