Sterilization is essential to ensure that medical products are free of harmful contaminants such as fungi, bacteria, viruses, and spore forms. However, sterilization processes can affect sensors and electronics. This PPT will describe the sterilization methods commonly used for medical devices, as well as their compatibility with sensors and electronics.

1. Sterilization for Medical Devices

2. Introduction
 Definition
 Sterilization
 Sterilization describes a process that destroys or eliminates all forms of microbial
life and is carried out in health-care facilities by physical or chemical methods.

3. Introduction
 Medical devices are sterilized in a variety of ways including
 Using moist heat (steam)
 Dry heat
 Radiation,
 Ethylene oxide gas,
 Vaporized hydrogen peroxide,
 And other sterilization methods (for example, chlorine dioxide gas, vaporized
peracetic acid, and nitrogen dioxide).

4. Methods of Sterilization
 FDA considers there to be two categories of sterilization methods currently used to
sterilize medical devices in manufacturing settings
1. Established Sterilization Methods
2. Novel Sterilization Methods

5. Established Sterilization Methods
 Classified in to
 Established Category A
 These are methods that have a long history of safe and effective use as demonstrated
through multiple sources of information such as ample literature, clearances of 510(k)s
or approvals of premarket approval (PMA) applications, and satisfactory QS
inspections.
• Eg-Dry heat
• EO with devices in a fixed, rigid chamber
• Moist heat or steam
• Radiation (e.g., gamma, electron beam)

6. Established Sterilization Methods
 Established Category B
Established methods for which there are no FDA-recognized dedicated consensus
standards, but for which published information on development, validation, and routine
control is available.
Examples of these Established Category B Sterilization Methods:
• Hydrogen peroxide (H2O2)
• Ozone (O3)
• Flexible bag systems (e.g., EO in a flexible bag system, diffusion method, injection
method)

7. Novel Sterilization Methods
 Newly developed methods for which there exists little or no published information, no
history of comprehensive FDA evaluation of sterilization development and validation data
through an FDA-cleared 510(k) or approved PMA for devices sterilized with such methods,
and no FDA-recognized dedicated consensus standards on development, validation, and
routine control. A Novel Sterilization Method is a method that FDA has not reviewed and
determined to be adequate to effectively sterilize the device for its intended use.
 Examples of Novel Sterilization Methods:
• Vaporized peracetic acid
• High intensity light or pulse light
• Microwave radiation
• Sound waves

8. Sterilization Information for Devices Labeled as Sterile
 A. Established Sterilization Methods
 Sponsors should ensure that a 510(k) submission includes all of the information outlined below.
• A description of the sterilization method
• A description of the sterilization chamber if not rigid, fixed
• If the sterilizer has received 510(k) clearance, the 510(k) number and the make (i.e., manufacturer)
and model of the sterilizer.
• If the sterilizer has not received 510(k) clearance, if the sterilization method has been evaluated
through clearance of a 510(k) or approval of a PMA or HDE for a device using that method, the
submission number where the method was previously evaluated or the identification of a Device
Master File containing this information.
• The sterilization site

9. Sterilization Information for Devices Labeled as Sterile
 In the case of radiation sterilization, the radiation dose
 For chemical sterilants (e.g., EO, H2O2), the maximum levels of sterilant residuals that remain on the device, and
an explanation of why those levels are acceptable for the device type and the expected duration of patient contact.
 In the case of EO sterilization, CDRH has accepted EO residuals information based on the currently recognized
version of the standard
 For the sterilization method, the sponsor should provide a description of the method used to validate the
sterilization cycle (e.g., the half-cycle method or overkill) but not the validation data itself
 The sponsor should state the sterility assurance level (SAL) of 10-6 for devices labeled as sterile unless the device
is intended only for contact with intact skin. FDA recommends a SAL of 10-3 for devices intended only for
contact with intact skin. For questions related to alternative SALs, we recommend direct consultation and pre-
submission meetings with FDA. Sterility Assurance Level: This is a Statement of Probability. The SAL is a
statement of the “probability of a single viable microorganism occurring on an item after
sterilization”

10. Sterilization Information for Devices Labeled as Sterile
 Pyrogenicity testing
• Used to help protect patients from the risk of febrile reaction due to either gram-negative
bacterial endotoxins or other sources of pyrogens (e.g., material-mediated pyrogens). To
address the presence of bacterial endotoxins, devices that fall under the following categories
should meet pyrogen limit specifications
• Implants
• Devices in contact directly or indirectly with the cardiovascular system, the lymphatic system,
or cerebrospinal fluid, including devices that are present for similar systemic exposure
• Devices labeled non-pyrogenic.

11. Sterilization Information for Devices Labeled as Sterile
 The sponsor should provide the information outlined below:
• a description of the method used to make the determination that the device meets pyrogen limit
specifications (e.g., bacterial endotoxins test (BET), also known as the Limulus amebocyte
lysate (LAL) test)
• a statement confirming that endotoxin testing will be conducted on every batch or if not,
information regarding the sampling plan used for inprocess testing and/or finished product
release, as recommended in the FDA guidance, Pyrogen and Endotoxins Testing: Questions
and Answers” (http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryIn
formation/Guidances/UCM310098.pdf)
• identification of the chosen testing limit
• an explanation supporting the selected endotoxin limit.

12. B. Novel Sterilization Methods
 A comprehensive description of the sterilization process
 The method used to validate the sterilization cycle (e.g., the half-cycle method)
 The validation protocol
 The sterilization validation data
 The submission should also identify any applicable published scientific literature. For
novel sterilization methods, FDA may also request additional information based on the
specific device submitted for review.

13. Validation Methods and Consensus Standards
Moist Heat (steam) ANSI/AAMI/ISO 17665-series Sterilization of health care products:
Moist Heat - Requirements for
development, validation, and routine
control of a sterilization process for
medical devices
Ethylene Oxide (rigid chamber) ANSI/AAMI/ISO 11135 Sterilization of Health-care Products:
Ethylene Oxide – Requirements for
the development, validation and
routine control of a sterilization
process for medical devices
Radiation ANSI/AAMI/ISO 11137-series Sterilization of health care products –
Radiation – Part 1: Requirements for
the development, validation and
routine control of a sterilization
process for medical devices, and Parts-
2 and -3

14. Validation Methods and Consensus Standards
(Almost) Everything Else ANSI/AAMI/ISO 14937 Sterilization of Health-care
Products - General
requirements for
characterization of a
sterilizing agent and the
development, validation, and
routine control of a
sterilization process for
medical devices

15. Sterilization information for devices
labeled as non-sterile
 Processed by End User (e.g., Cleaning and Microbicidal processing)
 Reusable medical devices are devices that healthcare providers can reprocess and
reuse on multiple patients. Examples of reusable medical devices include surgical
forceps, endoscopes, and stethoscopes
 All reusable medical devices can be grouped into one of three categories according
to the degree of risk of infection associated with the use of the device:
• Critical devices, such as surgical forceps, come in contact with blood or normally
sterile tissue.
• Semi-critical devices, such as endoscopes, come in contact with mucus membranes.
• Non-critical devices, such as stethoscopes, come in contact with unbroken skin.
 critical and semi-critical medical devices that are intended for reuse after
reprocessing.

16. Sterilization information for devices
labeled as non-sterile
 The scope of this guidance is limited to:
 1. Reusable medical devices are initially supplied as sterile, requiring
reprocessing for subsequent use.
 2. Reusable medical devices are initially supplied as non-sterile, requiring
initial processing, and reprocessing for subsequent use.
 3. Reusable medical devices are to be reused only by a single patient,
requiring reprocessing between each use.
 4. Single-use medical devices supplied as non-sterile, requiring processing
prior to use

17. Six Criteria for Reprocessing
Instructions
 1. Labeling should reflect the intended use of the device.
 2. All reprocessing instructions for reusable devices should advise users to
thoroughly clean the device.
 3. The instructions should indicate the appropriate microbicidal process ...
 4. Recommendations should be technically feasible and include only devices
and accessories that are legally marketed.
 5. The instructions should be comprehensive
 6. The instructions should be understandable

18. 1. Labeling should reflect the intended use of the device.
labeling should include instructions for a reprocessing method that reflects the
physical design of the device, its intended use, and the soiling and contamination
to which the device will be subject during clinical use.
2. All reprocessing instructions for reusable devices should advise users to
thoroughly clean the device
Cleaning is the first step in reprocessing and should be described in the labeling
as part of the overall reprocessing instructions. Adequate sterilization or
disinfection depends on the thoroughness of cleaning
3. Reprocessing instructions should indicate the appropriate microbicidal process
for the device.
FDA recommends thorough cleaning and sterilization after each use. FDA uses the
Spaulding Classification scheme described below for critical, semi-critical and
non-critical devices to describe the potential risk of infection caused by the
device and the appropriate microbicidal processes.

19. 4. Reprocessing instructions should be technically feasible and include
only devices and accessories that are legally marketed.
 FDA recommends that the instructions specify sterilization methods and
parameters that are technically feasible for the user.
 Ranges (Time and Temperature)
 Drying Time
 EXTENDED CYCLES
5. Reprocessing instructions should be comprehensive.
Reprocessing instructions should include the elements below.
A. Special Accessories
B. Point-of-Use Processing
C. Disassembly and Reassembly
D. Method of Cleaning
E. Cleaning Agents

20. F. Rinsing
G. Lubricating Agents
H. Visual Inspection
I. Method of Disinfection or Sterilization
J. Reduction of Sterilant Residual
K. Drying
L. Reuse Life
M. Additional Labeling Recommendations
N. Patient or Lay Use
O. Reference to Guidelines or Accessory Labeling
P. Manufacturer’s Contact Information
6. Reprocessing instructions should be understandable.
Reprocessing instructions should be clear, legible, and provided in sequential order
from the initial processing step through the terminal processing step.
The instructions should be written in simple language to the greatest extent possible.
They should also be sufficiently detailed to explain the correct procedures for all
steps.

21. VIII. Validation of Cleaning Process
 Using Worst-Case Testing
 1. Artificial Soil, Inoculation Sites, and Simulated Use Conditions
 2. Validation Protocols: Documentation of Methods Designed to Test the
Cleaning Process
 3. Testing: Test Types and Protocols
 a. Choice of Test Types
 b. Methods Validation
 c. Extraction Method

22. Documentation in 510(k)
 All 510(k)s must include proposed labels and labeling sufficient to describe
the device, its intended use, and the directions for its use
 For a reusable medical device as defined in the scope of this guidance, FDA
interprets this to include reprocessing instructions.
 Validation of the reprocessing instructions should be completed prior to
submission of a 510(k).
 When evaluating a 510(k), FDA generally compares the labeling for the legally
marketed predicate device to the proposed labeling for the new device.
 A description of FDA’s 510(k) decision-making process is described in FDA’s
guidance
 The 510(k)s for these devices should include protocols and complete test
reports of the validation of the cleaning instructions.

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