ASHRAE Journal - November 2019 - 50

ASHRAE - CELEBRATING 125 YEARS

TABLE 2 Cleanroom classifications.
the International
ISO
U.S.A.
U.S.A.
U.S.A.
Standards
STANDARD 209A,B
209C
209D
Organization (ISO)
ISO Class 1
established Technical
Committee ISO/
ISO Class 2
TC 209 with a goal
ISO Class 3
1
1
of producing a harISO Class 4
10
10
monization of interISO Class 5
100
100
100
national standards.
ISO Class 6
1,000 1,000
ISO 14644 Parts 1
ISO Class 7 10,000 10,000 10,000
and 2 were issued
ISO Class 8 100,000 100,000 100,000
in 1999, and several
other sections have
ISO Class 9
been issued since.
14644 introduced two cleaner classes and one less clean
class (Table 2). ISO/TC 209 continues to meet and guide
updates and issuing of 14644 documents (Table 3).

U.S.A. BRITAIN BS AUSTRALIA
FRANCE
209E
5295
AS 1386 AFNOR X44101

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JAPAN
JACA

EU
GGMP

ISO
STANDARD

ISO Class 1
-

ISO Class 2

M1.5

0.035

ISO Class 3

M2.5

0.35

ISO Class 4

M3.5

E or F

3.5

4,000

A/B

ISO Class 5

M4.5

G or H

ISO Class 6

M5.5

350

400,000

ISO Class 7

M6.5

3,500

4,000,000

ISO Class 8
ISO Class 9

TABLE 3 ISO 14644 cleanroom standards.
PART 1

Classification of air cleanliness by particle concentration

PART 2

Monitoring to provide evidence of cleanroom performance related to air
cleanliness by particle concentration

PART 3

Test methods

PART 4

Design, construction and start-up

PART 5

Operations

PART 7

Separative devices (clean air hoods, gloveboxes, isolators and minienvironments)

PART 8

Classification of air cleanliness by chemical concentration (ACC)

PART 9

Classification of surface cleanliness by particle concentration

PART 10

Classification of surface cleanliness by chemical concentration

PART 12

Classification of air cleanliness by nanoscale particle concentration

PART 13

Cleaning of surfaces to achieve defined levels of cleanliness in terms of
particle and chemical classifications

PART 14

Assessment of suitability for use of equipment by airborne particle
concentration

PART 15

Assessment of suitability for use of equipment and materials by airborne
chemical concentration

PART 16

Energy Efficiency in Cleanrooms and Clean Air Devices

PART 17

Particle deposition rate applications

Applications and Cleanroom Technology
Cleanroom applications spread quickly to other industries in the 1960s and 1970s, including NASA's space program, transistor and integrated circuit manufacturing,
pharmaceutical manufacturing and hospitals. Dr. Randy
Lovelace and The Bataan Hospital in Albuquerque put
the first "laminar flow" surgical suite into operation during 1966. Dr. E. O. Goodrich, M.D. (St. Vincent's Hospital
in Santa Fe, N.M.) began studies in using a "laminar
flow" operating table module, also in 1966. 1967 saw M.D.
Anderson's chemotherapy treatment center begin experimenting with cleanrooms. Over 300 "laminar flow" systems were being used in hospitals by 1972. Burn centers,
joint replacement surgery and other operations needing
strict aseptic control were all starting to deploy laminar
flow technology. A study of airflow patterns and levels of
airborne contamination at various critical sites in a simulated operating room equipped with a horizontal unidirectional airflow system was published in 1969.23 Medical
device manufacturers and even food packaging facilities
were also adapting cleanroom to their needs.21
Whitfield's development coincided with the introduction of integrated circuits into electronics design and
manufacturing. Based on breakthroughs by Jack Kilby
at Texas Instruments (1958), Robert Noyce and Jean
Hoerni at Fairchild Semiconductor, and Kurt Lehovec
of Sprague Electric Company, the first functional semiconductor integrated circuit was introduced in 1960.
Initially, feature sizes of these integrated devices were

GERMANY
VDI.2083

200 µm, but by 1971 they were 10 µm and less than 1 µm
by the early '80s. The rapid development of new and
more complex integrated circuits required the semiconductor industry to pioneer many new advances in
cleanroom designs, including the multilevel vertical
unidirectional cleanroom capable of achieving Class 1
cleanroom conditions (Table 2).
The 1970s also saw the publication of key good manufacturing practices (GMP) documents. GMPs for drugs

ASHRAE Journal - November 2019

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