Chemical Degradation in Reusable Medical Devices

Chemical Degradation in Medical Device Reprocessing 

Chemical degradation is a critical concern in the reusable medical device reprocessing. Although cleaning agents and sterilants are crucial for ensuring that medical devices are free from viable microorganisms, their use must be carefully managed. Interactions of chemicals in cleaning agents and sterilants with device materials can cause irreversible changes. These changes may jeopardise safety, performance, and regulatory compliance.  

What is Chemical Degradation in Medical Devices? 

Chemical degradation refers to the deterioration of a medical device’s material properties due to exposure to chemical substances during cleaning, disinfection, or sterilisation. These substances include detergents, enzymatic cleaners, disinfectants, and sterilants such as hydrogen peroxide and steam. 

Common Types of Chemical Degradation in Medical Devices 

Chemical degradation can present in various forms, each affecting the device’s safety and usability in different ways: 

• Corrosion
  Metals, particularly stainless steel, are vulnerable to corrosion when exposed to acidic or alkaline solutions, especially if protective passivation layers are compromised. 
• Polymer Breakdown
  Plastics and elastomers may degrade when exposed to oxidising agents, leading to embrittlement, softening, or loss of mechanical strength. 
• Discoloration and Staining
  Chemical reactions with surface residues or incompatible materials can cause visible changes, which may indicate deeper structural damage. 
• Leaching of Additives
  Plasticisers, stabilisers, or dyes may leach out of polymers, potentially affecting biocompatibility and device performance. 

Key Risk Factors for Chemical Degradation in Reusable Medical Devices 

Several variables influence the likelihood and severity of chemical degradation during medical device reprocessing: 

• Material Sensitivity: Some materials are inherently more reactive to certain chemicals. For example, polycarbonate is sensitive to alkaline detergents and oxidising agents. 
• Chemical Concentration and Exposure Time: Higher concentrations and prolonged exposure increase the likelihood of degradation. 
• Temperature: Elevated temperatures can accelerate chemical reactions, compounding degradation effects. 
• Residual Contaminants: Incomplete rinsing can leave behind reactive residues that degrade materials post-processing. Residuals may also affect biocompatibility. 

How to Minimise Chemical Degradation in Medical Devices 

To minimise chemical degradation in medical devices, targeted strategies should be implemented throughout the device lifecycle: 

• Material Compatibility Assessment
  Evaluate how medical device materials interact with commonly used cleaning agents and sterilants. Use validated test methods to assess chemical resistance. 
• Controlled Processing Parameters
  Standardise chemical concentrations, exposure times, and temperatures to minimise variability and reduce degradation risk. 
• Routine Monitoring and Inspection
  Implement protocols to detect early signs of chemical damage, such as discoloration, surface changes, or loss of flexibility. 
• Manufacturer Guidance and Labelling
  Ensure medical devices are clearly labelled with compatible chemicals and processing limits. Provide validated instructions for safe reprocessing. 

Chemical degradation is often invisible until it affects medical device performance or safety. By proactively managing chemical exposure and validating material compatibility, medical device manufacturers can ensure device longevity and maintain compliance with regulatory expectations.