How to Clean Surgical Instruments: Prevent Rust & Corrosion

To safely remove rust from surgical instruments and prevent corrosion of surgical instruments, follow proper care and handling and the recommended method of cleaning: immediately after use rinse and soak the instruments in an enzymatic detergent or cleaner, immerse stainless steel instruments when instructed and use ultrasonic cleaning or manual cleaning to dislodge soil from box-locks and hinges, then perform a final rinse with deionized or softened water to reduce chloride that can cause staining or rust; dry your instruments and clean and dry trays, dry your instruments thoroughly before placing on a tray for sterilization, because moisture and saline increase the risk of corrosion and spotting and corrosion that can lead to pit formation or discoloration on 400 series stainless and other stainless steel, which compromises corrosion resistance and can cause corrosion damage affecting patient care and the integrity of microsurgical instruments and hemostats; after cleaning and disinfection, lubricate all instruments according to the manufacturer using surgical instrument lubricant to protect the passive layer, keep instruments moving parts oiled (lubrication) and avoid replating unless necessary, then package and sterilize in an autoclave or sterilizer as part of the sterilization process so reusable instruments are cleaned and sterilized, following types of cleaning and prevention and control best practices in healthcare facilities to minimize the risk of corrosion and ensure instruments are ready to use for patient care.

Understanding How to Clean Surgical Instruments?

Oxidation on stainless steel surgical tools can lead to surface staining and dangerous pitting, so safely removing rust begins with personal protective equipment (PPE) and a systematic approach: start with gentle mechanical cleaning using soft brushes and non‑abrasive pads, follow with an ultrasonic cleaner to dislodge residues, and treat stubborn spots with approved chelating agents such as citric or phosphoric acid solutions rather than harsh abrasives; after rust removal, restore the passive layer through passivation, inspect instruments closely for irreparable corrosion, autoclave to sterilize, and consider applying temporary rust inhibitors and improved storage to prevent recurrence.

What Causes Corrosion of Surgical Instruments?

Faulty cleaning of surgical instruments may lead to corrosion damage. Residual protein causes corrosion of surgical instruments because it becomes concentrated during sterilization. Corrosion results from the adhesion of chlorides, such as those from blood or other bodily fluids, to surgical instruments. Chlorides can remain on instruments due to insufficient cleaning or improper handling. If the attachment of an RFID tag jig is not sufficiently tight, moisture may enter the gap, thereby increasing the risk of corrosion and subsequent damage. Residual protein on surgical instruments increases metal ion removal, thereby increasing the rate of corrosion in certain stainless steel instruments. Instruments undergo pitting owing to adhesion of chloride-containing blood or physiologic saline. Corrosion occurs where a high concentration of chloride is present on a surgical instrument, specifically the SUS304 material. Scratches to the passive layer can occur through improper handling or normal use. Harsh cleaners, including highly acidic and highly alkaline ones, can also damage passive layers. Soil residues that are allowed to dry on the surface of instruments can cause damage to the passive layer. Misusing disinfectants can damage instruments when they are allowed to soak overnight in strong disinfectant solutions. Exposure to chlorine compounds like bleach is very detrimental to the stainless steel surface. Hard-water deposits can form on instruments either from using detergents that are not hard-water tolerant or from rinsing instruments with water other than deionized or softened water. Flash sterilization can eventually damage passive layers, primarily due to the rapid temperature change at the surface.

Learn more about our recent article on Surgical Instrument Maintenance: Enhancing Patient Safety.

Types of Corrosion Affecting Surgical Instruments

Corrosion damage to surgical instruments can include pitting or general corrosion. Faulty cleaning of surgical instruments may lead to corrosion damage. Corrosion results from the adhesion of chlorides, such as those from blood or other bodily fluids, to surgical instruments. Pitting corrosion can occur owing to adhesion of chloride-containing blood or physiologic saline. The discoloration and friction observed on RFID tag jigs can be viewed as the start of corrosion. The change was suspected to be the metal surface being broken down and undergoing elution owing to the presence of chloride ions. Galvanic corrosion, where dissimilar metals exposed to a solution cause one to corrode and deposit onto the other, can cause staining.

Impact of Corrosion on Healthcare Facilities

Faulty cleaning of surgical instruments may lead to a higher risk of surgical site infection. Corrosion can reduce the strength of surgical instruments, thereby damaging them. Spotting, staining, and corrosion of surgical instruments can impair their function. For example, a hemostat may not open because of corrosion in the box area. Scissors and scalpels could become dull due to corrosion. Instruments could break during surgery as a result of severe corrosion. Spotting, staining, and corrosion also interfere with sterilization by protecting spores from destruction by layers of iron oxide (rust). Corrosion can shorten instrument life, leading to increased costs for healthcare facilities. Advanced corrosion from long-term insufficient cleaning increases the risk of infection or instruments falling out.

Cleaning of Surgical Instruments

When addressing how to safely remove rust from surgical instruments, remember that instruments are made from different metals and alloys so prompt cleaning of instruments is essential: rinse and begin cleaning immediately after use to prevent corrosion to occur and to minimize damage to the surgical instruments; the use of cleaning steps should include gentle mechanical removal with a soft-bristle brush, a soak in a neutral pH enzymatic solution followed by an optional mild detergent such as diluted dish soap for visible soils (not as a substitute for disinfection), and finally thorough rinsing and drying before applying approved sterilization solutions to restore instrument safety and function.

Learn more about our recent article on Sterile Processing & Sterilization for Infection Control.

Importance of Properly Cleaning Surgical Instruments

Improper cleaning of surgical instruments may lead to corrosion damage and an increased risk of surgical site infection. An SSI might occur owing to residual proteins from insufficient cleaning. Residual proteins cause corrosion of surgical instruments because they become concentrated during sterilization. The contamination risks caused by insufficient cleaning of surgical instruments are evaluated before introducing the instrument into the operating room. Surgical instruments and other reusable devices must be effectively reprocessed so they are safe and functional for patient use. Before an instrument can go through sterilization or high-level disinfection, it must be cleaned. To ensure quality outcomes for the patient, the cleaning process requires consistency and standardization. If devices are not clean, they cannot be properly sterilized or high-level disinfected. Cleaning reusable devices is important to prevent both visible damage and non-visible issues like pathogenic microorganisms or transmissible proteins. If, after manual and mechanical cleaning, soil is still present, this can pose several risks, the most severe being transmission to patients. Residual soil left on devices can damage their surfaces or impair their ability to function correctly.

Manual Cleaning Techniques for Surgical Instruments

The first step in properly cleaning instruments is to rinse off all blood, bodily fluids, and tissue immediately after use with plain water. Hot water should not be used for rinsing, because proteinous substances will coagulate. A corrosion-inhibiting detergent can be used to soak large, non-delicate instruments when other cleaning methods are impractical. Instruments should be rinsed and dried after soaking in detergent. Manual cleaning involves washing instruments with a product like Alconox, mixed according to the manufacturer’s directions. Appropriate brushes should be used to clean each surgical instrument. A microbrush is used to remove debris from hinged areas, box lock areas, ratchets, delicate tweezers tips, and all moving parts of retractors. A stiff brush is used to clean tip and handle serrations of dressing forceps and needle holders, and the teeth of tissue forceps. Delicate instruments should be brushed carefully and handled separately from general instruments. Ultrasonic cleaning is recommended for delicate instruments like micro scissors. After manual cleaning, instruments are transported to the decontamination area of the Sterile Processing Department (SPD). Devices must be removed from the transportation container and disassembled to expose all surfaces to the cleaning process. Manual cleaning should be performed on all instruments and is the preferred method for delicate or complex devices like endoscopes or microsurgical instruments. A three-bay sink configuration is recommended for manual cleaning. In a three-bay configuration, the first sink bay is for pre-rinsing with cold water. The second bay is for immersing and presoaking instruments in an enzymatic or neutral detergent solution, followed by manual brushing. Cleaning in the sink should be done under the waterline to prevent exposure to microorganisms and aerosol generation, especially when brushes are used for lumens. The cleaning detergent used should be low-foaming. The third sink bay is for the final treated rinse.

Disinfection Procedures for Reusable Instruments

Disinfection is the antimicrobial reduction of viable microorganisms on a product or surface to a specified appropriate level for further handling. Most automated washer/disinfectors accomplish disinfection through thermal disinfection. High-level disinfection eliminates all microorganisms on an instrument, except for small numbers of bacterial spores. After manual cleaning, most devices are processed through automated cleaning technologies such as ultrasonic cleaning systems and washer/disinfectors. The thermal rinse phase in a washer/disinfector provides a level of disinfection. An optional drying phase can be added to reduce manual drying.

Preventing Rust and Stains on Surgical Instruments

Preventing rust and stains on surgical instruments requires best practices in the cleaning process: immediately after use, reusable stainless steel instruments such as forceps and hemostats should be handled according to the manufacturer and undergo manual cleaning or automated cleaning (ultrasonic cleaning or an ultrasonic cleaner) with an enzymatic detergent or suitable cleaner to remove blood and saline that can cause chloride-induced corrosion; rinse thoroughly with deionized or softened water for a final rinse to avoid spotting and corrosion, then dry your instruments and lubricate hinges and moving parts to protect the passive layer and prevent pits that lead to corrosion damage, reprocess instruments through disinfection and the sterilization process (autoclave or sterilizer) to sterilize and disinfect for patient care, keep instruments on a clean tray while storing, and follow instrument cleaning, cleaning and disinfection, and sterilization protocols in healthcare facilities to minimize the risk of corrosion of surgical instruments and avoid costly replating or irreparable damage to the surgical set.

Learn more about our recent article on Surgical Instrument Care and Handling: Sterilize Surgical Tools.

Identifying and Removing Rust Spots

Discoloration and friction on RFID tag jigs were observed in less than 5% frequency on the top, bottom, side, and head of the jig. Discoloration at the instrument-bonding interface occurred in less than 20% of cases. Discoloration at the contact with the RFID tag was less than 13%. Spots are loose or semi-adherent deposits on the surface of instruments, which can typically be wiped off with a cloth. If removed, spots generally do not physically or chemically affect instruments. Water mineral deposits, chemical residues, steam residues, and poor soil removal can cause spots. Water mineral spotting can be avoided by using deionized or softened water in the final rinse. High-quality cleaning chemicals can avoid mineral deposit formation during the wash cycle. Cleaning chemicals themselves can cause spots if they are not hard-water tolerant or if used outside recommended dilution rates. Spotting from steam impurities can be avoided by maintaining high steam quality and monitoring steam and boiler water regularly. Inadequate boiler maintenance can cause boiler chemicals to be carried over into the steam system, causing spotting. Filters and traps associated with steam sterilizers should be cleaned, and steam lines flushed after major boiler adjustments. Spots resulting from poor soil removal can be avoided through the use of high-quality cleaning chemicals and proper dilution rates. Enzyme presoaks are recommended for initial protein soil removal.

Best Practices for Preventing Stains

The occurrence of discoloration and friction on the bonding with the instrument and contact surface with the RFID tag was 70% of the occurrence rate. Stains are tightly adherent deposits on the surface of instruments and can be an integral part of the surface. Stains can be caused by metal replating, impure steam, and other factors. Replating of metals, or galvanic corrosion, results in a rainbow-like appearance or a gold or rusty tint on instruments. This can be avoided by segregating dissimilar metals and washing them at different times, or by using a cleaner safe for soft metals, which are normally neutral pH cleaners. To avoid staining from disinfecting solutions, soak time should be limited according to label directions, and increased concentrations of disinfectants should not be used. Iodophors (iodine-containing products) should not be used on stainless steel instruments. Stains from steam can be avoided by maintaining high steam quality. A rainbow or bluish appearance on instruments after sterilization typically indicates excessive neutralizing amines in the steam. Neutralizing amines are normal in steam used to prevent corrosion of steam lines, but excessive amounts can be managed by working with boiler operators. Black stains in low-impingement washers are caused by insufficient neutralization of detergent alkalinity. Rust-colored stains in low-impingement washers are caused by over-neutralization of alkalinity. To avoid discoloration in these systems, ensure alkalinity is properly neutralized by monitoring the pH of the rinse water. If the rinse pH changes by more than 0.5 pH units from its initial value, adjust the amount of neutralizer.

Long-term Maintenance of Surgical Instruments

In our investigation of long-term usage, we examined 94 surgical instruments with RFID tags used in the operating room for 50 months. From long-term observations, friction from the RFID tag occurred in about 70% of the jigs. However, no pitting or general corrosion was seen. When a washer disinfector (WD) is used properly, there is only a minor risk of residual protein, and corrosion does not occur even with long-term use. The RFID tag jigs are installed by laser welding to the surgical instrument. If the welding is insufficient or there is a gap inside, blood or other chlorides can become trapped, increasing the risk of corrosion. The washing process for instruments with RFID tags was conducted in accordance with the process used in medical institutions that use WD, following specific rules for their placement. Even over the long term, when employing this cleaning method with RFID-tagged surgical instruments, the interface between the instrument and the jig showed no corrosion. There was no risk of RFID tag jigs falling off. The depths of the point of jig friction and discoloration were confirmed with a confocal laser microscope as being less than 20 mcm, which is the detection limit. For RFID-tagged instrument jigs used more than once a week for four years, no downward corrosion was seen, and indeed, there was no corrosion at all. There was no risk of infection or falling out because of advanced corrosion from long-term insufficient cleaning.

Disinfection and Its Role in Corrosion Control

Disinfection plays a crucial role in corrosion control and should be part of any protocol for how to safely remove rust from surgical instruments; by disinfecting and drying instruments immediately after use, proteinaceous soils and contaminants that accelerate oxidation are removed, reducing the need for aggressive mechanical scrubbing that can damage finishes, and allowing non-abrasive chemical rust removers and passivation treatments to work more effectively and safely while preserving instrument function and longevity.

Effective Disinfection Methods

The method using a washer disinfector (WD) was found to be highly effective for cleaning surgical instruments. The instruments subjected to ultrasonic cleaning underwent a 15-minute cleaning with 0.5%-adjusted low-foaming alkali detergent (pH 11.4–12.4) and three rinses. The acceptable value for residual protein was complied with in the following groups: WD (35.6 ± 23.7 mcg), thermostat chambers + WD (10.1 ± 0.5 mcg), thermostat chambers + ultrasonic cleaning (71.7 ± 53.9 mcg), and manual cleaning + thermostat chambers + ultrasonic cleaning (25.5 ± 25.3 mcg). All measurement results of the WD group or the thermostat chambers + WD group did not exceed the acceptable value. Washer disinfector cleaning offers consistency and productivity, as parameter control is easier. Staff must be properly trained on device loading to ensure effective use.

Choosing the Right Disinfectants for Surgical Instruments

Cleaning appraisal guidelines state that residual protein should be cleaned off using washer disinfectors (WD). The WD used DECOMAT 8666, manufactured by Getinge Co., Ltd. The ultrasonic cleaner used MU1100R, manufactured by Sharp Corporation. In the experiment, WD involved a two-minute pre-cleaning using cold water and a wash at 93°C for 10 minutes. The water temperature when introducing washing agents was set to 40°C, and the concentration of the agents was 0.5%. Subsequently, a rinse at 60°C was performed twice, followed by a rinse at 70°C for 1 minute. The group of instruments subjected to ultrasonic cleaning underwent a 15-minute cleaning with a 0.5%-adjusted low-foaming alkaline detergent (pH 11.4–12.4), followed by three rinses. Low-foaming enzymatic cleaners can be used in ultrasonic cleaners, provided the foam does not interfere with cavitation. The recommended cleaning chemistries for washer/disinfectors are determined by the washer/disinfector manufacturer and the IFUs for the devices being processed. Other factors to consider when selecting a cleaning chemistry are water quality and the chemistry’s concentration.

Monitoring and Evaluating Disinfection Efficacy

The cleaning effect at the jig of the RFID tag was verified by the amount of residual protein left by various cleaning methods. The limiting value of the residual protein amount on the surgical instrument after washing has been set to 200 mcg (limit value) per surgical instrument, and the acceptable value is 100 mcg. For detection, the Coomassie brilliant blue (CBB) method was used: 1 mL of the extracted liquid and 3 mL of the CBB reagent were mixed, and after being left at room temperature for 20 minutes, the measurement was performed using a spectrophotometer (Shimadzu Co.) at an absorption wavelength of 595 nm. The Coomassie Protein Assay Kit® (Thermo Fisher Scientific Co.) was used in the CBB method, and bovine serum albumin was employed to construct the protein standard curve. The detection limit of the CBB method is 10 mcg. All devices should be visually inspected thoroughly with a lighted magnifying glass after cleaning. Cleaning process indicators verify that the washer/disinfector cycle process parameters in all phases have been achieved. The indicator materials will break down or change color when the parameters have been successfully met. Many hospitals use a cleaning verification program such as ATP or Protein detection beyond visual inspection. Protein is found in almost all surgical soils and in any living organism; therefore, detecting it on a “clean” device can help identify gaps in cleaning procedures or hidden damage to devices.

For additional technical standards and global guidelines for medical instruments, consult trusted sources such as the World Health Organization (WHO) and the European Commission’s Medical Devices Regulation (MDR). These organizations provide up-to-date information on safety, compliance, and innovation in healthcare.

You can also explore additional Educational Resources and our Product Catalogs on our website, on pages such as About Us, Our Products, and Contact Us, where we regularly publish updates and technical information about sterile and single-use instruments.

FAQ’s

1. What are the first steps to take immediately after a procedure to protect surgical instruments from rust and corrosion?

Immediately after use, follow the clean-and-dry principles to minimize the risk of corrosion. Begin by removing gross soil at the point of use — wipe or rinse to prevent blood and body fluids from drying on the surface. If possible, perform manual cleaning or place instruments into an enzymatic presoak to begin the cleaning process. Handle hinged and delicate devices like microsurgical instruments and forceps carefully to avoid damage to the hinge or finishes. Never allow instruments to sit wet and contaminated for prolonged periods, as this increases the risk of rust becoming impossible to remove and promotes corrosion. Proper immediate actions—rinsing, soaking in appropriate solutions, and separating long/boxed items on a tray—are among the best practices to prevent discoloration and pit formation.

2. What are the recommended cleaning methods for preventing corrosion and stain formation?

Use a multi-step approach: gross soil removal; manual or mechanical cleaning (e.g., ultrasonic); thorough rinse; inspection; lubrication of moving parts; and drying. For most facilities, a combination of enzymatic or neutral-pH detergent for initial cleaning followed by ultrasonic cleaning (in an appropriate ultrasonic cleaner) yields effective results. Avoid harsh alkaline or chloride-containing solutions that can attack stainless steel and damage the passive layer. For delicate or microsurgical instruments, prefer gentle manual cleaning with soft brushes and specialized cleaners. After cleaning, always dry your instruments and apply a water-soluble lubricant (instrument milk) to protect hinge areas and preserve the passive layer that prevents corrosion.

3. How does ultrasonic cleaning help, and what are the precautions when using an ultrasonic cleaner?

Ultrasonic cleaning uses cavitation to dislodge soil from hard-to-reach areas and is especially useful for lumened or hinged devices. It is a recommended step in the cleaning process because it improves cleaning efficacy without abrasive scrubbing that could damage the stainless steel surface. Precautions: Use the correct detergent compatible with the device and the cleaner, maintain the recommended solution temperature and cycle time, and separate instruments to avoid contact. Do not place porous or heat-sensitive items into the ultrasonic cleaner unless indicated. After cycling, perform a thorough rinse to remove residual detergent and contaminants, then immediately dry and inspect for stains or initial rust so you can address issues before pit formation.

4. Which cleaning agents and detergents should be avoided because they accelerate corrosion or cause discoloration?

Avoid high-chloride solutions and strong alkaline or acidic cleaners that can damage the passive layer on stainless steel. Chloride ions (from salts or some disinfectants) are notorious for initiating pitting and rust. Avoid corrosive powdered or granular cleaning agents, and avoid bleach (sodium hypochlorite) or unrestricted chlorine-based products on delicate or surgical-grade instruments. Also avoid abrasive scrubbing pads that can scratch surfaces and create sites for corrosion to initiate. Use validated, instrument-compatible enzymatic or neutral detergent formulations recommended for cleaning of surgical instruments in healthcare facilities.

5. How important is drying, and what are the best practices to clean and dry instruments to prevent rust?

Drying is critical. Moisture promotes corrosion, encourages discoloration, and accelerates stain and pit formation. Best practices: after rinsing, use filtered compressed air or lint-free towels to remove residual water, paying attention to hinge areas and lumens. Open instruments and position them to allow full drainage on a clean tray. For hinged instruments, cycle the opening and closing while drying to evacuate trapped moisture. Once dry, apply a thin film of instrument lubricant (lubricate) on moving parts to protect the passive layer and facilitate future sterilization steps. Do not stack wet instruments or leave them in trays where condensation may form.

6. Does sterilization with an autoclave prevent corrosion, and are there autoclave-related risks?

Improper loading, residual soils, trapped moisture, or incompatible packaging can increase the risk of corrosion during sterilization cycles. Ensure instruments are thoroughly cleaned, clean and dry, and appropriately instrument-marked and arranged to allow steam penetration and drying. Use manufacturer-approved sterilization parameters and avoid prolonged exposure to high temperature and moisture when organic residues remain. After autoclaving, promptly remove instruments from the sterilizer, inspect for stain or rust, and store in a dry, controlled environment to maintain sterility without encouraging corrosion.

7. How should you inspect and handle instruments to detect early signs of corrosion, stain, or rust?

Inspect every instrument after cleaning and prior to sterilization. Look for discoloration, pitting, surface stain, roughness, or obvious rust. Run your fingernail along edges to detect burrs or rough areas. Pay special attention to crevices, hinge junctions, serrations, and lumens. If you discover minor surface rust, address it according to facility policy—often gentle mechanical removal with approved non-abrasive tools and re-passivation is recommended. For significant corrosion of surgical instruments, remove the instruments from service and notify biomedical or sterile processing leadership. Document findings and consider root-cause analysis addressing cleaning methods, detergent choice, chloride exposure, or handling practices that might be the cause of corrosion.

8. What role does material choice—such as stainless steel—play in resisting corrosion, and what care do different materials require?

Many reusable instruments are made of stainless steel, which relies on a thin, stable passive layer rich in chromium to resist oxidation. However, even stainless steel can suffer from pitting or rust if the passive film is damaged, contaminated by chlorides, or mechanically abraded. Some instruments use specialized alloys or coatings for enhanced resistance. Regardless of material, instrument handling and adherence to validated cleaning methods and compatible cleaners are decisive. For coated or specialty instruments such as microsurgical instruments, follow manufacturer instructions for cleaning, disinfection, and maintenance to avoid damage and maintain function.

9. How should you manage and maintain hinged and moving parts to prevent rust and ensure function?

Pay close attention to hinge areas and joints: during cleaning, open and close instruments to expose internal surfaces; use soft brushes and an appropriate detergent to remove all debris; thoroughly rinse to remove residues; and dry your instruments completely. Apply a sterile, water-soluble lubricant (instrument milk) to the hinge and moving parts after drying to protect against corrosion, preserve the passive layer, and ensure smooth function. Avoid oil-based lubricants that are not sterilizable. Regularly inspect for wear and perform routine maintenance per manufacturer best practices to reduce the risk of pit formation and mechanical failure.

10. What policies and training should healthcare facilities implement to minimize risk of corrosion and ensure safe instrument cleaning?

Develop and enforce written procedures for the complete lifecycle: point-of-use care (soaking or wiping), validated cleaning methods (including appropriate detergents and ultrasonic cleaning protocols), thorough rinsing and inspection, proper lubrication and drying, and validated sterilization workflows using autoclave processes. Train staff in manual cleaning, the use of ultrasonic cleaners, the identification of corrosion, and the correct handling of reusable instruments, including forceps and microsurgical instruments. Implement routine audits, instrument condition tracking, and maintenance logs to identify recurring problems and root causes—such as exposure to chloride or improper disinfection chemicals. Ensure procurement and replacement policies consider how instruments are made and the manufacturer’s recommended care. These best practices reduce the risk of corrosion, extend instrument life, and protect patient safety.