1.3 The Spaulding Classification System

Key Takeaways

  • Earle Spaulding developed a classification system in 1968 that categorizes medical devices by infection risk
  • Three categories: Critical (enters sterile tissue — must be sterilized), Semi-critical (contacts mucous membranes — requires HLD minimum), Non-critical (contacts intact skin — low-level disinfection)
  • Examples of critical items: surgical instruments, implants, cardiac catheters, needles
  • Examples of semi-critical items: flexible endoscopes, laryngoscope blades, respiratory therapy equipment
  • Examples of non-critical items: blood pressure cuffs, stethoscopes, bed rails, bedpans
  • The Spaulding system guides the MINIMUM level of reprocessing required
  • Always follow manufacturer IFU even if it requires a higher level of processing than the Spaulding minimum
  • High-level disinfection kills all microorganisms except high numbers of bacterial spores
Last updated: March 2026

The Spaulding Classification System

In 1968, Dr. Earle H. Spaulding developed a rational approach to disinfection and sterilization that categorizes patient care items based on the degree of infection risk associated with their use. This system remains the foundation of all reprocessing decisions in healthcare today.


The Three Categories

Critical Items — MUST Be Sterilized

Items that enter normally sterile tissue or the vascular system.

CharacteristicDetail
Risk levelHighest — direct contact with sterile body cavities
Minimum processingSterilization (destruction of ALL microorganisms including spores)
ExamplesSurgical instruments, implants, cardiac catheters, arthroscopes that enter joints, biopsy forceps, needles, scalpels

If the item enters sterile tissue or the bloodstream, it must be sterile. No exceptions.

Semi-Critical Items — Minimum High-Level Disinfection (HLD)

Items that contact mucous membranes or non-intact skin but do not enter sterile tissue.

CharacteristicDetail
Risk levelIntermediate — mucous membranes resist bacterial spores but not other organisms
Minimum processingHigh-level disinfection (HLD) — kills all microorganisms except high numbers of bacterial spores
Sterilization preferredWhen the device can tolerate it
ExamplesFlexible endoscopes (GI scopes, bronchoscopes), laryngoscope blades, respiratory therapy equipment, vaginal specula, anesthesia equipment

Key point: Although HLD is the minimum, sterilization is always preferred when the device can tolerate it. Many facilities choose to sterilize semi-critical items whenever possible.

Non-Critical Items — Low-Level Disinfection

Items that contact intact skin only (skin acts as an effective barrier to most microorganisms).

CharacteristicDetail
Risk levelLowest — intact skin provides natural barrier
Minimum processingLow-level disinfection (surface wipe or EPA-registered disinfectant)
ExamplesBlood pressure cuffs, stethoscopes, bed rails, bedpans, IV poles, patient furniture, pulse oximeters

Levels of Microbial Kill

LevelWhat It KillsWhat SurvivesMethod
SterilizationALL microorganisms including sporesNothing (complete kill)Steam, EtO, H₂O₂, ozone
High-Level DisinfectionAll microorganisms except high numbers of bacterial sporesLarge numbers of spores onlyGlutaraldehyde, OPA, peracetic acid, H₂O₂
Intermediate-Level DisinfectionVegetative bacteria, most viruses, most fungi, mycobacteriaBacterial sporesAlcohol, chlorine compounds, phenolics
Low-Level DisinfectionMost vegetative bacteria, some viruses, some fungiMycobacteria, bacterial spores, some non-enveloped virusesQuaternary ammonium compounds

Applying the Spaulding System

Step-by-Step Decision Process:

  1. Determine where the device will be used on or in the patient
  2. Classify the device as critical, semi-critical, or non-critical
  3. Identify the minimum reprocessing level required
  4. Check the manufacturer's IFU — always follow IFU even if it exceeds the Spaulding minimum
  5. Process the item using the appropriate method

Important Considerations:

  • Always default to the higher level when unsure of classification
  • Some items may be reclassified based on their specific use (e.g., a thermometer used rectally on a patient with non-intact skin becomes semi-critical)
  • Manufacturer IFU always takes precedence over Spaulding classification if IFU requires more stringent processing
  • Single-use (disposable) items should never be reprocessed unless the facility has a validated reprocessing program (regulated by FDA)
Reprocessing Requirements by Spaulding Classification
Test Your Knowledge

A flexible endoscope used for a colonoscopy contacts mucous membranes but does not enter sterile tissue. Using the Spaulding Classification, this device is classified as:

A
B
C
D
Test Your Knowledge

A scalpel blade used in surgery enters sterile tissue. What is the minimum reprocessing requirement?

A
B
C
D
Test Your Knowledge

High-level disinfection (HLD) kills all of the following EXCEPT:

A
B
C
D
Test Your KnowledgeMatching

Match each medical device to its correct Spaulding classification:

Match each item on the left with the correct item on the right

1
Surgical forceps
2
Flexible bronchoscope
3
Blood pressure cuff
4
Knee implant