Cleaning Validation Tests for Reusable Medical Devices

Cleaning validation for reusable medical devices is a critical process to ensure devices are safe for patient use after each reprocessing cycle. Below is a comprehensive list of cleaning validation tests, procedures, and expert tips, aligned with global standards such as AAMI TIR30, AAMI TIR12, ISO 17664, ISO 15883, and FDA guidance. 

• First-line check for residual soil, staining, or damage.
• Conducted under controlled lighting using magnification as needed.
• Often performed before and after cleaning for comparison.
   

• Detects residual organic material (e.g., blood, tissue).
• Common methods:
   
  • OPA assay (o-phthalaldehyde)
  • Ninhydrin test
  • Micro BCA assay
     
• Acceptance criteria: usually < 6.4 µg/cm² or as justified.
   

• Detects blood contamination.
• Modified Drabkin’s reagent or TMB test are commonly used.
• Important for surgical and endoscopic instruments.

• Measures total carbon in residual organic substances.
  Useful for validating automated cleaning processes.
• Sensitive and quantitative.
   

• Measures biological contamination via ATP presence.
• Often used as a fast check, not as definitive as TOC or protein assays.
   

• Confirms reduction or removal of viable microorganisms.
  Often part of disinfection validation, but applicable post-cleaning as well.
   

• Especially critical for devices contacting blood or CSF.
• LAL (Limulus Amebocyte Lysate) test used to detect bacterial endotoxins.
   

• Simulated soil with fluorescent markers used to assess cleaning efficacy visually.
• Often used in training and validation setup.
   

• Ensures no harmful chemical residues remain.
• UV spectrophotometry or specific chemical assays used.
   

• Ensures repeated cleaning does not degrade surface integrity or functionality.
• Often combined with accelerated aging tests.
   

Define Worst-Case Scenario Devices
 

• Choose most difficult-to-clean devices (e.g., lumens, hinges, porous surfaces).
• Include complex geometries and representative materials.
   

Soil Application
 

• Use standardized test soils (e.g., ATS - Artificial Test Soil) that simulate real clinical contamination (blood, protein, fat, etc.).
   

Controlled Drying
 

• Simulate clinical conditions where soil may dry before cleaning begins.
   

Validated Cleaning Procedure
 

• Follow manufacturer’s IFU for cleaning (manual or automated).
• Include validated time, temperature, detergent, mechanical action.
   

Sample Extraction & Analysis
 

• Extract residues from critical areas using validated techniques. 
• Analyze using appropriate residue tests (e.g., TOC, protein, etc.).
   

Establish Acceptance Criteria
 

• Based on clinical risk and regulatory guidance (e.g., FDA, ISO, AAMI).
• Must be justified and documented.
   

.Document Results in Validation Report
 

• Include worst-case testing, protocols, raw data, acceptance criteria, and conclusions.
   

• Start with risk analysis: Map device features to cleaning challenges.
• Use standardized test soils: Like ATS, coagulated blood, or ISO-compliant mixtures.
• Involve cross-functional teams: Regulatory, microbiology, materials, and engineering.
• Ensure cleaning doesn't damage embedded sensors or electronics.
  Consider impermeability and IP ratings for waterproof integrity.
  Document cleaning effects on user interface clarity (screens, LEDs, buttons).
   

• Control variability: Use automated cleaning if possible for consistency.
• Include multiple devices: To account for variability and material combinations.
• Use traceable instrumentation: Calibrate thermometers, flow meters, etc.
   

• Align validation plans with ISO 17664: Information provided by manufacturers for reprocessing.
• Link cleaninDocument worst-case rationale, soil selection, and recovery efficiency of test methods.