ASTM F51-00(2007)
(Test Method)Standard Test Method for Sizing and Counting Particulate Contaminant In and On Clean Room Garments
Standard Test Method for Sizing and Counting Particulate Contaminant In and On Clean Room Garments
SIGNIFICANCE AND USE
The test method for particulate sizing and numbers on garments is nondestructive and may be used to evaluate the contamination levels of fibers and particles on and in clean room garments. The test may be used for evaluating the cleanliness levels of new or newly cleaned garments. It also may be used to evaluate the extent of fiber and particulate contamination on garments that have been worn, if necessary. For this application, it is necessary to sample representative areas of the garment fabric.
SCOPE
1.1 This test method covers the determination of detachable particulate contaminant 5 m or larger, in and on the fabric of clean room garments.
1.2 This test method does not apply to nonporous fabrics such as Tyvek or Gortex. It only applies to fabrics that are porous such as cotton or polyester.
1.3 The values stated in SI units are to be regarded as the standard. The inch-pound values given in parentheses are for information only.
1.4 This test method provides not only the traditional optical microscopic analysis but also a size distribution and surface obscuration analysis for particles on a fine-textured membrane filter or in a tape lift sample. It utilizes transmitted illumination to render all particles darker than the background for gray level detection. Particles collected on opaque plates must be transferred to a suitable membrane filter.
This standard may involve hazardous materials, operations, and equipment. 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 and health practices and determine the applicability of regulatory limitations prior to use.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F51 − 00(Reapproved 2007)
Standard Test Method for
Sizing and Counting Particulate Contaminant In and On
Clean Room Garments
ThisstandardisissuedunderthefixeddesignationF51;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.2 Institute of Environmental Sciences and Technology
(IEST) Document:
1.1 Thistestmethodcoversthedeterminationofdetachable
IEST-RP-CC003.2, Garment System Considerations for
particulate contaminant 5 µm or larger, in and on the fabric of
Cleanrooms and Other Controlled Environments
clean room garments.
1.2 This test method does not apply to nonporous fabrics
3. Terminology
such as Tyvek® or Gortex®. It only applies to fabrics that are
3.1 Definitions:
porous such as cotton or polyester.
3.1.1 fiber, n—particle longer than 100 µm and with a
1.3 The values stated in SI units are to be regarded as the
length-to-width ratio exceeding 10:1.
standard. The inch-pound values given in parentheses are for -6
3.1.2 micrometre (µm), n—SIunitoflengthwhichis10 of
information only.
a metre or approximately 0.00004 in.
1.4 Thistestmethodprovidesnotonlythetraditionaloptical
3.1.3 particle size (L) (µm)—majorprojecteddimensionofa
microscopic analysis but also a size distribution and surface
particle.
obscuration analysis for particles on a fine-textured membrane
filterorinatapeliftsample.Itutilizestransmittedillumination
4. Summary of Test Method
torenderallparticlesdarkerthanthebackgroundforgraylevel
4.1 Filtered air is drawn through five designated 0.01-m
detection. Particles collected on opaque plates must be trans-
2 2
(1.5-in. or approximately 0.01-ft ) areas of a single thickness
ferred to a suitable membrane filter.
of the garment fabric at a rate of 14 L/min (0.5 cfm) for a
1.5 This standard may involve hazardous materials,
period of 1 min for each area.
operations, and equipment. This standard does not purport to
4.2 The air drawn through the garment subsequently passes
address all of the safety concerns, if any, associated with its
through a membrane filter disk, impinging the entrained
use. It is the responsibility of the user of this standard to
particles upon the filter surface.
establish appropriate safety and health practices and deter-
4.3 The filter disk is then examined microscopically for
mine the applicability of regulatory limitations prior to use.
particles removed from the garment.
2. Referenced Documents
4.4 For particles larger than 5 µm, use optical analysis. For
2.1 ASTM Standards: particles smaller than 5 µm, use automated image analysis.
E1216Practice for Sampling for Particulate Contamination
4.5 Cleaning and counting techniques are in accordance
by Tape Lift
with those established in Section 10.
F25Test Method for Sizing and CountingAirborne Particu-
late Contamination in Cleanrooms and Other Dust-
5. Significance and Use
Controlled Areas
5.1 The test method for particulate sizing and numbers on
garments is nondestructive and may be used to evaluate the
contamination levels of fibers and particles on and in clean
This test method is under the jurisdiction ofASTM Committee E21 on Space
room garments. The test may be used for evaluating the
SimulationandApplicationsofSpaceTechnologyandisthedirectresponsibilityof
Subcommittee E21.05 on Contamination. cleanliness levels of new or newly cleaned garments. It also
Current edition approved April 1, 2007. Published April 2007. Originally
may be used to evaluate the extent of fiber and particulate
´1
approvedin1965.Lastpreviouseditionapprovedin2002asF51-00(2002) .DOI:
contamination on garments that have been worn, if necessary.
10.1520/F0051-00R07.
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
Standardsvolume information,referto thestandard’sDocumentSummary page on Available from IEST, 940 E. Northwest Highway, Mount Prospect, IL 60056.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F51 − 00 (2007)
For this application, it is necessary to sample representative
areas of the garment fabric.
6. Apparatus
6.1 Filter Assembly and Adapter , see Fig. 1and Fig. 2.
6.1.1 Filter Holder, aerosol open type having an effective
filter area of 960 6 25 mm .
6.2 Vacuum Pump or Aspirator, capable of operating at a
pressure of 7 kPa (500 torr) with a flow rate of 14 L/min (0.5
cfm).
6.3 Flowmeter or Orifice, calibratedandhavingacapacity
inexcessof14L/min(0.5cfm),oralimitingorificecalibrated
withthepump,filterholder,andfilterusedforthistestmethod
at a flow rate of 14 6 0.5 L/min (0.50 6 0.02 cfm). Ensure,
visually, that the orifice is free of obstructing matter before
each test.
4,5
6.4 Membrane Filters :
FIG. 2 Adapter
6.4.1 Black, 0.80-µm pore size, 47-mm diameter with
3.08-mm imprinted grid for fabric particles.
6.4.2 White, 0.80-µm pore size, 47-mm diameter without
6.4.4 Plastic Petri Slides with Covers , plastic petri dishes,
imprinted grid for fabric particles and automated image ana-
60-mm diameter or glass microscope slides, 50 by 75 mm.
lyzer. 7
6.5 Binocular Microscope, withocular-objectivecombina-
6.4.3 White,5.0-µmporesize,47-mmdiameter(airprefilter
tionstoobtain40to45×and90to150×magnifications.Latter
used with the filters in 6.4.1 and 6.4.2).
objective shall have a numerical aperture of 0.15 min. Fig.
3shows suitable apparatus.
6.6 Programmable Image Analyzer, a Computer-Driven Mi-
croscope Which Counts and Sizes Particles With Automated
The following equipment is satisfactory for this test method except where Stage and Automated Focus Interface:
mentionedotherwise.Thefollowingpartnumbersrefertoequipmentavailablefrom
6.6.1 Microscope, with a large glass platform automatic
Millipore Filter Corp.:
stage and automated focus.
(1) Fabric Particle MonitoringAssembly, #XX50 047 40, Millipore Filter Corp.,
Bedford,MA01730,Gelman1200Awith1207AdapteravailablefromGelmanCo., 6.6.2 Objectives and Projection Lenses, to generate a pixel
Chelsea, MI or equivalent.
dimension of about 5 µm or less.
(2) Adapter No. XX50 047 45, or equivalent.
(3) Limiting Orifice XX50 000 00. 6.7 Forceps, with unserrated tips.
(4) Forceps with unserrated tips.
6.8 Normal Counter , (2 gang) or equivalent.
(5) Check Slide Photographic, XX 50 000 50 or equivalent.
(6) Aerosol Monitors Type M A BG037A0.
(7) Adapter, XX 62 000 04.
5 Analyslides,GelmanSciences,AnnArbor,MI,havebeenfoundsatisfactoryfor
Filters manufactured by the Millipore Filter Corp., Bedford, MA 01730 or
use with microscopes.
Gelman Co., Chelsea, MI, have been found satisfactory for this purpose.
Microscopes such as Bausch & Lomb No. TBV-5, Series C,American Optical
Co. X2BUHBW, Leitz SM 0.4.4S 25/81; and Zeiss Model KF 124-212 (with
accessories), or equivalent, have been found satisfactory for this purpose.
The Veeder Root counter has been found satisfactory for this purpose.
FIG. 1 Filter Assembly FIG. 3 Typical Air-Sampling Filtration Apparatus
F51 − 00 (2007)
6.9 Microscope Lamp , 6 V, 5 A high intensity. detergent, ketone-free, isopropyl alcohol and submicrometer-
10 filteredreagentgradepetroleumether(boilingrangefrom30to
6.10 Stage Micrometer , standard 0.01- to 0.1-mm scale.
60°C).
6.11 Ocular Micrometer Scale , 5-mm linear scale with
8.2 Maintain the laboratory equipment and area used for
100 divisions.
counting and sizing the particles in a condition of cleanliness
6.12 Standard Counting Specimens .
parallel or superior to the area sampled. Good clean room and
contamination control practices should be followed. Plastic
7. Sampling Requirements
microscope hoods have proven satisfactory as covering, in a
7.1 The sample shall be collected by drawing air filtered to
clean room, in the absence of a laboratory clean hood.
5 µm through the test garment, impinging the garment-borne
8.3 Personnel performing sizing and counting operations
particles on the membrane filter. The filter surface mounted in
shallweargarmentsandbehaveinamannerappropriatetothe
the open-type aerosol filter holder shall be placed on the outer
cleanliness conditions in which they are working.
surface of the test garment. The garment is firmly clamped to
the filter holder by means of the air-filter adapter. During
8.4 Cleanandpreparethemicroscopeslidesandpetridishes
sampling, the garment shall be hung or carefully positioned to
for preserving the membrane filter and specimen. Lens tissue
minimize extraneous contamination.
properly used is satisfactory for this operation.
7.2 The standard sample of this test method is secured with
8.5 Handle hazardous chemicals used in the test method
thepassageof14L(0.5ft )ofairthroughthetestfabricduring
with recognized precautions.
a 1-min period at each of five sampling areas as shown in Fig.
8.6 Establish a background count on membrane filters by
4. One sampling area is adequate for caps, helmets, towels,
examiningeachfilterusedforrefereepurposes.Examinationat
wipers,andbootieswithplasticsoles.Twoareasaresuggested
40 to 50× magnifications through the microscope will reveal
for all-fabric booties.
low or high background count.
7.3 Locations are approximate and may be modified to suit
8.7 Make a background count (Note 1) following the
a specific design factor by agreement.
microscopic methods outlined in this test method, upon any
filterwithacontaminationlevelapproximating10%orgreater
8. Preparation of Apparatus
of the estimated test sample (Note 2). This count will be
8.1 Beforesamplingwhenusingonlyamicroscope,remove
subtracted from the total count (P) obtained in 10.1 for each
t
dirtanddustfromthefilterholderbywashinginafree-rinsing
size range.
8.8 Place acceptable filters in clean petri dishes and cover.
9 Identify the dishes for test use.
The AO Spencer, or equivalent lamp, has been found satisfactory for this
purpose.
8.9 Whenusinganautomatedimageanalyzer,preparationis
Bausch&LombNo.31-16-00,orequivalentscale,hasbeenfoundsatisfactory
similar to the preceding except that the white, ungridded
for this purpose.
Bausch & Lomb No. 31-16-99, or equivalent micrometer, has been found 0.08-µm filter is used.
satisfactory for this purpose.
NOTE 1—For routine work, a background count on two filters per box
of 100 is adequate under present rigid production methods.
NOTE 2—If the background count is estimated to be greater than 10%
3 3
ofthetotalcountfroma0.3-m (10-ft )specimen,alargersample0.4-or
3 3
0.6-m (15-to20-ft )volumemaybeusedtoeliminatebackgroundcount
procedure.
9. Sampling
9.1 With the aid of laboratory pressure tubing, connect the
filter holder to a source of vacuum which has been found
adequate to produce a flow rate of 14 L/min (0.5 cfm), at
vacuum conditions test (pressure of 5 kPa or 350 torr). The
holder may be open, may contain a limiting orifice (Fig. 5), or
may be connected to the flowmeter. If a flowmeter is used
between the filter holder and vacuum source, correction to the
standard temperature and pressure must be made to determine
actual standard temperature and pressure flow.
9.2 With clean forceps, carefully remove the appropriate
membrane filter from the container and place, with grid side
up,whenappropriate,onthescreensupportofthefilterholder.
Twistthelockingringinplaceafterplacingthetaperedadapter
in position (Fig. 6). Similarly, place the 5.0-µm air filter in the
FIG. 4 Typical Counting and Sizing Microscope and Illuminator
(see Test Method F25) top portion of the adapter by removing the O-ring from the
F51 − 00 (2007)
9.4 Whenreadytosample,placetheoutersurfaceofthetest
garment over the tapered (male) adapter. Firmly lock into test
position by placing the air-filter tapered (female) adapter over
the test portion of fabric.
9.5 Apply vacuum at the predetermined flow rate of 14
L/min (0.5 cfm) for a period of 1 min for each area. Sample
required areas (Fig. 3) by repeating 9.3.
9.6 Removethefilterfromtheholderwithforcepsandplace
it between the clean microscope slides, in a clean transport
container(see6.4.4andFootnote5)orinacleanpetridishfor
transporttothemicroscopecountingarea.Themembranemust
be cleaned before placing it in the transport container.
10. Microscope Analysis Procedure
FIG. 5 Inserting a Typical Orifice
10.1 Place the ocular micrometer in one eyepiece. Using a
stage micrometer, calibrate the measuring eyepiece (ocular
micrometer) for each magnification (Fig. 7). A whipple disk
similarly calibrated is satisfactory for many inplant investiga-
tions.
10.2 Knowing the subdivisions of the stage micrometer
(top),thedivisionsofthemeasuringeyepiece(bottom)maybe
sized from it (Fig. 7).
NOTE3—Example:Stagethemicrometer100µmpermajordivision,10
µm per minor division: 100 divisions of the measuring eyepiece subtend
1050 µm, one division of the measuring eyepiece = 10.5 µm.
10.3 Remove the petri dish cover, then remove the filter
from the petri dish and place it, with filtering surface up, on a
50- by 76-mm (2- by 3-in.) microscope slide. Greasing the
FIG. 6 Placing the Filter on a Typical Screen Support
slide lightly with silicone stopcock lubricant before mounting
the filter will assist in holding the filter flat in place.
adaptertop,placinga47-mmwhitefilteronthesupportscreen 10.4 Adjust the external light source to obtain maximum
and replacing the O-ring. (This filter may be used for many particle definition with an illumination angle of approximately
tests.) 45°. High-intensity illumination is a critical requirement.
9.3 See IEST-RP-CC003.3 for additional recommendations 10.5 Useamagnificationofapproximately45×forcounting
on the sampling of garments. particles 50 µm or larger and approximately 100× for particles
FIG. 7 Calibrating the Measuring Eyepiece
F51 − 00 (2007)
smaller than 50 µm. Greater magnifications may be advanta-
geous for examination to identify particles.
NOTE 4—Analysis for particles in the 0.5- to 5.0-µm size range may be
achieved by using transmitted light techniques, after rendering the white
filter transparent by placing the filter on immersion oil of refractive index
1.515. A magnification of at least 500× is required. For transmitted light
microscopy, a white filter must be used (instead of black filter) since only
the white filter can be rendered transparent with immersion oil. If a
smaller pore size filter is used, the flowmeter used and the limiting orifice
will require calibration with the filter holder and filter in place.
10.6 Particles should be counted and tabulated in two s
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