1、Designation: F2101 07F2101 14Standard Test Method forEvaluating the Bacterial Filtration Efficiency (BFE) ofMedical Face Mask Materials, Using a Biological Aerosol ofStaphylococcus aureus1This standard is issued under the fixed designation F2101; the number immediately following the designation indi
2、cates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONWorkers, primarily those in the health car
3、e profession, involved in treating and caring forindividuals injured or sick, as well as the patient, can be exposed to biological aerosols capable oftransmitting disease. These diseases, which may be caused by a variety of microorganisms, can posesignificant risks to life and health. Since engineer
4、ing controls can not eliminate all possible exposures,attention is placed on reducing the potential of airborne exposure through the use of medical facemasks.1. Scope1.1 This test method is used to measure the bacterial filtration efficiency (BFE) of medical face mask materials, employing aratio of
5、the upstream bacterial challenge to downstream residual concentration to determine filtration efficiency of medical facemask materials.1.2 This test method is a quantitative method that allows filtration efficiency for medical face mask materials to be determined.The maximum filtration efficiency th
6、at can be determined by this method is 99.9 %.1.3 This test method does not apply to all forms or conditions of biological aerosol exposure. Users of the test method shouldreview modes for worker exposure and assess the appropriateness of the method for their specific applications.1.4 This test meth
7、od evaluates medical face mask materials as an item of protective clothing but does not evaluate materialsfor regulatory approval as respirators. If respiratory protection for the wearer is needed, a NIOSH-certified respirator should beused. Relatively high bacterial filtration efficiency measuremen
8、ts for a particular medical face mask material does not ensure thatthe wearer will be protected from biological aerosols since this test method primarily evaluates the performance of the compositematerials used in the construction of the medical face mask and not its design, fit or facial sealing pr
9、operties.1.5 UnitsThe values stated in SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in nonconforma
10、nce of the standard.1.6 This test method does not address breathability of the medical face mask materials or any other properties affecting the easeof breathing through the medical face mask material.1.7 This test method may also be used to measure the bacterial filtration efficiency (BFE) of other
11、 porous medical products suchas surgical gowns, surgical drapes, and sterile barrier systems.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health prac
12、tices and determine the applicability of regulatorylimitations prior to use.1 This test method is under the jurisdiction of ASTM Committee F23 on Personal Protective Clothing and Equipment and is the direct responsibility of SubcommitteeF23.40 on Biological.Current edition approved Feb. 1, 2007July
13、1, 2014. Published February 2007July 2014. Originally approved in 2001. Last previous edition approved in 20012007 asF2101 - 01.F2101 - 07. DOI: 10.1520/F2101-07.10.1520/F2101-14.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what
14、changes have been made to the previous version. Becauseit 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 versionof the standard as published by ASTM is to be considered the o
15、fficial document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:2E171 Practice for Conditioning and Testing Flexible Barrier PackagingF1494 Terminology Relating to Protective Clothing2.2 ANSI
16、/ASQC Standard:3ANSI/ASQC Z1.4 Sampling Procedures and Tables for Inspection by Attributes2.3 ISO Standard:4ISO 2859-1 Sampling Plans for Inspection by Attributes2.4 Military Standard:5MIL-STD 36954C (1973) Military Specification: Mask, Surgical, Disposable3. Terminology3.1 Definitions:3.1.1 aerosol
17、, na suspension of solid or liquid particles in a gas.3.1.2 agar, na semi-solid culture medium used to support the growth of bacteria and other micro-organisms.3.1.3 airborne exposure pathways, ninhalation routes of exposure to the medical face mask wearer.3.1.4 bacterial filtration effciency (BFE),
18、 nthe effectiveness of a medical face mask material in preventing the passage ofaerosolized bacteria; expressed in the percentage of a known quantity that does not pass the medical face mask material at a givenaerosol flow rate.3.1.5 biological aerosol, na suspension of particles containing biologic
19、al agents which have been dispersed in a gas.3.1.6 blood-borne pathogen, nan infectious bacterium or virus, or other disease inducing microbe carried in blood or otherpotentially infectious body fluids.3.1.7 body fluid, nany liquid produced, secreted, or excreted by the human body.3.1.8 protective c
20、lothing, nan item of clothing that is specifically designed and constructed for the intended purpose ofisolating all or part of the body from a potential hazard; or, isolating the external environment from contamination by the wearerof the clothing.3.1.9 medical face mask, nan item of protective clo
21、thing designed to protect portions of the wearers face, including themucous membrane areas of the wearers nose and mouth, from contact with blood and other body fluids during medical procedures.3.1.9.1 DiscussionMedical face masks also function to partly limit the spread of biological contamination
22、from the mask wearer (health care provider)to the patient.3.2 For definitions of other protective clothing-related terms used in this test method, refer to Terminology F1494.4. Summary of Test Method4.1 The medical face mask material is clamped between a six-stage cascade impactor and an aerosol cha
23、mber. The bacterialaerosol is introduced into the aerosol chamber using a nebulizer and a culture suspension of Staphylococcus aureus. The aerosolis drawn through the medical face mask material using a vacuum attached to the cascade impactor. The six-stage cascade impactoruses six agar plates to col
24、lect aerosol droplets which penetrate the medical face mask material. Control samples are collected withno test specimen clamped in the test apparatus to determine the upstream aerosol counts.4.2 The agar plates from the cascade impactor are incubated for 48 h and counted to determine the number of
25、viable particlescollected. The ratio of the upstream counts to the downstream counts collected for the test specimen are calculated and reportedas a percent bacterial filtration efficiency.5. Significance and Use5.1 This test method offers a procedure for evaluation of medical face mask materials fo
26、r bacterial filtration efficiency. This testmethod does not define acceptable levels of bacterial filtration efficiency. Therefore, when using this test method it is necessaryto describe the specific condition under which testing is conducted.2 For referencedASTM standards, visit theASTM website, ww
27、w.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American Society for Quality (ASQ), 600 N. Plankinton Ave., Milwaukee, WI 53203, http:/www.asq.org.4
28、Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.5 Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.F2101 1425.2 This test method has been s
29、pecifically designed for measuring bacterial filtration efficiency of medical face masks, usingStaphylococcus aureus as the challenge organism. The use of S. aureus is based on its clinical relevance as a leading cause ofnosocomial infections.5.3 This test method has been designed to introduce a bac
30、terial aerosol challenge to the test specimens at a flow rate of 28.3L/mm. (1 ft3/min). This flow rate is within the range of normal respiration and within the limitations of the cascade impactor.5.4 This test method allows the aerosol challenge to be Unless otherwise specified, the testing shall be
31、 performed with the insideof the medical face mask in contact with the bacterial challenge. Testing may be performed with the aerosol challenge directedthrough either the face side or liner side of the test specimen, thereby, allowing evaluation of filtration efficiencies which relateto both patient
32、-generated aerosols and wearer-generated aerosols.5.5 Degradation by physical, chemical, and thermal stresses could negatively impact the performance of the medical face maskmaterial. The integrity of the material can also be compromised during use by such effects as flexing and abrasion, or by wett
33、ingwith contaminants such as alcohol and perspiration. Testing without these stresses could lead to a false sense of security. If theseconditions are of concern, evaluate the performance of the medical face mask material for bacterial filtration efficiency followingan appropriate pretreatment techni
34、que representative of the expected conditions of use. Consider preconditioning to assess theimpact of storage conditions and shelf life for disposable products, and the effects of laundering and sterilization for reusableproducts.5.6 If this procedure is used for quality control, perform proper stat
35、istical design and analysis of larger data sets. This type ofanalysis includes, but is not limited to, the number of individual specimens tested, the average percent bacterial filtration efficiency,and standard deviation. Data reported in this way help to establish confidence limits concerning produ
36、ct performance. Examplesof acceptable sampling plans are found in references such as ANSI/ASQC Z1.4 and ISO 2859-1.6. Apparatus and Materials6.1 Apparatus:6.1.1 Autoclave, capable of maintaining 121-123C.6.1.2 Incubator, capable of maintaining 37 6 2C.6.1.3 Analytical Balance, capable of weighing 0.
37、001 g.6.1.4 Vortex Mixer, capable of mixing the contents of 16 mm 150 mm test tubes.6.1.5 Orbital Shaker, capable of achieving 100-250 rpm.6.1.6 Refrigerator, capable of maintaining 2-8C.6.1.7 Six-Stage Viable Particle Cascade Impactor.6.1.8 Vacuum Pump, capable of 57 L/m (2 ft3/mm).6.1.9 Air Pump/C
38、ompressor, capable of 15 psig minimum.6.1.10 Peristaltic Pump, capable of delivering 0.01 mL/min.6.1.11 Nebulizer, capable of delivering a mean particle size of 3.0 m 6 0.3 m and a challenge level of 2200 6 500 viableparticles per test, as determined according to step 12.3.6.1.12 Glass Aerosol Chamb
39、er, 60 cm by 8 cm diameter tube.6.1.13 Colony Counter, manual or automatic, capable of counting up to 400 colonies/plate.6.1.14 Timers, capable of 0.1 s accuracy.6.1.15 Automatic Pipetor, capable of delivering 1.0 mL 6 0.05 mL.6.1.16 Flow Meters, capable of 28.3 L/min.6.1.17 Aerosol Condenser.6.1.18
40、 Pressure Gauge, capable of 35 kPa 6 1 kPa accuracy.6.1.19 Air Regulator.6.2 Materials:6.2.1 Flasks, 250-500 mL Erlenmeyer.6.2.2 Petri Dishes, sterile 15 by 100 mm.6.2.3 Pipettes, 1 mL, 5 mL, and 10 mL.6.2.4 Test Tube Rack, stainless6.2.5 Bottles, sterile, glass, 100-500 mL capacity.6.2.6 Inoculatin
41、g Loop.6.2.7 Stoppers/Closures, of appropriate size to fit test tubes.6.2.8 Test Tubes, 16 mm 150 mm.F2101 1437. Reagents7.1 Tryptic Soy Agar TSATSA.6.7.2 Tryptic Soy Broth TSBTSB.6.7.3 Peptone WaterWater.6.7.4 Staphylococcus aureus, ATCC #65388. Hazards8.1 Sterilize all apparatus and supplies which
42、 come into contact with the bacterial challenge suspension, by autoclaving at121-123 C for a minimum of 15 min. Extreme care must be taken to avoid contamination of the laboratory spaces by completesterilization or high level disinfection of all apparatus and supplies. This will reduce the possibili
43、ty of laboratory contamination.8.2 Staphylococcus aureus is common to the normal flora of the body, however, it is a leading cause of nosocomial infectionsand is a human pathogen. Technicians conducting the testing must have proper microbiological training. Gloves and otherprotective clothing equipm
44、ent should be worn during testing to prevent contamination.8.3 All aerosols must be contained to prevent exposure and reduce laboratory contamination.9. Media Preparation9.1 Prepare media using standard microbiological techniques.9.2 Prepare agar plates for cascade impactor as specified by the manuf
45、acturer of the cascade impactor.10. Test Specimen10.1 Test specimens shall be taken from manufactured medical face masks, with all layers arranged in proper order.11. Conditioning11.1 Condition each specimen for a minimum of 4 h by exposure to a temperature of 21 6 5 C (70 6 10F) and relativehumidit
46、y of 85 6 5 % as described in Specification E171 using a controlled temperature and humidity chamber or space.12. Preparation of the Bacterial Challenge12.1 Inoculate an appropriate volume of tryptic soy broth with and incubate with mild shaking at 37 6 2C for 24 6 2 h.12.2 Dilute the culture in pep
47、tone water to achieve a concentration of approximately 5 105 CFU/mL.12.3 The challenge delivery rate will be maintained at 2200 6 500 viable particles per test. The challenge delivery rate isdetermined each day of testing and is based on the results of the positive control plates when the aerosol is
48、 collected in a six-stageviable particle cascade impactor, with no test specimen clamped into the test system. The dilution of the challenge suspension willneed to be adjusted to deliver the proper challenge level during testing.13. Test Procedure13.1 The aerosol challenge apparatus is outlined in F
49、ig. 1.13.2 Deliver the challenge to the nebulizer using a peristaltic or syringe pump. Connect tubing to nebulizer and peristaltic pumpand into the challenge suspension; purge tubing and nebulizer of air bubbles.NOTE 1The peristaltic pump or syringe pump must be calibrated to deliver a consistent challenge volume throughout the testing interval.13.3 Perform a positive control run without a test specimen clamped into the test system to determine the number of viableaerosol particles being generated. The mean particle size (MPS) of the aerosol
