ASTM E2042/E2042M-09(2021)

Standard Practice for Cleaning and Maintaining Controlled Areas and Clean Rooms

SIGNIFICANCE AND USE
4.1 This practice identifies methods for cleaning and maintaining controlled areas and clean rooms as defined by ISO 14644-1 and ISO 14644-2. Cleaning procedures are described, and cleaning frequency for different classes of facility are given. Compliance with this practice will make it easier and more likely that the required level of facility cleanliness will be maintained. A cleaner facility also will help to protect flight hardware from contamination and should reduce the frequency for cleaning flight hardware. This practice does not discuss operation and operational procedures for cleanrooms and controlled areas. Other documents such as IEST-RP-CC026 and Practice E2352 provide recommended practices for operating cleanrooms and controlled areas.
SCOPE
1.1 This practice covers the procedures to be followed for the initial cleaning and normal maintenance of cleanrooms and controlled areas. This practice is applicable to aerospace clean areas where both particles and molecular films (NVR) must be controlled.  
1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.3 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.  
1.4 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.

General Information

• Status: Published
• Publication Date: 31-Aug-2021
• ICS: 13.040.35 - Cleanrooms and associated controlled environments
• Technical Committee: E21 - Space Simulation and Applications of Space Technology
• Drafting Committee: E21.05 - Contamination

Relations

• Refers: ASTM E1235-12(2020)e1 - Standard Test Method for Gravimetric Determination of Nonvolatile Residue (NVR) in Environmentally Controlled Areas for Spacecraft
• Effective Date: 01-Apr-2020
• Refers: ASTM E1234-12(2020) - Standard Practice for Handling, Transporting, and Installing Nonvolatile Residue (NVR) Sample Plates Used in Environmentally Controlled Areas for Spacecraft
• Effective Date: 01-Apr-2020
• Refers: ASTM E1235-12(2020) - Standard Test Method for Gravimetric Determination of Nonvolatile Residue (NVR) in Environmentally Controlled Areas for Spacecraft
• Effective Date: 01-Apr-2020
• Refers: ASTM F24-20 - Standard Test Method for Measuring and Counting Particulate Contamination on Surfaces
• Effective Date: 01-Apr-2020
• Refers: ASTM E2352-19 - Standard Practice for Aerospace Cleanrooms and Associated Controlled Environments—Cleanroom Operations
• Effective Date: 01-May-2019
• Refers: ASTM E1560-18 - Standard Test Method for Gravimetric Determination of Nonvolatile Residue From Cleanroom Wipers
• Effective Date: 01-Nov-2018
• Refers: ASTM F24-09(2015) - Standard Test Method for Measuring and Counting Particulate Contamination on Surfaces
• Effective Date: 01-Oct-2015
• Refers: ASTM E1234-12 - Standard Practice for Handling, Transporting, and Installing Nonvolatile Residue (NVR) Sample Plates Used in Environmentally Controlled Areas for Spacecraft
• Effective Date: 01-Nov-2012
• Refers: ASTM E1235-12 - Standard Test Method for Gravimetric Determination of Nonvolatile Residue (NVR) in Environmentally Controlled Areas for Spacecraft
• Effective Date: 01-Nov-2012
• Refers: ASTM F50-12 - Standard Practice for Continuous Sizing and Counting of Airborne Particles in Dust-Controlled Areas and Clean Rooms Using Instruments Capable of Detecting Single Sub-Micrometre and Larger Particles
• Effective Date: 01-Apr-2012
• Refers: ASTM E1560-11 - Standard Test Method for Gravimetric Determination of Nonvolatile Residue From Cleanroom Wipers
• Effective Date: 01-Dec-2011
• Refers: ASTM E1560-11e1 - Standard Test Method for Gravimetric Determination of Nonvolatile Residue From Cleanroom Wipers
• Effective Date: 01-Dec-2011
• Refers: ASTM E2352-04(2010) - Standard Practice for Aerospace Cleanrooms and Associated Controlled Environments-Cleanroom Operations
• Effective Date: 01-Apr-2010
• Refers: ASTM F24-09 - Standard Method for Measuring and Counting Particulate Contamination on Surfaces
• Effective Date: 01-Apr-2009
• Refers: ASTM E1235-08 - Standard Test Method for Gravimetric Determination of Nonvolatile Residue (NVR) in Environmentally Controlled Areas for Spacecraft
• Effective Date: 01-May-2008

Standards Content (Sample)

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.
Designation: E2042/E2042M − 09 (Reapproved 2021)
Standard Practice for
Cleaning and Maintaining Controlled Areas and Clean
Rooms
ThisstandardisissuedunderthefixeddesignationE2042/E2042M;thenumberimmediatelyfollowingthedesignationindicatestheyear
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 Areas for Spacecraft
E1549 Specification for ESD Controlled Garments Required
1.1 This practice covers the procedures to be followed for
in Cleanrooms and Controlled Environments for Space-
the initial cleaning and normal maintenance of cleanrooms and
craft for Non-Hazardous and Hazardous Operations
controlled areas. This practice is applicable to aerospace clean
E1560 Test Method for Gravimetric Determination of Non-
areas where both particles and molecular films (NVR) must be
volatile Residue From Cleanroom Wipers
controlled.
E2352 Practice for Aerospace Cleanrooms and Associated
1.2 Units—The values stated in either SI units or inch-
Controlled Environments—Cleanroom Operations
pound units are to be regarded separately as standard. The
F24 Test Method for Measuring and Counting Particulate
values stated in each system may not be exact equivalents;
Contamination on Surfaces
therefore,eachsystemshallbeusedindependentlyoftheother.
F25 Test Method for Sizing and Counting Airborne Particu-
Combining values from the two systems may result in non-
late Contamination in Cleanrooms and Other Dust-
conformance with the standard.
Controlled Areas
1.3 This standard does not purport to address all of the F50 Practice for Continuous Sizing and Counting of Air-
safety concerns, if any, associated with its use. It is the
borne Particles in Dust-Controlled Areas and Clean
responsibility of the user of this standard to establish appro- Rooms Using Instruments Capable of Detecting Single
priate safety, health, and environmental practices and deter-
Sub-Micrometre and Larger Particles
mine the applicability of regulatory limitations prior to use.
2.2 IEST Standards:
1.4 This international standard was developed in accor-
IEST-RP-CC007 Testing ULPA Filters
dance with internationally recognized principles on standard-
IEST-RP-CC016 The Rate of Deposition of Nonvolatile
ization established in the Decision on Principles for the
Residue in Cleanrooms
Development of International Standards, Guides and Recom-
IEST-RP-CC0018 Cleanroom Housekeeping and Monitor-
mendations issued by the World Trade Organization Technical
ing Procedures
Barriers to Trade (TBT) Committee.
IEST-RP-CC003 Garment System Considerations for Clean-
rooms and Other Controlled Environments
2. Referenced Documents
IEST-RP-CC026 Cleanroom Operations
2.1 ASTM Standards: IEST-STD-CC1246D Product Cleanliness Levels and Con-
D1193 Specification for Reagent Water tamination Control Program
E1234 Practice for Handling, Transporting, and Installing
2.3 US Federal Standards:
Nonvolatile Residue (NVR) Sample Plates Used in Envi-
FED-STD-209E Airborne Particulate Cleanliness Classes in
ronmentally Controlled Areas for Spacecraft
Cleanrooms and Clean Zones
E1235 Test Method for Gravimetric Determination of Non-
TT-I-735 Isopropyl Alcohol
volatile Residue (NVR) in Environmentally Controlled
O-A-51 Acetone
1 3
This practice is under the jurisdiction of ASTM Committee E21 on Space Available from Institute of Environmental Science and Technology (IEST),
Simulation andApplications of Space Technology and is the direct responsibility of 5005 Newport Dr., Suite 506, Rolling Meadows, IL 60008-3841.
Subcommittee E21.05 on Contamination. IEST-STD-CC1246D replaced MIL-STD-1246.
Current edition approved Sept. 1, 2021. Published October 2021. Originally Available from Superintendent of Documents, US Government Printing Office,
approved in 1999. Last previous edition approved in 2016 as E2042/ Washington, DC 20402.
E2042M – 09(2016). DOI: 10.1520/E2042_E2042M-09R21. Cancelled Nov. 29, 2001 and replaced with ISO 14644-1 and 14644-2.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or FED-STD-209E may be used by mutual agreement between buyer and seller.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from U.S. Government Printing Office, Superintendent of Documents,
Standards volume information, refer to the standard’s Document Summary page on 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401. FS209E
the ASTM website. cleanroom classes are given for reference in parentheses after the ISO classes.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2042/E2042M − 09 (2021)
2.4 US Department of Defense Standards: 3.1.4 cleanroom, at-rest, n—a cleanroom that is complete,
MIL-D-16791 Detergents, General Purpose (Liquid, Non- with all services functioning and with equipment installed and
Ionic)
operable or operating, as specified, but without operating
personnel in the room.
2.5 International Standards:
ISO 14644-1 Cleanrooms and Associated Controlled
3.1.5 cleanroom, operational, n—a cleanroom in normal
Environments—Part 1: Classification of Air Cleanliness
operation, with all services functioning and with equipment
ISO 14644-2 Cleanrooms and Associated Controlled
and personnel, if applicable, present and performing their
Environments—Part 2: Specifications for Testing and
normal work functions in the room.
Monitoring to Prove Continued Compliance with ISO
3.1.6 clean facility, n—the total real property required to
14644-1
accomplish the cleanroom functions.
3. Terminology
3.1.6.1 Discussion—In addition to the cleanroom and asso-
ciated clean areas, this includes utility rooms, storage areas,
3.1 Definitions of Terms Specific to This Standard:
offices, lockers, wash-rooms, and other areas that do not
3.1.1 clean zone, n—a defined space in which the concen-
necessarily require precise environmental control.
tration of airborne particles is controlled to specified limits.
3.1.2 cleanroom, n—a room in which the air filtration, air
3.1.7 controlled area, n—an environmentally controlled
distribution, utilities, materials of construction, equipment, and
area, operated as a cleanroom, but without the final stage of
operating procedures are specified and regulated to control
HEPA filters. Controlled areas would meet ISO Class 8.5
airborne particle concentrations to meet appropriate airborne
(FED-STD-209E equivalent to Class 300 000) per Table 1.
particulate cleanliness classifications, as defined by ISO
3.1.7.1 Discussion—Only rough filters (50 to 60 % effi-
14644-1.
ciency) and medium efficiency filters (80 to 85 % efficiency)
3.1.3 cleanroom, as-built, n—a cleanroom that is complete
are required for a controlled area. The maximum allowable
and ready for operation, with all services connected and
airborne particle concentrations in a controlled area are
functional,butwithoutequipmentoroperatingpersonnelinthe
11 100 000⁄m per ISO Class 8.5 for particles ≥0.5 µm and 92
3 3 3
room.
500/m (2620 particles/ft per Class 300 000/ft (FED-STD-
209E) for particles ≥5.0 µm.
3.1.8 DI water, n—deionized water (see Specification
D1193).
Available from International Organization for Standardization (ISO), 1 rue de
Varembé, Case postale 56, CH-1211, Geneva 20, Switzerland.
TABLE 1 Comparison of ISO 14644-1 and FED-STD-209E Cleanliness Classes
Particle Concentrations
ISO Class N
Maximum Number of Particles per Cubic Meter / Cubic Foot
Nominal FS209E
of Air for Particle Sizes Equal to or Greater than the Stated Size
Class
A
0.1 µm 0.2 µm 0.3 µm 0.5 µm 1 µm 5µm
ISO Class 1 10 2 — — — —
ISO Class 2 100 24 10 4 — —
FS209E Class 0.1 3 1 — — — —
ISO Class 3 1000 237 102 35 8 —
FS209E Class 1 35 7 3 1 — —
ISO Class 4 10 000 2370 1020 352 83 —
FS209E Class 10 350 75 30 10 2 —
ISO Class 5 100 000 23 700 10 200 3520 832 29
B
FS209E Class 100 3500 750 300 100 24 —
ISO Class 6 1 000 000 237 000 102 000 35 200 8320 293
B B B
FS209E Class 1000 35 000 7500 3000 1000 236 7
C
ISO Class 6.7 — — — 176 000 41 700 1470
B
FS209E Class 5000 — — — 5000 1180 42
ISO Class 7 — — — 352 000 83 200 2930
FS209E Class 10 000 — — — 10 000 2360 70
ISO Class 8 — — — 3 520 000 832 000 29 300
FS209E Class — — — 100 000 23 600 700
100 000
C
ISO Class 8.5 — — — 11 100 000 2 630 000 92 500
FS209E Class — — — 300 000 74 500 2620
D
300 000
ISO Class 9 — — — 35 200 000 8 320 000 293 000
FS209E Class — — — 1 000 000 236 000 8280
D
1 000 000
A
No 1 µm designation is listed in FS209E Table 1 for particulate classes. The values shown are equivalents of the ISO values.
B
These values were not directly listed in FS209E. Allowances are made in FS209E for intermediate classes and associated calculations have been shown. If used, a
notation should be made indicating that they have been derived.
C
ISO 14644-1 does not include Class 6.7 or 8.5. The values shown are equivalent to those derived for FED-STD-209E Class 5000 and 300 000.
D
FS209E does not include Class 300 000 and 1 000 000. The values shown are equivalents of the ISO values for ISO Class 8.5 and 9.
E2042/E2042M − 09 (2021)
3.1.9 discrete-particle counter (DPC), n— an instrument,
Airflow Air Filtration Typical Airborne
Particle
such as an optical particle counter or condensation nucleus
Concentration
counter, capable of resolving responses from individual par-
Limits Under
ticles. Operational
Conditions
3.1.10 HEPA filter, n—(high-efficiency particulate air filter)
In Accordance
With
a throwaway, extended-medium, dry-type filter in a rigid
ISO 14644-1
frame, having a minimum particle-collection efficiency of
99.97 % (that is, a maximum particle penetration of 0.03 %)
Type I Unidirectional, formerly HEPA or ULPA Classes less than 7
known as 9laminar filtered with (Classes less
for 0.3-µm particles of thermally generated DOP of specified
flow9 prefilters than 10 000 per
alternative aerosol.
FED-STD-209E)
3.1.11 HVAC, n—heating, ventilating, and air conditioning.
Type II Nonunidirectional, HEPA filtered with Classes 7 to 8.5
formerly known as prefilters (Classes 10 000 to
3.1.12 nonvolatile residue (NVR), n—matter remaining after
“turbulent” flow 300 000 per FED-
solvent containing such matter has been evaporated or cleaned.
STD-209E)
3.1.13 ULPA filter, n—(ultra-low-penetration air filter) a
Type III Nonunidirectional without HEPA or Classes 8 to 8.5
throwaway, extended-medium, dry-type filter in a rigid frame,
ULPA filters but (Classes 100 000
having a minimum particle-collection efficiency of 99.999 % with prefilters to 300 000 per
FED-STD-209E)
(that is, a maximum particle penetration of 0.001 %) for
particles in the size range of 0.1 to 0.2 µm, when tested in 5.2 NVR Concentrations—There are two categories for
NVR requirements in clean areas:
accordance with the methods of IES-RP-CC007.1.
5.2.1 Category I—Critical clean areas that require specific
control and removal of molecular contaminants because of
4. Significance and Use
products that either are very sensitive to NVR or can not be
4.1 This practice identifies methods for cleaning and main-
cleaned. Quantitative NVR measurements may be required as
taining controlled areas and clean rooms as defined by ISO
defined in IEST-STD-CC1246D and IES-RP-CC016. NVR
14644-1 and ISO 14644-2. Cleaning procedures are described,
deposition criteria are defined in Tables 2 and 3.
and cleaning frequency for different classes of facility are
5.2.2 Category II—Standard clean areas that do not require
given. Compliance with this practice will make it easier and
quantitative measurements of NVR. All aerospace clean
morelikelythattherequiredleveloffacilitycleanlinesswillbe
facilities, including support shops for the fabrication of com-
maintained. A cleaner facility also will help to protect flight
ponents for aerospace hardware, must limit the deposition of
hardware from contamination and should reduce the frequency
nonvolatileresidue(NVR),alsoknownasmolecularfilms.The
for cleaning flight hardware. This practice does not discuss
cleaningsuppliesrecommendedinthispracticeareselectedfor
operation and operational procedures for cleanrooms and
the minimal production of NVR.
controlled areas. Other documents such as IEST-RP-CC026
5.2.2.1 Some clean areas require very low levels of NVR to
and Practice E2352 provide recommended practices for oper-
be compatible with product cleanliness requirements. These
ating cleanrooms and controlled areas.
areas require cleaning methods that will remove NVR. The
userwillstatewhenCategoryIisrequiredandallowablelevels
5. Cleanrooms and Clean Zones
of NVR on surfaces, that is, NVR level in accordance with
2 2
5.1 Airborne Particle Concentrations—The types of clean- IEST-STD-CC1246D (µg/cm or mg/0.1 m ). Category II is
rooms and clean zones used in this practice are based on assumed unless Category I is expressly specified.
airflow, air filtration, and airborne particle concentration limits. 5.2.3 NVR Verification—Measurement of NVR in clean
The classification of airborne particle concentration limits in facilities may be done in accordance with Practice E1234 and
cleanrooms, clean zones, and controlled areas are defined in Test Method E1235 or other methods that are compatible with
Table 1 which is based on ISO 14644-1 and ISO 14644-2. the product requirements and types of NVR. Typical NVR
E2042/E2042M − 09 (2021)
TABLE 2 Product Cleanliness Levels for NVR Based on TABLE 3 NVR Rate Levels from IEST-RP-CC016.2
IEST-STD-CC1246D
Maximum Average Deposition Rate Levels
A
NVR Limit
Average
NVR
NVR
Rate of
Surface Volume -2 -1
Rate
Level mg·0.1 m ·mo or
-2 -1B
A pg·m ·s Thickness
mg/0.1 m mg/L
-2 -1C
Level
µg·cm ·mo
Increase
AA5 0.00001
-1D
nm·s
AA4.7 0.00002
0 1.0 E+00 2.4 E-04 1.0 E-09
AA4.3 0.00005
0.6 4.0 E+00 9.7 E-04 4.0 E-09
AA4 0.0001
1 1.0 E+01 2.4 E-03 1.0 E-08
AA3.7 0.0002
1.6 4.0 E+01 9.7 E-03 4.0 E-08
AA3.3 0.0105
2 1.0 E+02 2.4 E-02 1.0 E-07
AA3 0.001
2.6 4.0 E+02 9.7 E-02 4.0 E-07
AA2.7 0.002
3 1.0 E+03 2.4 E-01 1.0 E-06
AA2.3 0.005
3.6 4.0 E+03 9.7 E-01 4.0 E-06
A/100 0.01 0.1
4 1.0 E+04 2.4 E+00 1.0 E-05
A/50 0.02 0.2
4.6 4.0 E+04 9.7 E+00 4.0 E-05
A/20 0.05 0.5
5 1.0 E+05 2.4 E+01 1.0 E-04
A/10 0.1 1.0
5.6 4.0 E+05 9.7 E+01 4.0 E-04
A/5 0.2 2.0
6 1.0 E+06 2.4 E+02 1.0 E-03
A/2 0.5 5.0
6.6 4.0 E+06 9.7 E+02 4.0 E-03
A1.0 10
7 1.0 E+07 2.4 E+03 1.0 E-02
B2.0 20
7.6 4.0 E+07 9.7 E+03 4.0 E-02
C3.0 30
8 1.0 E+08 2.4 E+04 1.0 E-01
D4.0 40
8.6 4.0 E+08 9.7 E+04 4
...