Standards - Newsletter
ARE THERE REALLY ANY CLEANROOM STANDARDS
TODAY?
YES…, BUT WHAT DO THEY ACTUALLY MEAN?
Officially on November 29th, 2001, the United States General
Services Administration (GSA) announced that Federal Standard
209E, Airborne Particulate Cleanliness Classes in Cleanrooms
and Clean Zones, has been canceled and is superseded by ISO
Standards for cleanrooms and associated controlled environments.
The new standards are: ISO 14644-1 Classification of air
cleanliness and ISO 14644 –2 Specifications for testing
and monitoring to prove continued compliance with ISO 14644-1.
The GSA, in doing this, has followed the recommendations
made by Institute of Environmental Science and Technology’s
(IEST) Working Group CC-100, chaired by Mr. Richard A. Matthews,
to “sunset” Federal Standard 209E.
For those who are interested, copies of the ISO documents
may be ordered through the IEST web site, www.iest.org
or via e-mail at publicationsales@iest.org.
Vol. 5, No. 1, page 2 March, 2002
As
for this writer, please give me the “old days”
with Federal Standard 209 - A, B, C or E. Those were the days
when you knew what you were dealing with regarding particle
counts, particle count locations and room pressure. With the
adoption of the new ISO standards, today, it's pot luck, “that's
it.”
During the Cleanroom East Show held last March, 2001, at
the World Trade Center in Boston, in order to “see what
was going on” with the new ISO standards and how the
IEST Working Group CC-100 was proposing to address critical
testing concerns, I attended the ISO-14644 Cleanroom Standards
Tutorial T-3, titled: What They Are, What They Mean and How
They Work.
The tutorial lasted about three hours and covered a wide
range of issues regarding ISO-14644. I had attended with the
hope of having all my concerns about these new global specifications
once and for all.
ISO 14644-1 REFERENCE CLEANLINESS CLASSES COMPARED
TO
ENGLISH AND SI CLASSES:
SELECTED AIRBORNE PARTICULATE CLEANLINESS CLASSES
FOR CLEANROOMS AND CLEAN ZONES: The chart below shows the
maximum concentration limits (particles/m3 of air) for airborne
particles equal to and larger than the particle sizes shown.
| ISO CLASS |
ENGLISH
(209 E) |
SI (209 E) |
0.1µm
|
0.2 µm
|
0.3µm
|
0.5 µm
|
1.0 µm
|
5.0 µm |
| 1 |
---
|
---
|
10
|
2 |
---
|
---
|
---
|
--- |
| 2 |
---
|
---
|
100
|
24 |
10 |
4 |
--- |
--- |
| 3 |
1 |
M1.5 |
1,000
|
237 |
102 |
35 |
8 |
--- |
| 4 |
10 |
M2.5 |
10,000 |
2,370 |
1,020 |
352 |
83 |
--- |
| 5 |
100 |
M3.5 |
100,000 |
23,700 |
10,200 |
3,520 |
832 |
29 |
| 6 |
1,000 |
M4.5 |
1,000,000 |
237,000 |
102,000 |
35,520 |
8,320 |
293 |
| 7 |
10,000 |
M5.5 |
--- |
--- |
--- |
355,200 |
83,200 |
2,930 |
| 8 |
100,000 |
M6.5 |
--- |
--- |
--- |
3,520,000
|
832,000
|
29,300 |
| 9 |
--- |
--- |
--- |
--- |
--- |
35,200,000 |
8,320,000 |
293,000 |
1.
µm = Micron
2. Reference class names are from
FEDERAL STANDARD 209E in English and SI units. These
classifications closely approximate the ISO class listed
in the table above. |
Unfortunately, I left more confused about the application of
these new ISO Standards than when I went in. However, to their
credit, the course instructors, Ken Goldstein and Mike Fitzpatrick,
did a superb and intelligent job in teaching a difficult subject.
What I did get out of this seminar was that ISO Documents
14644-1 and 14644-2 will allow you to test “fewer”
locations for cleanliness then Federal Standard 209E and allows
you one outlier. While this term was new to me and seemed
more nautical than technical, in actuality, it's a single
particle count that is excessively high or low. The ISO documents
14644-1 and 14644-2 also establish 0.1 µm as the “standard”
particle diameter, and creates three (3) new cleanliness classes.
Two (2) of these three (3) classes, Class 1 and 2, are “cleaner”
than Federal Standard 209E’s Class 1 and the third (defined
as Class 9) is “dirtier” than Federal Standard
209E’s Class 100,000.
Not one word was said in these new standards about airflow
velocity, room pressure, room temperature, the distance from
the floor or the filter face when taking an air sample for
a particle count. And yet, as we all know, these factors are
crucial in properly certifying the cleanliness level of a
cleanroom–any cleanroom. Barring filter leaks, improperly
mounted filters, gasket depression or holes, the farther the
test is from to the filter media, the higher the particle
count and the dirtier the results.
Vol.
5, No. 1, page 3 March, 2002
Conversely, the closer to the filter media, the lower the
particle count and the cleaner the sample. If I take the particle-count
sample six inches from the filter face, with no holes in the
media or problems with the filter, I’m going to get
either an ISO 144644-1 Class I or Federal Standard 209E Class
1/M1.5 particle count-guaranteed!
They do mention that testing and certification should be
done either at rest, as built or in operation.
In my opinion with no specifications set forth on particle
sampling distances from the floor or the filter face, it makes
no difference at all when testing or certifying whether it’s
at rest, as built or in operation. Again, if a particle count
is sampled 6" from the filter face with no holes in the
media or if these are no problems with the filters, you will
get an ISO 144644-1 Class 1 or Federal Standard 209E Class
1/M1.5 particle count! No air flow velocity is mentioned in
the ISO specification! Talking about making it easy to certify
a room! Wow! Like taking candy from a baby.
When I questioned the course instructors about this matter
they stated it was up to the user and contractor. Huh? If
the user is not fully educated on class certification and
doesn't know what he wants and asks the contractor, what do
you think is going to happen? Some where, some how, too much
will be left to chance. It doesn't make the industry look
very professional.
Our experience has been that many customers calling about
a cleanroom for the first time become very confused with the
mountains of specifications from Federal Standard 209A, B,
C, D and E, Mil Standards, Air Force Tech Orders, IEST Recommended
Practices, NASA Specifications. Where does it end? Well, I
too am confused! It's whatever you want. Right or wrong–or
anywhere in between!
Mr. Richard A. Matthews, chairman of the ISO technical committee
ISO/ TC209, in his series of nine articles which appeared
in CleanRooms Magazine, April thru December of 2000, entitled:
“The ISO Global Cleanroom Standards what do they really
mean?”, wrote how these new ISO Specifications were
the “mother of all standards” and were going to
sunset all the Federal Standard 209's, and everything else
on the block.
Likewise, it seemed that these standards would cure all our
ills in the cleanroom industry. Well, I learned from my course
instructors that, at that point in time, both the GSA and
the FDA have not approved the ISO Standards. I also learned
that the FDA was not even a member of the ISO Technical committee
that had written ISO 14644-1 and 2. And, it may be a year
down the road, possibly two to three years, maybe four or
never before FDA approves the ISO Standards “How's that!”
It goes to show you, you can't believe everything you read
or hear.
I guess, in view of what happened on November 29th, he was
right!
As it turned out, in less than one year from the date of
my seminar, ISO 14644-1 and ISO 14622-2 have become recommended
cleanroom standards.
Vol. 5, No. 1, page 4 March, 2002
Anne Marie Dixon’s article in June 2001 Issue
of Cleanrooms Magazine, “Hurry up and Wait,” stated
that she also wanted to know what was the status of Federal
Standard 209E. Just goes to show you that the industry was
confused. She also stated “As leaders in the field of
cleanrooms, we as a country have become the focus of jokes
in the international community, as the country that leads
but can’t make changes.”
Right or wrong, effective November 29th, 2001 Ms. Dixon has
her answer. Federal Standard 209E has been “put out
to pasture” or more technically, “sunset”
by the GSA! guess, we’ve finally made the change –
for better or worse!
As I said before, for this writer, please give me the “old
days” with Federal Standard - 209A, B, C or E, when
you knew what you were dealing with regarding particle classifications,
air flow velocities, particle counts, particle count locations
and room pressure. Today, it's pot luck, “that's it”.
Writer’s opinion: This is this writer’s opinion
only and not necessarily the opinion of Liberty Industries,
Inc. or it's employees. I don't mean to be sarcastic, but
coming from the old school it makes one think, “What’s
happening here?”
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Cleanroom News™ - Published by John J. Nappi, Jr.
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