ASTM E2042-99

Standard Practice for Cleaning and Maintaining Controlled Areas and Clean Rooms

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 The values stated in SI units are to be regarded as the standard.
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-Oct-1999
• 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

• Replaced By: ASTM E2042-04 - Standard Practice for Cleaning and Maintaining Controlled Areas and Clean Rooms
• Effective Date: 01-Apr-2004
• Referred By: ASTM E2352-19 - Standard Practice for Aerospace Cleanrooms and Associated Controlled Environments—Cleanroom Operations
• Effective Date: 10-Oct-1999
• Referred By: ASTM E1548-09(2022) - Standard Practice for Preparation of Aerospace Contamination Control Plans
• Effective Date: 10-Oct-1999
• Referred By: ASTM E2217-12(2019) - Standard Practice for Design and Construction of Aerospace Cleanrooms and Contamination Controlled Areas
• Effective Date: 10-Oct-1999

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E 2042 – 99
Standard Practice for
Cleaning and Maintaining Controlled Areas and Clean
Rooms
This standard is issued under the fixed designation E 2042; 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 Using Instruments Capable of Detecting Single Sub-
Micrometer and Larger Particles
1.1 This practice covers the procedures to be followed for
2.2 IEST Standards:
the initial cleaning and normal maintenance of cleanrooms and
IEST-RP-CC007 Testing ULPA Filters
controlled areas. This practice is applicable to aerospace clean
IEST-RP-CC016 The Rate of Deposition of Nonvolatile
areas where both particles and molecular films (NVR) must be
Residue in Cleanrooms
controlled.
IEST-CC0018.2 Cleanroom Housekeeping and Monitoring
1.2 The values stated in SI units are to be regarded as the
Procedures
standard.
IEST-RP-CC003 Garment System Considerations for
1.3 This standard does not purport to address all of the
Cleanrooms and Other Controlled Environments
safety concerns, if any, associated with its use. It is the
2.3 US Federal Standards:
responsibility of the user of this standard to establish appro-
FED-STD-209 Airborne Particulate Cleanliness Classes in
priate safety and health practices and determine the applica-
Cleanrooms and Clean Zones
bility of regulatory limitations prior to use.
TT-I-735 Isopropyl Alcohol
2. Referenced Documents
O-A-51 Acetone
2.4 US Department of Defense Standards:
2.1 ASTM Standards:
MIL-STD-1246C Product Cleanliness Levels and Contami-
D 1193 Specification for Reagent Water
nation Control Program
E 1234 Practice for Handling, Transporting, and Installing
T.O. 00-25-203 Contamination Control of Aerospace Facili-
Nonvolatile Residue (NVR) Plates Used in Environmen-
ties, U.S. Air Force
tally Controlled Areas for Spacecraft
MIL-D-16791 Detergents, General Purpose (Liquid, Non-
E 1235 Test Method for Gravimetric Determination of Non-
Ionic)
volatile Residue (NVR) in Environmentally Controlled
Areas for Spacecraft
3. Terminology
E 1549 Specification for ESD Controlled Garments Re-
3.1 Definitions of Terms Specific to This Standard:
quired in Cleanrooms and Controlled Environments for
3 3.1.1 clean zone, n—a defined space in which the concen-
Spacecraft for Non-Hazardous and Hazardous Operations
tration of airborne particles is controlled to specified limits.
E 1560 Test Method for Gravimetric Determination of Non-
3 3.1.2 cleanroom, n—a room in which the air filtration, air
volatile Residue from Cleanroom Wipers
distribution, utilities, materials of construction, equipment, and
F 24 Method for Measuring and Counting Particulate Con-
4 operating procedures are specified and regulated to control
tamination on Surfaces
airborne particle concentrations to meet appropriate airborne
F 25 Test Method for Sizing and Counting Airborne Par-
particulate cleanliness classifications, as defined by FED-STD-
ticulate Contamination in Clean Rooms and Other Dust-
209.
Controlled Areas Designed for Electronic and Similar
3.1.3 cleanroom, as-built, n—a cleanroom that is complete
Applications
and ready for operation, with all services connected and
F 50 Practice for Continuous Sizing and Counting of Air-
functional, but without equipment or operating personnel in the
borne Particles in Dust-Controlled Areas and Clean Rooms
room.
3.1.4 cleanroom, at-rest, n—a cleanroom that is complete,
This practice is under the jurisdiction of ASTM Committee E-21 on Space
with all services functioning and with equipment installed and
Simulation and is the direct responsibility of Subcommittee E21.05 on Contamina-
tion.
Current edition approved Oct. 10, 1999. Published February 2000.
2 5
Annual Book of ASTM Standards, Vol 11.01. Available from IEST, 940 E. Northwest Highway, Mount Prospect, IL 60056.
3 6
Annual Book of ASTM Standards, Vol 15.03. Available from Superintendent of Documents, US Government Printing Office,
Discontinued; see 1992 Annual Book of ASTM Standards, Vol 15.03. Washington, DC 20402.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 2042
operable or operating, as specified, but without operating cleaner facility also will help to protect flight hardware from
personnel in the room. contamination and should reduce the frequency for cleaning
3.1.5 cleanroom, operational, n—a cleanroom in normal flight hardware.
operation, with all services functioning and with equipment
and personnel, if applicable, present and performing their
5. Cleanrooms and Clean Zones
normal work functions in the room.
5.1 Airborne Particle Concentrations—The types of clean-
3.1.6 clean facility, n—the total real property required to
rooms and clean zones used in this practice are based on
accomplish the cleanroom functions.
airflow, air filtration, and airborne particle concentration limits.
3.1.6.1 Discussion—In addition to the cleanroom and asso-
The classification of airborne particle concentration limits in
ciated clean areas, this includes utility rooms, storage areas,
cleanrooms, clean zones, and controlled areas are defined in
offices, lockers, wash-rooms, and other areas that do not
Table 1 which is based on FED-STD-209.
necessarily require precise environmental control.
Airflow Air Filtration Typical Airborne Par-
3.1.7 controlled area, n—an environmentally controlled
ticle Concentration
area, operated as a cleanroom, but without the final stage of
Limits Under Opera-
tional Conditions In
HEPA filters.
Accordance With
3.1.7.1 Discussion—Only rough filters (50 to 60 % effi-
FED-STD-209
ciency) and medium efficiency filters (80 to 85 % efficiency)
Type I Unidirectional, formerly HEPA or ULPA Classes less than M
are required for a controlled area. The maximum allowable
known as 9laminar filtered with 5.5 (Classes less
airborne particle concentrations are Class M 7 (283 000) for
flow9 prefilters than 10 000)
particles M 0.5 μm and Class M 6.5 (100 000) for particles M
Type II Nonunidirectional, HEPA filtered with Classes M 5.5 to M 7
5.0 μm. This limit, for sizes M 5.0 μm, is 24 700 particles/m
formerly known as prefilters (Classes 10 000 to
or 700 particles/ft .
9turbulent9 flow 283 000)
3.1.8 DI water, n—deionized water.
Type III Nonunidirectional without HEPA or Classes M 6.5 to 7
3.1.9 discrete-particle counter (DPC), n—an instrument,
ULPA filters but (Classes 100 000
such as an optical particle counter or condensation nucleus
with prefilters to 283 000)
counter, capable of resolving responses from individual par-
5.2 NVR Concentrations—There are two categories for
ticles.
NVR requirements in clean areas:
3.1.10 HEPA filter, n—(high-efficiency particulate air filter)
5.2.1 Category I—Critical clean areas that require specific
a throwaway, extended-medium, dry-type filter in a rigid
frame, having a minimum particle-collection efficiency of control and removal of molecular contaminants because of
products that either are very sensitive to NVR or can not be
99.97 % (that is, a maximum particle penetration of 0.03 %)
for 0.3-μm particles of thermally generated DOP of specified cleaned. Quantitative NVR measurements may be required as
defined in MIL-STD-1246 and IES-RP-CC-016.1. NVR depo-
alternative aerosol.
sition criteria are defined in Tables 2 and 3.
3.1.11 HVAC, n—heating, ventilating, and air conditioning.
3.1.12 ULPA filter, n—(ultra-low-penetration air filter) a
5.2.2 Category II—Standard clean areas that do not require
throwaway, extended-medium, dry-type filter in a rigid frame,
quantitative measurements of NVR. All aerospace clean facili-
having a minimum particle-collection efficiency of 99.999 %
ties, including support shops for the fabrication of components
(that is, a maximum particle penetration of 0.001 %) for
for aerospace hardware, must limit the deposition of nonvola-
particles in the size range of 0.1 to 0.2 μm, when tested in
tile residue (NVR), also known as molecular films. The
accordance with the methods of IES-RP-CC007.1.
cleaning supplies recommended in this practice are selected for
the minimal production of NVR.
4. Significance and Use
5.2.2.1 Some clean areas require very low levels of NVR to
4.1 This practice identifies methods for cleaning and main- be compatible with product cleanliness requirements. These
taining controlled areas and clean rooms as defined by FED- areas require cleaning methods that will remove NVR. The
STD-209. Cleaning procedures are described, and cleaning user will state when Category I is required and alowable levels
frequency for different classes of facility are given. Compli- of NVR on surfaces, that is, NVR level in accordance with
2 2
ance with this practice will make it easier and more likely that MIL-STD-1246 (μg/cm or mg/0.1 m ). Category II is assumed
the required level of facility cleanliness will be maintained. A unless Category I is expressly specified.
TABLE 1 Airborne Particulate Cleanliness Classes
Class Name 0.1 0.2 Class Units 0.5 5
3 3 3 3 3 3 3 3 3 3
SI English (m ) (ft)(m ) (ft)(m ) (ft)(m ) (ft)(m ) (ft )
M1 350 9.91 75.5 2.14 30.9 0.875 10.0 0.283 . . . . . .
M1.5 1 1240 35.0 265 7.50 106 3.00 35.3 1.00 . . . . . .
M2 3500 99.1 757 21.40 309 8.75 100 2.83 . . . . . .
M2.5 10 12400 350 2650 75.0 1060 30.0 353 10.0 . . . . . .
M3 35000 991 7570 214 3090 87.5 1000 28.3 . . . . . .
M3.5 100 . . . . . . 26500 750 10600 300 3530 100 . . . . . .
E 2042
TABLE 2 Product Cleanliness Levels for NVR Based on MIL-
6.5 Deionized Water, shall have a minimum resistance of
STD-1246C
50 000 ohms and be filtered to remove all particles greater than
A
NVR Limit
30 μm in size. Total solids (both dissolved and undissolved)
NVR Level
Surface Volume
shall not exceed 25 ppm.
mg/0.1 m mg/L 11
6.6 Non-Ionic Detergent, MIL-D-16791, Type 1.
A/100 0.01 0.1
6.7 Isopropyl Alcohol, TT-I-735, Grade A.
A/50 0.02 0.2
6.8 Acetone, ACS reagent STD11 or Federal Specification
A/20 0.05 0.5
O-A-51.
A/10 0.1 1.0
A/5 0.2 2.0
6.9 Buckets, food grade, stainless steel or polypropylene or
A/2 0.5 5.0
polyethylene. Buckets with two compartments are recom-
A 1.0 10
mended.
B 2.0 20
C 3.0 30
6.10 Mop, synthetic sponge head, roller type, with corrosion
D 4.0 40
resistant handle and mechanism; or polyvinyl acetate string
E 5.0 50
F 7.0 70 mop.
G 10.0 100
6.11 Vacuum Cleaning System—Either a central facility
H 15.0 150
with vacuum outlets in the cleanroom or a portable, HEPA-
J 25.0 250
filtered, cleanroom vacuum with filters that have not been
A 2 2 2
1 mg/0.1m 5 1 μg/cm 5 0.929 mg/ft 5 10-nm-thick uniform film (r5 1
tested with DOP or other volatile aerosols.
g/cm ).
6.12 Tacky Roll Mop, for cleaning walls and ceiling.
(Warning—Tacky roll mops can generate a static discharge
TABLE 3 NVR Deposition Rates in Cleanrooms From IES-RP-
CC016.1 and may be unsuitable in the presence of ESD sensitive items.)
Maximum Average Deposition Rate
–2 –1A 7. Cleaning
NVR Rate Level mg·0.1 m ·month
7.1 Four types of cleaning operations are performed before
I 0.10
II 0.30
clean operations can begin in cleanrooms: construction, pre-
III 1.0
liminary, gross or primary, and final or precision cleaning.
IV 3.0
7.2 A new facility must proceed through all four stages of
V10
A cleaning.
Month 5 four weeks.
7.3 If a cleanroom has been operated previously but has
been shut down, has been decertified due to contamination, or
is visibly dirty when observed from a distance of 2 to3m(6
5.2.3 NVR Verification—Measurement of NVR in clean
to 9 ft) under normal room illumination, then both gross and
facilities may be done in accordance with Practice E 1234 and
final cleaning must be performed.
Test Method E 1235 or other methods that are compatible with
7.4 If a cleanroom that is in operation has been cleaned and
the product requirements and types of NVR. Typical NVR
meets current requirements but must be certified to a more
compounds that are found in cleanrooms include hydrocar-
stringent requirement then only a final cleaning is required.
bons, esters, and silicones.
The final cleaning operations shall be continued until the
requirements are met.
6. Materials Used
7.5 Construction/Renovation Cleaning:
6.1 Wipers, Cleanroom, polyester or cellulose, low NVR
7 7.5.1 Cleaning during the construction has been found to
and low particle generation.
improve significantly the cleanliness within cleanrooms when
6.2 Gloves, Cleanroom, polyurethane, nitrile or latex.
9 they are placed in operation.
6.3 Gloves, Cleanroom, lint and powder free, latex.
7.5.2 Construction shall be complete before the start of
6.4 Coveralls, Hoods, Shoe Covers.
preliminary cleaning. Construction includes the installation of
any utilities, sprinkler heads, penetrations, and all other per-
manent installations.
The sole source of supply of the apparatus known to the committee at this time
7.5.3 Debris and dust shall be removed frequently to pre-
is Miracle Wipe 4000, Texwipe Alpha Wipe, Texwipe Alpha 10, Texwipe/ICP TX
vent deterioration of room surfaces as a result of abrasion or
4012, Anticon 100, Allter Al Sorb. If you are aware of alternative suppliers, please
provide this information to ASTM Headquarters. Your comments will receive
careful consideration at a meeting of the responsible technical committee, which
you may attend.
8 11
The sole sources of supply of the apparatus known to the committee at this time The sole source of supply of the apparatus known to the committee at this time
are Pioneer Trionic E-194, QRP Q095, Q125, and Q145 (according to length) and is Van Waters and Rogers 9N9 and GAF Corp. Igepal CO-630. If you are aware of
27G-2700 (conductive) and Ansell-Edmont Nitrile. If you are aware of alternative alternative suppliers, please provide this information to ASTM Headquarters. Your
suppliers, please provide this information to ASTM Headquarters. Your comments comments will receive careful consideration at a meeting of the responsible
will receive careful consideration at a meeting of the responsible technical technical committee, which you may attend.
committee, which you may attend. The sole source of supply of the apparatus known to the committee at this time
Any available source not packaged in pink poly or other material that can is Hako Minuteman KX series with filtered motor cooling air and Nilfisk GS series
transfer molecular contaminants. or Tornado Model 320. If you are aware of alternative suppliers, please provide this
Garments worn for maintenance should be the same type and quality as those information to ASTM Headquarters. Your
...