Spaulding Classification Guidelines For Reusable Medical Devices
Why are Spaulding classifications important for reusable medical devices?
As part of the FDA’s criteria for medical device reprocessing, reprocessing instructions must include appropriate microbicidal processes for the device’s intended use. This article provides Spaulding classifications system guidelines that the FDA uses to determine the microbicidal methods needed for reusable device cleaning validations and sterilization validations. Spaulding classifications are based on exposure risk to various contaminants. The Spaulding classifications chart encompasses critical devices, semi-critical devices, and non-critical devices. Each of these device categories is described in further detail below.
What are cleaning validations?
Cleaning validations are protocols that ensure items, equipment, or areas are consistently cleaned to certain acceptance criteria. For reusable devices, cleaning validations prepare devices to undergo sterilization and ensure that tissues, proteins, lipids, bacteria, and cellular debris are effectively removed from used devices to acceptable levels. Cleaning validations have internationally accepted standards that must be met. These cleaning standards can be verified using test soils that simulate contaminants that the reusable devices would collect during use. For example, cleaning validations specify how contaminants like blood, tissues, and feces are removed from reusable medical devices during reprocessing.
What is the importance of cleaning validations for reusable devices?
Medical devices are extremely diverse in their shape, size, and use. Reusable medical devices require cleaning, disinfection, and sterilization before they can be used again. Each of these processes (cleaning, disinfection, and sterilization) must be validated to ensure patient safety and prevent hospital-acquired infections due to inadequate cleaning (and subsequent inadequate sterilization) of reusable devices.
What are sterilization validations?
Sterilization validations prove the efficacy of sterilization processes by verifying the presence or absence of microorganisms on the product after undergoing a sterilization cycle. Sterilization cycles can include heat, chemical gas, radiation, and other sterilization mechanisms such as filtration. The most popular method for sterilization validation is an overkill method.
Under the strictest definition of sterility, an item or product is sterile when there is a complete absence of viable microorganisms (bacteria, yeasts, viruses, and molds). For regulatory purposes, sterility is defined by acceptance criteria based on calculated contamination probability. An acceptable contamination risk for most items is the probability of contamination for one in a million products. However, sterility criteria may be more stringent or lax depending upon the intended use of the medical device or product. Please see our sterilization comparison chart for more information on which sterilization method is best for your medical device.
Why Are Sterilization Validations Important?
Since the sterility of a medical device or product is based on acceptance criteria, the process that a product or device undergoes to become sterile must be validated to prove that sterility acceptance criteria are consistently met. Sterility can be assured only by using a validated sterilization process under current good manufacturing practices (cGMP). Sterility cannot be demonstrated by reliance on periodic sterility testing of final products alone. Thus, sterilization validations are tests that accumulate data about a sterilization process and statistically prove that the sterilization process can consistently sterilize medical devices or products under “worst-case scenario” conditions.
Sterilization validations are an important quality control step proving that sterilization methods effectively kill any microbes in a product. As microorganisms exist on every surface (including our body), microbes can be accidentally introduced in many ways during the manufacturing or packaging process. Some of the most common examples are contamination through raw materials, technicians, tubing/piping used to transfer product between development stages in a process, or the manufacturing environment. Sterilization validations are used to ensure that the sterilization process can appropriately kill any viable microorganisms that accidentally enter the product during manufacturing and keep patients safe during parenteral product use.
What are the Spaulding classifications?
The Spaulding classifications system defines a device’s infection risk based on the intended use. A reusable device falls into one of three Spaulding classifications: critical, semi-critical, or non-critical devices.
Critical Devices
A reusable device is considered critical within the Spaulding classification system if it is introduced directly into the bloodstream or contacts an internal tissue or body space that is normally sterile during use. In other words, if there is a risk of microbial transmission to a sensitive tissue area during device use, the medical device is considered critical. Some examples of critical devices are surgical instruments, irrigation systems for instruments in sterile tissues, and endoscopes used in sterile body cavities (such as laparoscopes or arthroscopes). Cleaning protocols for critical reusable devices should include full disassembly of the device, followed by a validated cleaning and sterilization protocol after each use.
Semi-Critical Devices
Semi-critical devices within the Spaulding classification system contact body areas with some microbial resistance. Intact mucous membranes or non-intact skin are examples of areas resistant to microbes. Unlike critical devices, semi-critical items do not touch sterile body areas or tissues. Semi-critical devices include laryngoscope blades, gastrointestinal endoscopes, endotracheal tubes, and diaphragm fitting rings. Semi-critical devices should be reprocessed such that they are microbe-free. In most cases, semi-critical devices require sterilization (e.g., steam or ethylene oxide). However, devices that cannot be sterilized may undergo high-level disinfection with liquid chemical sterilants.
Non-Critical Devices
Reusable devices considered non-critical are items that touch but do not penetrate the skin. Non-critical devices are also medical devices that do not touch the patient but may become contaminated with microorganisms, blood, or bodily fluids during patient care. Some non-critical devices are ventilators, infusion pumps, blood pressure cuffs, and skin electrodes. Reprocessing protocols for non-critical devices involve a validated cleaning protocol followed by disinfection. Validated disinfection protocols will be intermediate or low-level depending on expected contamination during use. You can find additional information on disinfectant challenge testing here. Worst-case microbial situations should be considered when determining cleaning and disinfection processes for the medical device. Examples of devices that would receive intermediate disinfection are those that could be exposed to blood, body fluids, drug-resistant organisms, or Clostridium difficile infections. Devices that do not touch human skin and will likely remain clean during use (e.g., room vital signs monitor) may not need a validated disinfection protocol.
Summary
Overall, reusable medical devices require cleaning, disinfection, and sterilization before being used again. The FDA uses Spaulding classifications to determine the microbiocidal processes required to remove various contaminants from reprocessed medical devices. The Spaulding classifications are critical, semi-critical, and non-critical. Critical devices are those exposed to sterile areas of the body. In contrast, non-critical devices only touch the skin or don’t touch the patient. Semi-critical medical devices contact body areas with some microbial resistance. An intact mucus membrane is an example of a place with microbe resistance. MycoScience specializes in quick and effective cleaning validations and sterilization validations for their client’s reusable medical components and devices. Ensure you choose a contract testing organization that can support you with your unique device reprocessing needs.
MycoScience is a contract manufacturing organization specializing in sterile syringe and vial filling for parenteral products. MycoScience also offers testing services, including Preservative Efficacy Testing/Suitability Testing, Bioburden Testing, Microbial Aerosol Challenge Testing, Cytotoxicity Testing, Cleaning Validations, Accelerated Aging, Microbiology Testing, EO Residual Testing, Bacterial Endotoxin Testing, Package Integrity Testing, Sterilization Validations & Environmental Monitoring services medical devices and allied industries. MycoScience is an ISO 13485 certified facility.
References
Association for the Advancement of Medical Instrumentation Technical Information Report. A compendium of processes, materials, test methods, and acceptance criteria for cleaning reusable medical devices. Arlington, VA, USA. AAMI; 2011. (AAMI TIR30-2011).
International Organization for Standardization. Sterilization of health care products- Moist heat- Part 1: Requirements for the development, validation, and routine control of a sterilization process for medical devices. Geneva (Switzerland): ISO; 2006. (ISO 17665-1:2006/(R)2016).
Michael J. Akers. Sterile Drug Products Formulation, Packaging, Manufacture, and Quality. Drugs and the Pharmaceutical Sciences. Informa Healthcare. 2010.
Steven G. Richter. Cleaning Validations of Medical Products. Chapter 10: The Medical Device Validation Handbook 2nd Edition. RAPS.
United States Food & Drug Administration. Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling Guidance for Industry and Food and Drug Administration Staff. March 2015.
United States Pharmacopeial Convention. <1229> Sterilization of Compendial Articles. Rockville, MD, USA. 2021. (USPC <1229>).
