Elimination of Micro-Organisms using ETO sterilization process - Short Notes

Step 1: Preparation and Inspection

1. Glove Selection: Choose gloves made from materials compatible with ETO sterilization, such as latex, nitrile, or neoprene.
2. Inspection: Inspect the gloves for any defects or damage. Discard any gloves that are torn, punctured, or otherwise compromised.

Step 2: Packaging

1. Sterilization Pouches: Place the cleaned and dried gloves into sterilization pouches. These pouches must allow ETO gas penetration while maintaining sterility after the process.
2. Sealing: Seal the pouches securely to prevent contamination during handling and transportation.

Step 3: Loading the Sterilizer

1. Placement: Arrange the packaged gloves in the sterilizer chamber, ensuring adequate space between packages for effective gas circulation.
2. Monitoring: Include biological and chemical indicators with the load to monitor the sterilization process and confirm efficacy.

Step 4: Sterilization Cycle

1. Preconditioning: Adjust the temperature and humidity in the sterilizer chamber to create an optimal environment for ETO penetration. Typical conditions are 30°C to 60°C with 30% to 80% relative humidity.
2. Gas Introduction: Introduce ETO gas into the chamber. The concentration of ETO gas typically ranges from 450 to 1200 mg/L.
3. Exposure: Maintain the gloves in the ETO environment for a specified duration, generally ranging from 1 to 6 hours, depending on the load size and sterilizer specifications.
4. Post-Exposure Aeration: Remove the ETO gas and aerate the gloves to eliminate any residual ETO. Aeration can take from several hours to several days, depending on the aeration conditions and glove materials.

Step 5: Process Detail :

General Information

• Flammability: Pure EO vapor is flammable and explosive when mixed with 3 to 4% air by volume.
• Safety Measures: Process designed to avoid unsafe conditions through controlled cycle phases.

Process Overview

1. Initial Vacuum:
2. Gas Introduction:
3. Post-Sterilization Washes:

Detailed Steps

A. Environmental Preconditioning

• Purpose: Heat and humidify products to stable conditions before sterilization.
• Conditions: 118°F and 65% relative humidity.
• Considerations: Duration: 12 to 72 hours.

B. Initial Evacuation Process

• Purpose: Remove at least 95 to 97 % of air from the chamber.
• Methods: Deep vacuum.Partial vacuums with nitrogen injections since it is an inert gas
• Considerations: Product’s ability to withstand pressure changes.Maintain package integrity and sterile barrier properties.Pressure sensitivity of products..Pressure sensitivity of products.

C. Humidification

• Purpose: Replace moisture lost during initial vacuum.
• Method: Steam injections to achieve predetermined relative humidity.
• Considerations: Packaging strength to withstand moisture and heat. Avoid overheating; adjust process for temperature-sensitive products.

D. Gas Injections and Gas Dwell Time

• Purpose: Inject and expose product to EO gas for sterilization.
• Factors: Minimum gas concentration for sterility. Maximum gas concentration to avoid high residual levels.
• Considerations: Exposure time determined by product characteristics and desired sterility level.Preliminary lab tests may be needed.

E. Postexposure Gas Purging and Air Inbleed

• Purpose: Remove EO gas until levels are safe (below 3%).
• Method: Series of post-vacuums with nitrogen backfill.
• Considerations:Product integrity during post-vacuums. Adequate number of washes to reduce residues.

F. Heated Aeration

• Purpose: Further remove residual gases post-sterilization.
• Method: Place products in a heated room with continuous residue removal.
• Considerations:Aeration time depends on product material and intended use.Compliance with upcoming guidelines (AAMI and ISO 10993-74).

Step 6: Storage

1. Environment: Store the sterilized gloves in a clean, dry, and controlled environment. Ensure the storage area is free from contaminants such as dust and moisture.
2. Labeling: Label each package with the sterilization date, batch number, and expiration date to ensure proper inventory management.

Step 7: Quality Control

1. Verification: Periodically test gloves from different batches using biological indicators to ensure consistent sterilization quality.
2. Documentation: Maintain detailed records of each sterilization cycle, including parameters, indicators used, and results of quality control tests.