ASTM F51-00

Standard Test Method for Sizing and Counting Particulate Contaminant In and On Clean Room Garments

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 procedure 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.

General Information

• Status: Historical
• Publication Date: 09-May-2000
• Technical Committee: E21 - Space Simulation and Applications of Space Technology
• Drafting Committee: E21.05 - Contamination

Relations

• Replaced By: ASTM F51-00(2002)e1 - Standard Test Method for Sizing and Counting Particulate Contaminant In and On Clean Room Garments
• Effective Date: 10-May-2000
• Referred By: ASTM E2312-11(2019) - Standard Practice for Tests of Cleanroom Materials
• Effective Date: 10-May-2000
• Referred By: ASTM E2352-19 - Standard Practice for Aerospace Cleanrooms and Associated Controlled Environments—Cleanroom Operations
• Effective Date: 10-May-2000
• Referred By: ASTM E1549/E1549M-13(2022) - Standard Specification for ESD Controlled Garments Required in Cleanrooms and Controlled Environments for Spacecraft for Non-Hazardous and Hazardous Operations
• Effective Date: 10-May-2000

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: F 51 – 00
Standard Test Method for
Sizing and Counting Particulate Contaminant In and On
Clean Room Garments
This standard is issued under the fixed designation F 51; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method covers the determination of detachable 3.1 Definitions:
particulate contaminant 5 μm or larger, in and on the fabric of 3.1.1 fiber, n—particle longer than 100 μm and with a
clean room garments. length-to-width ratio exceeding 10:1.
–6
1.2 This test method does not apply to nonporous fabrics 3.1.2 micrometre (μm), n—SI unit of length which is 10 of
such as Tyvekt or Gortext. It only applies to fabrics that are a metre or approximately 0.000 04 in.
porous such as cotton or polyester. 3.1.3 particle size (L) (μm)—major projected dimension of
1.3 The values stated in SI units are to be regarded as the a particle.
standard. The inch-pound values given in parentheses are for
4. Summary of Test Method
information only.
4.1 Filtered air is drawn through five designated 0.01-m
1.4 This procedure provides not only the traditional optical
2 2
microscopic analysis but also a size distribution and surface (1.5-in. or approximately 0.01-ft ) areas of a single thickness
of the garment fabric at a rate of 14 L/min (0.5 cfm) for a
obscuration analysis for particles on a fine-textured membrane
filter or in a tape lift sample. It utilizes transmitted illumination period of 1 min for each area.
4.2 The air drawn through the garment subsequently passes
to render all particles darker than the background for gray level
detection. Particles collected on opaque plates must be trans- through a membrane filter disk, impinging the entrained
particles upon the filter surface.
ferred to a suitable membrane filter.
1.5 This standard may involve hazardous materials, opera- 4.3 The filter disk is then examined microscopically for
particles removed from the garment.
tions, and equipment. This standard does not purport to
address all of the safety concerns, if any, associated with its 4.4 For particles larger than 5 μm, use optical analysis. For
particles smaller than 5 μm, use automated image analysis.
use. It is the responsibility of the user of this standard to
establish appropriate safety and health practices and deter- 4.5 Cleaning and counting techniques are in accordance
with those established in Section 10.
mine the applicability of regulatory limitations prior to use.
2. Referenced Documents 5. Significance and Use
The test for particulate sizing and numbers on garments is
2.1 ASTM Standards:
E 1216 Practice for Sampling for Surface Particulate Con- nondestructive and may be used to evaluate the contamination
levels of fibers and particles on and in clean room garments.
tamination by Tape Lift
The test may be used for evaluating the cleanliness levels of
F 25 Test Method for Sizing and Counting Airborne Par-
ticulate Contamination in Clean Rooms and Other Dust- new or newly cleaned garments. It also may be used to evaluate
the extent of fiber and particulate contamination on garments
Controlled Areas Designed for Electronic and Similar
Applications that have been worn, if necessary. For this application, it is
necessary to sample representative areas of the garment fabric.
2.2 Institute of Environmental Sciences and Technology
(IEST) Document:
6. Apparatus
IEST-RP-CC003.2, Garment System Considerations for
6.1 Filter Assembly and Adapter , see Fig. 1 and Fig. 2.
Cleanrooms and Other Controlled Environments
The following equipment is satisfactory for this test method except where
This test method is under the jurisdiction of ASTM Committee E-21 on Space mentioned otherwise. The following part numbers refer to equipment available from
Simulation and Applications of Space Technology and is the direct responsibility of Millipore Filter Corp.
Subcommittee E21.05 on Contamination. (1) Fabric Particle Monitoring Assembly, #XX50 047 40, Millipore Filter Corp.,
Current edition approved May 10, 2000. Published July 2000. Originally Bedford, MA 01730, Gelman 1200A with 1207 Adapter available from Gelman Co.,
published as F 51 – 65. Discontinued in August 1998 and reinstated as F 51 – 00. Chelsea, MI or equivalent.
Annual Book of ASTM Standards, Vol 15.03. (2) Adapter No. XX50 047 45, or equivalent.
Available from IEST, 940 E. Northwest Highway, Mount Prospect, IL 60056. (3) Limiting Orifice XX50 000 00.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F51
6.4.2 White, 0.80-μm pore size, 47-mm diameter without
imprinted grid for fabric particles and automated image ana-
lyzer.
6.4.3 White, 5.0-μm pore size, 47-mm diameter (air prefilter
used with the filters in 6.4.1 and 6.4.2.
6.4.4 Plastic Petri Slides with Covers , plastic petri dishes,
60-mm diameter or glass microscope slides, 50 by 75 mm.
6.5 Binocular Microscope , with ocular-objective combina-
tions to obtain 40 to 453 and 90 to 1503 magnifications.
Latter objective shall have a numerical aperture of 0.15 min.
Fig. 3 shows suitable apparatus.
6.6 Programmable Image Analyzer, a Computer-Driven Mi-
croscope Which Counts and Sizes Particles With Automated
Stage and Automated Focus Interface:
6.6.1 Microscope, with a large glass platform automatic
stage and automated focus.
6.6.2 Objectives and Projection Lenses, to generate a pixel
FIG. 1 Filter Assembly
dimension of about 5 μm or less.
6.7 Forceps, with unserrated tips.
6.8 Normal Counter , (2 gang) or equivalent.
6.9 Microscope Lamp , 6 V, 5 A high intensity.
6.10 Stage Micrometer , standard 0.01- to 0.1-mm scale.
6.11 Ocular Micrometer Scale , 5-mm linear scale with
100 divisions.
6.12 Standard Counting Specimens .
7. Sampling Requirements
7.1 The sample shall be collected by drawing 5 μm of
filtered air through the test garment, impinging the garment-
borne particles on the membrane filter. The filter surface
mounted in the open-type aerosol filter holder shall be placed
Analyslides, Gelman Sciences, Ann Arbor, MI, have been found satisfactory for
use with microscopes.
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.
FIG. 2 Adapter
The Veeder Root counter has been found satisfactory for this purpose.
The AO Spencer, or equivalent lamp, has been found satisfactory for this
6.1.1 Filter Holder, aerosol open type having an effective
purpose.
filter area of 960 6 25 mm . Bausch & Lomb No. 31-16-00, or equivalent scale, has been found satisfactory
for this purpose.
6.2 Vacuum Pump or Aspirator, capable of operating at a
Bausch & Lomb No. 31-16-99, or equivalent micrometer, has been found
pressure of 7 kPa (500 torr) with a flow rate of 14 L/min (0.5
satisfactory for this purpose.
cfm).
6.3 Flowmeter or Orifice , calibrated and having a capacity
in excess of 14 L/min (0.5 cfm), or a limiting orifice calibrated
with the pump, filter holder, and filter used for this test method
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 :
6.4.1 Black, 0.80-μm pore size, 47-mm diameter with
3.08-mm imprinted grid for fabric particles.
(4) Forceps with unserrated tips.
(5) Check Slide Photographic, XX 50 000 50 or equivalent.
(6) Aerosol Monitors Type M A BG037A0.
(7) Adapter, XX 62 000 04.
Filters manufactured by the Millipore Filter Corp., Bedford, MA 01730 or
Gelman Co., Chelsea, MI, have been found satisfactory for this purpose. FIG. 3 Typical Air-Sampling Filtration Apparatus
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F51
on the outer surface of the test garment. The garment is firmly 8.7 Make a background count (Note 1) following the
clamped to the filter holder by means of the air-filter adapter. microscopic methods outlined in this test method, upon any
During sampling, the garment shall be hung or carefully filter with a contamination level approximating 10 % or greater
positioned to minimize extraneous contamination. of the estimated test sample (Note 2). This count will be
7.2 The standard sample of this test method is secured with subtracted from the total count (P ) obtained in 10.1 for each
t
the passage of 14 L (0.5 ft ) of air through the test fabric during size range.
a 1-min period at each of five sampling areas as shown in Fig. 8.8 Place acceptable filters in clean petri dishes and cover.
4. One sampling area is adequate for caps, helmets, towels, Identify the dishes for test use.
wipers, and booties with plastic soles. Two areas are suggested 8.9 When using an automated image analyzer, preparation is
for all-fabric booties. similar to the preceding except that the white, ungridded
7.3 Locations are approximate and may be modified to suit 0.08-μm filter is used.
a specific design factor by agreement.
NOTE 1—For routine work, a background count on two filters per box
of 100 is adequate under present rigid production methods.
8. Preparation of Apparatus
NOTE 2—If the background count is estimated to be greater than 10 %
8.1 Before sampling when using only a microscope, remove 3 3
of the total count from a 0.3-m (10-ft ) specimen, a larger sample 0.4- or
3 3
dirt and dust from the filter holder by washing in a free-rinsing
0.6-m (15- to 20-ft ) volume may be used to eliminate background count
detergent, ketone-free, isopropyl alcohol and submicrometer-
procedure.
filtered reagent grade petroleum ether (boiling range from 30 to
9. Sampling
60°C.
8.2 Maintain the laboratory equipment and area used for 9.1 With the aid of laboratory pressure tubing, connect the
counting and sizing the particles in a condition of cleanliness filter holder to a source of vacuum which has been found
parallel or superior to the area sampled. Good clean room and adequate to produce a flow rate of 14 L/min (0.5 cfm), at
contamination control practices should be followed. Plastic vacuum conditions test (pressure of 5 kPa or 350 torr). The
microscope hoods have proven satisfactory as covering, in a holder may be open, may contain a limiting orifice (Fig. 5), or
clean room, in the absence of a laboratory clean hood. may be connected to the flowmeter. If a flowmeter is used
8.3 Personnel performing sizing and counting operations between the filter holder and vacuum source, correction to the
shall wear garments and behave in a manner appropriate to the standard temperature and pressure must be made to determine
cleanliness conditions in which they are working. actual standard temperature and pressure flow.
8.4 Clean and prepare the microscope slides and petri dishes 9.2 With clean forceps, carefully remove the appropriate
for preserving the membrane filter and specimen. Lens tissue membrane filter from the container and place, with grid side
properly used is satisfactory for this operation. up, when appropriate, on the screen support of the filter holder.
8.5 Handle hazardous chemicals used in the method with Twist the locking ring in place after placing the tapered adapter
recognized precautions. in position (Fig. 6). Similarly, place the 5.0-μm air filter in the
8.6 Establish a background count on membrane filters by top portion of the adapter by removing the O-ring from the
examining each filter used for referee purposes. Examination at adapter top, placing a 47-mm white filter on the support screen
40 to 503 magnifications through the microscope will reveal and replacing the O-ring. (This filter may be used for many
low or high background count. tests.)
9.3 See IEST-RP-CC003.3 for additional recommendations
on the sampling of garments.
9.4 When ready to sample, place the outer surface of the test
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.
FIG. 4 Typical Counting and Sizing Microscope and Illuminator
(see Test Method F 25) FIG. 5 Inserting a Typical Orifice
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F51
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
slide lightly with silicone stopcock lubricant before mounting
the filter will assist in holding the filter flat in place.
10.4 Adjust the external light source to obtain maximum
particle definition with an illumination angle of approximately
45°. High-intensity illumination is a critical requirement.
10.5 Use a magnification of approximately 453 for count-
ing particles 50 μm or larger and approximately 1003 for
particles smaller than 50 μm. Greater magnifications may be
advantageous 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
FIG. 6 Placing the Filter on a Typical Screen Support
filter transparent by placing the filter on immersion oil of refractive index
1.515. A magnification of at least 5003 is required. For transmitted light
microscopy, a white filter must be used (instead of black filter) since only
9.5 Apply vacuum at the predetermined flow rate of 14
the white filter can be rendered transparent with immersion oil. If a
L/min (0.5 cfm) for a period of 1 min for each area. Sample
smaller pore size filter is used, the flowmeter used and the limiting orifice
required areas (Fig. 3) by repeating 9.3.
will require calibration with the filter holder and filter in place.
9.6 Remove the filter from the holder with forceps and place
10.6 Particles should be counted and tabulated in two size
it between the clean microscope slides, in a clean transport
ranges: particles greater than 50 μm and particles 5 to 50 μm.
container (see 6.4.4 and Footnote 5) or in a clean petri dish for
Particles smaller than 5 μm are not to be counted by the manual
transport to the microscope counting area. The membrane must
counting method. The size of particles is de
...