Report
WORKING CONFERENCE ON HEALTH INTELLIGENCE
FOR FUELS AND FUEL ADDITIVES
January 5 - 7, 1973
Durham, North Carolina
Convened by:
Fuels and Fuel Additive Registration Program
National Environmental Research Center - RTF
Environmental Protection Agency
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Contents
I. Participants
II. Foreward: John F. Finklea, M. D."
Di rector
National Environmental Research Center - RTF
III. Introduction
IV. Development of Toxicologic Screen for Fuels and Fuel Additives
A. Chemical Indicators of Toxicity
B. General Toxicology
1. Introduction
2. Methods
a. Sources and types of emissions
b. In_ Vitro methods
c. In Vivo methods
C. Carcinogenesis
1. Introduction
2. Methods
a. In Vitro methods
b. j£ Vivo methods
D. Mutagenesis
1. Introduction
2. Methods
a. In Vitro methods
b. Th~ Vivo methods
V. Background Information Engineering and Chemical Considerations
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FOREWORD
The composition of fuels and fuel additives has the potential of
altering emissions from combustion processes and the performance of
emissions control systems. Such alterations may be either beneficial
or detrimental to the public health and welfare. In cognizance of this
fact, Section 211 of the Clean Air Act of 1970 gives EPA the authority
to require the conduct of tests "to determine the potential public
health effects" of fuels or fuel additives and to control or prohibit
the use of fuels or fuel additives when emission products "will endanger
the public health or welfare." Furthermore, the demands posed by new
emission control systems may dictate considerable modification in exist-
ing fuels and new fuel additives. A systematic effort is required to
evaluate emissions to ensure that increased public health risks do not
ensue, either from the introduction of new toxic chemicals or by an
elevation of toxicants attributable to fuel blends and fuel additives
now in use.
Because of the complexity of the toxicological problems imposed by
the number and diversity of fuel additives already developed and the
many altered primary and secondary pollutants which may be potential
toxicants, a significant research program will be required.
The Conference on Health Intelligence for Fuels and Fuel Additives,
the report of which follows, was convened for the purpose of developing
the basis for protocols so that preliminary work on toxicological evalua-
tion of fuel and fuel additives could begin without delay.
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I should like to take this opportunity to express the appreciation
of the Environmental Protection Agency to the members of the Conference
who devoted several days of their time to this fruitful effort.
<
, John F. Finklea, M. D.
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WORKING CONFERENCE ON HEALTH INTELLIGENCE
FOR FUELS AND FUEL ADDITIVES
List of Participants
Dr. John Bertram
McArtle Laboratory
University of Wisconsin
Mr. Ronald L. Bradow
National Environmental
Research Center - RTF
Environmental Protection Agency
Dr. Paul Brubaker
National Environmental
Research Center - RTP
Environmental Protection Agency
Mr. Kirby Campbell
National Environmental
Research Center - Cincinnati
Environmental Protection Agency
Dr. David L. Coffin
National Environmental
Research Center - RTP
Environmental Protection Agency
Dr. Timothy Crocker .
Department of Preventive Medicine
University of California
Dr. Basil Dimitriades
National Environmental
Research Center - RTP
Environmental Protection Agency
Dr. Samuel S. Epstein
Department of Environmental
Health and Human Ecology
Case Western Reserve University
Dr. John F. Finklea
National Environmental
Research Center - RTP
Environmental Protection Agency
Dr. Gustave Freeman
Life Sciences Division
Stanford Research Institute
Dr. Donald E. Gardner
National Environmental
Research Center - RTP
Environmental Protection Agency
Mr. James Gentel
Dow Chemical Company
Mr. Thomas Gleason
Office of Research & Monitoring
Environmental Protection Agency
Dr. F. Gordon Hueter
National Environmental
Research Center - RTP
Environmental Protection Agency
Dr. K. E. Klinksiek
German Society for Mineral Oil
Science and Coal Chemistry
Hamburg
Dr. Marvin Kuschner
Department of Pathology
Health Sciences Center
State University of New York
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List of Participants (cont.)
Dr. Sidney Laskin
Department of Environmental
Medicine
New York University Medical Center
Dr. J. Douglas MacEwen
Toxic Hazard Research Unit
University of California - Dayton
Mr. Henry Miller
National Environmental
Research Center - RTP
Environmental Protection Agency
Dr. Richard L. Miller
Life Support Branch
Environmental Sciences Division
USAF School of Aerospace Medicine
Mr. John B. Moran
National Envi ronmental
Research Center - RTP
Environmental Protection Agency
Dr. B. Richardson
Environmental Sciences Division
USAF School of Aerospace Medicine
Dr. Donald Rounds
Pasadena Institute of Medical
Research
Dr. Eugene Sawicki
National Environmental
Research Center - RTP
Environmental Protection Agency
Dr. Klaus Schmidt
Institute for Experimental
Toxicology and Chemotherapy
German Cancer Research Center
Heidelberg
Dr. Frederick de Serres
Mutagenesis Branch
National Institute of Environmental
Health Sciences
Dr. Phillippe Shubik
Eppley Institute for Research
in Cancer
University of Nebraska
Mr. John Sigsby
National Environmental
Research Center - RTP
Environmental Protection Agency
Dr. Daniel Strauss
Mutagenesis Branch
National Institute of Environmental
Health Sciences
Dr. Theodore R.Torkelson
Chemical Biology Research
Toxicology and Industrial Hygiene
Dow Chemical Company
Dr. Benjamin L. Van Duuren
Institute of Environmental Medicine
New York University Medical Center
Dr. Michael D. Waters
National Environmental
Research Center - RTP
Environmental Protection Agency
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DEVELOPMENT OF TOXICOLOGIC SCREEN FOR FUELS AND FUEL ADDITIVES
Registration and testing procedures must be directed toward minimizing
the risk of adverse effects on human health that may reasonably be attri-
buted to changes in fuels or fuel additives. Such effects may be linked
to individual additive components, complete additives, blended fuels or
gaseous and particulate emissions from mobile and stationary sources.
Effects of concern include increased susceptibility to cancer, mutagenic
and teratogenic aberrations, respiratory infection, chronic pulmonary
diseases, subtle changes in cellular morphology and enzymatic function,
and increased pollutant burdens.
Because it is not possible to completely define chemically the combus-
tion products and the likely chemical and biological interactions of the
various components in the exhaust effluent, it appears essential to approach
the problem of fuel additive toxicology by testing the whole effluent.
Basically, this would consist in comparing the toxicity of emissions from
a reference fuel with the same fuel including additives at the concentra-
tion prior to combustion specified by the manufacturer. Whole exhaust
emission or condensates of whole exhaust effluent would be the best samples
for biological testing.
Because of the large number of toxicological tests which may be required
and the need to obtain preliminary information quickly, it is recommended
that in vitro methods be incorporated in the toxicologic screen. It would
appear that such methods can be utilized in hierarchical screening systems
to detect first effects and develop priorities for further study of toxic
chemicals in the environment.
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The purpose of this report is to present methods for toxicologic
screening that incorporate suggestions for in vitro and sub-whole animal
studies in an orderly screen together with validation by the more con-
ventional whole animal methods now commonly employed so that ultimately
some insight may ensue into the relative merits of various tests with
regard to cost, ease of applicability, sensitivity, reliability, etc., as
well as validity for correlation with heatlh effects in man. At this stage
it is fully realized that in the employment of sub-whole animal tests to
develop toxicologic information, certain tests now regularly employed for
toxicologic evaluation must be included for purposes of validation. However,
it is strongly felt that, in dealing with the multiplicity of toxicological
problems of the immediate future, the obvious potential advantages of
in vitro methods, other sub-whole animal tests, and tests employing specific
interactants should be given immediate attention in the screen so that
results can be compared with more conventional tests that require considerable
time.
The following report contains the recommendations of the Conference on
Health Intelligence for Fuels and Fuel Additives. It is a synthesis of
the various viewpoints of the members of the panel and thus is not likely
to wholly reflect the opinions of any one member.
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1. Chemical Indicators of Toxicity
a. Objectives: (1) To determine if the parent fuel additive is a
known carcinogen, mutagen, teratogen, or alkylating agent. If so, it should
be considered as a screening prospect on the grounds that the material may
act as a direct consumer hazard; also, a certain percentage of the unpyrolysed
parent compound is likely to appear in the exhaust. (2) To determine
whether mixing or burning additives in fuel gives rise to certain chemicals and
chemical structural types that are known or suspected to have deleterious
health effects. These include carcinogens, mutagens, teratogens, etc. A
limited group of compounds and compound types can be identified as chemical
indicators of potentially increased or decreased toxic effects. This informa-
tion may provide guidance in the selection of appropriate in vitro and in vivo
bioassays.
b. Test Methods: The following compound types and possible analytical
techniques are proposed:
Compound Type Analytical Method
(1) Aromatic and heterocyclic compounds, G.C. (Mass spec)
including carcinogens and non-
carcinogens
(2) Aliphatic hydrocarbons G.C.
(3) Olefinic hydrocarbons G.C.
(4) Alkylating Agents Colorimetric
(5) Phenols and Polyphenols Colorimetric/G.C.
(6) Trace Metals Atomic Absorption
(7) Aldehydes
(8) Nitroso compounds G.C., TCC
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When marked Increases In levels of these agents are observed, refined
analysis and structure determination will be required.
New Compounds: When compounds, such as known carcinogens, mutagens,
teratogens or alkylating agents, or close congeners of such compounds, are
isolated in the test condensate, they should be considered to be predictors
of potential human toxicity and evaluated in the absence of further toxicologi-
cal information.
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B. General Toxicology
1. Introduction: The adoption of a systematic "screen" for biological
effects of emissions from gasoline burned together with a series of unknown
"additives" in an automobile engine is of great importance. The basis for
any such comparative study would be an identified and characterized "standard"
fuel. The undesirable biological effects would constitute a "profile" of
toxicity, which is available in part for both irradiated and unirradiated '
whole emissions. However, it can be anticipated that much of the profile
is unknown. Profiles include observations in man, the whole animal, organ
systems, and cellular systems and take into account all categories of cellular
and biochemical responses. Effects from standard fuel emissions would be
compared with those from fuels plus additives.
The main objective is to provide EPA with evidence about whether or not
an emission with a particular additive effects a profile different from that
of the "standard" fuel emission and whether differences are biologically
more or less desirable. Effects, according to the spectrum of observations
from among the several systems to be selected, that will constitute a profile,
are to be described in quantitative terms.
2. Methods:
a. Source and Type of Emission: This is essentially the responsibility
of engineers and chemists.They should determine the types of fuels,
characterize their emissions chemically as far as reasonable, provide
the materials to biologists, and monitor the quality (quantitatively)
of the materials provided ~ or, as an alternative, provide biologists
with manageable techniques to do likewise. Irradiated, as well as
non-irradiated, emissions will be considered, if not studied. Exhaust
control devices affect the tendency of exhaust emissions to partici-
pate in photochemical smog development. The importance of this factor
for future automobile emissions is at this time unclear because of
the uncertainty of what control devices will ultimately be adopted.
Thus, it would appear important to provide for irradiation of exhaust
as part of the test system. For reasons of feasibility, non-irradiated
automotive emissions will probably be the initial source of material,
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both for atmospheric exposure of biologic test systems and
for collection of specific or whole crude samples (e.g., condensates).
However, piror work has shown that irradiated effluents have had more
significant biologic effects in rodents than non-irradiated effluents.
Therefore, every effort should be made to provide for irradiation
of automotive exhaust as part of the test system. If irradiation
cannot be incorporated into the exhaust testing process at the outset,
early provisions to include this feature must be made so that irradi-
ated samples will be available for the determination of hazards,
as new engines, fuels, additives, and control devices are developed
for use in areas having a high vulnerability for photochemical pollu-
tion.
b. First Approximation for Identification of Biological Effects;
Approach: The purpose of the vt± vitro segment of the screen is to
determine first effects and to establish priorities for further
testing.
(1) Primary animal cells should be used in preference to
cell lines for toxicity studies because such cells are
closer to the tissue of origin before undergoing modification in
in culture; and because pulmonary alveolar macrophages,
tracheobronchial, alveolar epithelial and conjunctival cells
can be included: normal cells of these types are not available
in continuous line culture.
(2) Cell lines of human fibroblasts (as WI-38) may be of
value because of differences which may exist between human
and rodent fibroblasts. Parallel rodent fibroblasts may be
used, but should be in a stage that precedes spontaneous
transformation.
(3) Applicable studies in above systems, additional to
macrophage studies, include (with emphasis on epithelial
cells): growth rate; duration of components of the mitotic
cycle; replicative fraction versus non-replicative (senescing)
fraction; preservation of capacity to differentiate as
respiratory epithelial cells; various functional parameters
in pulmonary macrophages.
(4) Organ cultures: In selected instances requiring identifica-
tion of cell types in biologic responses, this system can be
employed at a secondary test level rather than as a screen-
ing method.
(5) Organ Preparations: Ciliary beat, mucous secretion,
and transport of particles can be seen in the excised fresh
organ. This system should be considered for secondary (and po
possibly primary) screens.
c. Exposure methods for In Vitro Tests:
(1) Condensates: Whole crude or fractionated condensates
or filtrates of automotive exhaust can be added to culture
media for testing of cellular responses, by methods described
above.
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(2) Airborne Effluent: Appropriate systems for in vitro
exposure are needed to permit screens of atmospheric
contaminants suspended in air. These systems are incompletely
developed, but can be expected to become available. In such
systems cellular observations will be similar to those
described above.
d. In Vivo Tests: Generally, animals will be divided into three
groups, one to be exposed to filtered air, a second to "standard"
fuel emission, and the third to the emission produced by the
"standard" fuel with the additive to be tested.
Relatively sensitive and inexpensive species (two or more) should be
selected. Preference should be given to growing animals so that
growth rate may be observed also. (Subsequent studies could include
animals with increased susceptibilities.)
(1) Prepared standard condensates (non-volatile portion)
would be administered by parenteral and natural routes
in parallel experiments. Volatile fractions should be
trapped and administered concomitantly.
(2) Because "acute" and "chronic" are arbitrary terms, both
early and continual observations will need to be made as
indicated.
(3) Duration of observations will depend upon the time of
appearance of positive effects and/or upon-the urgency to
have data at arbitrary points in time.
A special toxicological problem is associated with exposure of
animals to automobile exhaust by inhalation, namely that the toxic
effect of carbon monoxide may mask changes which might develop from
other chemicals present. Therefore, unless a practical way can be
found to remove the carbon monoxide in the large volumes of exhaust
required for animal exposure, there must be reliance on methods of
exposure other than inhalation of whole effluent. However, since
toxicologic strides on whole effluent have been largely unsuccess-
ful (except for carbon monoxide and oxidant) it would appear that
exposure of whole animals should be carried out with emission
condensates. This will be important for validation of the in
vitro methods, as well as defining primary profiles for whole"
animal exposure.
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C. Carcinogenesis
1. Introduction: Automobile exhaust in the absence of additive compounds
contains known carcinogens, such as polycyclic hydrocarbons and trace metals
and potentially co-carcinogenic materials, such as phenols. Therefore, any
test system devised to examine the possible hazardous effects of additives
must be designed to identify increments in activity conferred by the addi-
tive. Additionally, since some of the additive may emerge unchanged in the
exhaust, the toxicity of the parent compound should be considered, as well
as its possible contribution to overall toxicity after combustion.
It would appear reasonable to devise a test system which would approach
the problem of potential carcinogenicity by evaluating the whole effluent.
For tests employing in vitro methodology, per cutaneous application, subcu-
taneous inoculation and intratracheal instillation, it would seem most
practical to utilize cryogenic condensates containing as much exhaust effluent
as it is possible to collect by this method, as well as volatile materials
collected by this means. If exposure by aerosol was to be performed, this
could be accomplished either by aerosolization of the whole extract, or by
use of the whole effluent atmosphere. In view of the low degree of success
achieved by exposure to carcinogens via aerosol, it would appear that such
exposures should be reserved for specific purposes and not routinely employed
in the screen specifically for carcinogens.
In view of the many condensates which must eventually be examined
for evidence of carcinogenicity, it would appear to be of value to devise a
hierarchical screen of tests including in vitro, sub-whole animal and whole
animal, so that the experience derived from preliminary work might be
applied to the subject of carcinogenesis testing for later studies, hopefully
reducing the time involved in reaching conclusive data.
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The proposed screen is as follows:
In Vitro
Cell Culture:
1. Hamster embryo
2. Mouse fibroblast
3. Paramecia
l£ Vivo
1. Mouse skin painting
2. Adult rat subcutaneous inoculation
3. Neonatal mouse subcutaneous inoculation
4. Intratracheal injectipn/F203
5. Inhalation of aerosolized tar
6. Inhalation whole exhaust.
2. Methods:
a. In Vitro: The induction of cancer in vitro has been basically
achieved in two cell systems: secondary cultures of hamster embryos
and cell lines of mouse fibroblasts. In both systems malignant
transformation is demonstrated by an alteration in morphology of the
cells, with changes from a pattern of order to one of disorder
(cross-crossing and piling-up). Validation of these systems
depends upon the ability of such altered cells to produce malignant
tumors when injected into the species of origin.
These i_n_ vitro test systems possess the attributes of speed (2-6
weeks versus 1 - 2 years in whole animal) and consequent economy,
but also allow more close control of experimental parameters. In
addition, doses may be used that are precluded in the whole animal
for reasons of toxicity. Furthermore, although relatively large
doses are employed in whole animal systems, they produce only a
small total mass, as compared with in vitro systems, which have
the additional advantage of requiring much smaller amounts of
inoculem (since they do not employ repeated doses). This latter
is an obvious advantage as it is often difficult to derive large
amounts of the test material for preliminary studies. These tests
should be looked on as range-finding and priority-setting steps
in the screen.
Listed below are the requirements of an in vitro screen for
carcinogenic activity, and means of meeting these requirements by
the currently available systems.
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(1) The morphological transformation caused by the
carcinogen should be produced rapidly and be readily
scored.
(2) The system should react in a quantitative manner
to all known carcinogens.
This goal may be unattainable in anything other than
a battery of tests yet to be devised. In the present
systems two major problems need to be overcome:
(a) Many carcinogens require metabolic activation and
it cannot be expected that any one cell type will
activate all such carcinogens (The present systems
activate many, but not all). The use of specifically
chosen feeder cells and host-mediated assay require more
extensive evaluation, (b) The present systems appear
to be insensitive to weak carcinogens. However, it
has been shown that the in vitro sensitivity to smog
abstracts can be greatly enhanced by infection with an
RNA tumor virus. Likewise, concurrent administration
of X-rays, repair inhibitors, or low doses or a strong
carcinogen may expose the effects of high doses of a
weak carcinogen. More research is needed in these
areas. '
(3) The system should be quick and economical to set
up and reproducible in its response. The moust fibre-
blast system, being a cell line, is preferrable in
all three respects to the hamster system.
Paramecia: The photodynamic bioassay employing paramecia or other
protozoa has been useful in demonstrating sensitization of the
organisms by a previous exposure to polycyclic and heterocyclic
compounds. In studies performed on many carcinogenic and non-
carcinogenic compounds there has been a strong statistical
association of positivity in this test and carcinogenicity. This
method might provide a quick, relatively simple means of obtaining
preliminary information on a very large number of extracts regarding
the presence of polycyclic and heterocyclic compounds with presumed
carcinogenic potential, and it might be evaluated together with
the preceding in vitro methods and the more conventional whole
animal tests described below.
b. In Vivo: A number of methods employing the response of whole
animals are more or less regularly utilized for evaluating the
carcinogenicity potential of various substances. Besides being
"time honored" in the field of toxicology, these methods have certain
other advantages, such as utilizing to a greater or lesser extent
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the whole potential of the animal as a reactor, which obviously
cannot be duplicated in the in vitro systems employing a single
cell line in isolated culture. Thus, whole animal systems
should be used to validate the in vitro tests and give more
definitive reference points.
(1) Skin Painting of the Mouse: This method will require
a large amount of material -- up to 100 grams per experi-
ment. The test substance should be utilized as a whole
carcinogen and as a parameter following DMBA initiation.
If positive results ensue, experiments should be repeated
to determine dose response.
(2) Subcutaneous inoculation of adult rats: This requires
somewhat less material for testing and gives additional
Information in that cells of more than one germinal layer
may be affected. The neonate mouse test has the virtue
of utilizing much less material and while presenting
problems of interpretation, also probably yields better
insight as to the nature of the carcinogen contained in
the inoculated material.
(3) The intratracheal injection method of testing
material combined with FepO^ is the most practical approach
to the determination of the potential of the test sub-
stance to elicit tumors of the lung.
(4) Inhalation methods seemingly should provide the most
naturalistic methods for evaluation of the potential
of a substance to elicit tumors of the lung in experi-
mental animals. However, it is fair to point out that
this method has been relatively unproductive in demonstrat-
ing carcinogenicity of even the most potent hydrocarbon
carcinogens administered in high concentrations. Thus,
it is unlikely that the comparative carcinogenicity of
the effluents of the reference fuels and the contained
fuel additives will be detected by such means until
better methods are devised for such experiments. If
inhalation exposures were to be undertaken, large amounts
of test substances would be required up to one kilogram
of tar for aerosolization or long continued exposure
to whole exhaust. Such tests would offer the possibility
of combining exposure with other air pollutants,
cigarette smoke, asbestos, etc., for research, into the
influences of interactants, but it is difficult to fore-
see their immediate value as a bioassay system for the
stated purpose of fuel additive evaluation.
A summary of the various test systems discussed appears in
the table which follows.
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TEST SYSTEM
MATERIAL REQUIRED
SYSTEMS NEEDED
A- IN VITRO TEST SYSTEMS
1. Cell Culture
a. Hamster embryo
b. Mouse fibroblast examined
for transformation jn
vitro and validated by
tumor production on
re-inoculation.
c. Paramecia - photodynamic
effect to detect carcino-
genic polycyclic and
heterocyclic compounds.
B. IN VIVO TEST SYSTEMS
1. Mouse skin painting as
whole carcinogen and as
promoter following DMBA
initiation. Dose response
if positive.
2. Adult Rat Subcutaneous
3. Neonatal Mice Subcutaneous
4. Intratracheal injection
combined with F6203
5. Inhalation
a. Whole exhaust (diluted
b. Aerosolized tar
Whole condensate - if cyto-
toxic, then appropriate frac-
tions -- mgs per test.
^
Material should be soluble in
acetone, DMSO, or water.
Microgram amounts required.
(Useful for rapid screening
of large numbers of fractions
and subfractions.)
100 Gms per experiment
50 Gms per experiment
5 Gms per experiment
1 kilo
Examination and development of human cell
lines, particularly those characterized by
genetic instability (e.g., Fasscessis, or .
X.P. cells) as hypersensitive indicators.
Development of in vitro systems for examina-
tion of promotion.
Possibility of enhancement by viruses of
transformation as a sensitive indicator of
activity (see Rihm, et al. Nature 29:
103-107, 1972.)
Exploration and improvement in techniques of
organ culture.
Examination of cells and tissue derived from
pre-exposed animals.
Fractionation if positive to identify the
"new" carcinogen.
Combined exposures with air pollutants,
cigarette smoke, asbestos, etc.
ro.
i
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B. Hutagenesis .;
1. Introduction;
The general objective of mutagenicity testing is to determine if
a new environmental chemical will produce genetic damage either alone or
in combination with other agents in the environment. Since the vast
majority of genetic damage is considered to be harmful either to the indi-
vidual (by making him more susceptible, for example, to the development of
cancer) or to his progeny, every effort should be made to prevent an increase
in the various types of genetic damage already present in the human popula-
tion. The genetic basis of many human diseases has been well established
and increases in the frequencies of these diseases in the population can
be avoided by careful screening of new man-made chemicals before they are
released into the environment. Since we do not have reliable methods for
monitoring the human population to determine whether the genetic load is
changing, it is especially important to establish a comprehensive screen
which can detect mutagenic activity before new chemicals are released for
widespread use.
2. Methods: Test systems for evaluating chemicals for mutagenic
activity fall into two main classes:
a. In vitro test systems: These include bacteria, fungi, insects,
higher plants and mammalian cells in culture.
b. In vivo test systems: These are assays performed on laboratory
animals, and include the dominant lethal test, the host-mediated
assay and in vivo cytogenetics.
a. In Vitro Test Procedures:
In general, the in vitro tests provide an assay of the mutagenicity of
the original chemical on somatic cells. The assay of the original chemical
and its potential metabolites is limited by the metabolism of the test
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organism. In many cases these metabolites may be quite different from those
found in mammalian test systems. In this respect negative results with
in vitro assays must not be interpreted as indicating that a chemical is
safe for man, but positive results are interpreted as indication of a
potential hazard.
Various methods are under development to mimic in vitro the type of
metabolic activation that occurs in vivo. These include various methods
of chemical activation as well as biological activation with microsome
preparations from mammalian liver and other organs. These in_ vitro activation
systems should be able to increase the sensitivity and general utility of
all in vitro test systems by providing a mechanism for rapid evaluation of
potential products of mammalian metabolism.
(1) C h romo s ome a be rra t i ons (non-disjunction and chromosome rearramgements)
(a) Mammalian cells in culture - Mouse lymphoma cells, human
fibroblasts, etc., can be used to determine whether chromosome
aberrations have been produced. By using synchronized popu-
lations of cells, it is possible to look for cell-stage
specificity. Periods of timed exposure with varying concentra-
tions can be used to obtain dose-response curves for particular
types of chromosome aberrations.
(2) Gene mutations (point mutations and deletions) Gene mutations in
man can be due to alterations in structure (point mutations) or
physical removal from the chromosome (deletions).
Bacteria - In Salmonella typhimurium a series of histidine-requiring
mutants have been developed by Ames and his colleagues (Ames, et al.,
1973) which can be used to detect the production of particular
types of genetic alterations that can produce point mutations.
The assay consists of a spot test, in its simplest form, that
provides semi-quantitative data. It assays for the production of
reverse mutations over a wide range of concentrations. The assay
is limited to the detection of particular types of genetic altera-
tions; but the development of highly sensitive strains (e.g., lacking
repair enzymes and a normal cell wall) which can detect specific
types of damage makes this assay especially valuable.
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Fungi - In Neurospora crassa by using a two-component heterokaryon
heterozygous for specific genetic markers, it is possible to detect
forward-mutations at two specific loci in the ad-3 region (de Serres
and Osterbind, 1962).
Gene mutations at each locus result from both point mutation and
chromosome deletion so that this test system can detect the same
range of genetic alterations that can give rise to gene mutations
in man.
By giving various acute levels of exposure to cell suspensions over
a constant period of time, dose-response curves can be obtained
which can be used to extrapolate to lower (chronic) levels of
exposure.
(3) Mitotic recombination (reciprocal and non-reciprocal exchange
[or gene conversion])
Mitotic recombination in heterozygous diploid organisms provides a
mechanism for making deleterious recessive genes homozygous.
Homozygosity provides a means for expression of deleterious effects
which would not be seen in heterozygous individuals.
In diploid yeast strains of Saccharomyces cereviseae heterozygous
for linked markers as well as (hetero; alleles at the same locus,
it is possible to assay for effects on mitotic recombination.
b. In Vivo Test Procedures
In general, the in vivo test procedures are used to evaluate effects
on germ cells of the original compoundsas well as its metabolites. No
really practical test exists which can be used to evaluate the production
of gene mutations in germ cells and it is generally accepted that the use
of specific locus test developed by Russell (1951) should be restricted to
particular situations because of the time, facilities and special training
required to make this test.
(l) Chromosome aberration (non-disjunctive and chromosome rearrangements)
(a) Dominant lethal test - The dominant lethal test in mice is used
to obtain presumptive data on the production of chromosome
aberrations. By mating treated males to new batches of females
at frequent intervals, it is possible to look for effects on
various cell stages during spermatogenesis. The detection of
a significant increase of dead embryos over the control level
is usually attributed to the production of germ cells with
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abnormal numbers of chromosomes, chromosome fragments and
rearrangements.
Breeding tests on the viable progeny obtained in such tests can
be used to determine the frequency of transmissible chromosome
rearrangements. Since Generoso, et al. (1973) have shown that
the frequency of spontaneous translocation is low, this assay
may provide a more sensitive test for the detection of chromosome
rearrangements.
In the dominant lethal test several acute levels of exposure
can be given to obtain dose-response curves. The sensitivity
of the test is limited by the high frequencies of spontaneous
dominant lethality which makes it difficult to detect signifi-
cant increases at low levels of exposure or positive effects of
weak mutagens.
(b)In vivo cytogenetics - Cytogenetic evaluation of cells that are
a normal component of the animal can be made by putting bone
marrow cells or peripheral lymphocytes into short-term tissue
culture. Cytogenetic evaluation of these cells in culture can
be used to obtain data from metaphase preparations to determine
whether chromosome aberrations have been produced.
(2) Gene mutations - No practical test exists for detecting gene mutations
in either somatic cells or germ cells of laboratory animals. To
compensate for this deficiency, a new technique was developed by
Legator and his associates (Gabridge and Legator, 1969) which
introduces indicator cells into the peritoneum of animals after
they have been treated with a mutagen. The cells are incubated
in the peritoneum for varying periods of time and then removed
for genetic assay. In this host-mediated assay many test systems
have been used as indicator organisms to detect gene mutations.
These include Salmonella, Neurospora and mammalian cells in culture.
The problems with the technique are the host reaction against the
indicator organism shown by Mailing (1972) and the fact that metabolic
activation may be organ-specific, mutagenically active metabolites
may not be present in sufficiently high concentrations in the
peritoneum (Mailing and Chu, 1973).
Under development is the utilization of specific locus assays in
mouse lymphoma cells in culture to overcome the problems in both
areas.
(3) Mitptic recombination - No in vivo assay for mitotic recombination
is known, and the test with diploid yeast can be performed utiliz-
ing yeast as the indicator organism in the host-mediated assay. This
approach permits a more thorough test for mutagenicity of any
products that may be unique to mammalian metabolism.
-------
-17- .
Preparation of Samples
- In general, samples must be sterile and solubilized in water. Dimethyl-
sulfoxide (spectrophotometric grade), dimethylformamide, tricaprylin
(redistilled), or other relatively non-toxic solvents should be used.
In each case controls will be performed to test possible toxic or mutagenic
effects of the solvents themselves. Controls will also be performed to
test the sterility of samples.
Positive controls
Positive controls will be performed using standard quantities of known
mutagens and mutagen precursors to monitor the responsiveness of tester
strains or cell lines and the activity of microsomal enzyme fractions.
Where necessary, controls will be performed along with each experiment to
monitor the genetic integrity of tester strains and cell lines.
One problem which may arise from the use of unfractionated or partially
fractionated materials in the mutagenesis tests is that a high background
level of toxicity and/or mutagenicity or some component or components in the
reference sample may mask the detection of new mutagens appearing in the
test samples. Another possibility is that some components of the reference
sample will inactivate the liver microsome preparations used for activation
or mutagen precursors. To approach these possible problems, positive
controls will be performed in which standard quantities of known mutagens
and mutagen precursors (e.g., 2-aminopurine, ICR 191, 2-aminofluorine)
will be added to the reference sample, and the resultant mixtures will be
run through the mutagen screening tests. In cases in which these positive
control experiments fail to register positive results, this will be taken
as an indication that further fractionation of the reference and test samples
is necessary.
-------
-18-
Testing Protocols
To simplify the testing and to make it possible to detect potentially
hazardous mutagens in the most efficient manner, the short-term tests are
preferred. The utilization of simpler in vitro tests singly, and in combina-
tion with various chemical or biological systems that mimic mammalian metabolism,
makes it possible to rapidly screen the original compound and some of its
metabolites for genetic activity. The test chemical should be tested alone
and in combination with those chemicals with which it will be associated
under the conditions of its intended use, over a wide range of concentrations.
These should be acute exposures for a fixed period of time (e.g., two hours)
under conditions that give 100% survival to 99.9% inactivation of cells.
Absence of the production of various types of genetic damage under conditions
that produce inactivation of cells shall be considered evidence for the lack
of a genetic effect. It is important to note that it must be shown with
the appropriate positive controls that mutagenic activity could have been
detected if it were present. In other words, the assurance must be given
with the appropriate positive controls that the presence of cytotoxic compounds
is not masking out the activity of mutagenic compounds.
Interpretation of Test Data
In general, in each of the in vitro and in vivo tests the spontaneous
frequency of genetic damage can be measured in the controls. A positive
result will be indicated when the treatment with the test chemical alone or
in combination with those chemicals with which it will be associated under
conditions of proposed use, give a doubling of the spontaneous frequency.
All other results will be considered to provide a negative test.
-------
-19-
Engineering and Chemical Considerations
January 5, 1973
-------
-20-
National Significance
Transportation, in general, is the major source of carbon monoxide,
hydrocarbons, and nitrogen oxides. In 1970, emissions from all trans-
portation sources in the United States contributed 50% of the total hydro-
carbons, 70% of the carbon monoxide, and 30% of the nitrogen oxides. The
principal source of such emissions is the gasoline-powered motor vehicle.
Gasoline-powered motor vehicles constitute three major types:
passenger cars (93 million in 1972), light-duty trucks, and gasoline-
powered heavy duty trucks. The total vehicular population in the U. S.
in 1972 exceeds 110 million. The average vehicle is driven 10,000 miles
per year at an average fuel consumption of 1 gallon per 12.5 miles. Com-
position of typical gasolines commercially sold in the U. S. is shown in
Tables 1 and 2. Figure 1 reflects, schematically, the basics of petro-
leum refining practice. Table 3 indicates typical ranges of key basic
components in commercial gasolines.
-------
-21-
Table 1
Commercial Gasoline Properties:
Research Octane
Motor Octane
Reed Vapor Pressure
% Olefins
% Aromatics
% Saturates
Initial Boiling Point
Final Boiling Point
Gravity (API)
Premi urn
99.9
92.4
13.1
4.4
29.7
65.9
81°F
410°F
60.5
Premi urn
99.4
91.5
13.0
2.6
28.0
69.4
82°F
398°F
59.9
Regular
93.1
87.0
12.9
7.4
21.9
70.7
84° F
420°F
60.7
Regular
91.9
85.6
12.3
10.6
20.3
69.1
88° F
390° F
63.0
Non-Lead
90.3
82.8
10.1
12.6
12.0
75.4
9f°F
368°F
67.5
The range of several factors measured in 30 commercial fuel samples
Including premiums, regulars, and 91 octane low and non-leaded
fuels is shown below:
-------
-22-
Table 2
PREMIUM GASOLINE
Typical - 98 - 100 RON
10-20% butane
10-20% Olefins
10 - 30% Lt. FCCU - (olefins) 20 - 35% Aromatics
40 - 50% Overall reformate
Balance paraffins
10-20% Udex extract
+ 1000 ppm TEL
10 - 40% Alkylate
REGULAR GASOLINE
typical yt - so KIM
10 - 20 % butane
20% + olefins
20 - 40% Heavy FCCU
15 - 30% aromatics
10 - 20% Light straight run
Balance paraffins
0-10% Udex raffinate
+ 400 ppm TEL
20 - 40% Lt. CRU
30 - 50% Overall reformate
-------
GASOLINE MANUFACTURE
Natural gas condensate
C4 - C.JQ hydrocarbons - boiling point - 70°F H
» butane, isobntane, Cg's to gasoline
to
Crude oil
C5"C35
paraffins
jpe
&
Dis
11
ti nation
i I iuht °
paraffi
1 1 +1 C\fC
(1)
tralght Run Gasoline - RON-40-70 5-10%
ns & cycloparaffins Cg-C7 B.P. <250°F
on f\r\y ,- --
1« «,o «41 nuuvy i.
Desu
/ ,
Vac.
Still
1
Residu
Asphal
Coker
y v, i v. yjuo u i i ' \^i uv,r>ci
\acid clay
catalyst
Nn ? Nn /I -furl nil ....
Diesel fuel
(6)
Overall
_,. . - _}, p(j(j| y-| | Kc 1 OiiiICi '
Pt. t
C-n 1 a 1 \/c + .. . , k
v^uiaiyii. ~*
nm __..,... IT c
t till"
1
(9)
. Olefinic-
. . k n-i e
» u is
till
-* butane
(4)
Gases
»-Lt. FCCU
B.P. <250
(3)
^ nsovy r vw
chemicals
C4-C3's to
> alkylation
-60% olefins
°F
> Premi urn
gasol i ne
U * Regular
60% olefins 9asol1ne
j , Mostl
' IVCVJU 1
(5)
-* Heavy CRU » Mostl
» Bottom
Udex
s ?
y paraffins
ar gasoline
y aroma tics
(7)
t aroma tics
(8)
k. Ra-F-finate nar'ira-finc
C3' C4
Olefins
Isobi
Alky
(10)
-» Al kyl ate
branched
ns
-------
-24-
Table 3
Range of Key Components in Gasoline:
Trace Elements:
Fe 0.5 to 1.0 wt %
Ca 0.5 to 0.9 "
Mg 2 to 3
Mn 0.2 to 0.3 "
Lead: .26 to 3.6 gms/gal.
Chlorine: .002 to .058 ppm
Bromine: .001 to .049 ppm
Phosphorous: 0.1 to 22.8 ppm
Sulfur: 12 to 1100 ppm
HC HO: 1.9 to 34.0 ppm
Carbon: 84.2 to 86.4 wt %
Hydrogen: 12.7 to 14.3 wt%
Typical additives used commercially in various fuels are shown in
Tables 4 through 12. A general classification of fuel additives by chemi-
cal type and the uses of fuel additives are also outlined in Table 13.
-------
Table 4 .26-
1969 CONSUMPTION OF ADDITIVES BY FUNCTION IN U.S.
Additive Function
Anti- Foams
Anti -Icing Compounds
Anti -Knocks
Anti -Oxi dants
Anti -Rusts -j
Anti -Squawk Compounds
Anti -Wear Compounds
Biocides
Buffers
Cetane Improvers
Cold Flow Improvers
Corrosion Inhibitors
Deposit Modifiers
Detergents
Detergent-Di spersants
Dispersants
Extreme Pressure Additives
Lead Scavengers
Lubricity Agents
Metal Deactivators
Oxidation Inhibitors
Pour Point Deoressants
Rust Inhibitors
Tackiness Agents
Storage Stabilizers
Viscosity Index Improvers
Viscosity Modifiers
Total
MM#
0.070
66.500
620.920
72.935
0.428
12.287
42.513
2.250
1.069
4.707
0.432
128.023
11.195
229.586
6.983
238.853
89.804
179.423
9.601
24.352
10.048
12.770
86.496
0.036
0.708
129.775
1.226
1,982.990
MM$
0.099
8.650
221.550
26.877
0.173
4.749
11.325
0.910
0.126
1.612
0.159
29.118
4.071
43.529
4.240
71.662
19.415
25.506
1.482
10.716
1.970
3.216
15.220
0.003
0.384
21.972
0.625
529.359
Includes Friction Modifiers and Anti-Chatter Compounds.
-------
-27-
Table 5
ADDITIVES FOR FUELS
1969 CONSUMPTION BY FUNCTION
Additive Function MMI MM$
Anti-Icing 66.500 8.650
Anti-Knock 620.920 221.550
Anti-Oxidants 15.385 8.774
Cetane Improvers 4.707 1.612
Cold Flow Improvers 0.432 0.159
Corrosion Inhibitors 21.320 9.942
Deposit Modifiers 11.195 4.071
Detergents 8.537 2.984
Lead Scavengers 179.423 25.506
Metal Deactivators 3.712 4.936
Rust Inhibitors 10-]41 ?-°??
Storage btabi nzers 0./u8 0.364
Total 942.980 290.607
-------
Table 6
-28-
GASOLINE ADDITIVES
A. Antiknocks
best in paraffinic fuels- 1000 ppm
10 Ibs/year
> best in aromatic fuels
- Tetraethyl lead
Tetramethyl lead -
Equilibrated mixtures/'""* in certa1n sPec1al blend "ses
Methyl cyclopentadienyl manganese_
Tricarbonyl
T
» best in aromatic
fuels- 400-100 ppm
B. Scavengers
C. Detergents
Anti-icing,
Deposit modifiers,
what-have-you!
D. Corrosion
Inhibitors
E. Antioxidants
F. Deposit Modifiers
G. Metal Deactivators
H. Hydrocarbons
- Ethylene dichloride / ,nn nnm
Ethylene dibromide_/~ IUU ppm
- Now mostly nitrogenous - 400 ppm+
HTA (Esso)
F-310 (Chevron)
LZ-580 (Mobile, Amoco & others)
Still some amine phosphates -
DMA - 4 Shell & others
DMA - 5A (going out)
- Mainly carboxylic acids
Di-sec. butyl p-phenylenediamine - 10-20 ppm
Di-t-butyl cresol
Phenyldicresyl phosphate
Di salicyl propanediamine
Carrier oils - 1000 > 5000 ppm
Polymers - 100 » 300 ppm
-------
Table 7
-29-
ADDITIVES USED IN AUTOMOTIVE GASOLINE - PREMIUM
Additive
Anti -Knocks
Tetraethyllead
Tetramethyllead
Possible Minor Use
Methyl cycl opentadi enyl -
maganesetri carbonyl
Subtotal
Anti-Oxidants
2,4-dimethyl 6-tert
butyl phenol
2,6-di-tert butyl-4-
methyl phenol
2,6-di-tert butyl
phenol
N^-bis (1,4-dimethyl
pentyl) p-phenylene
diamine
N ,n-butyl -p-ami no
phenol
N,N -diisopropyl-p-
phenylene diamine
N.^-di-sec-butyl-p-
phenylene diamine
Subtotal
1969 CONSUMPTION
Use
Price Level
$/lb wt, vol %
.35 2.34
cc/gal
.36 1.24
cc/gal
7#/
0.59 mbbls
7#/
0.57 mbbls
6#/
.37 mbbls
6#/
.87 mbbls
6#/
.66 mbbls
7#/
.62 mbbls
5#/
.97 mbbls
MM#
285.100
60.690
345.790
1.624
0.738
2.953
0.316
0.189
0.368
1.054
7.242
MM$
101.290
22.150
123.440
0.058
0.420
1.092
0.274
0.124
0.228
1.022
4.118
-------
-29-
ADDITIVES USED IN AUTOMOTIVE GASOLINE - PREMIUM (Cont.)
Additive
Corrosion Inhibitors
Alkyl and amine
phosphates
Alkyl -di amine naphtha-
lene sulfonate
Fatty acid amines
Fatty acid esters
Subtotal
Deposit Modifiers
Cresyl diphenyl phos-
phate
Methyl diphenyl phos-
phate
Methyl phenyl phos-
phates, mixed
Trimethyl phosphate
Possible Minor Use
Tris (B-Chloroisopropyl)
thionophosphate
Subtotal
Detergents
Fatty acid amides
Surface active alkyl
ammonium di alkyl
phosphates
Subtotal
1969
Price
$/lb
0.51
0.20
0.35
0.25
0.30
0.33
0.35
0.55
0.30
.41
CONSUMPTION
Use
Level
wt, vol %
101
mbbls
50 ppm
50 ppm
50 ppm
6 Ibs
mbbls
6 Ibs
mbbls
6 Ibs
mbbls
6 Ibs
mbbls
50 ppm
2 Ibs
mbbls
MM#
8.966
0.664
0.664
0.664
10.958
2.531
1.899
0.633
1.265
6.328
3.322
1.582
4.904
MM$
4.572
0.132
0.232
0.166
5.102
0.759
0.626
0.221
0.695
2.301
0.996
0.648
1.644
-------
-30-
ADDITIVES USED IN AUTOMOTIVE GASOLINE - PREMIUM (Cont.)
Additive
Lead Scavengers
Ethyl ene di bromide
Ethylene dichloride
Possible Minor Use
1969
Price
$/lb
0.20
0.09
CONSUMPTION
Use
Level
wt, vol % MM#
0.617
cc/gal 43.315
0.653
cc/gal 53.582
MM$
8.663
4.822
Calcium sulfonate and
dichlorotoluene
Cresyl diphenyl phosphate
Subtotal 96.897 13.485
Metal Deactivators
N,N]-disalicylidene- 1.5 Ibs
l.?-di-aminopropane 1.40 mbbls 1.580 2.120
Possible Minor Use
N,N2-disalicylal ethy-
lene diamine
Salicylal-orthoamino-
phenol
Rust Inhibitors
Alkyl amine salts of
orthophosohoric acids 0.47
Linoleic acid
derivatives 0.15
Possible Minor Use
2 Ibs/
mbbls
7 Ibs
mbbls
0.843 0.396
4.430 0.664
Ammonium dinonyl naphtha-
lene sulfonate
Fatty acid amides
-------
-31-
ADDITIVES USED IN AUTOMOTIVE GASOLINE - PREMIUM (Cont.)
Additive
Isononyl phenoxy tetra-
ethoxy ethanol
Isooctyl phenoxy tetra-
ethoxy ethanol
Subtotal
Total
1969 CONSUMPTION
Price
$/1b
Use
Level
wt, vol %
MM#
MM$
5.273
478.972
1.060
153.270
-------
Table 8
-32-
ADDITIVES USED .IN AUTOMOTIVE GASOLINE - REGULAR
Additive
Anti -Knocks
Tetraethyllead
Tetramethyllead
Subtotal
Anti-Oxidants
2,4-dimethyl 6-tert
butyl phenol
2,6-di-tert-butyl-4-
methyl phenol
2,6-di-tert-butyl
phenol
N.N'-bis (1,4-dimethyl
pentyl) p-phenylene
diamine
N,n-butyl-p-amino
phenol
N,N -diisopropyl-p-
nhenylene-diamine
N.N^di sec butyl-p-
phenylene diamine
Subtotal
Corrosion Inhibitors
Alkyl and amine
phosphate
Alkyl -diamine naphtha-
lene sulfonate
Fatty acid amines
1969
Price
$/1b
0.35
0.36
0.59
0.57
0.37
0.87
0.66
0.62
0.97
0.51
0.20
0.35
CONSUMPTION
Use
Level
wt, vol %
2.03
cc/gal
0.8
cc/gal
7#/
mbbls
7#/
mbbls
8#/
mbbls
6#/
mbbls
6#/
mbbls
7#/
mbbl<:
5#/
mbbls
10#/
mbbls
50 ppm
50 ppm
MM#
227.750
36.028
263.770
1.499
0.681
2.7e6
0.292
0.175
0.340
0.973
6.686
8.276
0.613
0.613
MM$
80.900
13.160
94.060
0.884
0.388
1.008
j-
0.254
0.115
0.210
0.943
3.802
4.220
0.123
0.215
-------
-33-
ADDITIVES USED IN AUTOMOTIVE GASOLINE - REGULAR (Cont.)
Additive
Fatty acid esters
Subtotal
Deposit Modifiers
Cresyl diphenyl
phosphate
Methyl diphenyl
phosphate
Methyl phenyl phosphate,
mixed
Trimethyl phosphate
Possible Minor Use
Tri (B-chloroisopropyl )
thionophosphate
Subtotal
Detergents
Surface active alkyl
ammonium u! alkyl
phosphate
Fatty acid amides
Subtotal
Lead Scavengers
Ethyl ene di bromide
Ethylene dichloride
1969
Price
$/lb
0.25
0.30
0.33
0.35
0.55
0.41
0.30
0.20
0.09
CONSUMPTION
Use
Level
wt, vol %
50 ppm
5#/
mbbls
5#/
mbbls
5#/
mbbls
5#/
mbbls
2#/
mbbls
25 ppm
0.51
cc/gal
0.538
cc/gal
MM#
0.613
10.115
1.947
1.460
0.487
0.973
4.867
1.460
1.534
2.994
33.114
40.749
MM$
0.153
4.711
0.584
0.481
0.170
0.535
1.770
0.528
0.459
1.057
6.622
3.667
-------
-34-
ADDITIVES USED IN AUTOMOTIVE GASOLINE - REGULAR (Cont.)
1969 CONSUMPTION
Use
Price Level
Additive $/lb wt, vol % IW MM$
Possible Minor Use
Calcium sulfonate and
dichlorotoluene
Cresyl diphenyl phosphate
Subtotal 73.863 10.289
Metal Deactivator
N.^-disalicylidene- 2#/
1,2-diaminopropane 1.40 mbbls 1.946 2.724
Possible Minor Use
2
N,N -disalicylal ethylene diamine
Salicylal-orthoaminophenol
Rust Inhibitors
Alkyl amine salts of 2#/
orthophosphoric acids 0.47 mbbls 0.779 0.366
Linoleic acid 7#/
derivative 0.15 mb^s 4.089 0 613
Possible Minor Use
Ammonium dir.onyl naph-
thalene sulfonate
Fatty acid amides
Isononyl phenoxy tetra-
ethoxy ethanol
Isooctyl phenoxy tetra-
ethoxy ethanol
Subtotal 4.868 0.979
Total 369.109 119.392
-------
Table 9
-35-
ADDITIVES USED IN AVIATION GASOLINE
1969 CONSUMPTION
Additive
Anti -Knock
Tetraethyllead
Anti-Oxidants
N,N -diisopropyl-p-
phenylene-diamine
N.^-di-sec butyl-p-
phenylene-diamine
2,4 dimethyl -6-tert
butyl phenol
2,6-di tert butyl 4-
methyl phenol
2,6-dl tert butyl
phenol
Mixed tertiary butyl
phenols
Subtotal
Corrosion Inhibitors
Alkylaminoalkyl phos-
phate in kerosene
Fatty acid amines
Esters of fatty acids
Alkyl diamine naph-
thalene sulfonates
Amine salt of mixed
alkyl acid phosphates
in kerosene
Subtotal
Pri ce
$/lb
0.35
0.62
0.97
0.37
0.57
0.37
0.44
0.51
0.35
0.25
0.20
0.51
Use
Level
wt, vol %
2.61
cc/gal
8#/
mbbls
8#
mbbls
6#/
mbbls
6#/
mbbls
m
mbbls
8#/
mbbls
!#/
mbbls
2#/
mbbls
2#/
mbbls
2#/
mbbls
2#/
mbbls
MM#
11.360
0.011
0.045
0.017
0.017
0.059
0.034
0.183
0.023
0.003
0.003
0.003
0.003
0.035
MM$
4.050
0.007
0.044
0.006
0.009
0.022
0.015
0.103
0.012
0.001
0.001
0.005
0.0014
0.016
-------
-36-
ADDITIVES USED IN AVIATION GASOLINE (Cont.)
Additive
Lead Scavengers
Ethylene dibromide
Metal Deactivates
Alkylamine alkyl phos-
phate in kerosene
Total
1969 CONSUMPTION
Use
Price Level
$/lb wt, vol % MM#
1.52
0.20 cc/gal 8.663
hos- !#/
e 0.51 mbbls 0.029
20.270
MM$
1.732
0.015
5.916
-------
Table 10
-37-
ADDITIVES USED IN INDUSTRIAL DIESEL FUEL OIL
Additive
Cetane Improvers
Amyl Nitrate
Hexyl Nitrate
Possible Minor Use
Methyl cycl opentadi eny 1 -
manganesetr i carboxy 1
Subtotal
Cold Flow Improver
Nitrated organics
(e.g. Oronite OFA 410)
Delerytinlb
Ethyl MPA-D
Lubrizol 560
Subtotal
Storage Stabilizers
Methacrylate polymers
in kerosene
Organic amine
Subtotal
Total
1969 CONSUMPTION
Use
Price Level
$/lb wt, vol %
0.36 .1-vol
0.33 .1-vol
0.37 .001-wt
0.44 .02-wt
0.45 .02-wt
0.53 .002-wt
0.73 .OC2-wt
MM#
0.202
0.431
0.633
0.006
0.075
0.040
0.115
0.072
0.007
0.079
0.833
MM$
0.072
0.142
0.214
0.002
0.033
0.018
0.051
0.038
O.C05
0.043
0.310
-------
Table 11
-38-
ADDITIVES USED IN JP-4 JET FUEL
Antl-Icing Compounds
Ethylene glycol mono-
methyl ether and
glycerine
Anti-Oxidants
2,4-dimethyl-6-tert
butyl phenol
2,6-di tertiary butyl
4-methyl phenol
2,6-di tertiary butyl
phenol
N.N diisopropyl-para
phenylene diamine
N,N di-secondary butyl
para phenylenediamine
Tertiary butyl
phenols
Subtotal
Corrosion Inhibitors
Alkylamino alky! phos-
phates in kerosene
Amine salts of mixed
alkyl acid phosphates
in kerosene
Subtotal
Metal Deactivators
Alkylamino alkyl phos-
phate in kerosene
Total
1969
Price
$/lb
0.13
0.59
0.57
0.37
0.62
! 0.97
0.44
0.57
0.51
0.51
CONSUMPTION
Use
Level
wt, vol %
.15-vol
8#/
mbbls
6#/
mbbls
7#/
mbbls
mbbls
8#
mbbls
6#/
mbbls
1.250/
mbbls
2#/
mbbls
1.25#/
mbbls
MM#
66.500
0.209
0.078
0.319
0.052
0.210
0.078
0.946
0.082
0.130
0.212
0.038
67.696
MM$
8.650
0.123
0.044
0.118
0.032
0.203
0.034
0.554
0.047
0.066
0.113
0.017
9.334
-------
Table 12
-39-
ADDITIVES USED IN JP-5 JET FUEL
Additive
Anti-Oxidants
2, 4-dimethyl- 6- tertiary
butyl phenol
2, 6-di- tertiary butyl
4-methyl phenol
2, 6-di -tertiary butyl
phenol
N,N -di-isopropyl-para
phenylene diamine
N,N -di -secondary butyl -
para phenylenediamine
Tertiary butyl phenols,
mixed
Subtotal
Metal Deactivator
Alkylamino alkyl phos-
phate in kerosene
Possible Minor Use
1969 CONSUMPTION
Use
Price Level
$/lb wt, vol % MM#
8#/
0.59 mbbls 0.076
6#/
0.57 mbbls 0.029
6#/
0.37 mbbls 0.099
8#/
0.62 mbbls 0.019
8#/
0.97 mbbls 0.076
6#/
u.4t> moDis 0.02y
0.328
2.5#/
0.51 mbbls 0.119
MM$
0.045
0.016
0.037
0.012
0.074
U.UM
0.197
0.060
Amine salts of mixed alkyl
acid phosphates in
kerosene
V
Total
0.447
0.257
-------
Table 13
-40-
GENERAL CHEMICAL CLASSES OF REGISTERED GASOLINE ADDITIVES
Chemical Class
Number of
Chemical Compounds
Present in Class
Total of
Registered Fuel
Additives Containing
Chemical Compounds
Listed in Class
Alcohols
Alkyl Hal ides
Alkyl Phosphates
Alkyl Poly amines
Amines
Anthroqui nones
Aroma tics
Aromatic Phosphates
Azo Compounds
Azo-Naphthels
Imines
Lead Compounds
Naphthalenes
Phenels
Phenylenedi amines
Pyrimidines
Trace Substances
29
79
23
30
42
22
33
26
16
67
4
95
11
29
32
3
10
154
720
97
97
73
44
130
58
32
363
37
912
4
111
175
3
15
Total Individual Additives Registered for Use in Gasoline as of
December 31, 1972 = 322.
-------
-41-
Average exhaust gas emissions for U. S. vehicles by age group
are reflected below. These data are for vehicles tested at the
condition specified in the cities shown:
Average Exhaust Emissions*
City and
Year Group
Los Angeles
pre 66
66-67
68-69
70
Chicago
pre 66
66-67
68-69
70
2500
HC (ppm)
390
220
190
130
410
330
220
120
ppm
CO («)
3.1
1.3
1.2
0.9
2.9
2.4
1.2
0.9
HC (ppm)
720
370
350
230
690
590
350
250
idle
CO (%)
4.9
3.1
3.7
2.4
4.4
4.4
3.5
2.6
* Voelz, et al; Journal of the Air Pollution Control
Association, December 72.
-------
-42-
Gaseous Emissions Relative to Fuel Composition and Fuel Additives
John E. Sigsby, Jr.
Dr. Richard Miller
Dr. Theodore R. Torkelson
Nature:
The gaseous emissions of automobiles operated on a dynamometer are
typically shown in Table I. The emissions from the same vehicle operated
with a catalytic system are shown in Table II.
All tests were made on a car operated on Shell no-lead gasoline.
These tables are very brief summaries and do not include all of the
detailed composition. Almost all hydrocarbons can be detected and all
fuel components are directly reflected in the emissions.
Possible oxygenated materials are reflected in Tables III, IV, and
V. Nitrogen containing organic compounds is usually found at very low
levels.
Operational parameters such as break-in, history, vehicle type, fuel
composition, and operating cycle are all critical to the results and
must be standardized.
Fuel composition is directly reflected in exhaust composition and
also in particle oxidation and cracked products. Benzaldehyde and styrene
relfect the C+ mono alkyl benzene concentration.
-------
-43-
'71 Ford
Table I
Current Systems
Emissions in gm/mile operated on LA-4 cycle (Fed. Procedure)
HC
CO
NOX
Paraffin
Olefin
Aromatic
Dilution Ratio
Exhaust Vol CF/Mile
Methane
Ethane
Acetylene
iso Butane
n Butane
iso Pentane
n Pentane
Hexanes
Heptanes
Total
Ethylene
Propylene
Butenes
2-me-l-butene
3-m3-l-butene
Others
Benzene
Toluene
Tehylbenzene
o, p-xylene
m-xylene
Mesitylene
1,2,4-trimethylbenzene
Others
Cold Start
2.32 ± 0.065
39.30 ± 1.910
4.02 ± 0.41
1.13 ± 0.049
1.07 ± 0.058
0.15 ±
10.11 ± 0.15
92.87 ± 1.65
0.169 ± 0.005
0.031 ± 0.001
0.208 ± 0.004
Hot Start
0.004
0.045 ±
0.051 ±
0.008
0.111 ±
0.120
0.342 ±
0.272 ±
0.139 ±
0.077 ±
0.012 ±
0.007 ±
0.164 ±
0.670 ±
0.188 ±
0.201 ±
0.046 ±
0.078 ±
0.070 ±
0.011 ±
0.054 ±
0.061 ±
0.724 ±
0.006
0.005
0.017
0.087
0.006
0.005
0.002
0.001
u.OOl
0.009
0.022
0.008
0.007
0.001
0.005
0.004
0.001
0.004
0.003
0.023
1.81 ±
15.60 ±
4.06 ±
0.90 ±
0.84 ±
0.10 ±
11.23 ±
82.27 ±
0.091 ±
0.021 ±
0.158 ±
0.005
0.077 ±
0.085 ±
0.019 ±
0.108 ±
0.118
0.432 ±
0.212 ±
0.117 ±
0.026 ±
0.011 ±
0.003
0.146 ±
0.572 ±
0.142 ±
0.142 ±
0.031 ±
0.050 ±
0.047 ±
0.005
0.035 ±
0.040 ±
0.504 ±
0.078
2.230
0.13
0.05
0.036
0.007
0.14
0.47
0.010
0.005
0.011
0.016
0.013
0.001
0.002
0.083
0.002
0.006
0.002
0.039
0.050
0.024
0.020
0.001
0.002
0.003
0.002
0.002
0.045
-------
-44-
Table II
With Catalyst
'71 Ford Emissions in gm/mile operated on LA-4 cycle (Fed. Procedure)
Hot Start, No Air Added
HC 0.16
CO 5.69
NOV 4.38
A ..
Paraffins . 0.11
Olefins 0.035
aromatics 0.010
Dilution
Dilution Ratio 11.16
Exhaust Vol, CF/Mile 82.06
Methane 0.025
Ethane 0.008
Acetylene 0.003
0.036
Isobutane 0
n-butane 0.004
Isopentane 0.005
C(. u.OOi
C^ 0.005
C7 0.001
1 0.016
Ethylene 0.019
C3= 0.006
C4= 0.006
C5= 0.001
C6= 0.001
Others °-004
0.037
Benzene 0.022
Toluene 0.016
Ethyl benzene 0.004
o,p-xylene 0.006
n-xylene 0.006
Mesitylene 0.001
1,2,4-trimethylbenzene 0.003
Others 0.004
-------
-45-
Table IV
Oxygenates in Exhaust from Simple Hydrocarbon Fuels
Oxygenate Concentration range, ppm
Acetaldehyde . 0.8-4.9
Propionaldehyde (+ acetone) 2.3-14.0
Acrolein 0.2- 5.3
Crotonaldehyde (+ toluene) 0.1- 7.0
Tiglaldehyde <0.1- 0.7
Benzaldehyde <0.1-13.5
Tolualdehyde <0.1- 2.6
Ethyl benzaldehyde <0.1- 0.2
o-Hydroxybenzaldehyde (+ C,Q <0.1- 3.5
aromatic)*11 .
Acetone (+ propionaldehyde) 2.3-14.0
Methyl ethyl ketone , <0.1- 1.0
Methyl vinylketone ( + benzene) 0.1-42.6
Methyl propyl (or isopropyl)
ketone <0.1- 0.8
3-Methyl-3-buten-2-one <0.1- 0.8
4-Methyl-3-penten-2-one <0.1- 1.5
Acetophenone <0.1- 0.4
Methanol 0.1- 0.6
Ft.hannl ^ <0.1 0.6
C5 alcohol (+ GS aromatic)' <0.1- 1.1
2-Buten-l-ol (+ C5H80) <0.1- 3.6
Benzylalcohol <0.1- 0.6
Phenol + cresol(s) <0.1- 6.7
2,2,4,4-Tetramethyltetrahydrofuran <0.1- 6.4
Benzofuran <0.1- 2.8
Methyl phenyl ether <0.1
Methyl formate <0.1- 0.7
Nitromethane <0.8- 5.0
CrHfiO <0.1- 0.2
CO <0.1- 0.3
Values represent concentration levels in exhaust from a'M test fuels,
Data represent unresolved mixture of propionaldehyde + acetone.
Chromatographic peak shape suggests acetone to be the predominant
component.
cToluene is the predominant component.
The C]Q aromatic hydrocarbon is the predominant component.
p
Benzene is the predominant component.
The aromatic hydrocarbon is the predominant component.
-------
Table V
Observed and calculated level* (ppm) of oxygenates In exhaust from simple hydrocarbon fuels
Fuel
2 -Me thy 1-
2-butene
+ Iso-
pentone
Obg.
Calc.
2 -Me thy 1-
2-butene
f Iso-
octane
Obs. |Calc.
2-M thyl-
2- utene
+ Iso-
octene
Obs.
Calc.
2 -Me thy 1-
2-butcne
+ toluene
Obs.
Calc.
2-Methyl-
2-butene
+ o-xylene
Obs. |Calc.
Isooctene
+ 180-
octane
Obs.
Calc.
Isooctane
+ toluene
Obs. [Calc.
Isooctane
+ Iso-
pentane
Obs. [Calc.
Isopencane
+ .o-xylene
Obs. [Calc.
Zaooctene
+ £-xylene
Obs. [Calc.
Isooctane
* o-xylene
Obs. |Calc.
2-Methyl-
2-butene
+ Isooctane
+ o-xylene
Obs.
Calc.
Isooctane
t- Isooctene
+ toluene
Obs. [Calc.
HLDEMYDKS
Acroletn -f propylcne oxide
Prop tonaldeh yd 6
Methacroleln + methylfuran
Tlglaldfhyde
Ethyl benzaldehyde
Total aldehydes
6.3
3.0
3
3 1
1.0
.7
1 2
1
.5
.0
16.2
8.2
3.6
t,
2.2
.4
1
7
1
2
.0
15.9
7.8
2.6
,1
4.0
.9
.9
.8
2
.3
.0
17.6
6.2
2.3
.3
1.4
.3
.2
.3
.1
.1
.0
11.2
6.1
2.5
.0
.4
.6
1.4
1.1
2
.1
.3
12.7
7.2
3.4
.4
1.5
1.2
.6
.7
.7
.1
.0
15.8
4.9
3.4
0
1.5
.0
.4
8.3
1
.2
.0
18.8
6.8
2.5
2
1.5
.5
.1
4.0
1
.1
.0
15.8
8.5
3.5
1
5.3
.0
.0
2.2
10.7
.1
.1
30.6
4.9
3.2
2
1.4
.2
.1
.7
7.5
.2
.1
18.5
4.2
2.3
.0
.1
.0
.5
.5
.2
.2
.0
8.0
5.0
2.3
.3
.2
.9
.6
.5
.2
.1
.0
10.1
3.2
2.5
.1
.4
.0
.0
8.4
.1
.2
.1
15.0
4.4
1.4
. 1
.1
.0
.1
3.3
. i
.1
.0
9.6
9.9
4.7
.0
1.7
.7
.0
.3
1
.5
.0
17.9
4.8
1.6
.2
.4
.1
.1
.4
.1
.2
.0
7.9
KE TONES
Kcthv Ivlny Ike tone .........
Methyl ethylKptonc ><* .
3-Kethyl-3-buten-2-one. . . .
4-Methyl-3-pentcn-2-one. . .
Total kctones
7.9
2.3
1.1
3
.5
2
2
12.5
5.2
1.8
. 7
2
.3
1
1
8.4
9.1
2.3
1.0
2
.7
.0
2
13.5
6.1
1.5
.5
1
.2
1
1
8.6
11.8
3.8
1.2
4
1.0
3
2
18.7
10.4
2.3
.7
1
f 2
.5
1
14.3
8.8
.0
.5
.0
.0
3
2
9.8
4.3
1.4
.5
1
.2
.0
1
6.6
9.5
.0
1.0
.0
.7
.1
3
11.6
3.7
1.3
.5
1
. 2
0
1
5.9
8.5
.8
.3
1
.0
.4
1
10.2
8.6
1.0
.3
. 1
.0
.6
1
10.7
2.8
.0
.0
0
.0
.0
2
3.0
3.2
.1
.1
0
.0
.0
1
3.5
3.7
.8
.3
.1
.0
.0
2
5.1
3.5
.3
.2
.1
.1
.1
.1
4.4
6.8
3.9
.4
1. 1
.0
.0
4.4
17.8
.2
.4
35.1
3.5
2.4
1
.4
.1
.0
.8
7.0
.2
.1
14.6
1.7
2.4
.0
.0
.0
.2
3.4
5.9
.2
.2
14.0
4.2
2.8
.2
.1
1.0
.6
.9
6 9
.2
.1
17.0
2.4
1.1
.1
.8
.0
1.4
8.7
3.1
.2
.0
17.8
3.1
2.1
.1
.1
.0
.1
.5
6 8
.1
.1
13.0
9.8
4.5
.2
2.0
.0
.0
2.1
6.8
.2
.2
25.8
5.5
2.6
.0
.9
.2
.1
.5
4.7
.1
.1
14.9
2.4
2.4
.2
.0
.0
.0
9.4
2
.2
.0
14.8
5.2
2.0
.2
.2
.7
.4
2.5
.1
.1
.0
11.4
2. 1
.0
.0
.0
.9
.0
.3
3.3
1. 1
.1
.1
1
.0
.1
1
1.7
6. 1
.0
.2
.9
.0
.0
.2
7.4
7. 1
.9
.3
1
.0
.6
1
9.1
2.6
.0
.0
.0
.0
.0
.2
2.6
2.8
.2
2
1
.1
.1
2
3.7
9. 7
1.3
.4
.0
.2
.1
2
11.9
4.1
1.0
.3
.1
.2
.0
1
5.8
4.6
.0
.0
.0
.0
.0
.1
4.7
6.8
.8
.2
.1
.0-
.4
.1
8.4
N0NCARBONYLS
Methyl formate
E thanol *
Tetramethyltetrahydrofuran
Propeneni t rile . .
C H, -0
c H 6
C.H O
r H 0
Benzo Cuiran *««...«
Phenol + cresol. .........
2.3
.0
1.9
4
.0
.8
6.8
.5
.7
.4
.0
.0
.1
.1
.0
.0
14.0
42.7
2.3
.0
4.1
5
.0
4
4.7
.0
1.1
.1
.0
.0
.0
.1
.0
.0
13.3
37.6
2.3
.0
.6
.5
1.0
,3
1.3
.3
.9
.0
.0
.0
.0
.0
.0
.0
7.2
38.3
2.2
.0
3.4
.4
.1
.3
2.8
.1
.2
.0
.1
.0
.0
.1
.0
.0
9.7
29.5
1.8
.0
.4
5
.0
4
4.1
.6
.3
2.8
.0
.0
.1
.1
.0
.0
11.1
42.5
2.3
.0
3.2
5
.0
.1
3.0
.1
.2
3.2
.1
.0
.0
.0
.0
.0
12.7
42.8
1.7
.0
.1
6
.0
5
1.8
.6
.0
.6
.0
.0
.0
.1
.0
.4
6.4
35.0
1.5
.3
2.9
3
.0
5
2.4
.1
.2
.0
.1
.0
.0
2
.0
.0
8.5
30.9
1.4
.0
.0
.0
.0
.7
1.2
.0
.5
.0
.0
.0
.0
.2
.2
.8
5.0
47.0
1.3
.0
2.6
3
.0
I
2.3
.1
.2
.0
.1
.0
.0
5
.1
3
7.9
32.3
1.6
.0
1.-'.
5
.0
8
2.6
.0
.2
3.2
.0
.0
.1
.1
.0
.1
10.6
28.8
2.5
.0
1.3
2
.1
1
1.8
.1
.0
.0
3.5
.0
.1
1
.0
1
9.9
30.7
1.4
.0
1.2
8
.0
5
1.0
.0
. .0
.0
.0
.1
.0
1
.3
1 2
6.6
24.6
1.8
.2
.8
. 1
.1
3
1.1
.0
.0
.0
.0
.0
.0
2
.0
.0
4.6
17.7
3.3
.0
2.1
1 2
.6
5
3.8
.0
.0
.2
.0
.0
.0
1
.0
.1
11.9
34.9
2.3
.0
1.5
.2
.1
3
2.6
.0
.6
.1
.0
.0
.0
.1
.0
.0
7.8
20.1
1.6
.0
.0
o
.0
4
2.3
.0
.0
.0
.0
.0
.1
.5
.5
1.6
7.0
45.4
1.4
.0
.6
1
.0
2
2.1
.0
.6
.1
.0
.0
.0
.4
.1
3
5.9
22.2
1.3
.0
.5
1 0
.0
8
2.6
.4
.0
4.2
.0
.0
.0
.4
.2
1.1
12.5
33.9
1.9
.0
.6
.2
.0
0
1.4
.1
.0
3.9
.0
.0
.0
.5
.1
.3
9.0
35.1
1.4
.0
.0
.0
.0
.5
.5
.0
.0
.0
.0
.0
.1
.4
.2
1.1
4.2
24.8
1.7
.0
.8
.1
.1
.1
1.2
.0
.0
.0
.0
.0
.0
.5
.1
.3
4.9
21.6
2.2
.0
.0
.0
.0
.9
.9
.0
.4
.0
.0
.0
.0
.3
.3
.7
5.7
43.4
1.7
.0
2.2
.3
.0
.2
2.1
.1
.1
.0
1.0
.0
.0
.3
.1
.2
8.3
29.0
1.7
.0
.7
.5
.0
.3
.6
.0
.1
.7
.1
.0
.0
.1
.1
.6
5.5
25.3
2.2
.2
1.0
.2
.0
.2 '
1.4
.1
.0 ..
2.6
.0
.0
.1
.2
.0
.6
8.2
28.0
en
-------
-47-
Sampling of the exhaust stream depends upon the ultimate goal
of the study., "Constant Volume Sampling Systems" (CVS), see Federal
Register, November 1972, are adequate for the gross analysis of controlled
species, i.e., CO, N(L and total hydrocarbon. Such systems can be used
for detailed hydrocarbon analysis. This latter is performed for
between 100 and 200 individual compounds by programmed gas chroma-
tography.
Oxygenates in exhaust are extremely likely. Any surface that may
be moist will remove large amounts of them. The relative humidity
must be maintained at less than 50% to prevent this phenomenon.
Any sample-handling system must be thoroughly evaluated for its
adequacy in handling the specific compounds of interest.
Oxygenates are determined by a variety of techniques including
direct gas chromatoqraphy, gas chromatoqraphy-mass spectoscoD.v.
and gas chromatography of chemical derivatives. There are no satis-
factory continuous analyses.
Large volume samples can be collected by cryogenic trapping
(see attached) or by collection on packed traps. Unpacked traps may
not be quantitative due to the passage of particles through the trap.
Packed traps may react with components of the system through changing
the composition of the samples. Reactions of condensed phase
materials with other exhaust gas components, such as NO^ are very
common and must be avoided. These reactions should be determined
analytically by comparing gas phase concentrations and composition
with lhat of the condensed phase.
-------
-48-
Whatever witchcraft is necessary to obtain an accurate sample
must be performed.
The effects of emission control systems may be major. The obvious
primary effect is to lower the concentration of the controlled components,
In addition, composition changes may occur depending upon its operating
condition.
-------
-49-
Report of Particulates Subcommittee
Members Affiliation
1. Mr. Kirby Campbell EPA - Cincinnati
2. Mr. Thomas Gleason EPA - ORM
3. Dr. Sidney Laskin NYU - School of Environmental Medicine
4. Dr. R. L. Bradow EPA - RTP
Sampling for lexicological Studies
Practicality of toxicological experiments with 200 to 1000
animals suggests an ultimate need of at least 15 grams, preferably
50 to 100 grams of material. The sampling system used in collection
of particulate must, therefore, be compatible with large scale collection
of particulate material. Automobile exhaust for typical leaded fuels
contains mostly lead particles with MMED less than 0.2 p. Typical
emission rates of these particles are in the order of 0.5 grams/mile.
Filtration of the whole exhaust can yield adequate amounts of material
in about 100 miles of operation, mostly of lead particles. With
unleaded fuels typical emissions rates are in the order of 0.04 g/mile.
Concequently, 300 - 400 miles of LA-4 operation or 40 to 50 22-minute
cycles are required. Results of extraction experiments suggests that
the organic matter is essentially completely extractable in appropriate
solvents. Therefore, it appears that standardized filtration experiment
is the most appropriate route.
The combination of methods including cryogenic trapping and
adiabotic expansion plus filtration may result in higher collection
rates. An alternative scheme might employ centrifugation as a means
-------
-50-
of collection of large volumes of participates.
Analytical Results
Analysis of inorganic matter in particulate matter has been
the main thrust of DOW Chemical Company research for EPA. With
leaded fuels, mixed lead halides and oxyhalides are the primary
constituents of the total particulate. Other inorganic compounds
found in the particulate include PbSO^, Ni 0, NH4 Br, PbgC(CPOJ3,
Quartz, calcite, NaCl, NH4C1, 4Pb Pb S04, Fe304, Fe203, Fe 0 OH, ZnO,
Fe.
Particle sizes characteristic of these compounds were obtained
in this work by atomic absorption spectroscopy of Andersen sampler.
Results for a few characteristic elements are shown below in Table 1.
The Table indicates that organic matter is present primarily in the
very small particles. Under most conditions, lead particles are also
very fine, about 0.1 u in effective median diameter, there are conditions
in which the particle size distribution is shifted toward larger
particles.
Organic substances in the particulate range in molecular size
from about C,r to about C as judged by a boiling point type
G. C. separation. This molecular weight range is similar to that
of organics in air samples. Although filters differ in collection
efficiency, the molecular weight distribution of compounds extracted
from various filter batches is similar. With non-leaded fuels, the
-------
-51-
majority of the collected parti oil ate matter is solvent extractable
although protic solvents may be necessary to complete this extraction.
With leaded fuels, the solvent soluble fraction composes 2 to 6%
of the total. Table 2 presents some of the detailed analytical data
obtained in the DOW work showing small amounts of carboxylic acids
(presented as wt. % benzoic acid), phenolics, aldehydes and aromatic
ketones. Carbon, hydrogen, and nitrogen analysis of the overall
organic particulate and of the extract have been made in a few cases.
The data for the material on the filter and for the extract is quite
similar; the majority of the extract weight is accounted for by
carbon and hydrogen and the C/H ratio is approximately 2. Nitrogen
accounts for about 2% by weight of the extract. Therefore, there is
H lllfPllhnnH that cnmo nvnanir- ni t^nnonnuc mal-ov*-! al i.iill k« nv.*%<-'M»4-
"" -'*/ - ., ^ ....-«._ . . . « ~ s» f I M »**. ftt.v'W*!**
as a background even with no N-bearing additive present.
Table 3 presents high resolution mass spectrometric analysis
of the overall particulate indicating appreciable quantities of both
nitrogen and oxygen bearing substituents. Table 4 presents possible
hydrocarbon types by mass spectrometry. It is apparent that the
great majority of the organic matter is aliphatic with appreciable
amounts of alkyl benzenes and smaller amounts of higher aromatic
compounds. In a number of runs with 0.5 g/gal TEL bearing fuels,
the BaP content of the total particulate ranged from 30 to 1000 ppm
by weight.
-------
-52-
Table 1
Mass Median Equivalent Diameter, Microns
Component
Fuel Run No. Pb Cl Br Organics
Gasoline 1+ 7 0.1 0.1 0.1 0.1
3 g. TEL as
motor mix
Gasoline 2 + 23 <0.1 <0.1 <0.1 <0.1
3 g. TEL as
motor mix
Gasoline 1+9 2.0 1.2 <0.1
3 g. TEL + EDC
Amoco No Lead 29 0.1 3.3 <0.10 <0.1
-------
Fuel
Run No.
Table 2
Organic Analysis of Collected Particulates
Benzene and
Methanol Soluble
wt. %
Acidity as Phenolics as
wt. % C00H (fr-OH. wt. %
Carbonyl
Asbenzophene Aldehyde
wt. % wt. %
Gasoline 1 +
3 cc TEL
Amoco
no lead
Gasoline 2 +
3 cc TEL
Amoco + 0.5 g TEL
19
22
24
40
8.6
55
1.7
6.5
1
0.7
0.3
0.1
0.8
0.08
0.2
0.02
0.2
<1.7
2.0
2.5
1.7
1
0.6
2.5
I
in
CO
-------
-54-
Table 3
Percent of Total Ion Content by High
Resolution Mass Spectrometry of Extract
Ion Types
CH
CHO
CH02
CHN
CHN2
Sample A
90.2
4.2
4.3
1.3
0.03
Sample B
89.3
3.2
6.8
0.7
0.01
-------
-55-
Table 4
HYDROCARBON TYPE ANALYSIS
HIGH RESOLUTION MASS SPECTROMETRY
Sample A* Sample B
Hydrocarbon 7 mg 10% Organic 122 mg <1.0%
Type
Orqa
nic
% Volume
C H
n 2n
CnH2n
Cn"2n
CnH2n
CnH2n
CM,.
n 2n
cnH2n
f 1 1
"n"2n
CnH2n
CnM2n
CnH2n
CLI
«"o«
n 2n
CnH2n
CnH2n
CnH2n
C H0
n 2n
+ 2
- 2
- 4
- 6
- 8
- 10
1 0
1 i-
- 14
- 16
- 18
- 20
- 22
- 24
- 26
- 28
21.0
23
!4.
3
26
10
1
A r>
U . O
0.02
0.83
0.45
0.05
--
--
--
.. «.
46.
20
14
3
16
<0.
0.
^
u .
0.
-
0.
_
0.
0.
-
_
0
1
1
-------
-56-
Apparently the exhaust particulate is composed primarily
of paraffinic and olefinic hydrocarbons, alkylbenzenes with lesser
amounts of carboxylic acids, probably esters and polynuclear aromatics
Small but significant amounts of nitrogenous species are also present.
-------
-57- ' ' ..'. . Y '.
Automotive Exhaust Emissions Control Devices
The 1970 Clean Air Act Amendment requires that exhaust emissions
from motor vehicles be reduced by at least 90% from 1970 levels. Such
reductions are to be achieved by 1975 for carbon monoxide and hydrocar-
bons and by 1976 for oxides of nitrogen. As a result of these required
emissions reductions, much attention has been paid to add-on catalytic
devices, engine modifications, etc. It appears, at the present time,
that catalytic devices will provide the only reasonable method for
achieving the emissions standards in model years 1975 and 1976. Although
little data are available which reflect the effect of such devices on
emissions other than those regulated (HC, CO, NO ), the following dis-
/\
cussion provides research data currently available on prototype devices.
-------
-57-
Effect of Emission Control Devices on Participate Emissions
Attached is a summary of data which shows the effect on
participates of some control devices which are currently being
considered for use on vehicles.
These devices were tested on a 1972 400 CID Pontiac engine. The
particulate was collected on fiberglass filter pads, and in an
Andersen impactor. The sampling period in all cases was 2 hours.
The federal 23 minute LA-4 cycle does not give enough particulate
collected for a meaningful analysis.
The devices are proprietory, and therefore are coded. Catalysts
B and C are oxidation catalysts, while A is a reducing catalyst.
Some preliminary conclusion are as follows:
1. Grams/mile particulate increased at 60 mph for all
catalysts, compared to the baseline.
2. At 30 mph, grams/mile increased in one instance, but
decreased in 2 cases.
3. Aldehydes in the conden^ate decreased in all cases.
4. NH3 did not appear to be significantly changed.
5. Carbon percentage in the particulate decreased with
use of the catalysts.
6. BaP was somewhat less, but not significantly so.
7. Trace metals which could be attributed to catalyst degradation
did not increase as a percent of the total particulate.
8. Grams/mile particulate decreased with time and miles on
vehicle studies.
-------
Baseline, Unleaded Fuel, 400 CID Pontiac Engine
Test Mode
30
60
30
60
30
60
30
60
mph
mph
mph
mph
mph
mph
mph
mph
Grams/Mile
Parti cul ate
.0238
.0167
.0968
.0905
.0048
.1052
nil
.0554
rrn i
HCHO
210
360
14
12
19
5
28
5
ii ounu-iiaa i.
NH3
6
10
Catalyst A,
4
Catalyst B
36
.9 7
Catalyst C
.3
c rrn
Hydrocarbon
275
145
Unleaded Fuel ,
75
20
, Unleaded Fuul
40
5
, Unleaded Fuul
37.5
1
10 n i
in Parti cul ate
<.153
400 CID Pontiac
.05
, 400 CID Pontiac
.02
, 400 CID Pontiac
.09
o
in Parti cul ate
76
59
Engine
<1
Engine
7
2
Engine
11
.9
.4
.0
.6
.9
.9
.1
(jpiii oar \J\J\
in Parti cul ate N00
11
1
<.
2 850
2 850
35 450
1
7 330
in
NO
260
575
570
1250
145
1
1
0 65
6
9
1600
1100
1500
00
-------
-59-
PARTICULATE COMPARISONS
1 CFM FILTER - 142 mm fiberglass
VEHICLE VEH/MILES CONV/MILFS MODE G/MILES
BASELINE 2886 - 60 MPH ,0049
BASELINE 8572 - 60 MPH ,0067
61314 4816 * 60 MPH ,0544
61314 34000 * 60 MPH ,0066
61329 6700 3200 60 MPH ,0519
61329 11300 7800 60 MPH ,0291
PONTiAC 4325 455 60 MPH ,0504
6000 2130 60 MPH ,0360
10841 6971 60 MPH ,0385
15851 11981 60 MPH ,0257
CONV, MILES UNKNOWN
-------
-60-
Polycyclic Aromatic Hydrocarbons (PAH)
and Other Possible Hazards in Automotive Exhaust
In terms of carcinogenic bioassay studies, as to some extent in
analytical studies, the following factors are of importance: The
sample should be large enough for biological study. Two types of
samples must be collected -- vapor phase and particulate material.
The sample to be meaningful must be representative of automotive
exhaust material in the air as breathed by human beings. The integrity
of the sample must be maintained over the period of time necessary
for analytical and biological studies.
Since another group is covering direct sampling of automotive
exhaust, we will briefly mention sampling of ambient air mainly polluted
with automotive exhaust materials. The vapor phase can be collected
on wood charcoal, a chromosorb or some other gas chromatographic
material, a liquid phase organic material bonded to an inorganic
phase. The reason for collecting a vapor is because some carcinogenic
materials are vapors or partial vapors, e.g., tetracyclic aromatic
hydrocarbons, azo arenes (such as some of the methyl benzacridines),
long chain aliphatic hydrocarbon epcxides, diepoxides, slkyl sulfonates,
aultones, nitrosamines, etc. Only the polynuclear compounds have been
identified in automotive exhaust or in air polluted by exhaust fumes.
However, EPA has a contract to sample atmospheric vapors and assay
for the above types of carcinogens. Phenols are of some importance
here since they have been shown to have some carcinogenic effect.
-------
-61-
A list of some of these phenols found in auto exhaust is shown
in Table I. Phenols are emitted in much larger amounts from the
automobile than are the PAH. They are usually collected in an impinger
containing 0.1 N NaOH. A small proportion of the monocyclic phenols
is found in the particulate phase. EPA has a contract to develop a
better method of sampling for phenols. In this case a solid device
will be used for collection. Total phenols can be determined by
several colorimetric methods, e.g., 4-aminoantipyrine and p-nitro-
benzenediazonium salts are usually used.
For analysis of the various individual vapors gas chromatography
has been the method of choice. It is probably the best method. For
nitrosamines gas chromatography - mass spectroscopy has been used to
assay and characterize nitrosamines found in the environment.
The particulate phase of automotive exhaust-polluted air is usually
collected on glass fiber filters. Studies are available on efficiency
and reproducibility of collection. Some of the hydrocarbons (vapor
and particulate) that have been found in automotive exhaust are shown
in Table II. Those compounds with carcinogenic activity are starred.
About a dozen of the compounds are carcinogenic. Some of the methyl
derivatives, such as the methylfluoranthenes, and methylbenzanthracenes
could have biological activity.
Another group of compounds that could be of importance are the
long chain aliphatic hydrocarbons. These can be analyzed by molecular
sieve chromatography, iodination to get rid of the olefins and
chromatography followed by gas chromatography. The total aliphatic
hydrocarbons are of possible importance as carcinogens.
-------
-62-
Table I
Phenols in Auto Exhaust
Phenol
0-Cresol
m-Cresol
p-Cresol
2,4-Dimethylphenol
2,3-Dimethylphenol
3,4-Dimethylphenol
2,3,5-Trimethyl phenol
Salicylaldehyde
Table II
Polycyclic Aromatic Hydrocarbons in Auto Exhaust
Naphthalene'
Acenaphthylene
Anthracene, A
Alkyl As
Phenanthrene
Trimethylphenanthrenes
Benz(a)anthracene, BaA*
Methyl BaA
Dimethyl BaA
Chrysene, C*
Methyl C
Dimethyl C
Fluoranthene, Ft
Methyl Ft
Pyrene, P
Methyl P
11 H-Benzo(b)fluorene, BbF
Methyl BF
Triphenylene
Naphthacene
Benzo(a)pyrene, BaP*
Methyl BaP
Dimethyl BaP
Benzo(e)pyrene, BeP*
Methyl BeP
Dimethyl BeP
Benzo(ghi)fluoranthene
Benzo(b)fluoranthene*
Benzo(j)f1uoranthene*
Benzo(k)fluoranthene*
Dibenz(a,h)anthracene*
Dibenzofluorenes
Pentaphene
Perylene
Anthanthrene
Benzo(ghi)perylene
Dibenzo(a,l)naphthacene
Dibenzo(a,e)pyrene*
Di benzo(a ,h)pyrene*
Dibenzo(a,ljpyrene*
Indeno(l,2,3-cd)fluoranthene
IndenoO ,2,3-cd)pyrene*
Coronene
Dibenzo(b,pqr)perylene
8
Tribenzo(h.rst)pentaphene
*Carcinogenic
-------
-63-
'Multi-Stage Cryogenic Trapping System
JAMES P. CONKLE, M.S., JAMES W. REGISTER, B.S., and GORDON L. WORTH
A portable, easily operated, multi-stage cryogenic trapping
system contained in a box 86 x 66 x 61 centimeters has been
developed. Liquid nitrogen, gaseous nitrogen, ice, dry ice and
110 volt 60 cycle power required for operation of the system are
available to most military installations.
Ice formation in the -78:C trapping cylinder entrance tube
and liquid oxygen formation in the -175:C trapping cylinder
were eliminated in the design of the system. Catalytic conversion
of trapped materials was minimized by use of stainless steel and
Teflon. Operation of the system was simplified by inclusion of
a liquid nitrogen level-controller.
Partial separation of compounds was accomplished by oper-
ating the trapping cylinders of the system at three different
temperatures. Several compounds are listed according to the
temperature at which they are expected to be concentrated in
significant quantities. The system is clTicient for concentration
of micro and macro contaminants in an atmosphere. The con-
centration of a contaminant in a sample area may be estimated
from the total trapping time, the flow through the system during
trapping and the concentration of the contaminant in the trap-
ping cylinders.
DETERMINATION of trace contaminants in a
* spacecraft, an aircraft or the ambient atmosphere
1 . .!
DC 111
sample collection, sample concentration, separation of
the individual contaminants, identification and quanti-
tation.
Techniques that have been used for sample collec-
tion, sample concentration and separation of the indi-
vidual contaminants include gas pressurization in steel
bottles,* activated carbon bed sampling1-1-* and cryo-
genic trapping.1 Each of these methods has its dis-
advantages. Gas pressurization in the steel cylinders
does not concentrate the sample appreciably. Carbon
bed sampling, while it effectively concentrates the
sample, requires additional operations to separate the
contaminants from the carbon. In carbon bed sampling
catalytic reaction may cause degradation of a contami-
nant or interaction between contaminants. One cryo-
genic system5 that has been used effectively to concen-
trate samples is constructed of delicate material and
requires that the sample be maintained at the temper-
ature at which it was taken, or that the sample be
transferred to another container for shipment or storage.
One approach which does not have the disadvantages
of other techniques is multi-stage cryogenic trapping.
This technique permits greater concentration than the
prcssurization approach, separates the contaminants
according to their vapor pressures and degradation is
minimized due to the relatively low temperatures in-
volved. This paper will describe the design and evalu-
From the Chemical Support Section, Environmental Systems
Branch, Bioastronautics Department, USAF School of Aerospace
Medicine, Brooks Air Force Base, Tcx.is.
ation of such a system and discuss the potential uses
of this device.
METHOD
The air stream from which the contaminants are to
be removed and concentrated is passed through sample
cylinders maintained at three different temperatures.
The trapping system uses an ice bath at 0CC, a pulver-
ized dry ice bath at -7SCC and a liquid nitrogen bath
regulated to -175"C to fractionate the contaminants in
the air stream. Materials which are not concentrated
are oxygen, nitrogen and compounds which have suffi-
cient vapor pressure at -175CC to pass through the
system.
The air stream, consisting of atmospheric gas, first
enters a flow meter (Figure 1) and then passes to the
first trapping cylinder, which is maintained at a tem-
perature of 0~C with ice water. The gas, having passed
through the ice bath trapping cylinder, flows through a
heated inlet into the trapping cylinder, maintained at
-7SCC with pulverized dry ice. The pulverized dry ice
reouires occasional tamnine to ensure contact with the
wall of the trapping cylinder. The gas then passes to
a trapping cylinder maintained at -175"C where many
of the materials not previously removed from the gas
stream are condensed. The remaining gas is conducted
to the vacuum inlet of a circulating pump and ex-
hausted by the pump into the atmosphere or into a
closed ecological system.
The trapping cylinders (Figure 2) are stainless steel
with an internal volume of 150 cc. The cylinders are
S'ted with Swagelock connections, modified pipe fittings
and needle valves. Teflon and stainless steel arc used
throughout the system to minimize catalytic conver-
sions and contamination of samples. A thermocouple is
mounted through a tapped port in th*5 bottom of the
cylinder. Temperatures are monitored with copper-
constantan thermocouples on a pyrometer calibrated in
degrees centigrade.
In the -7SCC trapping cylinder there is a rapid ice
formation in the inlet tube. This formation, due to the
Fig. 1. diagrammatic flow representation, multi-stage cryo-
genic trapping system.
Reprinti-d from Acrosjiacc Medicine, Vol. 36, No. 9, September 1965
-------
. A MULTI-STAGE CRYOGENIC TRAPPING SYSTEMCON KLE, ET AL
-64-
Fig. 2. Trapping cylinders, multi-stage cryogenic trapping
system.
temperature gradient along (or down) the entrance
tube, is prevented by heating the entrance tube. The
heater consists of a 1/16-inch stainless steel rod in-
serted through a Teflon insulated Swagelock fitting at
the top of the cylinder. It is positioned in the center
of the entrance tube and projects to the bottom where
it is bent at a 90° angle. The rod is threaded and
secured to the wall of the entrance tube with a nut.
This connection serves as the electrical contact between
the cylinder and the rod. Electrical energy from a
variable transformer is applied across the primary of
a filament transformer, the secondary of which is con-
nected to the rod and cylinder wall. Sufficient energy
is applied to the healei to prevent the formation of ice
in the tube without affecting the operational tempera-
ture of the trap.
The final trapping cylinder is controlled at a tem-
perature of -175CC in order to prevent the formation
and entrapment of liquid oxygen (-1S3?C at standard
pressure). The presence of liquid oxygen in the trap
would present an explosive hazard for personnel han-
dling the cylinders, and it would make available a
supply of oxygen for degradation of the original con-
taminants and the formation of new compounds.
This cylinder is positioned with two glass-phenolic
rings in a well which is surrounded by liquid nitrogen
(Figure 3). A flow of dry warm nitrogen from the
bottom of the well controls the temperature of the
trapping cylinder. The flow of gaseous nitrogen is regu-
lated with a micrometer needle valve. One of the glass-
phenolic rings covers the top of the well to maintain a
positive pressure of gaseous nitrogen and prevent back
870 Aerospace Medicine September 1965
diffusion of atmospheric air and liquid oxygen forma-
tion.
The well is positioned by a fitted lid for the Dewar
flask. .The lid also contains a vent, a well for the liquid
nitrogen level sensor and the liquid nitrogen filling
device.
A liquid nitrogen level control device was developed
to simplify the operation of the system (Figure 4). The
level controller uses a thermister as a sensor so that a
change in resistance of the thermister, in or out of liquid
nitrogen, results in a change in current. The change
in current operates a control meter which actuates a
solenoid operated liquid nitrogen transfer valve.
The trapping system was desicned for use in studies
of trace contaminants in simulated space cabin atmos-
pheres but may be used in any situation where there
is a desire to concentrate atmospheric contaminants for
identification and quantisation. The unit is portable
and easily operated, making air contaminant studies
feasible in locations which do not have facilities for
analysis of complex chemical mixtures. The multi-stage
cryogenic trapping system (Figure 5) is put into oper-
ation by connecting liquid nitrogen and gaseous nitro-
gen to their respective inputs and providing 110 volt
60 cycle power. The liquid nitrogen controller is acti-
vated and the -175:C trap Dewar filled, ice water is
placed in the 0°C trap Dewar and pulverized dry ice
in the -IS'C trap Dewar. Caseous nitrogen flow is
adjusted to achieve the desired temperature in the
liquid nitroeen tran well. Thf «\-<;tpm i«
VCMT-
_T" LIOUlO NITROGEN
SUPPLY
TO THERMOCOUPLE READOUT
IIOUIO NITROGEN
LEVEL SENSOR
OEWAR FLASK
LIQUID NITROGEN TRAP
CROSS SECTION
Fig. 3. Liquid nitrogen trap, multi-stage cryogenic trapping
system.
-------
A MULTI-STAGE CRYOGENIC TRAPPING SYSTEMCONKLE, ET AL
-65-
Fig. 4. Sche-
matic of liquid
nitrogen level
controller.
a box 86 X 66 x 61 centimeters. The unit requires 25
liters of liquid nitrogen, 11.3 kilograms dry ice, 11.3
kilograms ice and 1.41 standard cubic meters of gaseous
nitrogen for six hours' operation. The need for a gase-
ous nitrogen source may be eliminated by heating the
boil-off of liquid nitrogen to provide the required dry
warm nitrogen for the control of the trapping cylinder
temperature.
Preliminary evaluation of the multi-stace cryogenic
trapping system was made using a 255-liter chamber.
The chamber was evacuated and 5 microliters ol acetone
JJ 1 rpl 1 1 r t ' l 1 tr\ T^ 'II* of 1
of Hg with nitrogen. The amount of acetone in the
chamber was determined by extraction of a sample into
a 10-meter multi-path infra red cell, and quantitated
by infra red absorbance (Figure 6).
The trapping system was attached to the chamber
and operated for six hours. The flow through the sys-
tem was indicated by a variable-area flow meter. At
the end of the trapping period the amount of acetone
in the chamber and the trapping cylinders was deter-
mined by infra red absorbance.
RESULTS AND DISCUSSION
Information gained during the preliminary tests of
the system (Table I) indicate that a useful tool for the
study of trace contaminants was developed. Initial
chamber, final chamber and the -175:C trapping cylin-
der contents and concentrations were determined by
infra red absorbancc and are reported in milligrams or
parts per million.
The amount of acetone in the chamber at any time
t can be expressed by the 1st order reaction equation:
Fig. 5. Portable multi-stage cryogenic trapping syiteni.
-kt
C, = C0e (equation 1)
where
Ct = amount of acetone in the chamber at time t in
minutes.
C0 = initial amount of acetone in the chamber.
k = a constant.
e=2.71S2S.
t = trapping time in minutes.
Assuming complete removal of acetone from the gas
passing through the trapping system, a theoretical value
for k in equation 1 was determined. The amount of
acetone removed in successive one minute increments
was summatcd for a period of ten minutes. The result-
ant was subtracted from the initial amount of acetone
TABLE i. RESULTS OF PRELIMINARY EVALUATION: EFFICIENCY AND RECOVERY
Amount of Acttone Amount of Acetone in Percent Percent
Flow Time in Chamber (mg.) 175°C Trapiiini; Cylinder (m?.) Recovery Efficiency
Run cc/min min Initial Final .Measured Predicted Calculated F_ _F
A B C . D E F C D-E D-E C
1
2
3
380
300
300
360
SCO
360
4.072
4.210
4.210
2.610
3.117
2.900
1.50
1.07
1.19
1.702
1.457
1.457
1. 49 1
1.093
1.310
102.6
97.9
90.8
88.1
73.4
81.7
Aerospoce Medicine Scprembcr 1965 871
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A MULTI-STAGE CRYOGENIC TRAPPING SYSTEMCONKLE. ET AL
-66-
IT -, '-i,'-i -nrpV,
-i-i
-J -
. i
I I
T~n~t:T~t~!"F~T -Tt:1-rr\
-; rJ7{-:l-j4-!-T-tH- -|~[~-f"Hf\
"1" ^^tTVtT7"'" ~ llillli
4000 MOO
- -l-i-
.1 i J.
' I I
1800 ^ZOOO
-r
BOO rroo ~^~ BOO ' ooo uoo
' woo eoo eoo
Fig. 6. Typical initial and final infra
red scans.
i i ' i II
. _._._._ -J. FINAL - -i 1" ,- < T t-II-
I ' ! i I ' I I I ! I , ' I
i I , I [ I I - I I II
o -t -,~.- -:T - f -r-
I ' I - I « ! : ' ' I
_'....i_.*i I_L._. _'_ J . __i ^Jli
4000
J2CO
In nVifnin HIP amount of arr>tonr> in tlip rJininhcr n
ten minutes. The initial amount of acetone in the cham-
ber (C0), the final amount oi acetone in the chamber
('Ct) and the time (t = 10 minutes) were substituted
in equation 1 to obtain k.
To predict the amount of acetone in the chamber
after a trapping period of 360 minutes the initial amount
(C0), the trapping time (t = 360 minutes) and the
theoretical value for k were substituted in equation J.
The predicted amount of acetone in the -175:C trap-
ping cylinder was determined by subtraction of the
predicted final amount of acetone (C,) from the initial
amount of acetone (C0) in the chamber.
The multi-stage cryogenic trapping system efficiency
was determined using equation 2.
amount of acetone in -175°C
Per cent efficiency = trapping cylinder
X 100
predicted amount of acetone
in 175°C trapping cylinder
(equation 2)
The values obtained for the efficiency of the system
were 73.4, 81.7, and 88.1 per cent (Table I). A varia-
tion of plus or minus 10 per cent in flow gives values
of 76.2 'or S9.S per cent for the 81.7 per cent value.
Creator accuracy in the control of flow and the incor-
poration of a mass flow meter will decrease the varia-
tion in values obtained. The change in amount of
acetone from the initial to final chamber values and
the amount of acetone in the -175:C trapping cylinder
were used to determine the recovery of the system. The
indicated recovery of the system was 102.6, 97.9 and
SO.S per cent.
The results indicate that the average concentration
in the chamber can be directly estimated. The amount
of acetone present in the -175'C trapping cylinder, the
flow rate of the sample gas through the system and the
. total trapping time were used to calc'.'hte the average
acetone, concentration in the chamber during the trap-
ping period. This is compared in Table II with the
result determined by averaging the initial and final con-
centrations of the chamber.
Water vapor is concentrated in the 0:C and the
-78CC trapping cylinders (Figure 7). Tin's aids in
analysis by minimizing the interference of water absoqv
tion bands in the -175:C trapping cylinder sample.
TABLE II. RESULTS OF PRELIMINARY EVALUATION: CONCENTRATION
872 Aerosnarp
Run
A
1
2
3
Flow
cc/min
B
3EO
300
300
Time
min
C
SCO
360
360
Chamber Concentration (ppm)
Initial Final Average
D E D + E
6.65
6.S8
6.88
4.25
5.08
4.73
2
5.45
5.98
5.80
-175'C
Trapping
Cylinder
Concentration
(ppm)
F
4164
2970
3304
Estimated
Chamber
Concentration
(ppm)
G
4.56
4.12
4.58
Sample
Concentration
2F
D + E
7C4.04
496.66
SOT. 16
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A MULTI-STAGE CRYOGENIC TRAPPING SYSTEMCONKLE, ET AL
-67-
:J ,- . ,
:-,. i rp1 i cr:
1 £0 r-i rl l«
; r j : ;.;_ ;M [ ; -
4OOO 3200 2800 200O BOO TOO BOO BOO ICO BOO 800 800
; 1 !!--(-' ' ' I', i :. -;-f }
. , .,y ,.
M i ;
i... - . i
i
r
1
i :
f '-!-
1 "j
i -i.-. : '
' } <" '! r
1 . i
1 , '.
i
i ; ""
. i '
r_i i .
.
:
. .'
..... .... _
_
. I,. :
T f ! : !
| r 7-t- \
: . . i ,
j - |; :
! ' ' ! i
':
" | ' j J
. ! ! ' 1 i
i; .- ;;-;
:.,/., . '
I
s
4000 3200 2800 2OOO DOO (700 BOO BOO ICO COO ftOO 600
-
. 4000
3200
iSOO 2OOO
1400
r/oo
BOO
DOO
100
COO
800
600
TABLE HI. DISTRIBUTION OF COMPOUNDS BY TRAPPING
CYLINDER TEMPERATURE
Fig. 7. Typical 0:C, -7S:C and -J75:C trapping cylinder infra red scans.
Acetone is present in all three traps but concentration
occurs in the -175rC trapping cylinder.
The acetone concentration was several hundred times
greater in the -1T5:C trapping cylinder than in the
chamber after trapping. This degree of concentration
aids identification of materials present in trace amounts.
The multi-stage cryogenic trapping system will con-
centrate a compound if the vapor pressure at the trap
temperature is less than its partial pressure in the
sample stream. Partial separation of compounds occurs
due to the different operational temperatures of the
three traps. This separation simplifies identification and
quantitation.
After liquification and/or solidification there is no
significant loss from a trap by transfer of participate
material in the form of fog or snow. This is minimized
by the construction of the trapping cylinders.
Multi-Stage Cryogenic Trapping Cylinder
-------
-68-
Table III depicts the distribution of several com-
pounds as a function of the temperature at which they
are expected to be concentrated in significant quanti-
ties. Substances are identified in each column accord-
ing to the state in which they exist at that temperature,
either as a h'quid(L) or as a solid(S). Any material
existing as a solid at a given temperature will not be
found concentrated in a succeeding trapping cylinder.
ACKNOWLEDGMENTS
The authors wish to thank Richard Dawson, Binclectronics,
for assembly of the liquid nitrogen level control unit, James D.
Wise, Machine Shop, for the construction of special equipment,
F. Duepner and Dr. B. E. Welch for their encouragement and
suggestions.
REFERENCES
1. Fnosr, A. A. and PEARSON, R. C.: Kinetics and Mechanism.
John Wiley & Sons, Inc., New York, New York, p. 13.
1953.
2. JOHNSON, J. E.: Nuclear Submarine Atmospheres, Analysis
and Removal of Organic Contaminants. NRL Report
5800. 1962.
3. JOHNSON, J. E.: Atmosphere Monitoring in the Nuclear
Submarine. Presented at the USN-LMSC Toxicity Sym-
posium in Palo Alto, Calif., July 1963.
4. SAUNDEHS, R. A.: Analysis of the Spacecraft Atmosphere.
NRL Report 5816, 1962.
5. WEUER, T. B., DICKEY, J. E., JACKSON, N. N., REGISTER,
J. W. and CONKLE, J. P.: Monitoring of Trace Contami-
nants in Simulated Manned Spacecraft. Aerospace Mcd.,
35:148-152.
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