United States
                           Environmental Protection
                             Office Of Air Quality
                             Planning And Standards
                             Research Triangle Park, NC 27711
Volume VI, No. 2
Spring 1995
                           THE CHIEF

                              PAST  AP-4E  EMISSION  FACTORS:
                    "To BOLDLY  Go  WHERE No  ONE HAS  GONG BEFORE"
    Many people assume that AP-42 has all the answers to
questions about estimating air emissions from a source cat-
egory (or even specific source).  Although that is giving this
most excellent document more credit than it is due, you can use
AP-42 emission factors to estimate emissions when specific
source test information is not available from the source or an
almost identical source. Under ideal conditions all of the needed
emission factors are in the section that addresses the source
category from whichyou are trying to estimate emissions. This
use of the process specific emission factor would result in an
estimate that is potentially in error by the inherent variability of
the AP-42 emission factor. This variability is dependent on the
process  and the representativeness of the data used to  de-
velop the emissionfactor.  However, the usual situation is that
some of the emission points or pollutants that you are trying to
estimate emissions for are not in the section.
    By accepting the risk of additional error, emission esti-
mates can sometimes be made by using emission factors for
other process sources that are in AP-42. A good working knowl-
edge of the physical characteristics of the processes that are
being compared is needed. For example, the paniculate emis-
sions from different types of dryers would depend on the mate-
rial being dried and the fuel used to supply the heat. A process
that dried fabric using indirect heat from a process (using heat
exchangers) would have significantly different emissions from
a process that was drying a crushed mineral using direct heat
from pulverized coal combustion. As a result, emissionfactors
for these two processes would not be interchangeable.
    Following an investigation of the key operating and physi-
cal characteristics of a process, the known characteristics of
potential similar sources  should be obtained.  This type of
                           information is sometimes available in the process description
                           for the individual source categories. Other available resources
                           are the compliance inspectors or other individuals that have
                           visited the source categories that are believed to be similar.
                           Generally, all of the information that is available on the source
                           category is published in either the AP-42 section or the back-
                           ground report for the section. In addition, any usable informa-
                           tion that is not in a final AP-42 section is available on the
                           CHIEF BBS under "Draft Sections Under Review." There-
                           fore, calling the person responsible for the development of the
                           section would not reveal any additional relevant information.
                           If a suitable contact person is not known, posting a message to
                           the CHIEF BBS public message board may reveal a suitable
                           contact to get more detailed process information or a person
                           that has already done all of the work to identify the best surro-
                           gate for the process being evaluated.
                               A simple checklist can be assembled to compare the pro-
                           cess of interest to all the potential surrogates that have been
                           identified.  The pertinent variables should be listed below the
                           surrogate processes in approximate importance. Then a quali-
                           tative comparison with the process of interest should be made
                           to identify whether the surrogate process is estimated to have
                           lower, higher or  about the same  emissions as the process of
                           interest.  This is where your homework into the process condi-
                           tions becomes most important. The choice of what surrogate
                           emission factor should be used is a matter of selecting the best
                           fit from the surrogate possibilities. This will also allow you to
                           evaluate whether your choice is an under estimate or an over
                           estimate. You may wish to make adjustments to the factor to
                           make the estimate closer to whatyoubelieve is the most appro-
                           priate (or to provide some margin of safety).
                                 THE AP-42 FIFTH EDITION Is DONE!
        After months of anticipation, the Fifth Edition is now on both the CJHZEFBBS and the Fax CHIEF, It will be
     available on the Air CHIEF CD-ROM by early June and on paper by the end of June.
        Call Info CHIEF, (919) 541-5285, for more information. Order paper copies now from the Government Printing
     Office, (202) 512-1800, StockNo. 055-000-00500-1, price $56:00,

(Cont. from p. 1)

    The following example will illustrate the above methodology:
    You are asked to estimate PM-10, NO and CO emissions from two product dryers at a plant. The same product is being dried
by the two dryers. However, one of the driers uses oil or gas to dry the product and the other dryer uses waste heat from another
process at the plant.  The product that is being dried is a material that has been sized to a powder, 90 percent of which will pass
through a 100 mesh screen. The material entering the dryer has been de-watered mechanically with a typical residual moisture
content of 5 percent.  After drying, the moisture content of the product is less than !/2 percent. The product is not physically or
chemically changed as a result of the drying. The dryer is an inclined rotary kiln that is fired counter current to the product flow.
The drier that is fossil fuel fired uses a combinationburner firing either number 2 fuel oil, natural gas or a combination of both. One
gallon of fuel oil, or 131 cubic feet of gas, can dry approximately one ton of product.
    Although your process is not included in AP-42, there are similar processes in AP-42 where there are emission factors.  These
processes include portland cement manufacturing (wet process or long dry process), lime manufacturing (gas fired), batch mix hot
mix asphalt (HMA) production, taconite ore processing (indurating furnace), phosphate rock processing (dryer),  oil combustion
and gas combustion.  The closest process for these sources in AP-42 has the information shown in Table 1:
             TABLE 1.
                            Emission factors for processes with similar characteristics to dryers evaluated.
Portland Cement Manufacturing
(wet process)
Portland Cement Manufacturing
(long dry process)
Lime Manufacturing
HMA Production (gas fired)
HMA Production (oilfired)
Taconite Ore Processing
Phosphate Rock Processing
Oil Combustion (fuel basis)
Oil Combustion (process basis)
Gas Combustion (fuel basis)
Gas Combustion (process basis)
Filterable Particulate
(.004 condensable)
(.045 condensable)
2 Ib/gal
2 Ib/ton
4.5 Ib/MMcf
0.006 Ib/ton
Filterable PM-10
(.004 condensable)
(.045 condensable)
1 Ib/gal
1 Ib/ton
4.5 Ib/MMcf
0.006 Ib/ton
20 Ib/gal
20 Ib/ton
100 Ib/MMcf
0.13 Ib/ton
5 Ib/gal
5 Ib/ton
0.03 Ib/ton
              ND = No Data

    In evaluating the processes for similarities with the process being estimated, the following characteristics are known:

Portland Cement Manufacturing - Both processes are coal fired and the raw material is physically and chemically changed in the
process.  The process reaches very high temperatures and although a significant amount of heat is reused in the process to
conserve fuel probably more fuel is combusted than would be necessary for drying the material.  Therefore, the combustion
products NO  and CO, are not similarto the dryer of concern. However, the raw material feed to the process is either in the form
of a slurry or a finely divided dry material, so that the paniculate emissions may be physically carried out of the process in a
manner similar to the dryers in question.

Lime Manufacturing - The process of manufacturing lime is very similar to portland cement manufacturing. Although the
emission factor is for gas fired kilns, the combustion conditions are similar to those of portland cement manufacturing and
therefore not reflective of the process in question.  However, like portland cement manufacturing, the raw material feed to the
process is either in the form of a slurry or a finely divided dry material, so that the paniculate emissions may be physically carried
out of the process in a manner similar to the dryers in question.

Hot Mix Asphalt Manufacturing - Batch mix asphalt plants heat a mixture of aggregate to a relatively warm temperature so that the
mixture when combined with asphalt will stay formable after transport. The aggregate mixture contains a relatively high percent-
age of fines (< 75|jM physical diameter) but may also contain material up to 3/4 inch in diameter.  The moisture content of the
aggregate is typically  1 l/i percent or less. As a result of the larger material being contained in the batch plant aggregate these
factors may underestimate the particulate emissions from the process being evaluated. However, the combustion conditions may
(Cont. on p. 3)

(Cont.fromp. 2)
 be similar to the dryer being evaluated since the higher temperatures encountered in the batch mix plant are compensated by the
lower moisture content of the feed material.

Phosphate Rock Processing - Dryers at phosphate rock plants would not estimate paniculate emissions from the dryers of
concern since the material smaller than 150 mesh is removed from the raw feed material and sent to a tailings pile.

Oil Combustion and Gas Combustion - Since no material is being dried these factors would not be suitable choices for estimating
the particulate emissions from the dryers of concern. However, the products of combustion (NOx, CO, TOC, CO2 and SO2) should
always be considered when evaluating any combustion source. It should be remembered that the emission factors are for
combustion in a water boiler and therefore the combustion conditions will be significantly different from many direct fired process
    A selection process that uses the above information may be performed for evaluating the various process similarities. The
evaluations of the similarities are entered into a simple table with estimates as to whether each process would underestimate,
overestimate or be reflective of the process being evaluated. The tables 2, 3 and 4 illustrate the methodology for this example.
                   Table 2. Evaluation of similarities of processes forPM-10.
PM-1 0 evaluation

Portland Cement
Lime Manufacturing
Hot Mix Asphalt
Taconite Ore
Phosphate Rock
Oil Combustion
Gas Combustion
Characteristic Evaluated
Physical Process
Number of Good Matches
1/1 1 II
I/I 1 1 1
(Cont. on p. 4)
                   Table 3. Evaluation of similarities of processes for NOt.
NOX evaluation

Portland Cement
Lime Manufacturing
Hot Mix Asphalt
Taconite Ore
Phosphate Rock
Oil Combustion
Gas Combustion
Characteristic Evaluated
Physical Process
Number of Good Matches
01 —
01 —
                   Table 4. Evaluation of similarities of processes for CO.
CO evaluation

Portland Cement
Lime Manufacturing
Hot Mix Asphalt
Taconite Ore
Phosphate Rock
Oil Combustion
Gas Combustion
Characteristic Evaluated
Physical Process
Number of Good Matches
01 —
01 —

(Cont. from p. 3)

    As can be seen in the evaluations for paniculate, any of
the paniculate emission factors forportland cement manufac-
turing or lime manufacturing may be appropriate choices, con-
sidering that there are two good matches and only two situa-
tions where factor may be underestimates. However, given the
uncertainty of the estimates, a value of 200 Ib of total particu-
late and 30 Ib of total PM-10 is chosen. Since hot mix asphalt
production is the only process which has an estimate of con-
densable emissions, those factors would be used if a very effi-
cient (99 percent or better) air pollution control device were
installed. The emission factors for NO and CO from the hot
mix asphalt production are selected because the firing condi-
tions appear similar to the process of concern and had the
highest ratings in the tables. &

        The Winter 1995 CHIEF Newsletter incorrectly
    lists Henry Feingersh as the Region II contact for O3
    /CO Inventory.  The contact should be Demian Ellis,
    (212) 637-4249.

        The new Region III contact is Rose Quinto, (215)
    597-9800 ext 3164.

        The PM-10 contact name forRegion X was mis-
    spelled. It should read: Rindy Ramos, (202) 553-6510.
                 WE HEAR You!

        A recent issue asked you to tell us what source
     categories you'd most like to see addressed in
     AP-42,  The most frequently mentioned topic was
     "Welding", and we're glad to report that a new sec-
     tion on this activity is includedin the emergent Fifth
     Edition. This section is already on the CHIEFBB&.
     Also mentioned was "Electroplating And Metal Fin-
     ishing", now onthe CHZEFBBS indraft form,
        We do like your comments and suggestions,
     and we try to comply. Thanks for letting us know.

    Due to the influx of inquiries regarding the 1990 Clean Air
Act Amendments Title V Permits, the Emission Factor And In-
ventory Group has seen an increase in client support. In March
1995, the CHIEF Bulletin Board System (BBS) was accessed
over 5,400 times by 3,000 users. These users downloaded over
7,200 files, making it the second most used BBS out of seven-
teen bulletin board systems on the OAQPS TTN! Fax CHIEF,
our automated document delivery service, was accessed 655
times to successfully transmit 924 AP-42 sections or guidance
papers to end users.  The Info CHIEFhslp desk responded to
965 phone calls and the EPA technical staff responded to 485
phone calls, for a grand total of 1,450 phone calls among eight
individual staff members!
    We apologize for any frustrations you may encounter when
trying to contact us, but as you can see, we are keeping very
busy with requests for information. We encourage you to uti-
lize the CHIEFBBS and Fax CHIEF services before coming
to us with technical questions, but the Info CHIEF help desk
is always available whenyou need technical assistance, (919)
541-5285. &

    An Emissions Data Reporting Options Paper was distrib-
uted for comment in December 1994. The comments were com-
piled and summarized and are on the CHIEF BBS under the
"Factor & Inventory Information, Important Memos & Letters"
menu item.  The file name is EM-OP-CM.  Thirty-two people
provided comments representing seven EPA Headquarters
groups, eight EPA Regional Offices, four state and two local air
pollution agencies.  The insights provided by the reviewers
will help EPA's understanding of the issues that impact both
providers and users of emissions information. Concerns rang-
ing from the burden placed on data providers to the  utility of
the information for data users will be taken into consideration
as EPA evaluates methods for obtaining emissions  informa-
tion. EPA management is being briefed on the comments and
the Work Group will be meeting to decide on the next steps for
the rulemaking effort. jeH
            OCTOBER 10-13, 1995 ~ RALEIGH, NC

       The Emission Inventory: Programs And Progress,
    an international specialty conference sponsored by the
    Air & Waste Management Association and the U. S.
    EPA has been rescheduled to be held October 10-13,
    1995 in Raleigh. The conference will address the de-
    velopment, use and improvement of emission invento-
    ries, and will focus on evolving methods and issues in
    the inventory development process. Papers are invited
    for this conference and will be accepted until May 15.
    For mo re information regarding paper submittals,
    contact Garry Brooks, (919) 461-1360 or fax, (919)

                                    QUESTIONS & ANSWERS
        In the Fall 1994 issue of the CHIEF Newsletter, we asked for readers' questions and comments concerning emission
estimation tools. Here are some questions our readers asked with answers from the Info CHIEFhelp desk.
Q:  May we get a copy of FIRE for Microsoft Windows®!

A: The latest version (3.0) of the Factor Information Retrieval
System (FIRE) operates under the Microsoft9 (MS) Disk Op-
erating System (DOS). Although FIRE is aMS-DOS program,
it contains a user interface which simulates a Windows envi-
ronment—including pull-down menus and mouse capabilities.
Plans for a Windows®version of FIRE have been delayed, but
this new format may appear as early as Spring 1996. Nonethe-
less, youcan always download the latest version of FIRE from
the CHIEF BBS under the "AP-42/E F Guidance" menu item.

Q:  When will the Air CHIEF CD-ROM, which includes the
Fifth Edition of AP-42, be available, and how much will it cost?

A: The Air CHIEF CD-ROM version4.0 should be available
by July 1995 from the U. S. Government Printing Office (GPO),
(202) 512-1800.  Costhasnotyetbeendeterminedbut we esti-
mate that it will be about $20. This version of Air CHIEF will
require Microsoft Windows® and will include the Fifth Edition
of AP-42, several AP-42 background reports, plus FIRE, all
Locating & Estimating (L & E) documents, the Source Classi-
fication Codes (SCC), Standard Industrial Codes (SIC), and the
Registry Of Toxic Effects Of Chemical  Substances (RTECS)
Synonym list.

Q:  Should not there be some type of table of contents file that
one can read for the AP-42 on the CHIEFBBS?  Right now, if
you do not know the section numbers, you do not know which
section to download.

A: Each of the AP-42 files on the CHIEFBBS includes a short
title description  along with the file name, so location of the
section you need should be fairly easy. AP-42 is  structured so
that each chapter pertains to a general type of industry, such as
"Evaporation Loss Sources" or "Metallurgical Industry", and
sections within each chapter pertain to particular industry pro-
cesses, such as "Surface Coating" or "Ferroalloy Production".
When using the  CHIEF BBS to obtain AP-42 sections, you
will go through a series of menus, the first of which lists each
chapter and its short title.  Just select the  general industry
category of your choice to get a more detailed list of the sec-
tions within each chapter. From this menu, you can select the
specific industry process of your choice by the short title de-
scription for each section.
     If you would like to see a hard copy of the AP-42 table of
contents, you can call Fax  CHIEF from your fax machine,
(919) 541-5626 or -0548, and select document number "1" to
have the table of contents faxed to you.  Call Info CHIEF for
further details.
Q:  When are the services of the CHIEF BBS going to be
available through the Internet?

A: The Office of Air Quality Planning and Standards (OAQPS)
Technology Transfer Network (TTN), of which the CHIEF BBS
is a part, has been accessible through the Internet for some
time now. You can connect to the OAQPS TTNby using TEL-
NET, a protocol or software that allows your computer to com-
municate with the TTN Internet host.
    Unfortunately, not all types of TELNET interfaces allow
the user to download most files (binary files) from the TTN,
although ASCII text files can usually be downloaded or "cap-
tured".  In order to be able to download binary files using
TELNET, you must either have a KERMIT protocol or a slip
account. KERMIT is a protocol that allows binary file transfers
between your terminal and the Internet host server.  A slip
account is a serial line interface protocol that allows you to dial
into your Internet host through a modem and uses the proto-
cols associated with the modem communication software. Check
your computer system setup or contact your computer system
administrator to see if either of these options are available to
    Many sites on the Internet are known as File Transfer Pro-
tocol (FTP) sites, which are data file servers that allow both
ASCII and binary file downloads by remote Internet users. Plans
are in effect to create an FTP site for the  OAQPS TTN, which
would alleviate the current barriers for  downloading, but no
date has been set for its completion.   If you would like to try
accessing the CHIEFBBS through the Internet, TELNET to

Q:  How can I obtain the L & E document series? How much
will it cost?

A: All of the L & E documents, a guidance series for locating
and estimating sources of specific toxic air pollutants, are
available from the National Technical  Information Service
(NTIS),  1-800-553-6847.  The cost of each of these documents
varies and is determined by NTIS.   Many of the recent or
"popular" L & Es may be downloaded from the CHIEFBBS,
which is accessible via modem, (919) 541-5742 or via Internet
(see above).  They are also available on the Air CHIEF CD-
ROM.  If you would like more information about the L & E
documents, contact Info CHIEF.  j@$
     Info CHIEF
      Help  Desk
  (919)  541-5285

                                 EFIG EMISSION ESTIMATION TOOLS
                                            •  STATUS UPDATE-
AP-42:  The Fifth Edition Compilation Of Air Pollutant Emission Factors (AP-42) is now in its final stages of editing and
reformatting. In April it was ready to go to the Government Printing Office for printing in its 2,017 pages of "glory." It normally
takes 8 weeks for printing, and a few days for distribution and stocking, so it should be on sale in the GPO sales offices and mail
order by July 1,1995.  The price will be $56 per copy, which will include all information and updates published to date, along with
materials that have been residing on the CHIEF Bulletin Board System (BBS) and Fax CHIEF since Supplement F.

FIRE: The Factor Information Retrieval System (FIRE) is being updated sequentially with AP-42. New criteria, toxic/hazardous
and global warming factors are being included. Currently, the files are being cross-checked with the AP-42 files to verify that they
present the same factor for the same process, and that Source Classification Codes have been properly defined/transferred. Any
corrections or deletions of out of date information in FIRE should be completed soon. The criteria and toxics modules will be
updated then, but global factors will not be completely updated till mid-summer' 95. The FIRE files on the CHIEF BB S will
continue to be updatedperiodically, no less frequently than annually, but not likely to be updated more than two or three times per
year. Hopefully, AIRS will be modified to take machine loaded updates from FIRE within a year or so.

Source Classification Codes (SCO: The latest SCC file is now located on CHIEF and can be accessed interactively.  Ron Ryan
updates the file approximately quarterly. The updated SCCs are also given to AIRS for updating into the AFS, which is now
viewed as the "official" file.

SCC/Factor Report: There continues to be demand for a hard copy list of emission factors and SCCs. FIRE will be used to
produce a hard copy document for criteria pollutants by about June '95, which will resemble the old AFSEF report last produced
several years ago. Many changes have been made since then. This report may also go on the CHIEFBBS for downloading, if

Air CHIEF CD-ROM: The Air CHIEF CD-ROM will be improved with a new search engine (Folio VIEWS®*), which will make
searches easier and quicker.  The initiation of the pressing of the delayed CD-ROM has awaited the completion of the final
electronic files for the 5th Edition of AP-42, quality assurances/corrections of FIRE, and other components.  New Locating &
Estimating... documents issued since the last version will be included. The new version (4.0) will be produced and sold by GPO
and is planned forrelease in June 1995, at a cost of $18.

TANKS: The software for calculating emissions from organic liquid storage vessels is now being updated and  improved to
include new seal factors and other technical improvements. The new software is to be completed by early summer and put on the
CHIEF BBS. This new version of TANKS is not expected to be available in time to be included in the Air CHIEF CD-ROM
version 4.0, though the current MS-DOS version will be included for downloading to one's hard drive.

CHIEF BBS and Fax CHIEF: The CHIEF section of the TTN electronic bulletinboard and the "faxback" device we call Fax
CHIEF will continue to be major vehicles for disseminationof information and updated emissionfactors. We continue to "push"
our clients to help themselves with these services rather than calling our staff who are overburdened with 500 or more calls per
month wanting emission factor assistance. All updates to AP-42 are first put on the CHIEFBBS and Fax CHIEF and are final
sections before they are accumulated periodically and printed (usally on an annual basis) in paper form.

APTI Satellite Training: On April 26,1995, there was a satellite down link to the APTI/NC State centers established around the
country for a session aimed at assisting the states put together information packages on emission estimation that they can pass
to industry, etc. for permit purposes. Our tools were discussed as well as other methods of estimation, and other issues related
to permits.  The audience was composed of both inventory and permit personnel.  Industry  representatives were admitted as
space was available.  The crux of the presentation was to get the users of the information to go to documents, CHIEFBBS, Fox
CHIEF, FIRE, TANKS, etc. as much as possible without calling the EFIG staff.  e$


    This month I have a plea. The EPA AP-42 Team has been
responding to over 450 telephone calls a month related to esti-
mation of emissions for permits. Our limited staff is sympa-
thetic with the needs of all of our clients, but we cannot do
productive work to  improve emission factors and other tools
that we produce while responding to telephone calls.  Please
review the references, review the background documents, check
the CHIEF BBS for any related questions and answers that
others may have generated, and take every effort possible prior
to callingthe staff regarding a specific factor. Chances are that
if we have the information, we will have already published it
somewhere in the tools we have.  Also, if you do need to con-
tact us directly, first put a question on the CH7EFBBS. These
messages are easier to respond to efficiently and make it easier
to share the question and answer with others. If you do place
a phone call and get someone on the line or have to leave a
voice mail message,  please be patient and remember that we are
trying to support and service the permit community as part of
our clientele, but our organizational charter does not really
give us responsibilities in that area.
    The AP-42 Team has been working extremely hard to get
the Fifth Edition of Compilation Of Air Pollutant Emission
Factors, AP-42, published and available for distribution.  We
have continued to have more delays than we anticipated, and
we apologize for any incoveniences you may be experiencing
as a result. Please see the update on page 6 for information on
the latest expected  releases of AP-42, FIRE, TANKS, Air
CHIEF, and the other emission factor estimation tools which
fall under the purview of the AP-42 Team, composed of Dennis
Beauregard, Roy Huntley, Whit Joyner, Ron Myers, RonRyan,
Dallas Safriet and me.  In spite of the problems we have had
getting these products to you in the manner we expected, we
were very pleased to receive many supportive comments from
our clients as we were in the process of updating our mailing
key.  Please feel free to communicate with us via mail and the
CHIEF BBS—we appreciate your input because it helps us
focus our limited resources on the highest priorities of our cli-
ents. Thanks!  je$
                                    — Jim Southerland

                                  The " Adopt-a-Factor" program was proposed to
                              be a means of support for state emission factor devel-
                              opment projects by providing funds through the grant
                              process.  Under the current climate, we now expect
                              that the program grants for this activity will be rolled
                              together  with other funds into  the popular "block
                              grant" process. We will still make an effort to coordi'
                              nate and act as a sounding board and clearinghouse
                              for emission factor development activities, but to a
                              lesser degree than we had first  envisioned.  Check
                              future issues of the CHIEF Newsletter for more de-
                              finitive and final news regarding this topic,  -jsS
                                      EPA EMISSION INVENTORY
                                          CONTACTS MEETING

                              The second EPA Emission Inventory Contacts meeting
                          was held in Research Triangle Park, NC, onMarch29 - 30. The
                          meeting was hosted by the  Emission Factor And Inventory
                          Group.  Attendance at the meeting was good, with representa-
                          tives from nine of the ten EPA Regional Offices, from the Office
                          Of Mobile Sources, and from several groups within OAQPS.
                              Agenda items included Periodic Emission Inventories, Fed-
                          eral RegisterProcessingof 1990 SIP Inventories, documenting
                          inventory reports and  data bases on compact disk-read only
                          memory (CD-ROM), AIRS, and the Emissions Reporting Rule.
                          Status reports were presented on several other activities. The
                          primary follow-up activity to the meeting will be the gathering
                          of electronic files (text and data bases) that make up the 1990
                          SIP inventories to archive on CD-ROM.  This effort will ad-
                          dress past problems concerning difficulty in storing and ac-
                          cessing SIP inventory information and providing information
                          for Freedom Of Information Act requests.
                                  Thanks to all who attended the meeting formaking it
                          another successful one!  &
  Emission Factor And Inventory Group
    The CHIEF Newsletter is produced quarterly by the Emission Inventory Branch,
Technical Support Division, of EPA's Office Of Air Quality Planning And Standards. Its
purpose is to enhance communication within the emission factor and inventory community
by providing new and useful information and by allowing for the exchange ofinformation
between and among its readers. Comments on the Newsletter and articles for inclusion
in it are welcome and should be directed to Emission Factor And Inventory Group (MD-
14), US EPA, Research Triangle Park, NC 27711; telephone (919) 541-5493.
    The contents o/The CHIEF Newsletter do not necessarily  reflect the views and
policies of the Agency, neither does the mention of trade names or commercial products
constitute endorsement or recommendation for use.



                                           HOW BIG IS A BARREL?
        Units from AP-42 "Appendix A":
        An often confusing unit of measure is a barrel. A barrel's capacity is determined often by who uses the term,
        or what it contains. For example:
        1 barrel (bbl) of petroleum or related products = 42 gallons
        1 barrel of Portland cement is 375 pounds, flour-196 pounds, pork orfish-200 pounds, etc..
        1 barrel of beer (US, liquid) is 31.5 (36 in Britain) gallons (more "kick" per gallon than petroleum?)
        1 barrel of (US) dry measure, is 3.29122 bushels or4.2104 cubicfeet.
        Abarrel may be called a "drum", but a drum usually holds 55 gallons!
        A barrel roll does not have weight, but is a complete "turn" in an airplane.
        2 barrels (of tobacco) is equal to one hogshead, or about 1000 pounds.

            Just watch the units and contents so they don't "barrel" you over!  Can you think of others?
                                            The CHIEF Newsletter
                                                 Volume VI, No. 2
                                                   Spring 1995