Make High-Level Disinfection A Thing of the Past

Residual chemicals left after high-level disinfection (HLD) can pose significant risks to both patients and healthcare workers. Here are the main issues associated with residual chemicals after HLD as compiled from the publicly available writings of U.S. Center for Disease Control (CDC) and industry experts:

1. Toxicity and Chemical Exposure

• Patient Safety: If residual chemicals from disinfectants remain on medical instruments or surfaces, they can cause irritation, allergic reactions, or toxic effects when in contact with skin, mucous membranes, or internal tissues. Otherwise, hydrogen peroxide (plasma) sterilization leaves no residual.
• Healthcare Workers: Prolonged exposure to residual disinfectants can lead to respiratory issues, skin irritation, and other health risks for healthcare professionals handling disinfected instruments or surfaces. Otherwise, the byproducts of hydrogen peroxide sterilization are oxygen and water vapor.

2. Increased Risk of Infection

• Biofilm Formation: Residual chemicals, particularly if they are ineffective at removing microorganisms, can contribute to biofilm formation on medical devices, which can harbor pathogens and increase the risk of infection.
• Antimicrobial Resistance: Persistent exposure to sub-lethal concentrations of residual disinfectants may contribute to the development of antimicrobial resistance in certain microorganisms.

3. Incomplete Rinsing or Removal

• Inadequate Rinsing: After HLD, instruments or surfaces may not be thoroughly rinsed, leaving behind harmful chemical residues. For instance, glutaraldehyde, peracetic acid, or ortho-phthalaldehyde (OPA) can be harmful if not properly removed.
• Unclear Guidelines: Inconsistent or unclear protocols for rinsing and decontaminating surfaces or instruments can result in residual chemicals being left on equipment.

4. Corrosion and Damage to Equipment

• Material Degradation: Some disinfectants, particularly strong oxidizing agents can corrode or damage medical equipment over time, reducing their effectiveness and lifespan.
• Breakdown of Sterility: Residual chemicals can react with the materials of medical instruments, leading to micro-cracks or damage that compromise sterility and increase the risk of infection.

5. Interference with Sterilization

• Incompatibility: Residual disinfectants can interfere with subsequent sterilization processes by interacting with sterilizing agents, reducing the efficacy of sterilization.
• Contaminated Instrumentation: Instruments that retain residual chemicals may not be effectively sterilized, increasing the risk of transmitting infections.

6. Environmental Impact

• Wastewater Contamination: Improper disposal or rinsing of disinfectants can lead to chemical residues entering the wastewater system, posing environmental hazards, such as pollution of water bodies and harm to aquatic life.
• Hazardous Waste: Residual disinfectants may require special handling as hazardous waste, which can increase costs and complicate disposal procedures.

7. Compliance and Regulatory Issues

• Regulatory Standards: Failure to properly manage residual disinfectants can result in non-compliance with health regulations (e.g., OSHA, EPA, or FDA guidelines), leading to legal or financial consequences for healthcare facilities.