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No. 16
PAO (Emery 3004) Liquid
ATI frequently receives many different questions
from customers regarding the use of Emery 3004. This Technical
Bulletin addresses the most frequently asked questions.
EMERY 3004 is a brand name for POLY-ALPHA
OLEFIN (PAO)
4 CST, CAS #68649-12-7. The Henkel Company originally
manufactured the Emery 3004 brand of PAO used in the initial
research performed by Dr. Hugh Carlon et al. ATI carries PAO
in stock for the convenience of its customers. It is sold
in 1 or 5-gallon containers and can be shipped via UPS or
Federal Express. The 5-gallon container has a built in pour
spout to aid customers in filling the aerosol generators.
The US Army Surgeon General has approved
PAO as the official replacement liquid for Di (2-ethylhexyl)
phthalate (DOP, DEHP), CAS #117-81-7. Please note that it
is not up to the liquid manufacturer to approve it for a specific
use. Most government agencies or departments do not approve
anything. For example, PAO is not approved by the Department
of Energy. However the Department of Energy accepts the use
of PAO as a replacement for DOP. In a letter from Robert L.
Sorensen of the Food and Drug Administration to the Director
of Quality Assurance of Eli Lilly and Company he states that
based on submitted documentation, research work, and papers,
the FDA concurs with the military that PAO is an acceptable
replacement for DOP.
There have recently been rumors that PAO
manufactured at different sites are not suitable replacements
for DOP.
The following is an excerpt from the Food
& Drug Administrations Human Drug CGMP Notes (Vol. 4, Number
4), December 1996.
"The original manufacturing site which
produced the Emery 3004 (PAO) for the data submitted has changed
since the study and Emery 3004 (PAO) is now manufactured at
a different site. Discussions with the Army and the companies
involved in the original studies indicate the product remains
the same from the new site of manufacturing. CDER has also
compared the original specifications and the new site specifications
along with data from the Material Safety Data Sheets and agrees
that there is no significant difference in the product from
either site."
"The Chemical Abstracts Service (CAS)
number which identifies this product also remained as 68649-12-7."
"Other reported alternatives used in
the industry include DOS
(Di (2-ethylhexyl) sebacate) and Ondina Oil. However,
no manufacturer has yet submitted all the necessary data to
evaluate these alternatives."
"As such, Emery 3004 PAO
with the CAS number 68649-12-7 still remains an acceptable
replacement for DOP."
Contact for further information:
Michael J. Verdi, HFD-322
Phone: 301-594-0095
E-mail: verdim@cder.fda.gov
The full text of the referenced document
is available at: http://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/Manufacturing/UCM193376.pdf.
Another interesting development ATI feels
its customers should be aware of is that the U.S. Army, in
conjunction with some Government attorneys, has acquired patents
on the use of this liquid to generate aerosols. The first
patent number 5,059,349 was issued on 22 October 1991. This
patent is very specific in nature and covers the use of PAO
and its use as a liquid to generate a monodispersed aerosol
in the ATI TDA-100 Aerosol Penetrometer that is used for measuring
the efficiency of respirator filters. The second patent 5,059,352 was issued on the same date. This particular patent covers
the liquid PAO and its use in a prototype aerosol penetrometer
that is no longer used for performing aerosol filter testing.
The third patent 5,076,965 was issued on 31 December 1991
and covers the use of PAO liquid as the substance in a TSI
model 8110-filter tester.
These three patents really have no application
in the normal in-place filter certification work that is carried
out world wide in the pharmaceutical, electronic, and aerospace
industries, although it is believed that one pharmaceutical
company did pay the Army for a license agreement.
Related Technical Bulletins:
No. 2 - Substitute Liquids for DOP
No. 20 - More Emery vs. DOP (Follow-up
to Technical Bulletin # 16)
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