Cleaning is a process that aims to remove contamination from reusable medical devices and equipment. Cleaning does not necessarily destroy microbes, but it should reduce their numbers. Cleaning can also remove chemical residues, degradation products, pyrogens, soil and dust, which could otherwise jeopardise the performance of a medical device or cause a harmful effect in the next patient you use the device on. The level of cleanliness you achieve will depend on the efficiency of your cleaning process.

Cleaning is an appropriate method of decontamination for medical devices and environmental surfaces within the healthcare environment (e.g. walls, floors, furniture) that are categorised as low-risk. However, disinfection of these items may also be necessary when there is a known infection risk or following a spill of blood or body fluids (refer to the spillage policy). Cleaning is also an essential first step in preparing medical devices for disinfection or sterilisation. If you do not clean items thoroughly prior to disinfection or sterilisation, blood and other matter can coagulate on them during these stages and the decontamination process will not be effective.

Cleaning involves washing the item with warm water and a solvent (usually detergent). To reduce microbial contamination, the process must involve thorough scrubbing of all the surfaces of the item and rinsing of the item in clean water (to remove the detergent, microbes and organic matter). You must also dry the item thoroughly as any remaining microbes will thrive on a wet surface. However, the exact cleaning procedure will vary according to the physical nature of the medical device or surface you are cleaning. For example, you cannot submerge electrical equipment in water.

For some low-risk surfaces that you cannot properly scrub and rinse (e.g. trolley tops, furniture, electrical equipment) wiping with a cloth soaked in detergent and warm water to remove visible dirt may be all that is required. However, wiping may only remove visible dirt and will not remove as many microbes as thorough cleaning does.

The correct methods for cleaning low-risk environmental surfaces (e.g. walls, floors, baths, toilets) are detailed in the NHS Healthcare Cleaning Manual (http://patientexperience.nhsestates.gov.uk/)¹. Your local policy should detail which cleaning detergents and chemicals you should use and appropriate cleaning frequencies. Levels of decontamination of the environment will depend on assessment of the clinical activities undertaken within the area. Cleaning schedules should be developed in accordance with NHS Estates guidance². The Association of Domestic Management provides best practice for minimum cleaning frequencies³.

You can clean reusable medical devices using either manual or mechanical methods (e.g. using an automated washer-disinfector or an ultrasonic bath). You should only use manual cleaning when automated methods are inappropriate or unavailable (e.g. if the device would be damaged by mechanical cleaning). Methods of cleaning are fully described by the Medical Devices Agency (http://www.medical-devices.gov.uk/mda/)⁴. Effective manual cleaning requires a high level of training and is time consuming. Mechanical cleaning processes can be validated and give more consistent results, provided you use and maintain the equipment correctly.

Only use manual cleaning when mechanical methods are unavailable or inappropriate, e.g. for delicate or complex medical devices that will not withstand rigorous mechanical cleaning. For manual cleaning, you may use either an immersion or a non-immersion method (see below), depending on the construction of the device. If you are not sure whether you can submerge a medical device in water, seek advice from the manufacturer. Always take care to follow the manufacturer’s instructions and refer to your local policy.

• Wearing appropriate personal protective equipment, fill a clean sink or an appropriate size receptacle (not a hand basin) with warm water and detergent (detergent dilution and water temperature should be in accordance with the manufacturer’s instructions and local policy). It is important to use water below 35 °C to prevent protein coagulating on the equipment.
• Consider using a protein-enzyme dissolving solution, if you are cleaning medical devices with lumens or complex parts (according to local policy).
• Dismantle or open the medical device (according to the manufacturer’s instructions) and fully submerge it in the detergent solution. Ensure that no air bubbles remain in lumens or serrations, by irrigating them with running water.
• Brush, wipe, agitate, jet wash or hand spray the device to remove all visible dirt, taking care to keep the device under the surface of the water to prevent splashing and spraying.
• Only connect jet guns to the cold water supply.
• Remove the item from the sink and drain any excess detergent prior to submerging the item in a second sink or receptacle containing clean rinsing water.
• Rinse the item thoroughly with clean water or a water jet gun under the surface of the water.
• During cleaning, if the detergent solution or the rinsing water becomes obviously soiled or contaminated, change it and repeat the cleaning process.
• Remove and drain the device and then dry it thoroughly using an appropriate method (e.g. using a disposable absorbent non-shedding cloth, an industrial hot air dryer or by placing it inside a drying cabinet).
• Thoroughly wash and dry the sink or receptacle.
• After cleaning, dispose of any cleaning materials safely in the appropriate waste containers in accordance with your local policy.
• Remove your personal protective equipment and decontaminate your hands.
• Complete any necessary documentation to record that you have cleaned the device and the method and solutions you used.

The non-immersion method is only appropriate for reusable medical devices that you could damage by submerging in water, e.g. electrical and electronic equipment. Make sure you clean these devices according to the manufacturer’s instructions.

• If the item is electrical, disconnect it from the power supply before commencing cleaning.
• Wearing appropriate personal protective equipment, prepare a warm water and detergent solution according to the manufacturer’s instructions.
• Soak the cleaning cloth in the detergent solution and wring it out thoroughly.
• Starting with the upper surface of the device, wipe it thoroughly with the cloth, ensuring that the detergent solution does not touch any electrical components or enter any ventilation slots.
• Periodically rinse the cloth in clean water and continue wiping with the detergent solution until you have thoroughly cleaned the device.
• During cleaning, if the detergent solution becomes obviously soiled or contaminated, change it and repeat the cleaning process.
• Carefully dry all the surfaces of the device using a disposable absorbent non-shedding cloth, an industrial hot air dryer, or by placing the device in a drying cabinet.
• Wipe clean any electrical contacts on the device with an alcohol wipe.
• If necessary, wipe dry the surfaces of the equipment with an alcohol wipe.
• Avoid leaving alcohol on the equipment, by forced air-drying if necessary. Take care to ensure that alcohol does not enter the device.
• After cleaning, dispose of any cleaning materials safely in the appropriate waste containers in accordance with local policy.
• Remove personal protective equipment and decontaminate your hands.
• Complete any necessary documentation to record that you have cleaned the device and the method and solutions you used.

You can mechanically clean reusable medical devices using a washer-disinfector with a cycle comprising rinse, power wash, disinfection, and drying phases, or by using an ultrasonic washer. Ultrasonic cleaning may be an integral part of some washer-disinfector cycles. Using a washer-disinfector also provides disinfection of the medical device. Thermal disinfection is the preferred method. However, chemical disinfection may be necessary for heat sensitive devices. All washer-disinfectors and ultrasonic cleaners must be operated, designed, validated and verified according to Health Technical Memorandum 2030⁵.

• Make sure the ultrasonic cleaner is clean and dry.
• Wearing appropriate personal protective equipment, fill the tank with sufficient warm water (not greater than 35°C) and detergent to enable complete immersion of the device.
• Use the appropriate amount of a suitable, compatible detergent as recommended by the manufacturer.
• Switch the machine on and leave it for the time recommended by the manufacturer to allow any air to disperse from the water.
• Remove the lid and carefully immerse the device in the detergent solution, making sure that you displace any trapped air.
• Irrigate devices with lumens.
• Replace the lid and leave the machine running for the recommended time.
• Switch off the machine, remove the device and drain off any excess water before transferring it to a clean rinsing receptacle.
• Thoroughly rinse the detergent solution off with clean water, ensuring you irrigate devices with lumens.
• Drain off any excess water and carefully dry all the surfaces of the device using a disposable absorbent non-shedding cloth, an industrial hot air dryer, or by placing the device in a drying cabinet.
• Thoroughly wash and dry the ultrasonic cleaner and store it dry.
• Remove personal protective equipment and decontaminate your hands.
• Complete any necessary documentation to record that you have cleaned the device and the method and solutions you used.

Thermal washer-disinfectors are only acceptable for cleaning and disinfecting reusable medical devices that will withstand repeated exposure to wet heat at temperatures of approximately 80°C. The device must be able to withstand the powerful water jets and be compatible with the detergent used. Hollow and porous devices are not suitable for this method unless a special adaptor is available.

The machine cleans the devices by spraying them with water and detergent. This initial clean should be at or below 35°C. Then, the machine provides a hot water disinfection rinse where the surface temperature of the devices should reach at least 71°C for three minutes, 80°C for one minute, or 90°C for one second⁷. The machine must have a validated cycle and you must maintain and test the washer-disinfector in accordance with the manufacturer’s instructions and Health Technical Memorandum 2030⁵. You need to retain all the maintenance and test records in the machines logbook for at least 21 years⁶.

The correct method for using thermal washer-disinfectors is fully described by the Medical Devices Agency (www.medical-devices.gov.uk/mda)⁴. Only staff who are trained to operate the machine should use it. The procedure includes the following steps.

• Check that the machine is operational.
• Use a suitable, compatible detergent and rinse aid as recommended by the manufacturer.
• Wearing appropriate personal protective equipment, load the machine in a way that does not impede the cleaning process (refer to the manufacturer’s instructions).
• Close the door, and select and start the cycle.
• When the process is complete, check that the machine achieved all necessary parameters.
• Remove the load and visually check it for cleanliness.
• Drain off any excess water and carefully dry all the surfaces of the device using a disposable absorbent non-shedding cloth, an industrial hot air dryer, or by placing the device in a drying cabinet.
• At the end of each session, drain the machine and thoroughly clean the inside.
• Dispose of any cleaning materials safely in the appropriate waste containers in accordance with local policy.
• Remove personal protective equipment and decontaminate your hands.
• Complete any necessary documentation to record that you have cleaned the device and the method and solutions you used.

You may use a chemical washer-disinfector to process heat sensitive endoscopes and accessories, if recommended by the device manufacturer. The machine cleans the devices by soaking, spraying, irrigating channels or deluging them with water and detergent or by ultrasonic cleaning. During cleaning, the water temperature remains at or below 35°C. The machine then disinfects the devices by exposing them to a disinfectant for a predetermined time. Subsequent rinse cycles then remove any disinfectant residues. Finally, air pressure expels any fluid from lumens and the machine may provide a warm air dry or alcohol rinse. The machine must have a validated cycle and you must maintain and test the washer-disinfector in accordance with the manufacturer’s instructions and Health Technical Memorandum 2030⁵. You need to retain all the maintenance and test records in the machine’s logbook for at least 21 years⁶. In some cases, microbiological surveillance of the machine, processed devices and the rinse water may be necessary. Refer to your local policy.

The correct method for using chemical washer-disinfectors is fully described by the Medical Devices Agency (www.medical-devices.gov.uk/mda)⁴. This document also indicates design requirements for the machine. Only staff who are trained to operate the machine should use it. The procedure includes the following steps.

• Check that the machine is operational.
• Use detergents and disinfectants that are compatible with the machine and with the devices you are going to process (as recommended by the manufacturer).
• Wearing appropriate personal protective equipment, manually clean the external surfaces and lumens of the endoscope and accessories with a disposable non-shedding cloth, test for leaks and check instrument function. Ensure that all valves and taps are in the open position (refer to Decontamination of endoscopes).
• Load the machine so as not to impede the cleaning process and attach channel connectors to ensure irrigation of all lumens.
• Close the lid, and select and start the cycle.
• When the process is complete, check that the machine achieved the necessary parameters.
• Remove the load and visually check and inspect the endoscope and accessories for cleanliness and damage.
• Drain off any excess water and carefully dry all the surfaces of the device if necessary, using a disposable absorbent non-shedding cloth.
• Check the function of the endoscope and accessories.
• Complete any necessary documentation to record that you have cleaned the device and the method and solutions you used.
• At the end of each session, drain the machine’s tanks and thoroughly clean any accessible surfaces and strainers according to the manufacturer’s instructions.
• Before commencing a further session, disinfect all fluid pathways, tanks and immersion trays.
• If the machine connects to a water treatment system, disinfect or sterilise the connecting pathway according to the manufacturer’s instructions.
• Remove personal protective equipment and decontaminate your hands.
• Complete any necessary documentation to record that you have cleaned the device and the method and solutions you used.