ASTM F3276-22

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F3276 − 19 F3276 − 22
Standard Guide for
Using a Force Tester to Evaluate the Performance of a
Brush Part Designed to Clean the External Surface of a
Medical Device
This standard is issued under the fixed designation F3276; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This guide describes methods for characterizing the efficacy, under prescribed laboratory conditions, of a brush part designed
to clean the external surface of a medical device. The method utilizes force testers to mechanically actuate a brush part across a
surface at a constant rate and constant pressure. In the first method, the force required to actuate across the surface is measured.
In the next method, which utilizes the same force testers and protocol (actuation motion), the brush part is actuated on a soiled
surface and the amount of soil removed is measured, as another indicator of performance.
1.2 Brushes designed to clean medical devices after clinical use play an important role in the effective reprocessing of those
medical devices.
1.3 Inclusions:
1.3.1 This guide describes objective, quantifiable, and reproducible methods for evaluating the cleaning characteristics of a brush
part, under prescribed laboratory conditions, with a test method that simulates the cleaning challenge of a defined target area(s)
of a medical device. This also makes it possible to compare one brush part design to another.
1.3.2 By use of this guide, manufacturers of cleaning brushes will be able to evaluate and characterize the cleaning performance
of their brushes for the target area(s) of medical device(s) and evaluate modifications to design and construction that might improve
performance.
1.3.3 By use of this guide, this information can also be shared with the users of the brushes (medical device reprocessors) to help
them evaluate the performance of commercially available brushes.
1.4 Exclusions:
1.4.1 This guide is not intended to be used for brushes designed to clean medical devices using rotational motion.
1.4.2 This guide does not assess potential damage that may be inflicted by the brush, or degradation of the brush that may occur
during repeated use. Brushes with rigid bristles (e.g., (for example, stainless steel or other metals) are predicted to be more likely
This test method guide is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of Subcommittee
F04.15 on Material Test Methods.
Current edition approved Feb. 15, 2019Jan. 1, 2022. Published March 2019January 2022. Originally approved in 2019. Last previous edition approved in 2019 as
F3276 – 19. DOI: 10.1520/F3276-19.10.1520/F3276-22.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3276 − 22
to damage medical devices than brushes with flexible bristles (e.g., (for example, nylon); damage from rigid-bristled brushes
should be assessed. Assessing repeated use would require a greatly increased number of test repetitions than what is described in
this guide.
1.4.3 This guide does not specify acceptance criteria, and the results will be dependent on the specific parameters that are tested
(e.g., (for example, test soil, drying time, surface area, and materials, etc.) that are tested.
1.4.4 This guide is not intended to constitute all steps required to conduct validation of cleaning instructions for a medical device,
including use of brushes for this purpose, but provides methods that may be part of a broader protocol to conduct a complete
cleaning instructions validation. Separate medical device cleaning instruction validation studies must be conducted.
1.5 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
F3208 Guide for Selecting Test Soils for Validation of Cleaning Methods for Reusable Medical Devices
2.2 ISO Standards:
ISO/TS 15883-5 Washer-disinfectors—Part 5: Test soils and methods for demonstrating cleaning efficacy
ISO 22254:2005 Dentistry—Manual toothbrushes—Resistance of tufted portion to deflection
2.3 AAMI Documents:
AAMI:TIR12 Designing, testing and labeling reusable medical devices for reprocessing in health care facilities: A guide for
medical device manufacturers
AAMI:TIR30 A compendium of processes, materials, test methods, and acceptance criteria for cleaning reusable medical
devices
2.4 FDA Document:
FDA Guidance for Industry and FDA Staff for Industry and FDA Staff, Processing/Reprocessing Medical Devices in Health Care
Settings: Validation Methods and Labeling, 2017
3. Terminology
3.1 Definitions:
3.1.1 cleaning—removal of contamination from a medical device to the extent necessary for further processing or for its intended
use.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 brush part—working end of the brush that comes in contact with the targeted surface of the substrate.
3.2.2 surface roughness—the shorter frequency of real surfaces relative to the troughs.
4. Summary of Practice
4.1 This guide provides details for testing the resistance of a brush part moved across a surface to simulate the resistance of a brush
used to clean the external surface of a medical device.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, http://www.iso.org.
Available from Association for the Advancement of Medical Instrumentation (AAMI), 4301 N. Fairfax Dr., Suite 301, Arlington, VA 22203-1633, http://www.aami.org.
https://www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/guidancedocuments/ucm253010.pdf
F3276 − 22
4.2 This guide also provides details for soiling a surface, actuating a brush part across that surface, and measuring the soil removed
from that surface to simulate the cleaning of the external surface of a medical device.
4.3 Surface substrate selection is based upon the physical characteristics (i.e., (that is, smoothness, material, etc.) of the medical
device being simulated.
4.4 Composition and application of the test soil should be based upon an evaluation of the clinical-use clinical use of the device
(Guide F3208, FDA 2017, AAMI TIR12, ISO/TS 15883-5).
5. Significance and Use
5.1 This guide provides two test methods for evaluating the performance characteristics of a brush part designed to clean external
surface(s) of a medical device by utilizing force testers.
5.1.1 The first test method utilizes a force tester to measure the force required to actuate a brush part across a surface. This is an
indicator of the friction a brush exerts on a surface, a parameter of cleaning effectiveness.
5.1.2 The second test method measures the removal of soil from a surface by a brush part actuated across the surface. This is a
further indicator of the effectiveness of a brush part to loosen and remove soil from a surface.
5.2 By providing objective, repeatable methods for evaluating performance,performance under test conditions, this guide can
improve the ability to assess the effectiveness of various brush part designs
6. Description of Test Apparatus
6.1 A force testing machine with moving crosshead, force gauge, and a suitable clamp for substrates (see Fig. 2).
6.1.1 The crosshead shall be programmable for the speed and the distance it travels.
6.1.2 The force required to move the brush up and down shall be measured.
6.1.3 The clamp attaches to the crosshead and holds the test substrates in place.
6.2 Brush Fixture:
6.2.1 The brush fixture is secured underneath the crosshead of the force tester.
6.2.2 The clamp to hold brushes shall be adjustable to accommodate different size brushes.
6.2.3 The brush clamp shall be on a sliding track that is adjustable horizontally so the brush can be moved closer to and further
from the substrate.
6.2.4 A force gauge is attached to the fixture to measure the force of the brush pushing against the substrate. This force gauge
should be able to measure aover 5 N force.
6.2.5 The brush fixture also includes a support to prevent the substrate holder from being deflected. This support also does not
cause resistance against the substrate holder from being actuated up and down.
6.3 Sensitive Analytical Scale:
6.3.1 To determine the weight differences in the soiled substrates, the scale shall be sensitive to at least 0.1 mg.
6.3.2 The scale shall have a large enough stage to weigh the selected substrate size.
F3276 − 22
7. Selection Criteria for Testing Parameters
7.1 Selection of Surface Substrate for Testing:
7.1.1 The physical characteristics of the surface should be similar to the physical characteristics of the surface of the medical
device(s) the brush is intended to clean. This includes the surface roughness and any geometric features like crevices, ridges, etc.
(AAMI TIR30). At a minimum, the following should be considered in selecting the surface substrate for testing: (1) material the
substrate is made of (e.g., (for example, stainless steel, polytetrafluoroethylene, silicone, etc.); (2) surface finish (e.g. (for example,
machined, ground, polished); and (3) device geometry (i.e., (that is, crevices, ridges).
7.1.2 Since the same brush design may be used on more than one type of device, testing of multiple substrates with different
material compositioncompositions may be necessary to fully characterize performance.
7.1.3 The length of the surface substrate should be at least long enough to allow the complete travel of the brush part across the
surface. Complete travel may be defined as a displacement equal to the length of the brush part, with contact maintained between
the full length of the brush part and the substrate during the entirety of travel.
7.2 Selection of Test Soil and Application Method:
7.2.1 The test soil should be similar in composition and physical qualities to the clinical soil the medical device comes in contact
with during patient use (Guide F3208, FDA 2017).
7.2.2 The volume of test soil applied to a device should reflect worst-case clinical conditions.
7.2.3 The application of the soil should simulate the worst-case soiling that a medical device is likely to experience during clinical
use (see Guide F3208, FDA 2017).
7.2.4 Soil is applied to the area of the substrate where the bristles of the brush will contact.
7.2.5 The time the soil is allowed to dry on the surface of the substrate should simulate worst-case drying during clinical use.
7.2.6 A cleaning solution that is similar to the cleaning solution likely to be used to clean the device after clinical use should be
selected. Excess cleaning solution should be removed from the brush.
7.3 Selection of Force:
7.3.1 Selection of Force Applied to Brush Part duringDuring Resistance Testing:
7.3.1.1 Often, a brush intended to clean the surface of a medical device is similar in design and function to a brush intended to
clean teeth, so the guidance in ISO 22254 is a reasonable starting point to determine the force to use. According to ISO 22254,
the force applied to determine the resistance of bristles to d
...