Ethylene Oxide:

Ethylene Oxide:
The Way We Choose to Go

By R. Michael Festa

Ethylene Oxide (EO) sterilization is used in our facilities because it is efficacious, safe to use, and the most cost-effective low temperature sterilization process. Selection and use of present sterilization methods were based upon efficacy of the process, safety and cost effectiveness. The use of written protocols ensures that sterile processing functions are consistently performed according to best practices, current regulatory requirements, and manufacturer's written instructions.

Efficacy: EO is particularly efficacious because it not only penetrates medical devices, but it permeates porous materials.1 In addition, it is an alkalyating agent that does not change the surface of material. Our facility has chosen EO as our only low temperature sterilization procedure because of its 50-year history of reliability and recognized effectiveness as a sterilant. Neal Danielson states in Ethylene Oxide Use in Hospitals that EO sterilizers provide a degree of assurance of sterility of many orders of magnitude.2

Safety: EO can be used in a safe and effective manner. OSHA has three established limits that protect workers from exposure to EO. In 1984, two exposure levels were established. The first was the permissible exposure limit or PEL. An employee cannot be exposed to more than 1 part per million (ppm) of ethylene oxide over an 8-hour time weighted average. The second level is an action level or Al. If an employee is exposed to less than 0.5 ppm over an 8-hour time weighted average, then some provisions of the standard do not have to be followed as frequently, such as employee monitoring. In 1988, an additional requirement called the excursion limit, or EL, was established. That value is 5 ppm over a 15-minute sampling period.

To determine the PEL and AL levels in our facility, ethylene oxide dosimeter badges are placed on employees for 8 hours. Excursion limit or EO monitoring, on the other hand, is task related. For the EL testing in our facility, badges are placed on employees for 15 minutes while they are performing the task of unloading and transferring the contents of a processed, unaerated load to the aerator. Testing is performed at the time of each new employee's orientation. Any additional testing would be performed upon request of an employee or if there were a change in production, process, etc., where such a change would require additional testing per current OSHA regulations. Also, additional testing is required when an employee is exposed to more than 0.5 ppm of EO over an 8-hour time weighted average.

EL testing is also required when other tasks are performed such as removing the biological indicator from the load, unloading the aerator, and handling of the materials during this time. If the sterilizer is an EO mixture type using an external cylinder tank, additional monitoring of employees will need to be performed during maintenance activities such as tank or tank line changes. This is required since higher exposures occur during these times.2 If you are considering using an EO sterilization system, read the OSHA regulations (CFR 29, Part 1910.1047), available on the Internet at www.osha.gov., to become comfortable and knowledgeable of personnel and environmental requirements. Understanding the requirements will help in making an informed decision about this well-publicized sterilization method.

Current and past staff testing at our facilities:

The exposure values, obtained from our facility testing, are way below the PEL, AL and EL limits so our facilities are exempt from the additional OSHA personal monitoring requirements. These low values are a result of using the updated 3M Steri-Vac 5XL and 8XL EO Sterilizers that have local exhaust and continuous purge features. The Sterilizers are located in the main processing area of the department, not a separate room, where there is 10-air exchanges/hour and dedicated venting of the sterilizer and aerators. In addition, the staff is trained to follow recommended safe work practices. An inexpensive duct sail switch is connected to a bell and light system as the ventilation failure detector for the sterilizers and aerators. A dedicated vent line exhausts EO to the outside during the sterilization process. Use of the 3M Steri-Vac 5XL and 8XL sterilization systems negates the need for an expensive continuous area monitoring system.

Cost Effectiveness

We have remained committed to using the 100% 3M Steri-Vac EO sterilizer systems as our only low temperature sterilization system because in a cost analysis it was determined to be the most cost effective low temperature sterilization process per load when compared to the other low temperature sterilization methods. In part, the review included a comparison of labor, supply, preventative and service costs. Other financial and non-financial factors included its influence on operations, available surgical and medical instrumentation/equipment resources and their reuse time requirements. The present strategy is to use steam sterilization to the greatest extent possible. With the introduction of steam sterilizable endoscopic system components, primarily scopes and cameras, and the expected introduction of other same category medical devices in the near future, the need for the more expensive and complex low temperature sterilization methods will be diminished. We will continue to use 100% EO for our low temperature sterilization processes because it is efficacious, safe, and cost effective.

Validation Tools

The use of written protocols (in the form of a validation tool) ensures that critical knowledge and competencies are successfully met. For each function, the employee is expected to verbalize an understanding and perform a return demonstration of the written protocol up to three times, before being validated to perform the function independently.

Sterile processing department validation tools are used for decontamination/cleaning, preparation/packaging, inspection and assembly of surgical and medical instrumentation/devices, high level disinfection and sterilization, to mention a few. The validation tools for proper loading technique and monitoring of a 3M EO sterilizer, EO biological monitoring process and evaluation of processed devices prior to release are listed here. Validation tools are also used to instruct and validate knowledge of how to respond appropriately in the event of an EO-dedicated venting system failure or an EO spill, leaks or fire.

Summary

In conclusion, EO can be used safely and cost-effectively, with minimal risk of hazardous chemical exposure to personnel by following recommended practices and meeting current OSHA EO regulations. The use of steam sterilization as the primary sterilization process is your best choice because it is efficient, the most cost effective and is now capable of processing a wider range of medical devices. As sterile processing professionals we must consistently perform recommended best practices, current regulatory requirements and follow manufacturer's written instructions. The use of written protocols (validation tools) facilitates instruction and training to ensure critical behaviors are consistently and successfully met by personnel performing critical and non-critical sterile processing functions.

R. Michael Festa is the Director of Sterile Process of the HealthEast St. Joseph's Hospital in St. Paul, Minn. He has more than 18 years of experience in the sterile processing management field and is known for his innovative and cost effective approaches to improving the quality of the sterile processing services.

For a complete list of references, visit www.infectioncontroltoday.com

Employees Facilities 8 Hour (TWA) Result < 1 ppm PEL, < 0.5 ppm AL 15 Minute (EL) Result < 5 ppm
20 2 None detected-0.12 ppm None detected-0.64 ppm

Objectives

1. Describe how EO can be used cost-effectively and with minimal risk of hazardous chemical exposure to personnel by following current OSHA EO regulations.
2. Describe the 3 OSHA established limits that protect workers from exposure to EO.
3. Demonstrate that you always use steam sterilization as the primary sterilization process in a healthcare facility because it is fast and the most cost effective.
4. Discuss the value of written protocols (validation tools) to ensure critical behaviors are consistently and successfully met by personnel performing sterile processing functions.

Test Questions

1. EO is efficacious because it penetrates medical devices and permeates porous materials.
2. EL monitoring is for 15 minutes and is accomplished when employees perform tasks such as transferring a load to an aerator or changing a tank of a gas mixture.
3. Safe worker practices minimize worker exposure to EO.
4. Steam sterilization is the fastest and least expensive sterilization process available.
5. Load items into the EO sterilizer so that they touch the chamber walls, ceiling and operators hands when the cart or basket is transferred to the aerator.
6. Stack paper/plastic peel pouches to facilitate EO and humidity penetration.
7. Place an EO biological indicator in each load.
8. Incubate a positive biological indicator control each day you incubate a processed biological indicator to ensure correct incubation temperature, viability of spores and capability of media to promote growth.
9. Do not inspect items prior to storage or distribution.
10. Use a record keeping system to record load contents, sterilization parameters, and monitoring results.


Validation Tool: Evaluation of Processed Devices Prior to Release

Name:
Site:

Objective: To ensure the processed peel pouch, wrapped package, wrapped tray, or closed container is properly evaluated for package integrity, verification that the device was processed, required information is visible, etc. prior to release to the customer or distribution to storage.

Critical Behaviors
Successfully Met (Yes)?
Date/Initials

1. Prior to examination and distribution of the sterilizer load contents, the packaging of the medical devices and /or other products must be properly cooled and dried.
2. Prior to unloading, each individual processed item will be inspected. The criteria for inspection will be based upon the type of package enclosure (i.e., peel pouch, wrapped package, wrapped tray, closed container).
3. Peel Pouch:

a. Package integrity (absence of holes, tears, etc.)?
b. Chemical indicator is processed (reached end point response)?
c. Visible and correct load/lot label?
d. Establish owner of package (OR, L&D, Diagnostic Imaging, etc.)?

4. Wrapped Packages:

a. Packaging material is firm around the device?
b. Sterilization tape adheres to and holds the sterilization wrap firm?
c. Sterilization wrap integrity (absence of holes, tears, etc.)?
d. Chemical indicator is processed (reached end point response)?
e. Visible and appropriately completed continuous quality improvement form?
f. Visible and correct load/lot label?
g. Establish owner of package (OR, L&D, Diagnostic Imaging, etc.)?

5. Wrapped Tray:

a. Packaging material is firm around the tray.
b. Sterilization tape adheres to and holds the sterilization wrap firm?
c. Sterilization wrap integrity (absence of holes, tears, etc.)?
d. Chemical indicator is processed (reached end point response)?
e. Visible and correct load/lot label?
f. Establish owner of package (OR, L&D, Diagnostic Imaging, etc.)?

6. Rigid Container System

a. Locking arrows properly inserted?
b. Chemical indicator is processed on arrow (reached end point response)?
c. Visible and correct load/lot label?
d. Paper filter holding mechanism(s) (top and bottom) is visible and properly aligned?
e. Tray name tag visible?
f. If applicable, "This Tray is INCOMPLETE" adhesive label visible?


Validation Tool: Proper Loading Techniques and Monitoring of a 3M E0 Sterilizer

Name:
Site:

Objective: To ensure the preparation of a sterilization load has been performed according to recommended practices and guidelines. To monitor the units progress during the sterilization cycle.

Critical Behaviors
Successfully Met
Date/Initials

1. List all items to be processed and complete all other required information on the EO Record Sheet.
2. Add load/label to each package.
3. Basket Loading Guidelines:

a. Loosely place items in the appropriate baskets to facilitate the sterilization process.
b Items must not touch chamber walls and ceilings or the operator's hands when the cart or basket is transferred from the sterilizer to the aerator.
c. Place packages on edge unless it is a perforated, wire-mesh-bottom tray or a rigid container. Place flat.
d. Place plastic/paper peel pouches on edge in wire baskets with plastic side of one facing paper side of the other.
e. If plastic/paper peel pouches are placed flat, place plastic side up. Do not stack.

4. Place the correctly labeled 3M Attest 1278 EO Pack in the center of each load in the bottom basket, if two baskets are required.
5. Insert appropriate 3M Steri-Gas cartridge (4-100 for 5XL and 8-170 for 8XL) into cartridge holder in the sterilizer unit. The sound of a click is your assurance that the cartridge has been properly installed.
6. Check the water level before each load. Fill if needed.
7. Carefully slide prepared baskets into the chamber using lift or cart.
8. Close the door and turn handle in downward clockwise motion to secure door seal.
9. Check and select sterilization temperature setting. Warm is 55°C and cool is 37°C.
10. Advance graph paper through vertical slot and place a load/label on the paper graph.
11. Complete documentation on the EO record sheet.
12. Periodically monitor the progress of the sterilization cycle to ensure the unit is operating properly. Inspect the unit for mechanical or electronic malfunction. Check for Error or Caution Codes (example: E76), printout correctness or malfunction, etc. Refer to Users Manual for Error or Caution Codes. Follow instructions; call for service if noted. Notify the Supervisor ASAP of the situation.


Answers

1. T
2. T
3. T
4. T
5. F
6. F
7. T
8. T
9. F
10. T

Validation Tool: EO Biological Monitoring Process

Name:
Site:

Objective: To demonstrate that conditions necessary for sterilization were achieved by means of the biological monitoring process.

Critical Behaviors
Successfully Met (Yes)?
Date/Initials

1. Place the appropriate load/label on the 3M Attest 1278 EO Pack.
2. Place the Attest EO pack in each load in the center of the bottom basket, if two baskets are required.
3. Start the sterilizer according to the manufacturer procedures.
4. Retrieve the Attest EO pack at the completion of the sterilization and aeration phases.
5. Remove the biological indicator from the Attest EO pack. Document the date, load number and sterilizer number on the information strip on the Attest EO biological indicator.
6. Record all required information on the EO Record Sheet.
7. Prepare the Attest EO biological indicator for incubation (follow manufacturer's procedure for crushing the ampule) and place in the dedicated Attest EO biological incubator.
8. For a single day, one biological indicator control is required unless the load/lot number is different. If different, a new biological indicator control is required.
The purpose of the control is to ensure correct incubation temperature, viability of spores and capability of media to promote growth. The positive control must be yellow at 48 hours for the processed biological indicator test results to be valid.
9. Biological indicator incubation must be monitored closely at time intervals of no greater than 8 hours up to the 48th hour. Any color change in the processed biological indicator (purple to yellow) indicates a positive result. Alert the supervisor at once.
10. Following the final reading at or as soon after the 48th hour, record the control and processed biological indicator results on the corresponding EO Record Sheet. The (+) symbol indicates a positive result and the (-) symbol represents a negative result.
11. Quarantine implantable items until the biological indicator results are available.
12. Place completed documents in appropriate file.


Continuing Education Credit for NICHSPDP

CEU Applicant Name:
Address:
City:
State/Province: Zip Code:

For NICHSPDP certification only: NICHSPDP has awarded 1.0 CEU for completion of this continuing education lesson. Managers should administer the lesson and examination to their employees. The test results should be kept with the employee's continuing education records. Do not submit test or grades to the NICHSPDP. Do not submit this lesson to the NICHSPDP, since it has been pre-approved. To obtain additional information: Contact the NICHSPDP, P.O. Box 558, Annandale, NJ 08801, or phone 908-730-8902.

For IAHCSMM certified members only: IAHCSMM has awarded .1 credit hours for completion of this continuing education lesson. Departmental managers/supervisors should administer the lesson and examination to their employees. The test results with an authorized signature should be kept with the employee's continuing education records. Do not submit test grades or this lesson to IAHCSMM since it has been pre-approved. To obtain additional information, contact the IAHCSMM, 213 West Institute Place, Suite 307, Chicago, IL 60610 (800) 962-8274.

In addition for the Nursing credits you will need to add the standard application form.



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