United States Office of International Activities 160-B-99-001
Environmental Protection Mail Code2760R http://www.epa.gov/oia/itc.htm
Agency
vvEPA Implemented Guide To
Phasing Out Lead In
^^
Gasoline
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Disclaimer
This document was supported in part by the U.S. Environmental Protection
Agency under grant number CX-817119-01. Mention of trade names, products,
or services does not convey, and should not be interpreted as conveying, official
EPA approval, endorsement, or recommendation.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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Acknowledgements
The Implemented Guide to Phasing Out Lead in Gasoline was prepared by
Engine, Fuel and Emissions Engineering, Inc. in association with Hagler Bailly
Services, Inc. This document represents a collaborative effort between the United
States Agency for International Development (USAID) and the United States
Environmental Protection Agency (USEPA). The authors wish to thank
Mr. David Hales, Deputy Assistant Administrator, Global Environment Center,
USAID, and Mr. William Nitze, Deputy Assistant Administrator, Office of
International Activities, USEPA, for their leadership in reducing the threat of
lead in the environment. In addition, the authors gratefully acknowledge the
extensive review, comments and guidance provided by Sylvia Correa, David
Kortum and John Holly of USEPA and by John Borrazzo, Regina Ostergaard-
Klem and Robert MacLeod from USAID.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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Foreword
Lead in the environment is an important hazard to human health. Epidemiologi-
cal and clinical studies conducted over the last two decades have demonstrated
significant links between lead concentrations in the body and a variety of ills.
These include impaired mental development, reduced intelligence, and behavioral
disorders in children; and high blood pressure, cardiovascular disease, and cancer
in adults. These effects have been found at levels of lead exposure that were
previously considered safe.
Human exposure to environmental lead occurs through many pathways, includ-
ing exposure to lead-based paints; lead dissolved in water from lead pipes, brass
fittings, and solder joints; and lead in food from improperly glazed pottery and
soldered cans. However, the single most important source of human exposure to
lead is lead aerosol formed by the combustion of lead antiknock additives in
gasoline. The elimination of these additives is the most important single step
toward reducing lead exposure and the resulting damage to public health.
Because of progress in refining technology, lead additives are no longer required
to achieve gasoline octane specifications. The United States has successfully
eliminated lead from its own gasoline, and the U.S. Government supports
phasing out the use of lead in gasoline worldwide. Among the most important
obstacles to promptly phasing out lead in gasoline in many countries is the
uncertainty felt by many policy makers regarding the technical alternatives to
lead, the costs and benefits of reducing or eliminating lead use, and the potential
impacts on the refining sector and on the vehicle fleet. In many cases, political
decisions to eliminate lead have already been taken, but the implementation of
these decisions is impeded by uncertainty as to how best to carry them out.
This Guide is intended to support the worldwide phaseout of lead in gasoline by
providing a checklist and guidance for government officials tasked with develop-
ing and implementing a lead phaseout policy, and by assembling the data and
resources these officials need to carry out their task.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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Acronyms
ASTM American Society for Testing and Materials
BTX benzene-toluene-xylene
CH4 methane
CD carbon monoxide
DIPE di-isopropyl ether
EPA United States Environmental Protection Agency
ETBE ethyl tertiary butyl ether
FCC fluid catalytic cracker
g gram
GC-OFID gas chromatography, using an oxygenate flame ionization detector
HC hydrocarbon
HC1 hydrochloric acid
Hg mercury
HNO3 nitric acid
H2S hydrogen sulfide
IQ intelligence quotient
km
kPa
1
LPG
kilometer
kilopascals
liter
liquefied p
MIBK methyl isobutyl ketone
ug microgram
MMT methylcyclopentadienyl manganese tricarbonyl
Mn manganese
MON motor octane number
MTBE methyl tertiary-butyl ether
NGO non-government organization
NMHC non-methane hydrocarbon
NOf oxides of nitrogen
Pb lead
PM2.5 fine paniculate matter
PONA paraffin, olefin, naphthene, and aromatic
ppb parts per billion
ppm parts per million
PSI pounds per square inch
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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RON research octane number
RVP Reid vapor pressure
SO2 sulfur dioxide
TAME tertiary amyl methyl ether
TEL tetraethyl lead
UNECE United Nations Economic Commission for Europe
U.S. EPA United States Environmental Protection Agency
VOC volatile organic compound
VOSL value of a statistical life saved
WTP willingness to pay
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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IMPLEMENTER'S GUIDE
TO PHASING OUT
LEAD IN GASOLINE
March 1999
Submitted by:
Environmental Pollution Prevention Project
Hagler Bailly Services, Inc.
US AID
vvEPA
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Contents
Chapter 1. Overview 1
1.1 Why Phase Out Lead In Gasoline? 1
1.2 Myths And Misconceptions About Lead Phaseout 2
1.3 How To Use This Guide 2
1.4 Summary Of Issues And Actions To Consider
In Phasing Out Lead In Gasoline 3
1.4.1 Identifying Technical Options For Reducing Or
Eliminating Lead Additives 5
1.4.2 Assessing Lead Phaseout Impacts On The Vehicle Fleet... 6
1.4.3 Assessing Lead Phaseout Effects On Vehicle Emissions
And Air Quality 6
1.4.4 Assessing The Health Benefits Of Lead Phaseout 7
1.4.5 Conducting A Cost-Benefit Analysis 7
1.4.6 Choosing Policy Instruments 8
1.4.7 Monitoring Compliance 8
1.4.8 Conducting Followup Evaluation And Reporting 9
1.4.9 Conducting Public Education 9
1.4.10 Ensuring Public Consultation And Involvement 10
1.5 Examples Of Successful Lead Phaseout 10
1.5.1 United States 10
1.5.2 Mexico City 11
Chapter 2. Identifying Technical Options For Reducing
Or Eliminating Lead Additives 15
2.1 Knock And Octane Rating 17
2.2 Hydrocarbon Classifications And Octane Values 18
2.3 Properties Of Tetraethyl Lead 20
2.4 Petroleum Refining And Gasoline Supply 21
2.4.1 Different Refinery Types And Capabilities 21
2.4.2 Principal Process Streams Used In Gasoline 24
2.4.3 Examples Of Refinery Upgrades To
Produce Unleaded Gasoline 25
2.5 Oxygenates As Gasoline Blending Components 28
2.5.1 Sources, Supply Volumes, And Prices 29
2.5.2 Impact On Vehicles 30
2.5.3 Impact On Pollutant Emissions 30
2.5.4 Impact On Soil, Groundwater, And Surface Waters 32
2.5.5 Health Risks Associated with MTBE 33
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2.6 MMT Properties And Performance 33
2.7 Lead Phaseout Strategies 34
Chapter 3. Assessing Lead Phaseout Impacts On The Vehicle
Fleet 39
3.1 Lead's Role In The Engine 40
3.1.1 Valve Seat Recession 40
3.1.2 Valve Corrosion And Guttering 42
3.1.3 Oil Changes And Engine Life 42
3.1.4 Spark Plug Fouling And Replacement Frequency 42
3.1.5 Exhaust System Corrosion 43
3.2 U.S. Fleet Experience 43
3.3 Worldwide In-Use Experience 44
3.4 Monetizing Maintenance Costs And Savings 44
Chapter 4. Assessing Lead Phaseout Effects On Vehicle
Emissions And Air Quality 47
4.1 Emission Control Technologies For Gasoline Vehicles 47
4.2 Systems Of Emission Standards 49
4.3 Effect Of Leaded Vs. Unleaded Gasoline 50
4.4 Effect Of Gasoline Properties And Composition Of Emissions . 51
4.4.1 Sulfur 52
4.4.2 Volatility 52
4.4.3 Olefins 53
4.4.4 Aromatics And Benzene 54
Chapter 5. Assessing The Health Benefits Of Lead Phaseout
5.1 Emissions Vs. Ambient Concentrations 57
5.2 Ambient Concentrations Vs. Blood Lead Concentration 58
5.3 Estimating The Reduction In Blood Lead
Due To Lead Phaseout 59
5.4 Assessing The Health Benefits Of Lead Phaseout 61
5.4.1 Lead And Neurodevelopmental Effects In Children 61
5.4.2 Lead And Blood Pressure In Adults 63
5.4.3 Lead And Cancer 64
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5,5 Economic Value Of Reducing Adverse Health Impacts , 67
Chapter 6, Conducting A Cost-Benefit Analysis.... 69
6.1 Cost-Benefit Analysis And Strategy Selection 69
6.2 Cost-Benefit Comparison Of Alternative Strategies 70
6.3 Potential Lead Phaseout Strategies 72
6.4 Example Of Cost-Benefit Comparison 72
Chapter?. Choosing Policy Instruments 77
7,1 Command-And-Control Instruments 79
7.2 Market-Based Instruments 81
7.3 Lessons From The U.S. Experience 82
Chapter 8. Monitoring Compliance 85
8.1 Gasoline Sampling 86
8.1.1 Sampling Precautions 86
8.1.2 Sampling Terms 86
8.2 Measuring Lead In Gasoline 88
8.2.1 Standard Method Test By
Atomic Absorption Spectrometry 88
8.2.2 Automated Method Test By
Atomic Absorption Spectrometry , 88
8.2.3 X-Ray Spectrometry 88
8.3 Octane Measurements , 89
8.4 Gasoline Composition 89
8.4.1 Sulfur 90
8.4.2 Olefins 90
8.4.3 Reid Vapor Pressure 90
8.4.4 Distillation , 90
8.4.5 Benzene 90
8.4.6 Aromatics 90
8.4.7 Oxygen And Oxygenate Content Analysis 91
8.5 Laboratory Equipment And Costs 92
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Chapter 9. Conducting Follow-Up Evaluation and
Reporting 93
9.1 Measuring Lead Concentrations In Blood 93
9.2 Measuring Lead In Ambient Air 94
Chapter 10. Conducting Public Education 95
10.1 Defining The Goals Of The Public Education Strategy 96
10.2 Developing A Public Education Strategy 97
10.3 Media And Other Techniques For Public Communication 99
10.4 Assigning Responsibility For Public Education 101
10.5 Tracking Progress And Measuring Effectiveness 101
10.6 The Timing Of Public Education Activities 102
Chapter 11. Involving Key Stakeholders In The Development
Of A Lead Phaseout Strategy 103
11.1 Stakeholder Identification 103
11.2 Stakeholder Involvement Strategies 105
Chapter 12. Bibliography 109
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List of Tables
1. World Specifications For Gasoline Octane Rating And Lead Content 18
2. Blending Octane Values Of Some Typical Hydrocarbons
And Gasoline Components 19
3. Typical Octane Values For Some Process Streams
Used In Gasoline Blending 24
4. Typical Feed And Product Composition For A Catalytic Reformer 25
5. Example Of Meeting Octane Requirements With Reduced Use of Lead 37
6. Costs of Phasing Out Lead in Gasoline - Hypothetical Case 38
7. Hypothetical Maintenance Cost Savings With Low-Lead
And Unleaded Gasoline 46
8. Comparison Of Pollutant Emissions Using Leaded, Low-Lead, And Unleaded
Gasoline In Vehicles Without Catalytic Converters 51
9, Toxic Air Contaminant Emissions Using Leaded And Unleaded Gasoline 51
10. Lead Emissions Vs. Ambient Concentration For A Selection
Of World Megacities 57
11. Reduction In Blood Lead Concentrations Due To Reducing Lead In Gasoline:
A Hypothetical Example 60
12. Calculating The Reduction In Mortality Due To A Hypothetical Reduction In Blood
Lead Concentration 64
13. Carcinogenic Compounds Associated With Gasoline Combustion 65
14. Example Of Change In Cancer Risk Due To Lead Phaseout 66
15. Estimated Benefits Of Reducing Blood Lead Concentrations In The United
States By 1.0 ug/dl 68
16. Effect Of Lead Phaseout Strategies On Blood Lead Concentrations:
Hypothetical Case 73
17. Effect Of Changes In Adult Blood Lead Concentrations On Mortality:
Hypothetical Case 74
18. Calculation Of Population-Wide Health Benefits: Hypothetical Case 74
19. Cost-Benefit Comparison Of Lead Phaseout Strategies: Hypothetical Case 75
20. Summary Of Gasoline Sampling Procedures And Applicability 86
21. Prices For Analytical Equipment 92
List of Figures
1. Lead Emissions And Average Blood Level Content In
The United States, 1970-1995 11
2. Use Of Lead In Gasoline In The Valley Of Mexico, 1988-1998 12
3. Airborne Lead Concentrations In The Valley Of Mexico, 1988-1998 13
4. Average Blood Lead Content in Mexico City, 1977-1997 13
5. Octane Enhancement Vs. Lead Concentration For Some Typical Gasolines 20
6. Distillation Of Crude Oil 22
7. Simplified Process Diagram For A Hydroskimming Refinery 22
8. Process Diagram Of A Deep Conversion Refinery 23
9. Evolution Of The Slovnaft Refinery, Slovak Republic 26
10. Expected Change In Average Blood Concentration Due To A Change In
Lead Concentration In Ambient Air 59
11. Blood Lead Concentration In Children Vs. Quarterly Sales Of Lead In Gasoline,
Chicago, USA 60
12. Blood Lead Concentration In Children Vs. Quarterly Sates Of Lead In Gasoline,
New York, USA 61
13. Effect Of Changing Average Blood Lead Level On Percentage Of Learning-
Disabled And Gifted Children 63
IMPLEMENTER'S GUIDE JO PHASING OUT LEAD IN GASOLINE
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1. OVERVIEW
This Guide is written for officials who are responsible for implementing the
phaseout of lead additives in gasoline. It assumes that their governments have
already made the decision to eliminate the use of lead additives, but have not yet
determined how and when to accomplish this.
The activities described in this Guide are not necessarily sequential; they may be
best applied simultaneously so that the output of each step is evaluated as a
whole, and not solely as an input to the next step along a critical path. For
example, although involving key stakeholders is presented as the last activity in
the development of a lead phaseout strategy, it should not be conducted sepa-
rately at the end of the process. In fact, stakeholders need to be involved at the
outset if the phaseout plan is to be successful.
This chapter provides a summary and checklist of the issues and
actions to consider in developing and implementing a lead
phaseout policy. It also gives two examples of successful lead
phaseout programs.
1.1 Why Phase Out Lead In Gasoline?
Using lead additives to increase the octane rating of gasoline enabled the develop-
ment of modern high-compression gasoline engines. But these additives have also
produced dangerously high levels of lead aerosol (fine particles suspended in air)
pollution in cities worldwide. Lead is a dangerous air pollutant, contributing to
high blood pressure, cancer and heart disease in adults, and to reduced intelli-
gence, behavioral disorders and impaired development in children. Health risk
assessments in cities around the world where leaded gasoline is common have
shown that lead aerosol is one of the most important causes of health damage
due to air pollution. Lead in gasoline also increases vehicle maintenance costs and
reduces the life of automobile engines.
Widi modern refining technology, lead additives are no longer needed to meet
gasoline octane specifications. High gasoline octane ratings can be achieved
without lead, at an incremental cost to the refiner of about US $0.005 to $0.02
per liter. These costs are less than the resulting savings in vehicle maintenance
costs, and far less than the health benefits of reducing lead pollution. Thus, there
is a clear economic case for phasing out lead additives as quickly as possible, and
a strong movement toward doing so worldwide.
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OVERVIEW
1.2 Myths And Misconceptions About Lead Phaseout
Efforts to phase out lead in gasoline have been impeded by a number of myths
and misconceptions that have concerned both government officials and the
public. In some cases, these myths have been fostered or promoted by organiza-
tions with vested interests in continuing leaded gasoline sales. Three very
common misconceptions are:
Myth 1: Older engines require leaded gasoline, and will suffer damage
if it is not available. This was a widespread concern in the United States
during the 1970s and 1980s. Although laboratory tests have demon-
strated that unleaded gasoline can damage valve seats in extreme cases, it
affects only a negligible percentage of vehicles in actual use on the road.
Where such damage occurs, it can be repaired and further damage can be
prevented by replacing the seats with hardened inserts. The use of
unleaded gasoline reduces corrosion and extends the lives of valves, spark
plugs, engines, and exhaust systems. Unleaded gasoline use reduces
maintenance costs overall, as the savings from reduced corrosion are far
more than the costs of the occasional cases of valve seat damage with
unleaded fuel.
Myth 2: Vehicles using unleaded gasoline must be equipped with
catalytic converters. It is true that vehicles with catalytic converters
require unleaded gasoline to prevent lead deposits from poisoning the
catalyst and blocking exhaust flow through the converter. However, it is
also true that vehicles without converters can successfully use unleaded
gasoline. Thus, reducing or eliminating the lead content of gasoline will
reduce lead emissions from both new and existing vehicles. Exhaust
hydrocarbon emissions are likely to decrease as well, due to the effect of
reducing lead deposits in the combustion chamber.
Myth 3: Emissions of toxic hydrocarbons such as benzene could
increase greatly from unleaded gasoline use. The changes in gasoline
composition needed to meet octane specifications without lead may
change the emissions of other pollutants. For instance, the use of
alcohols or ethers as high-octane blendstocks tends to reduce hydrocar-
bon and carbon monoxide emissions, but may raise aldehyde emissions.
Increasing the fraction of benzene or other aromatic hydrocarbons in the
fuel — if permitted — may lead to higher emissions of these compounds.
However, increased benzene emissions can be prevented by using such
technologies as alkylation and isomerization to increase fuel octane levels
instead of catalytic reforming, or by specialized processes that extract or
chemically eliminate benzene. In any event, the effects of increased
benzene emissions on public health would be minor compared to the
benefits of reducing lead aerosol exposure.
1.3 How To Use This Guide
The remainder of this chapter contains a checklist and summary of the issues and
actions to consider in developing and implementing a lead phaseout policy. The
involvement of key stakeholders is presented last among these actions, but its
importance cannot be overstated. Because it is critical to a lead phaseout
strategy's success, it should be emphasized throughout the process.
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Implementers should first review the checklist, and then read the corresponding
summaries in Section 1.4. Detailed information on each of the topic areas
addressed in the checklist is presented in Chapters 2 through 1 1.
1.4 Summary Of Issues And Actions To Consider In Phas-
ing Out Lead In Gasoline
There are ten main issues and actions to consider in developing and implement-
ing a lead phaseout policy. Each of these topics is addressed in the subsections
that follow.
Checklist For Phasing Out Lead In Gasoline
Identify technical options for reducing or eliminating lead
additives (Chapter 2)
Q Characterize present gasoline supply
Q Assess the domestic refining industry
Q identify alternative sources of gasoline octane value
Q Evaluate gasoline supply scenarios
P Assess the impacts on gasoline distribution and marketing
systems
Q Assess the costs of alternative strategies to the fuel supply
sector
Assess lead phaseout impacts on the vehicle fleet (Chapter 3)
Q Assess maintenance benefits of unleaded gasoline
Q Assess potential for valve seat damage
Q Assess potential valve seat protection strategies
Q Evaluate net costs and savings for the vehicle fleet
Assess lead phaseout effects on vehicle emissions ami air
quality (Chapter 4)
Q Assess gasoline composition effects on emissions and air quality
Q Assess need for policies affecting gasoline composition
Q Consider vehicle emission control policy
Assess the health benefits of lead phaseout (Chapter 5)
Q Estimate the air quality impacts of lead and lead alternatives
Q Conduct risk assessment for lead and lead alternatives
Q Assess the public health benefits of phasing out lead
Q Conduct economic valuation of public health benefits
Conduct a cost-benefit analysis (Chapter 6)
Q Identify alternative phaseout strategies
Q Assess net costs to public and public health benefits of each
strategy
Q Select preferred phaseout strategy
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Choose policy instruments (Chapter 7)
O Identify legal authority
Q Assess available policy instruments
Q Evaluate "fit" between strategy and instruments
Q Select "best" combination of instruments
Monitor compliance (Chapter 8)
Q identify monitoring needs
O Identify legal authority/requirements for monitoring gasoline
composition
Q Identify institutional and physical requirements for monitoring
Q Identify responsibilities for monitoring and enforcement
Q Plan gasoline monitoring and enforcement program
Q Implement gasoline monitoring and enforcement program
O identify and prosecute violators
Q Follow up to ensure that monitoring and enforcement are effective
Conduct followup evaluation and reporting (Chapter 9)
Q Monitor trends in ambient lead and other air pollutants
Q Monitor trends in human exposure to lead
Q Evaluate the effectiveness of the phaseout program
Q Identify the cause of any problems found
Q Communicate results to the public, politicians, and legal authori-
ties
Conduct public education (Chapter 10)
Q Define public education goals
Q Develop public education strategy
Q Identify potential communication media
Q Assign responsibilities for communication and public education
Q Follow up to assess effectiveness of the communication program
Q Begin public education activities
Ensure public consultation and involvement (Chapter 11)
Q Identify stakeholders
Q identify strategy for stakeholder involvement
Q Communicate risk assessment and benefit estimates
Q Communicate/consult on alternative phaseout strategies
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1.4.1 Identifying Technical Options For Reducing Or Eliminating
Lead Additives
Lead additives typically improve the octane rating of gasoline by about 6 to 12
octane numbers, depending on the amount of lead added and the octane response
of the base fuel. To reduce or eliminate the use of these additives, it is necessary
to find other ways to attain gasoline octane specifications.
Some Options For Making Up Octane Shortfall
When Lead Is Reduced Or Eliminated
Near-term options. These include blending gasoline with such
high-octane components as blending gasoline with methyl
tertiary-butyl ether (MTBE), ethanol, alkylate, or mixtures of
aromatic compounds. Some countries have also used the
manganese-based octane enhancer MMT (however, please see
EPA's cautions about MMT in Section 2.6).
Longer-term options. Here, the most economical approach is
usually to add new refinery process units to convert the low-
octane straight-chain paraffins in crude oil to higher-octane
hydrocarbon types such as branched-chain paraffins,
naphthenes, and aromatic compounds.
Gasoline supply. The first step in identifying options for making up the octane
shortfall is to characterize the existing gasoline supply. This includes the volume
of gasoline consumed and its projected growth, and the sources of supply. It is
also necessary to identify the octane value; the paraffin, olefin, naphthene, and
aromatic (PONA) content; and the lead content of gasoline from each source.
Alternative sources of gasoline supply should also be identified.
Refining industry. The second step is to assess the capabilities of the domestic
refining industry, if one exists. This would include its installed capacity, process
units, octane production capability, the overall condition and economics of each
refinery, and its technical and financial capabilities to invest in the construction
of new process units. This assessment should be carried out in consultation with
the industry involved, and may require the assistance of specialist consultants.
Octane value sources. After characterizing gasoline supplies and the local refining
industry, implementers are now ready to quantify the shortfall in the "octane
pool" that would result from reducing or eliminating lead. Once this is done,
they should identify additional sources of octane value available to make up this
shortfall, as well as the costs and investment needed per "octane-barrel" for each
source. The minimum time required to provide additional octane from each
source should also be identified.
Supply scenarios. Once potential octane sources are identified, various combina-
tions of sources can be assembled to make up the octane shortfall under different
lead phaseout schedules.
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Impact assessment. Different lead phaseout strategies may mean different
requirements and costs for transporting and distributing gasoline
blendstocks and finished gasoline. Changes in the volume of imported
gasoline and blendstocks may affect port and pipeline capacities, and possi-
bly require additional investment to overcome bottlenecks. Similarly,
changes in the number of gasoline grades, or in the sales volume of different
grades may affect distribution and marketing costs.
Cost assessment. The circumstances of a country will determine which specific
lead phaseout schedules and strategies are to be assessed. For each scenario
assessed, the implementer should characterize the costs, investment requirements,
and the reduction in lead emissions over time. To ensure that all of the options
are considered, the scenarios evaluated should include at least the two extreme
cases:
A very quick phaseout in six months or less, with the octane shortfall made
up by imported blendstocks.
A very slow phaseout over three to five years, in which lead concentrations
would gradually be reduced as new refinery process units come on line.
1.4.2 Assessing Lead Phaseout Impacts On The Vehicle Fleet
Maintenance benefits assessment. To assess the maintenance benefits of unleaded
gasoline, the implementer should quantify how often such maintenance as spark
plug changes, oil changes, valve repairs, valve seat repairs, and exhaust system
replacements must take place and their costs. The change in these maintenance
requirements can then be estimated using the information in Chapter 3.
Valve seat assessment. The implementer should also assess the potential for some
engines to suffer valve seat damage from using unleaded gasoline and the costs of
potential valve seat protection strategies if these are indicated.
Cost/savings evaluation. Here, the implementer should calculate and evaluate the
resulting net benefits or costs to the vehicle fleet as functions of time for each of
the lead phaseout scenarios considered, in order to compare them with the other
costs and benefits.
1.4.3 Assessing Lead Phaseout Effects On Vehicle Emissions And Air
Quality
Gasoline composition effects assessment. Phasing out lead will entail changes in
gasoline composition, and these changes will affect the emissions of lead and
other pollutants from gasoline vehicles. For instance, raising the aromatic
hydrocarbon content of gasoline may increase emissions of benzene and other
aromatics in exhaust and evaporative emissions. Changes in gasoline composition
may also affect the photochemical reactivity of volatile organic compound
(VOC) emissions, and thus affect the formation of ground-level ozone (photo-
chemical smog). In a number of cases, public concerns over these secondary
effects have delayed lead phaseout programs.
It is thus important to assess and quantify the potential secondary effects of lead
phaseout on emissions and air quality. The assessment should be included as part
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of the phaseout plan, and - where necessary - measures should be taken to
mitigate any adverse impacts. Such measures might include setting limits on or
taxing the benzene, aromatic, and/or olefin content of fuels, and limiting vapor
pressure to minimize evaporative emissions (see Chapter 4).
Policy assessment. Lead phaseout also provides an opportunity to assess the need
for policies affecting gasoline composition. This would include a more general
review of emission control policies for vehicles and fuels, such as the adoption of
catalytic converters and/or evaporative emission controls, and limits on gasoline
sulfur content. To the extent that such policies will mean changes in either the
composition or the market shares of different fuels, they will affect investment
plans in the refining and fuel distribution sectors. To avoid waste and confusion,
it is best that they be adopted as an integrated package with the lead phaseout
policy, rather than in piecemeal fashion.
1.4.4 Assessing The Health Benefits Of Lead Phaseout
Lead exposure risk and health benefits assessments. To assess the health benefits of
reducing or eliminating lead emissions, the implementer should ideally know
how the distribution of lead concentrations in ambient air and in human blood
will change in response to changes in gasoline lead concentrations. Given this
information, dose-response relationships derived from epidemiological data can
be used to estimate the change in the incidence of high blood pressure, impacts
on children's health, cardiovascular illness, and other health outcomes due to a
given lead phaseout scenario. Detailed data and calculation examples are given in
Chapter 5.
Economic valuation. In comparing the health benefits with the costs of reducing
lead in gasoline, it is often useful to express the health benefits in monetary
terms. The value to society of preventing a case of lead-related illness or prema-
ture death can be estimated based on treatment costs, lost productivity, and
peoples willingness to pay to reduce the risk of premature death and other
adverse consequences. If the decision has already been made to phase out lead,
the best use of cost-benefit analysis is to compare and evaluate the costs and
benefits of different options for phaseout. Chapter 5 describes some of the bases
for developing such estimates.
1.4.5 Conducting A Cost-Benefit Analysis
Selecting a strategy should take into account the costs and benefits of the
different alternatives, and such considerations as technical and political feasibility,
the legal basis for the strategy, equity among different social sectors, and accept-
ability to political decision makers and to the public.
Strategy identification, assessment, and selection. First, the implementer should
identify a number of alternative phaseout strategies. Then, the strategies should
be assessed to determine which of them are technically feasible, legally viable,
equitable, and acceptable to decision makers and the public. From these, he or
she should select the one with the greatest net benefits. The evaluation and
selection processes are discussed in more detail in Chapter 6.
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1.4.6 Choosing Policy Instruments
One goal of this Guide is to provide tools to help the implementer carry out the
appropriate lead phaseout strategy for his or her country. Any one of these tools
may be useful to a particular country, but not all of them will be useful to all
countries.
The potential policy instruments for implementing a lead phaseout strategy
include regulatory "command-and-control" measures and market-based incen-
tives. Examples of command-and-control measuresinclude limiting the maximum
lead content of gasoline and prohibiting imports of lead additives. Examples of
market-based incentives might include a tax on lead additive imports, or on the
lead content of gasoline sold. Where legally feasible, market-based measures are
generally preferable, as their flexibility reduces the chance that a regulatory
mistake would disrupt the gasoline market, and may allow a faster phaseout
overall.
Legal authority and instruments. In choosing policy instruments, the
implementer should first identify the legal authority or authorities available as a
basis for such instruments, and then assess the types of instruments legally
permissible under that authority. For example, governments often have the
authority to limit or prohibit toxic substance emissions, but may require new
legislation in order to change tax rates on fuel.
Strategy fit and instruments selection. The implementer should also assess the
compatibility between the strategy chosen and the instruments available to
implement it. He or she should then select the best combination of instruments,
considering their effectiveness, costs and benefits, timing, flexibility, and political
acceptance.
1.4.7 Monitoring Compliance
Sampling and checks to confirm that the gasoline sold complies with the lead
limits and quality specifications in effect are integral parts of the lead phaseout
strategy. To guard against adulteration or smuggling, gasoline samples should be
collected for analysis at retail service stations, as well as at the refinery and/or the
port of importation. Chapter 8 gives details on the sampling and analytical
procedures for lead, gasoline octane, and gasoline properties and composition.
Needs identification. In developing this portion of the lead phaseout strategy, the
implementer should identify the monitoring requirements. These would include
the number of samples and the types of locations to be sampled to ensure
adequate coverage.
Authority and responsibilities identification. The implementer should identify the
legal authority that will monitor fuel composition, including any ongoing
monitoring efforts.
Physical and institutional monitoring requirements identification. The
implementer should then identify the equipment and personnel required for the
monitoring program, the institutional responsibilities of these personnel, and the
sources of financing for any new equipment or personnel needed.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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Enforcement program planning and implementation, and prosecuting
violators. Based on the information developed, the implementer should work
with the organizations responsible for enforcement to prepare a detailed plan
for the enforcement program and obtain any necessary authorizations or
approvals. The agency responsible should then implement the plan, which
should include provisions for identifying and prosecuting individuals who
are violating the lead phasedown requirements.
FoUowup. Once the program is underway, the implementer should follow up to
confirm that monitoring is being done according to the plan.
1.4.8 Conducting Followup Evaluation And Reporting
Followup monitoring and evaluation are needed to ensure that the lead phaseout
program achieves its goals, and to demonstrate to decision makers and the public
that these goals have been achieved.
Trends monitoring. In addition to monitoring changes in the lead content of
gasoline, implementers should assess the changes in concentrations of lead and
other pollutants in ambient air and changes in the distribution of blood lead
concentrations among the exposed population, particularly children. Chapter 9
gives more information on monitoring and measurement techniques.
Program effectiveness and communications. In most cases, the followup evalua-
tion will demonstrate that lead concentrations in air and in human blood have
declined significantly. This information should be communicated to decision
makers and the public in order to maintain their support for the phaseout
program. Should the monitoring show that lead concentrations in either the air
or the exposed population have not declined as expected, it may indicate that
other sources of lead exist and need to be identified.
1.4.9 Conducting Public Education
Goals definition. An effective public education program will help assure public
support for the lead phaseout policy. The program goals ("the message") should
include:
• Making the public aware of the health and developmental problems caused
by exposure to lead, and the importance of gasoline additives as the main
source of lead in the environment,
• Counteracting myths by providing accurate information about the ability of
older vehicles to use unleaded gasoline and the maintenance benefits of
reducing or eliminating lead.
• Providing for effective dissemination and consultation about the overall lead
phaseout strategy.
Strategy, media, and responsibilities identification. Specific strategies should be
designed to meet the program's goals and be targeted to specific audiences. The
implementer should also identify appropriate communication media and assign
responsibilities for communication and public education to the appropriate
organization.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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Program followup. During and after the public education process, followup
studies should be conducted. These should assess the effort's effectiveness and
determine whether further public education efforts are required.
1.4.10 Ensuring Public Consultation And Involvement
The type and amount of public consultation and involvement needed in develop-
ing a lead phaseout strategy will vary depending on a country's institutional
arrangements and practices. As a general rule, active consultation with the
businesses and organizations affected by the lead phaseout is important in
reducing opposition and guarding against unforeseen consequences. Consultation
with public health and environmental organizations, and with concerned mem-
bers of the public will generally help gain their support of the lead phaseout
program.
Stakeholder identification. Effective public consultation should begin by identify-
ing the stakeholders: the individuals and organizations whose interests will be
affected. These include oil refiners and importers, retail service station owners
and operators, vehicle owners and their representatives, public health officials and
the medical profession, parents, educators, and environmental organizations.
Strategy identification and communications. Implementers should define a
strategy for communicating with stakeholders, and for involving them in the
decisions on the lead phaseout through such means as public workshops. This
strategy should be closely linked to the public education strategy discussed in
Section 1.4.9, to ensure that a consistent and effective message is communicated.
Equally important, implementers should pay careful attention to the questions
and objections that surface during the public consultation process. In some cases,
these may only indicate a need for more effective public education, but they will
often identify real problems that must be addressed in the program's design.
During meetings with stakeholders, implementers should communicate the
results of risk assessments, benefit estimates and alternative phaseout strategies.
1.5 Examples of Successful Lead Phaseouts
1.5.1 United States
In the 1970s, average lead concentrations measured in U.S. cities often far
exceeded EPA's average air quality standard of 1.5 ug/m3 (today, it is recognized
that even this standard does not adequately protect human health). The manda-
tory sale of unleaded gasoline was introduced in 1974 in order to meet the needs
of cars equipped with catalytic converters. At that time, leaded gasoline con-
tained an average of 2.4 grams of lead per gallon (0.63 g/liter), and average blood
lead concentrations among children in major cities were around 20 ug/dl (twice
the level now considered to warrant medical action).
Through a phased program, the allowable lead concentration in leaded gasoline
was reduced to 1.1 gram per gallon (0.29 g/1) by 1982. This program also
introduced the trading of lead rights between refineries, so that a refinery that
was able to produce gasoline containing less than 1.1 gram per gallon could sell
the excess "lead rights" to another refinery that needed them. In 1984, a major
cost-benefit evaluation (Schultz et al., 1985) concluded that the benefits of
further reducing lead use in gasoline greatly outweighed the costs, and that
10 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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allowable lead concentrations should be reduced to a minimum as quickly as
possible. The allowable lead concentration was reduced to 0.5 gram per gallon in
July 1985 and to 0.1 gram per gallon (0.026 g/1) on January 1, 1986. The
allowable concentration was retained at this level until sales of leaded gasoline
were finally banned in 1995.
During the same period, emissions of lead from other sources were also reduced,
as was the use of lead solder in cans. Steps were also taken to reduce human
exposure to lead in drinking water. Figure 1 shows the resulting changes in
nationwide lead emissions and in average blood lead content as measured in
nationwide health studies. Lead emissions to the atmosphere have been virtually
eliminated in the United States, and average blood lead concentrations have been
reduced more than 85 percent, to 2.3 ug/dl. Today, the main sources of human
exposure to lead in the United States are the legacy of past use: lead paint and
water pipes in old buildings, and lead-contaminated soil near roadways and
industrial sites.
Figure 1: Lead Emissions And Average Blood Lead Content
In The United States, 1970-1995
200,000
-. 150,000
w 100,000
UJ
50,000
Lead in Blood
Lead in Gasoline
All Other Sources
Year
1.5.2 Mexico City1
Measured lead concentrations in Mexico City's air have fallen more than 98
percent in the last 10 years, despite increasing gasoline consumption. This has
been a result of gradual reductions in the lead content of leaded gasoline, as well
as the introduction and increasing use of unleaded gasoline. The reduction in lead
content began in 1986, when a new specification of 0.5-1.0 ml of tetraethyl lead
(TEL)/gallon was established, replacing the previous limit of 3.5 ml TEL/ gal (1
ml TEL contains approximately 1 gram of lead). The standard was then succes-
sively reduced to 0.3 to 0.54 ml in 1991, 0.2-0.3 ml in 1992, and 0.2-0.1 ml/
gallon in 1 994. As a result of these increasingly stringent standards, lead emis-
sions from gasoline decreased until they were practically eliminated, as shown in
Figure 2.
This description was provided by Eng. Sergio Sanchez, former director of environmental planning for the
Government of the Federal District of Mexico City.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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\ '
V
Figure 2: Use Of Lead In Gasoline In The Valley Of Mexico, 1988-1998
1400
1200 -
1000 -
1986* 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
Year
Unleaded gasoline was introduced in Mexico in September 1 990 in order to
accommodate the new vehicle emission standards adopted nationwide in 1991.
These required the introduction of catalytic converters in new vehicles. Unleaded
gasoline sales in the Valley of Mexico increased as the catalyst-equipped vehicle
fleet grew - especially after a change in tax structure in 1992, which brought the
prices of leaded and unleaded gasoline closer together. In 1995, the Mexican
government announced its commitment to phase out leaded gasoline by the year
2000. This goal was achieved by the end of 1997. Since then, only unleaded
gasoline has been distributed in Mexico.
Reducing the lead content in leaded gasoline and the introduction.of unleaded
gasoline have been part of a comprehensive gasoline reformulation process
intended to improve air quality by reducing toxic and ozone-forming compo-
nents. This reformulation process required a series of refinery improvement
projects, including continuous catalytic reforming plants, isomerization plants,
and plants for the production of methyl tertiary butyl ether (MTBE) and tertiary
amyl methyl ether, as well as the addition of alkylation plants.
Figure 3 illustrates the evolution of airborne lead concentrations, from 1988 to
1998, for three representative stations of the Air Quality Monitoring Network.2
In the late 1980s, lead levels peaked to more than 6 ug/m3, and exceeded the 1.5
ug/m3 three-month average standard throughout Mexico City. With the reduc-
tions in fuel lead content, atmospheric lead concentrations gradually decreased to
very low levels throughout the urban area. The corresponding trend in average
blood lead concentrations is shown in Figure 4. These concentrations have
decreased dramatically, from about 16 u/dl in 1988 to about 6 u/dl today.
2 The Xalostoc station is located in an industrial area chat is norrh ajid upwind of the urban area. Merced station is
located downtown, in the middle of an active commercial area. The Pedregal station is sited downwind in a
residential area.
12 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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Figure 3: Airborne Lead Concentrations In The Valley Of Mexico,
1988-1998
7.00
—•— MERCED STATION
-*- XALOSTOC STATION
—*- PEDREGAL STATION
- - -STANDARD (1.5 ug/m3)
introduction of unleaded gasoline
(September 1990)
lead specification is reduced from
0.5-1.0 ml TEUgal to 0.3-0.5 ml TEL/gal
lead specification is reduced to
0.2-0.3 ml TEUgal
lead specification is
reduced to 0.1-0.2 ml
TEUgal
Year-Quarter
Source: Mexico City Air Quality Monitoring Network.
Figure 4: Average Blood Lead Content In Mexico City, 1977-1997
20
18
16
14
a 12
B
B 10
1
-• 'NEWBORN (UMBILICALCORD).
-•- SCHOOL CHILDREN
—*• -ADULTS
1977 1990 1991 1992 1993 1994 1995 1996 1997
Year
Source: Mexican Institute of Public Health and American British Cowdray Hospital.
The effects of lead on health and the impact of atmospheric lead levels have been
extensively studied in Mexico (Pardon and Martinez, 1998). Some investigations
made in the 1980s demonstrated impacts on weight at birth, IQ reduction and
neurological and metabolic disorders related to lead. A cost/benefit estimation of
the reduction in airborne lead levels and health was made in 1993 (GIEP, 1993).
According to that analysis, the total cost of lead content reduction and the use of
unleaded gasoline was estimated at $717 million.3 The benefits for health and
vehicle maintenance improvement were calculated at around $ 1,740 million.4
Therefore, the net benefit was estimated at $ 1,022 million.
J Cost estimates included technology changes at refineries, consumer costs for using unleaded gasoline, and costs
for introducing catalytic converters in new cars.
4 Benefit estimates considered medical treatment costs, special education costs, prevention of death from heart
disease, reductions in lost work and school days, etc.
OVERVIEW
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
13
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Lead from gasoline has been eliminated as a threat to health in the Valley of
Mexico. However, other sources of lead exposure remain serious, such as lead
from leaded pottery and paints.
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IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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2. IDENTIFYING TECHNICAL OPTIONS
FOR REDUCING OR ELIMINATING
LEAD ADDITIVES
Lead is added to gasoline to improve knock resistance, as measured by the
gasoline's octane rating. Lead additives can be reduced or eliminated by employ-
ing other means to attain gasoline octane specifications. A number of options are
available to achieve increased octane levels without lead. These options can be
broadly categorized as:
• Purchasing high-octane gasoline components and blending them into low-
octane fuel.
• Upgrading and adding refinery equipment to produce higher-octane gasoline
components.
• Using octane-enhancing additives based on substances other than lead.
Lead additives typically improve the octane rating by about 6 to 12 octane
numbers, depending on the amount of lead added and the octane response of the
base fuel. The technical options for making up the octane shortfall due to
reducing or eliminating lead include:
• Near term: These include blending gasoline with oxygenates such as ethanol
and methyl tertiary-butyl ether (MTBE), blending with high-octane
hydrocarbon components such as alkylate and benzene-toluene-xylene (BTX)
blends, and using the manganese-based octane-enhancer MMT.
• Longer term: The most economical way to increase octane is usually to add
new refinery process units to convert low-octane hydrocarbons such as
straight-chain paraffins into higher-octane hydrocarbon types such as
branched-chain paraffins, naphthenes, and aromatic compounds.
This chapter helps implementers to evaluate the physical and
chemical options available for reducing or eliminating lead
additives in gasoline, while maintaining octane levels. It
discusses:
Octane ratings worldwide.
The blending octane values attained with a number of
gasoline components.
The relationship between lead concentrations and octane
levels.
The octane producing capabilities of various refinery types.
The sources, volumes and prices of the oxygenates blended
in gasoline and their impacts.
The properties and performance of the anti-knock additive
MMT.
Considerations in developing a lead phaseout strategy.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 15
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The Steps In Identifying Technical Options
1. Characterize the current gasoline supply
To identify the options for making up the octane shortfall by reducing or
eliminating lead, one should first characterize the existing gasoline
supply. This includes the volume of gasoline consumed and its pro-
jected growth, and sources of supply. It is also necessary to identify
the octane value; the paraffin, olefin, naphthene, and aromatic (PONA)
content; and the lead content of gasoline from each source. Alternative
sources of gasoline supply should also be identified and characterized
where possible.
2. Assess the domestic refining industry
If there is a domestic refining industry, its capabilities should be
assessed. These include the installed capacity, process units already in
place, octane production capability, the overall condition and economics
of each refinery, and its technical and financial capabilities to invest in
the construction of new process units. This assessment should be
carried out in consultation with the industry involved, and may require
the assistance of specialist consultants.
3. Identify alternative sources of gasoline octane value
Having characterized gasoline supplies and the local refining industry,
implementers can now quantify the shortfall in the "octane pool" that
would result from reducing or eliminating lead. Once this is done, they
should identify the sources of additional octane value available to make
up this shortfall, as well as the costs and investment requirements per
"octane-barrel" for each source. The minimum time required to provide
additional octane from each source should also be identified. Different
combinations of sources can then be assembled to make up the octane
shortfall under different lead phaseout schedules.
4. Evaluate gasoline supply scenarios
Once potential octane sources are identified, various combinations of
sources can be assembled to make up the octane shortfall under
different lead phaseout schedules.
5. Assess the impacts on gasoline distribution and marketing
systems
The requirements and costs for transporting and distributing gasoline
blendstocks and finished gasoline may vary under different lead phase-
out strategies. Changes in the volume of imported gasoline and
blendstocks may affect port and pipeline capacities, and possibly
require additional investment to overcome bottlenecks. Similarly,
changes in the number or sales volume of different gasoline grades
may affect distribution and marketing costs.
6. Assess the costs of alternative strategies to the fuel supply
sector
The specific lead phaseout schedules and strategies to be assessed
will depend on each country's circumstances. For each scenario, the
implementer should characterize the costs, investment requirements,
and the reduction in lead emissions over time. To ensure that the full
range of options is considered, the scenarios evaluated should include
at least the two extreme cases: a very quick phaseout in six months or
less, with the octane shortfall made up by imported blendstocks; and a
very slow phaseout in three to five years, in which lead concentrations
would gradually be reduced as new refinery process units come on line.
16 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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2.1 Knock And Octane Rating
Definitions. The octane number of a fuel is a measure of its resistance to detona-
tion and "knocking" in a spark-ignition engine. Knock reduces engine power
output, and severe or prolonged knock will likely result in damage to the pistons
and/or overheating of the engine. The tendency for a fuel to knock increases with
increasing engine compression ratio. Higher-octane fuels are more resistant to
knocking, and can thus be used in engines with higher compression ratios. This
is desirable, as higher compression ratios result in better thermodynamic effi-
ciency and power output. Engines designed for use with high-octane fuels can
thus produce more power and have lower fuel consumption than engines de-
signed for lower-octane fuels. For a given engine design, however, there is no
advantage in using a higher-octane fuel than what the engine requires.
Measuring Octane Number
The octane number is measured by two standard tests — the
research and motor octane tests. The results of these tests are
expressed as either the research octane number (RON) or the
motor octane number (MON) of the fuel. Both tests involve
comparing the antiknock performance of the fuel to that of a
mixture of iso-octane and n-heptane, with the "octane number"
being defined as the percentage of iso-octane in the octane/
heptane mixture that gives the same antiknock performance as
the fuel under test. For fuels with octane numbers above 100,
mixtures of iso-octane and tetra-ethyl lead are used to extend
the octane scale to 130.
The research and motor tests differ in detail: the research test
reflects primarily low-speed, relatively mild driving, while the
motor test reflects high-speed, high-severity driving. Most fuels
have a higher RON than MON. In the United States and parts
of Latin America, gasoline antiknock ratings are expressed as the
average of RON and MON, denoted by (R+M)/2. Elsewhere,
the RON is typically the value quoted, but specifications limit
the minimum MON value as well.
Why people buy high-octane gasoline. In many countries, gasoline vendors have
sought to associate high octane ratings with "quality" in the public mind,
allowing them to charge much higher margins for "premium" gasoline, thus
increasing their profits. The public may buy this "premium" gasoline in the belief
that they will reduce their vehicle's maintenance costs or improve its reliability.
Except for a few vehicles that require higher-octane gasoline (generally high-
performance and luxury models), the extra money spent on higher-octane grades
provides little or no benefit, while the extra lead and/or aromatic compounds
that may be used to achieve the higher octane rating contribute to environmental
degradation.
Specifications for gasoline octane rating and lead content among some of the main
automobile-producing countries and regions. As Table 1 shows, the two main
unleaded gasoline grades are an unleaded "regular" grade with typical RON and
Engines designed for
use with high-octane
fuels can produce
more power and
consume less fuel than
engines designed for
lower-octane fuels.
Except for a few
vehicles that require
higher-octane gasoline,
the extra money spent
on higher-octane grades
provides little or no
benefit.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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MON values of 91 and 82 (corresponding to the U.S. (R+M)/2 specification of
87); and an unleaded "premium" grade with typical RON and MON values of 95
and 85, respectively. Most cars produced or sold in North America since 1975
have been designed to use unleaded regular fuel, while most cars produced or sold
in Europe in the last decade have been designed to use unleaded premium.
Table 1 : World Specifications For Gasoline
Octane Rating And Lead Content
Country/Grade
United States
Regular
Mid-grade
Premium
European Union
Unleaded super
Unleaded premium
Leaded premium
Japan
Premium
Regular
South Korea
Unleaded
Thailand
Premium
Regular
Proposed Latin America/
Caribbean Harmonized Standard
Regular
Premium
Octane Rating
RON
98
95
96-99
96
89
91
95
87
91
95
(R+M)/2
87
89
91-95
MON
82
87-88
85
86-87
83
84
76
82
85
Max. Lead*
(g Pb/lt)
0.0
0.0
0.0
0.0
0.0
0.15
0.0
0.0
0.0
0.0
0.0
0.0
0.0
* Most countries allow a tolerance of up to 0.013 grams of lead per liter to account for possible
cross-contamination by leaded gasoline. Actual lead concentrations are normally well below this
level, and often below detection limits.
Sources: Owen and Coley (1995), ESMAP (1998).
2.2 Hydrocarbon Classifications And Octane Values
The octane rating of a given gasoline blend is determined by:
• The hydrocarbon composition of the fuel.
• The content of high-octane non-hydrocarbon blendstocks such as ethers and
alcohols.
• The amount of antiknock additives used, if any.
Because of non-linearities and interactions between different gasoline compo-
nents, the effect of adding a given component to a given gasoline blend may not
be strictly proportional to the octane value of the pure component. For this
reason, refiners have defined "blending" octane values for different compounds
that reflect their effects when blended into typical gasolines.
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Blending octane values. Table 2 gives blending octane values for a number of
typical gasoline components. As this table shows, straight-chain "normal"
paraffinic hydrocarbons have low octane values, while branched-chain
isoparaffins, olefins, naphthenes, and aromatic hydrocarbons have higher octane
values. Oxygenated compounds such as alcohols and ethers also have very high
blending octane values.
"Straight run" gasoline distilled from typical crude oils has a high percentage of
normal paraffins, and thus tends to have relatively low octane value. Typical
RON values for straight-run gasoline are in the range of 60 to 75. A major focus
of modern refining technology is to improve the octane value of the hydrocar-
bons that are eventually blended into gasoline by converting them from normal
paraffins to higher-octane aromatics, naphthenes, olefins, and isoparaffins.
Table 2: Blending Octane Values Of Some Typical
Hydrocarbons And Gasoline Components
n-Hexane
n-Heptane
n-Octane
Normal Paraffins
Isoparaffins
2,3-Dimethylhexane
2,2,4-Trimethylpentane (iso-octane)
1-Butene
1-Pentene
Otefins(Alkenes)
Aromatics
Benzene
Methylbenzene (toluene)
1 ,2-Dimethylbenzene (o-xylene)
1 ,4-Dimethylbenzene (p-xylene)
Cyclopentane
Cyclohexane
Naphthenes (Cycloalkanes)
Oxygenates
Methanol
Ethanol
Tertiary butanol
Methanol/TBA (50/50)
Methyl tertiary butyl ether (MTBE)
Tertiary amyl methyl ether (TAME)
Ethyl tertiary butyl ether (ETBE)
RON
19
0
-19
71
100
144
119
99
124
120
146
141
110
127-136
120-135
104-110
115-123
115-123
111-116
110-119
MON
22
0
-15
76
100
126
109
91
112
103
127
141
97
99-104
100-106
90-98
96-104
98-105
98-103
95-104
Source: Owen and Coley (1995).
,T.
/.- MCAi.
Refiners have defined
"blending" octane
values for different
compounds that reflect
their effects when
blended into typical
gasolines.
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I
With the development
of advanced refining
technologies, it is now
possible to achieve
high octane ratings
without the use of
lead.
2.3 Properties Of Tetraethyl Lead
Tetraethyl lead (TEL) has been used to reduce the knocking tendencies of
gasoline since 1922. Before advanced refining technology was developed, the
antiknock properties TEL imparted to gasoline enabled the development of
efficient, high-compression gasoline engines. By adding approximately 0.8 to 1.0
gram of lead per liter to straight-run gasoline, the octane rating can be raised to
around 85 RON. The first higher-octane gasolines were produced in this way,
and many of the smaller and older refineries in developing countries are still
configured in this manner.
With the development of advanced refining technologies, it is now possible to
achieve high octane ratings without the use of lead. Where permitted by law,
however, lead additives are still the cheapest means of producing high-octane
gasoline.
The relationship between lead concentration and octane increase. As Figure 5
shows, the octane boost due to lead typically varies both with the lead content
and with the octane value of the base fuel. The octane increase resulting from a
given amount of lead is greater for low-octane regular gasoline than for higher-
octane premium fuel. This increase also varies with the amount of lead already in
the fuel. The first 0.1 g/liter of lead additive gives the largest octane boost, with
subsequent increases in lead concentration giving progressively smaller returns.
This non-linear relationship between lead addition and octane increase has very
important implications for a leadphaseout strategy.
Figure 5: Octane Enhancement Vs. Lead Concentration
For Some Typical Gasolines
$
0 0.2 0.4
Grams of lead/liter
Derived from NPRA Paper AM-79-46.
Source: Abt( 1996).
If refinery octane capacity is limited, the quickest and most economical way to
reduce lead emissions will generally be to reduce the lead content of existing
leaded gasoline grades as much as possible, rather than to encourage refiners and
vehicle owners to switch from leaded to unleaded fuel. The non-linear relation-
ship between lead and octane means that less lead is required to produce two
20
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liters of low-lead gasoline than to produce one liter of high-lead gasoline and one
liter of unleaded with the same octane value.
TEL additive package. In order to prevent excessive buildup of lead deposits in
the engine, TEL is normally sold and blended into gasoline in combination with
a mixture of ethylene dibromide and ethylene dichloride; this mixture is known
as "motor mix." The bromine and chlorine atoms combine with lead in the
combustion chamber to form lead bromide and chloride, limiting the buildup of
lead oxide on the combustion chamber walls.
TEL is extremely toxic and (unlike inorganic lead compounds) is readily ab-
sorbed through the skin, making it dangerous to handle. Both ethylene
dibromide and ethylene dichloride have been identified as possible carcinogens,
as has inorganic lead.
2.4 Petroleum Refining And Gasoline Supply
Gasoline is produced by refining crude oil as a co-product with other oil prod-
ucts such as liquefied petroleum gas (LPG), kerosene, jet fuel, diesel fuel, fuel
oils, lubricating oils, and feedstocks for the petrochemical industry. Gasoline and
diesel fuels comprise a large percentage (between 30 and 70 percent) of the
products from most refineries. Because of increasing demand for gasoline and
diesel fuels compared to other products, and increasingly stringent environmental
requirements for gasoline and diesel quality, the refining industry has had to
undergo an important transition in technology and product slate.
Crude oil contains a wide range of hydrocarbons, organomctallics and other
compounds containing sulfur, nitrogen, etc. It varies in chemical composition,
from oil field to oil field, and also with time within a given oil field. The
hydrocarbons (HCs) in crude oil are as simple as CH4 (methane) or as complex
as C^H^, with each of these compounds having its own boiling temperature. A
refinery will distill crude oil into various fractions and, depending on the desired
final products, will further process and blend those fractions. With gasoline
making up only a fraction of the constituent hydrocarbons in crude oil, a refinery
must either sell the remainder as marketable products or convert the larger
molecules into smaller gasoline molecules.
2.4.1 Different Refinery Types And Capabilities
Petroleum refineries vary greatly in size and complexity, depending on the level
and sophistication of the physical and chemical processes they perform. One
commonly used classification divides refineries into three groups: topping
refineries (the simplest), hydroskimming refineries, and "complex" refineries.
Topping refinery. The initial processing step in all petroleum refineries is the
separation of crude oil by distillation into a variety of process streams with
different boiling ranges (Figure 6). In a topping refinery, these "straight run"
process streams receive minimal further processing (e.g., to remove impurities
such as sulfur) before being blended into final products. Topping refineries do
not include process units designed to increase the octane of the "straight-run"
gasoline they produce, and must therefore rely on the use of lead additives or
other blending components such as oxygenates in order to meet octane specifica-
tions.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 21
When refinery octane
capacity is limited, the
quickest and most
economical way to
reduce lead emissions
is to reduce the lead
content of existing
leaded gasoline grades
as much as possible,
rather than to en-
courage a switch from
leaded to unleaded
fuel.
-------
Figure 6: Distillation Of Crude Oil
< 32° C Butane and lighter
lex
DN COLUMN
i
w
Q
'•^••H
32-104° C —Light naphtha
104-157° C— Heavy naphtha
157-232° C— Kerosene
232-343° C— Light gas oil
343-427° C— Heavy gas oil
> 427° C
• Straight run residue
Although many older
refineries were originally
built as topping refineries,
most of these have since
been upgraded to
hydroskimming or complc^
types. The few remaining
topping refineries are mostly
small units serving isolated
markets in developing
countries.
Hydroskimming refinery. A
hydroskimming refinery is
similar to a topping refinery,
except that it includes one or
more catalytic reformer
units. As discussed in Section 2.4.2, the catalytic reformers convert some of the
low-octane paraffinic components in "straight run" gasoline into higher-octane
aromatics and naphthenes. This operation produces excess hydrogen, which is
often used for hydrotreating the jet and diesel fuel streams to remove sulfur and
improve combustion quality. Otherwise, it may be burned as fuel. Figure 7
shows a simplified process diagram for a typical hydroskimming refinery.
Topping and hydroskimming refineries have little flexibility to change the
proportion of crude oil input that goes to different products. The relative
amounts of gasoline, jet fuel, diesel, and fuel oil produced are determined
primarily by the hydrocarbon composition of the crude oil. A crude oil with a
high percentage of light hydrocarbons will make it possible to produce more
gasoline and diesel fuel, while a heavier crude oil will result in greater production
of heavy fuel oil. In the last two decades, the demand for (and hence the value
of) "white" products such as gasoline and diesel fuel has increased more than that
for "black" products such as fuel oil. As electrical generation increasingly shirts
from oil-fired steam turbines to natural gas-fired combined-cycle plants, this
trend is likely to continue.
Figure 7: Simplified Process Diagram For A Hydroskimming Refinery
»• Refinery Gas
Overhead
Crude
Oil-
Fractionation
li
to
1
I5
-+-LPG
Butane
Naphtha
Catalytic Reformer I , . , .. _ . —
^^^^^^^^^J Catalytic Reformate
L _l |_|
Hydrotreater I i 2
2
1
m
g
-»• Kerosene/Jet Fuel
Gas Oil
Hydrotreater
->• Autodiesel
-*• Heavy Gas Oil
Residuum
-*• Fuel Oil
22
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
Complex or "conversion" refineries. These refineries are distinguished from
topping and hydroskimming refineries by possessing one or more process units
intended to convert low-value residual products into higher-value products such
as gasoline and diesel fuel. The most common conversion unit is a fluid catalytic
cracker (FCC). This process unit heats the heavy gas oils produced by vacuum
distillation of the residual oil in the presence of a catalyst, causing the large
hydrocarbon molecules present in these oils to "crack" into smaller molecules.
The resulting product is high in naphthenes, aromatics, and olefins, and thus has
a relatively high octane value. This process also produces a significant amount of
light olefins (propene and butenes). These can be used in subsequent process
units to produce high-octane species such as alkylate and ethers. Figure 8 shows a
process diagram for a typical deep conversion refinery.
Figure 8: Process Diagram Of A Deep Conversion Refinery
Gas _ .. . | If H2 (for HDS)
LPQ
•^Gasolines
Atmos-
pheric
Residue
Kerosene,
Jet Fuel,
Distillate
Fuel
Oil, and
Dtew!
Fuel
Residual
Fuel
Oil
*-Coke
Source: Abt( 1996).
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
ICAL
OPTIONS
23
-------
Hydrocracking, a related process, is carried out in the presence of excess hydro-
gen, and thus tends to produce less in the way of unsaturated aromatics and
olefins. This process is becoming increasingly popular, however, because it
produces very high-grade, low-sulfur diesel and jet fuels. The gasoline-range
product produced by the hydrocracker is often further processed by catalytic
reforming to increase its octane rating.
The residuum left after the vacuum distillation of crude oil is a heavy, tarry
substance that must be heated in order to be pumped, and which contains much
of the sulfur and metallic contaminants found in the crude oil. This residual oil
can be used as fuel in power plants and marine vessels. As environmental concerns
have shifted fuel demand for electric generation from oil to low-sulfur natural gas
for power generation, however, an increasing number of refineries have adopted
"deep conversion"techniques such as thermal cracking or coking to crack this
residual material as well.
2.4.2 Principal Process Streams Used In Gasoline
In a modern refinery, a number of process streams are blended together to form
the gasoline "pool." Table 3 lists some of these, along with the corresponding
octane numbers. In the simplest case, a topping refinery, the gasoline pool
comprises light naphtha, heavy naphtha, and enough butane to bring the vapor
pressure of the resulting product up to specification. In a hydroskimming
refinery, the heavy naphtha is sent to the catalytic reformer, producing reformate
to be blended into the gasoline pool. Within some limits, the octane value of the
reformate can be varied by increasing or decreasing the severity of reforming.
More severe reforming gives a higher octane rating, but a lower gasoline yield.
Table 4 shows typical feed and product composition for a catalytic reformer.
Catalyst manufacturers are continually working to improve the efficiency and
octane yields of catalytic reformers.
Table 3: Typical Octane Values For Some Process
Streams Used In Gasoline Blending
Blending Component
Butane
Straight-run light naphtha
Straight-run heavy naphtha
Catalytic reformate
Alkylate
Pen-hex isomerate
Cat cracked gasoline
Coker gasoline
Light hydrocrackate
Heavy hydrocrackate
RON
93
66
62
94-100
97
84-89
92
85
75
79
MON
92
62
59
84-88
96
81-87
77
77
74
76
Sources: Leffler (1984), Meyers (1996).
24
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
Table 4: Typical Feed and Product Composition
for a Catalytic Reformer
Hydrocarbon Type
Paraffins
Olefins
Naphthenes
Aromatics
% Volume
Feed
50
0
40
10
Product
35
0
10
55
Source: Leffler (1984).
Light straight-run naphtha includes a large percentage of n-pentane and n-hexane,
compounds with very low octane values. The octane value of this stream can be
raised considerably by processing it in a pentane-hexane isomerization unit to
convert these straight-chain paraffins to their branched-chain equivalents. The
resulting isomerate can vary from 84 to 89 RON, depending on the process
configuration.
Gasoline-range hydrocarbons from catalytic or thermal cracking (coking) are rich
in aromatics, naphthenes, and olefins, and thus have relatively high RON values.
The gasoline-range products of hydrocracking are much lower in aromatics and
olefins, and thus have lower RON, but good MON, values.
Catalytic cracking and deep conversion processes also produce significant
quantities of light olefins such as butenes and propene. In a process called
alkylation, these compounds are reacted with isobutane to form isoparaffins
containing seven or eight carbon atoms. The resulting alkylate has an extremely
high RON and MON, making it very valuable in meeting octane specifications.
Isobutene and isoamylene can also be reacted with methanol in an etherification
unit to form MTBE and TAME (tertiary amyl methyl ether), respectively.
Unlike olefins and aromatic compounds, the isoparaffins in alkylate and
isomerate are not considered highly toxic or carcinogenic, and have low reactivity
in the formation of photochemical smog. Thus, these compounds are especially
desirable for producing cleaner-burning "reformulated" gasoline.
2.4.3 Examples Of Refinery Upgrades To Produce Unleaded Gasoline
The worldwide demand for petroleum products has shifted strongly toward
unleaded gasoline and low-sulfur, high-cetane diesel fuel, and away from "black"
products such as heavy fuel oil. In response, many refineries are installing
additional process units to upgrade the clear octane rating of gasoline in order to
do without lead, and to convert an increasing fraction of low-value residual oil
into high-value products such as gasoline and diesel.
Slovak Republic. The upgrade of the Slovnaft refinery in the Slovak Republic
over the last decade (Lovei, 1997) is a typical example of the upgrading process.
Originally configured as a hydroskimming refinery, the Slovnaft refinery was
upgraded in several stages. The first stage was to increase the severity of catalytic
reforming, making possible a reduction in gasoline lead content from 0.7 to 0.4
grams per liter. Blending MTBE and adjusting the distillation process made it
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 25
Many refineries are
installing additional
process units to
upgrade the clear
octane rating of
gasoline in order to
do without lead.
-------
possible to reduce lead further, to 0.25 gram per gallon. In the second stage, a
hydrocracker was added to convert part of the crude residue to gasoline and
diesel fuel stocks. Reforming the hydrocracked gasoline stream made it possible
to reduce the lead content of 96 RON fuel to 0.15 g/gallon, and at the same
time to introduce unleaded gasoline at 95 RON. In the third stage, an isomeriza-
tion unit was added as well, making it possible to eliminate lead completely.
Figure 9 shows how the Slovnaft refinery evolved during this period.
Figure 9: Evolution Of The Slovnaft Refinery, Slovak Republic
26
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
LP.G.
M
O
B T
L O
E R
N
D G
I A
N S
G O
L
O I
F N
E
S
LP.G.
Butane
Isomerate
^ I I Light Reformate,
Reformate
Heavy
Reformate
7RS3clSI#=^>
MTBE
M
O
B T
L O
E R
N
D G
I A
N S
G O
L
O I
F N
E
S
Source: Lovei (1997).
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
IDENTIFYING
v } p » 4 1 *\ '*
>*•* * * K " * -*1 *
27
-------
Brazil has successfully
blended 22 percent
ethanol in gasoline for
many years, thus com-
pletely eliminating the
use of lead additives
m
while requiring little in
the way of refinery
process equipment to
increase gasoline
octane.
Russia. Many Russian refineries are being updated to be able to produce unleaded
gasoline, both to meet Russian lead phasedown targets and for export. The Perm
refinery, opened in 1958 and located in the North Urals region, provides an
example. This refinery is one of the largest in Russia, with a crude oil capacity of
300,000 barrels per day. The first step implemented was to replace the catalyst in
the largest of the four existing catalytic reformers with an improved catalyst
provided by UOP. This and related operational changes increased the octane
value of the reformate from 91 to 99.5, while nearly doubling the cycle time
between catalyst regenerations. Two other catalytic reformers were subsequently
shifted to use the new catalyst type (Shuverov et al., 1997). At the same time,
the crude distillation units were revamped, and a vacuum distillation unit was
installed to recover additional heavy gas oil from the residue from the crude
distillation units.
The next steps at the Perm refinery will include a hydrocracking unit to break
down the heavy gas oil into lighter products in the gasoline and diesel fuel
ranges, revamp the existing catalytic cracking unit, make further upgrades to the
catalytic reformers, and install a di-isopropyl ether plant. The cost of these
changes is estimated at US $340 million (Rudin, 1998). A later set of upgrades is
planned to include another hydrocracker for the vacuum distillation residue and
an alleviation unit to increase gasoline octane capacity. These and related changes
are expect to cost $290 million.
Another Russian refinery going through the upgrading process is Sibneft's Omsk
refinery in Siberia. This refinery is increasing octane capacity by constructing a
sulfuric acid alkylation unit with 8,600 barrels per day capacity, and a
semiregenerative catalytic reforming unit capable of processing 25,000 barrels per
day. The project is estimated to cost $55 million, and will be completed in 2000.
Persian Gulf. Many refineries in the Persian Gulf are also being upgraded to meet
market demands for unleaded gasoline and lower fuel oil production. A good
example is the Sitra refinery in Bahrain. The refinery plans to cut fuel oil produc-
tion by more that half, from 26-27 percent of total product output to 10-12
percent, while increasing gasoline production by the same amount. The proposed
upgrade includes replacing four atmospheric distillation units with a single
15,000 barrel per day unit, a 7,500 barrel per day LPG recovery unit, an 18,000
barrel per day catalytic reformer, a 750 barrel per day MTBE unit, and a 4,600
barrel per day alkylation unit. The project is expected to cost about $600
million.
2.5 Oxygenates As Gasoline Blending Components
Several oxygenated compounds are commonly used as high-octane blending
components for gasoline. They include methyl tertiary butyl ether (MTBE),
tertiary amyl methyl ether (TAME), di-isopropyl ether (DIPE), and ethanol
(ethyl or grain alcohol). Of these, MTBE and ethanol account for by far the
largest shares. MTBE is typically blended with gasoline at levels up to 15 percent
by volume, while ethanol is blended up to 10 percent by volume in the United
States. Brazil has successfully blended 22 percent ethanol in gasoline for many
years, thus completely eliminating the use of lead additives while requiring little
in the way of refinery process equipment to increase gasoline octane.
28 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
In the past, methanol (methyl or wood alcohol) was also blended with gasoline to
some extent, combined with tertiary butyl alcohol as a cosolvent. Such use is no
longer common, however, due to economic considerations.
In addition to increasing octane, the blending of gasoline with oxygen-containing
compounds such as ethanol and the ethers helps to reduce carbon monoxide and
hydrocarbon emissions from vehicles using the fuel. This effect is greatest for
vehicles without emission control systems, and relatively small for modern
vehicles equipped with closed-loop control of the air-fuel ratio. To take advan-
tage of this effect, U.S. specifications for reformulated gasoline require at least 2
percent oxygen by weight, and 2.7 percent in winter months, when CO emis-
sions tend to be highest.
As Table 2 shows, the blending RON of MTBE is about 115 to 123. Thus,
blending 15 percent MTBE into gasoline having a base RON of 87 will result in
a blend with RON in the range of 91 to 92: an increase of four to five octane
numbers, or the equivalent of 0.1 to 0.15 g/liter of lead. Similarly, the blending
octane value for ethanol is 120 to 135, so that a 10 percent blend of ethanol
with 87 RON gasoline will give a RON of 90 to 92 for the blend.
At current prices, MTBE is considerably cheaper than ethanol. Most of the
reformulated gasoline sold in the United States thus contains MTBE, except
where state tax subsidies encourage ethanol blending. MTBE is also very widely
blended into gasoline in Mexico, Egypt, Thailand, Argentina, and other coun-
tries. MTBE use has recently become controversial in the United States, how-
ever, due to concerns over ground and surface water contamination.
2.5.1 Sources, Supply Volumes, And Prices
MTBE is produced by reacting isobutene (2 methyl propene) and methanol in
the presence of a catalyst. The isobutene may be obtained from a refinery, but
more commonly is produced in a stand-alone plant by the dehydrogenation of
isobutane extracted from natural gas. Methanol, the other feedstock, is usually
produced by the partial oxidation of methane from natural gas. Methanol can
also be reacted with isoamylene (2 methyl butene) to produce TAME, and
ethanol can be reacted with isobutene to produce ETBE using the same process
unit, thus providing some flexibility in feedstock selection (Meyers, 1996).
Due to the worldwide phaseout of leaded gasoline and the increasing demand for
clean-burning "reformulated" gasoline, demand and production capacity for
MTBE and other ethers have been growing rapidly over the last two decades. In
1997, there were 172 MTBE plants in operation worldwide, with a total
production capacity of 502,000 barrels per day (80,000 m3/day), and 20 TAME
plants with a combined capacity of 46,000 barrels per day (7,300 m3/day)
(Saunders, 1997). Another 76 oxygenate plants were planned or under construc-
tion at that time. If all of these plants were completed, they would add another
337,000 barrels per day to world MTBE capacity by 2000, significantly exceed-
ing the projected demand of 582,000 barrels per day.
Market prices for MTBE and methanol have historically been highly volatile, due
to a combination of low short-term elasticity of supply and unpredictable
fluctuations in demand. For example, September 1998 MTBE prices of US $215
to $230 per metric ton were 25 percent less than those prevailing one year
Although MTBE is
considerably cheaper
than ethanol at current
prices, its use has
become controversial
due to concerns over
ground and surface
water contamination.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
29
-------
.!
The leaner air-fuel
mixture produced by
the addition of
oxygenates to gasoline
helps reduce CO and
HC emissions, while
NOx emissions may
increase slightly.
earlier, and more than 40 percent below the peak prices of over $355 per ton
reached in 1992 and 1994. The price of methanol on the world market has
fluctuated even more dramatically, from around US $0.25/gallon in the early
1980s to $0.60-0.70 in the late 1980s, to as much as $1.80 in 1994, and then to
$0.30 per gallon in summer 1998. The lower prices reflect the effects of a glut,
while the higher values reflect shortages.
Ethanol is produced primarily by the fermentation of starch from grains or sugar
from sugar cane. As a result, the production of ethanol for fuel is in direct
competition with food production in most countries. The resulting high price of
ethanol (ranging from $1.00 to $1.60 per gallon in the United States in the last
few years) has effectively ruled out its use in motor fuel except where (as in Brazil
and the United States) it is heavily subsidized. New developments in the fermen-
tation of cellulosic biomass offer some potential for lower-cost production of
ethanol in the future, but this technology has not yet been demonstrated in a
full-scale plant.
2.5.2 Impact On Vehicles
Corrosion and materials compatibility. Blends of MTBE and other ethers in
gasoline have been used successfully for many years in several countries, including
the United States. No problems with materials compatibility or corrosion have
been identified in either the vehicle or fuel distribution system. There have been
some reports of corrosion problems with alcohol blends (Owen and Coley,
1995). However, analyses of the available data by EPA (1985) indicate that
alcohol mixtures did not result in corrosion or damage to fuel system elastomers
when the base gasolines were blended properly and typical corrosion inhibitors
were used. In practice, the widespread addition of ethanol to gasoline has not
created significant problems in the United States or Brazil.
Leaner air-fuel mixtures. Unless the fuel system is adjusted to compensate for the
oxygen content, the use of oxygenate/gasoline blends results in a somewhat leaner
mixture than would result from an all-hydrocarbon fuel. This is the major source
of the emission reductions experienced with the use of oxygenates, and usually
presents no performance problems. If a vehicle were adjusted with the air-fuel
ratio already near the lean limit, however, the additional enleanment due to the
oxygenate could cause performance problems.
Fuel and energy consumption. Because oxygenated gasolines contain less energy
per unit volume than gasolines without oxygen, the volumetric fuel consumption
(liters per 100 km) may increase by a few percent using oxygenated fuel. Specific
energy consumption usually improves slightly, however, due to the overall leaner
mixture.
2.5.3 Impact On Pollutant Emissions
Carbon monoxide and hydrocarbons. Assuming no change in the settings of the
fuel metering system, the addition of oxygenates to gasoline will result in a leaner
air-fuel mixture, thus helping to reduce exhaust CO and HC emissions. This
approach has been made mandatory in a number of localities suffering from high
wintertime CO emissions. (CO emissions are highest at low temperatures, with
low traffic speeds, and at high altitude.)
30 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
Oxides of nitrogen. Recently a test program that studied the impact of ethanol
and MTBE on NOs emissions attracted considerable attention when it stated
that, although HC and CO emissions are reduced by the use of oxygenates, NOx
emissions may increase slightly by the leaner operation (see the Auto/Oil Air
Quality Improvement Research Program, AQIRP, 1992). EPA studied this issue
carefully and reached a different conclusion from the AQIRP study. In developing
the Agency's own highly complex model, EPA concluded that NOx emissions are
not significantly affected by the addition of oxygen to the fuel. These data were
based on more than 4,000 individual vehicle tests of 1990 technology vehicles
and on many test programs.
Moreover, the use of oxygenates in a real-world refining situation typically results
in significant decreases in olefins and sulfur as well as aromatics, due to both
simple dilution and to octane considerations. This, EPA found, results in
significant NO^ decreases, especially in vehicles with catalysts.
Research results. The Auto/Oil Air Quality Improvement Research Program
(AQIRP) study in the United States tested the effects of adding 10 percent
ethanol (3.5 wt. percent oxygen) and 15 percent MTBE (2.7 wt. percent
oxygen) to industry average gasoline. For late-model gasoline vehicles with three-
way catalysts, the ethanol addition results showed a net decrease in non-methane
hydrocarbon (NMHC) and CO emissions of 5.9 percent and 13.4 percent,
respectively, and a net increase in NOX emissions of 5.1 percent. The MTBE
addition results showed net decreases in NMHC and CO of 7.0 percent and 9.3
percent, respectively, and a net increase in NOX emissions of 3.6 percent
(Hochhauser and others, 1991). In tests performed in Mexico City, the addition
of 5 percent MTBE to leaded gasoline was found to produce a 14.7 percent
reduction in CO and an 11.6 percent reduction in HC emissions from non-
catalyst gasoline vehicles.
Mandating the use of oxygenates to reduce emissions. The State of Colorado
(USA) initiated a program to mandate the addition of oxygenates (such as
ethanol and MTBE) to gasoline in the Denver metropolitan area during winter
months when high ambient CO tends to occur. The mandatory oxygen require-
ment for the winter of 1988 (January to March) was 1.5 percent by weight,
equivalent to about 8 percent MTBE. For the following years, the minimum
oxygen content required was 2 percent by weight, equivalent to 11 percent
MTBE. These oxygen requirements were estimated to reduce CO exhaust
emissions by 24-34 percent in vehicles already fitted with three-way catalyst
systems. The success of this program led the U.S. Congress to mandate the use
of oxygenated fuels (minimum 2.7 percent oxygen by weight) in areas with
serious winter-time CO problems.
Evaporative emissions. Although exhaust HC emissions tend to be lower with
oxygenate blended fuels, the use of alcohols as blending agents may increase
evaporative emissions considerably. Because of their non-ideal behavior in
solution, blends of ethanol or methanol with gasoline have higher vapor pressure
than either component alone.
However, although mass HC emissions may increase from a higher Reid vapor
pressure (RVP) caused by the use of ethanol, data indicate that the ozone-causing
Tests in Mexico City
found that adding 5
percent MTBE to
leaded gasoline
produces reductions in
CO and HC emissions
from non-catalyst
gasoline vehicles.
The U.S. Congress has
mandated the use of
oxygenated fuels in
areas with serious
winter-time carbon
monoxide problems.
IMPLEMENJER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
31
-------
reactivity of the resulting emissions is less, thus resulting in no real ozone
degradation.
Effects of oxygenates. The presence of oxygenates in the fuel changes the hydrocar-
bon composition of the exhaust and evaporative emissions. For gasoline contain-
ing 11 percent MTBE, exhaust MTBE emissions account for about 2.5 percent
of total exhaust VOC emissions, and 8 to 10 percent of total evaporative
emissions (California EPA, 1998). Formaldehyde emissions also tend to increase
with MTBE, while emissions of benzene and 1,3 butadiene are reduced signifi-
cantly. The use of ethanol in gasoline increases ethanol and acetaldehyde emis-
sions, while also reducing emissions of benzene and 1,3 butadiene.
2.5-4 Impact On Soil, Groundwater, And Surface Waters
Unlike most hydrocarbons, both alcohols and ethers dissolve readily in water.
Thus, where spilled gasoline comes in contact with water, the oxygenate can be
expected to migrate from the gasoline into the water. This presents little problem
in the case of the alcohols, as these have been shown to biodegrade fairly rapidly.
In the case of MTBE and other ethers, however, this degradation appears to be
slower, if it occurs at all.
Soil. Gasoline containing oxygenates is no more hazardous than ordinary gasoline
when spilled on or leaked into soil. Indeed, because these oxygenates tend to
replace more hazardous compounds such as benzene or TEL, spills of oxygenated
gasoline will generally be less hazardous. In addition, alcohols in soil tend to
biodegrade rapidly.
Groundwater. In a number of cases, leaking underground tanks containing
MTBE-gasoiine blends have resulted in the contamination of groundwater with
MTBE. Although the level of health risk posed by this contamination appears to
be small, the taste and odor of MTBE can be detected in water at concentrations
as low as 50 parts per billion (ppb). The current EPA Drinking Water Advisory
level for MTBE is 20 to 40 ppb, based on the taste and odor thresholds, and a
10,000-fold safety factor below the lowest observed adverse effect level in animals
(California EPA, 1998).
Surface waters. MTBE contamination of surface waters has also been detected on
occasion as a result of fuel spills into the water body. The use of two-stroke
gasoline engines in outboard motors and personal watercraft has also contributed
to contamination in some cases. These engines emit as much as 50 percent of the
total fuel they consume in their exhaust, which is injected into the water. So far,
the levels of surface water contamination due to this source have all been found
to be well below the EPA advisory levels (California EPA, 1998). However,
concerns about the potential for widespread contamination of drinking water
sources with MTBE have led to calls for the use of MTBE in gasoline to be
banned in California.
32 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
2.5.5 Health Risks Associated with MTBE
Chronic inhalation studies in animals suggest that MTBE may be weakly
carcinogenic, with an estimated unit risk of 7.5 x 10~8 for mouse liver tumors
and 1.7 x 10"7 for rat kidney tumors. For comparison, unit risk values for
benzene and 1,3 butadiene — two other toxic air contaminants associated with
gasoline - are 8.3 x 10~6 and 2.8 x 10~4, respectively.
An analysis by the California Air Resources Board found that overall toxic risk
from using reformulated gasoline containing MTBE was reduced by more than
40 percent compared to that to be expected from industry-average gasoline
without MTBE (California EPA, 1998).
2.6 MMT Properties And Performance
The only non-lead antiknock additive now offered commercially is
methylcyclopentadienyl manganese tricarbonyl (MMT). Its manufacturer recom-
mends the use of MMT concentrations up to 0.0165 grams of Mn (manganese)
per liter in gasoline intended for non-catalyst vehicles, and half this concentration
in gasoline intended for catalyst cars. At the 0.0165 gram per liter concentration,
it adds about 1.9 octane numbers to gasoline. In the United States, MMT
concentrations are limited to 0.00825 gram per liter to protect emission control
systems.
The use of MMT as an octane-enhancing additive in gasoline is controversial,
due to concerns over its possible effects on automotive emission control systems,
and over the toxicity of the resulting manganese emissions. During the 1980s,
when lead concentrations in U.S. gasoline were severely limited, MMT was used
extensively to improve the octane rating of leaded gasoline. MMT was also used
extensively in both leaded and unleaded gasolines in Canada.
MMT was not permitted in unleaded gasoline sold in the United States until
1996, when EPA lost a lawsuit filed by the manufacturer, Ethyl Corporation,
after rejecting the company's application to approve MMT for unleaded gasoline
use. EPA's disapproval was due to uncertainty over the potential toxic effects of
manganese emissions. In its 1994 rejection of Ethyls petition to approve MMT,
EPA concluded that "Although it is not possible based on the present information to
conclude whether specific adverse health effects will be associated with
manganese... [exposures resulting from the use of MMT]...neither is it possible to
conclude that adverse health effects will not be associated with such exposures'^ Auto
manufacturers had also opposed the approval of MMT, arguing that it could
impair the effectiveness of vehicle emission control systems. EPA concluded in its
evaluation, however, that this was not the case.
With the U.S. court decision, and another decision in Canada overturning a ban
on interprovincial trade in MMT, it can legally be used in unleaded gasoline in
both the United States and Canada. EPA's administrator has stated, however,
that a definitive risk evaluation is not possible until more data are collected, and
that use of MMT in unleaded gasoline in the United States ought to be delayed
until such data are collected (Browner, 1996). In determining the advisability of
MMT use, or the use of any fuel or fuel additive, in any particular country or
5 59 FR 42260, August 17, 1994.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
In California, concerns
about the potential for
widespread contamin-
ation of drinking water
sources with MTBE has
led to calls to ban the
use of MTBE in
gasoline.
33
-------
The time required to
phase out lead in
gasoline has ranged
from a few months
(e.g., Egypt) to more
than 15 years (the
United States).
The approach recom-
mended here is first to
reduce the lead
content of leaded
gasoline as quickly as
possible, and then to
eliminate leaded
gasoline as quickly as
possible thereafter.
regional setting, an assessment of health risk ought to be taken into consider-
ation.
2.7 Lead Phaseout Strategies
Slow vs. fastphaseout. Different countries have taken different approaches to
phasing out lead in gasoline, and have pursued very different schedules. The time
required to phase out lead has varied from periods of more than 15 years in the
United States to a few months in Egypt. In general, a slower phaseout schedule
will reduce the costs of the lead phaseout to the refining industry, and give more
time for any old cars that might suffer valve seat damage to retire from the fleet.
However, it also means that more people are exposed to high lead concentrations
for a longer time, and thus suffer from the adverse effects of lead on their health
(and in the case of children, their mental development). In addition, vehicle
maintenance costs tend to be higher with leaded than with unleaded gasoline, so
that continuing the production of leaded fuel will mean higher maintenance
costs.
Considering a range of scenarios. Because the costs and benefits of rapid vs. slow
lead phaseout will vary from one country to another, implementers should
consider a range of phaseout scenarios, including very rapid and less rapid
reductions. In the short term, the feasible reduction in lead use is likely to be
limited by the refining capacity available. It may take three to five years to
design, finance, and upgrade or build the refinery process units required to
produce high-octane unleaded blending components. In the meantime, some of
the octane shortfall may be recovered by importing oxygenates such as MTBE,
high-octane hydrocarbon blendstocks, or unleaded gasoline.
EPA recommends that lead phaseout be accomplished as quickly as possible.
There are two main reasons for this. First, lead poisoning is one of the most
important preventable diseases associated with urbanization. Although lead in
gasoline represents only 2.2 percent of total global lead use, it remains by far the
single-largest source of lead exposure in urban areas. Approximately 90 percent
of all lead emissions into the atmosphere are due to the use of leaded gasoline.
Second and most important, some of the health effects associated with lead
poisoning, such as lowered IQin children, cannot be reversed no matter how
high the future investment.
Managing the transition to unleaded gasoline. Although it is sometimes possible
to eliminate leaded gasoline overnight, more commonly some transition period is
required. Two approaches have been taken to managing this transition. One
approach has been to encourage refiners and vehicle owners to switch from leaded
to unleaded fuel, without changing the lead content of leaded fuel. This approach
has been typical of Western Europe. The second approach, followed in the
United States and Mexico, has been to reduce the lead content of the leaded
gasoline as quickly as possible, while providing enough completely unleaded
gasoline to meet the needs of vehicles equipped with catalytic converters. This
second approach (reducing the lead content of leaded fuel instead of shifting from
leaded to completely unleaded fuel) has several advantages, and is recommended
in most cases.
• Lower total lead emissions. As discussed in Section 2.2, the octane-improving
effects of lead are not a linear function of lead concentration. The first 0.1 g/
34 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
liter of lead additive gives the largest octane boost, with subsequent increases
in lead concentration giving progressively smaller returns.
• Refining costs. Reducing the lead content in leaded gasoline reduces the
difference in refining costs between leaded and unleaded gasolines. This, in
turn, makes it easier to adopt a policy taxing gasoline so as to set the pump
price of unleaded gasoline lower than that of leaded gasoline. This policy is
considered important to minimizing the chances of misfueling catalyst-
equipped cars with leaded gasoline.
• Improved public perception. Another advantage of this approach is in the area
of public relations. This is because no changes are required in consumer
behavior, and the change in lead concentration is not visible at the gasoline
pump. Since only a tiny amount of lead is required to prevent valve seat
recession even in extreme cases, a change in lead concentration even to very
low levels is unlikely to worry the public. For example, EPA's decision to
limit lead to 0.1 g/gal (0.03 g/1) in 1986 reduced ambient lead
concentrations by 90 percent, but was little noticed by the gasoline-buying
public.
Of course, all countries should move to eliminate leaded gasoline entirely, and as
quickly possible. This is most readily accomplished by leaving the change from
leaded to unleaded for the end of the phase-out process, when there has been
more opportunity to educate the public and when the elimination of most of the
economic benefits from the use of lead will have reduced the motivation for vested
interests to spread misinformation.
An example of near- and longer-term leadphaseout. Table 5 shows a simplified
example of how octane requirements could be met while phasing out the use of
lead additives. The example assumes that the existing gasoline market comprises
equal shares of 85 RON leaded regular and 93 RON leaded premium gasoline,
produced in a mix of topping and hydroskimming refineries. As the "existing
situation" column shows, the regular gasoline is blended from a combination of
straight-run naphtha and butane, with a "clear" RON (before the addition of
lead) of 73.2. Adding 0.7 grams of lead per liter raises the octane rating by 12
numbers, to slightly more than 85 RON. The leaded premium gasoline is
blended from a combination of straight-run gasoline, reformate, and butane,
with a clear RON of 83.6. Adding 0.7 grams of lead per liter raises the RON by
10 numbers, to 93.6. The difference of two octane numbers between the octane
boost from lead in the premium gasoline, compared to that produced by the
same amount of lead in the lower-octane regular gasoline, is due to the reduced
lead susceptibility of aromatics and naphthenes in the reformate.
The second, near-term column shows how the total lead in gasoline might be
reduced within a relatively short period. In this example, the base regular gasoline
is blended from the same components as before, but with the addition of 9
percent by volume of imported high-octane (97 RON) hydrocarbon compo-
nents. These could be either alkylate or aromatics, or a combination of both
(although alkylate would be preferred in order to minimize benzene emissions),
and increase the octane value of the clear gasoline by 2.3 numbers. The resulting
clear gasoline is then blended with 15 percent MTBE (contributing 7.1 octane
numbers). The remaining shortfall of 2.5 octane numbers is made up by blending
0.1 gram of lead per liter, taking advantage of the non-linear relationship be-
tween lead and octane boost.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 35
LOYiCAl
P'HONS
This very simplified
example shows the
potential to reduce
lead emissions subs-
tantially, even before
new refinery process
units can be brought
on line.
-------
iPENT!
OPTION
Table 6: Costs Of Phasing Out Lead In Gasoline —
Hypothetical Case
1998
Prices
Contribution of Gasoline Cost
Existing
NearTerm
Long Term
Regular Gasoline 85 RON
Gasoline 73 RON $/liter
Gasoline 85 RON $/liter
MTBE $/liter
TEL $/gram Pb
High octane imports $/liter
Total Cost
Increase US$/liter
$0.066
$0.090
$0.183
$0.021
$0.138
$0.066
$0.015
$0.080
$0.056
$0.027
$0.002
$0.011
$0.096
$0.015
$0.090
$0.090
$0.009
Premium Gasoline 93 RON
Gasoline 84 RON $/liter
Gasoline 87 RON $/liter
Gasoline 93 RON $/liter
MTBE $/liler
TEL$/gramPb
High octane imports $/liter
Total Cost
Increase USS/liter
$0.088
$0.094
$0.106
$0.183
$0.021
$0.138
$0.088
$0.015
$0.102
$0.080
$0.027
$0.007
$0.114
$0.012
$0.106
$0.106
$0.003
38
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
3. ASSESSING LEAD PHASEOUT
IMPACTS ON THE VEHICLE FLEET
Using lead additives in gasoline has many effects on a vehicle's engine, in addition
to its effects on fuel octane level. Most of these effects are undesirable, including
the corrosion of exhaust valve materials, the contamination of engine oil with
corrosive acids, the fouling of spark plugs, and the corrosion of exhaust systems.
Gasoline lead does have one desirable effect, however: it serves as a lubricant
between exhaust valves and their seats, helping to prevent excessive wear. In the
absence of lead, older-technology engines can suffer from the rapid wear of the
exhaust valve seats when operated at high speed for long periods of time. This
phenomenon, known as valve seat recession, has been the subject of considerable
misinformation and public concern, which in turn poses a serious obstacle to
eliminating leaded gasoline in many countries. However, detailed studies and
extensive practical experience in a number of countries show that the potential
problems due to valve seat recession have been highly exaggerated and that use of
low-lead or unleaded gasoline will result in longer engine life and lower mainte-
nance costs overall.
This chapter first describes the reasons underlying EPA's finding
that the maintenance costs for vehicles using unleaded gasoline
are less than those for vehicles using leaded gasoline.
This conclusion has been supported by actual experience in
countries using unleaded gasoline. In the United States, several
studies covering thousands of vehicles found no maintenance
problems that could be attributed to the effects of unleaded
gasoline. Likewise, Brazil has not experienced such problems as
valve seat recession, which have been commonly attributed to
the use of unleaded gasoline.
Last, the chapter shows how to calculate the maintenance cost
savings resulting from the use of low-lead and unleaded gasoline.
The results show that, for typical maintenance costs, using low-
lead gasoline would result in savings of about US $550 over the
life of a car; the total savings for unleaded fuel would be about
$800.
Valve seat recession
(where the exhaust
valve seats of older
engines that run
without lead suffer
rapid wear) is not as
serious a problem as
once thought. Low-
lead or unleaded
gasoline produces
longer engine life and
lower maintenance
costs for these and
other engine types.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
39
-------
The Steps In Assessing Lead Phaseout Impacts
On The Vehicle Fleet
1. Assess maintenance benefits of unleaded gasoline
To assess the benefits of reducing or eliminating lead in gasoline for
the vehicle fleet, implementers should quantify the frequency of
occurrence and the costs of maintenance items such as spark plug
changes, oil changes, valve repairs, valve seat repairs, and exhaust
system replacements. The savings in maintenance costs due to
lead phaseout can then be estimated using the information provided
in Section 3.4.
2. Assess potential for valve seat damage
The implementer should also assess the potential for some engines
to suffer valve seat damage.
3. Assess potential valve seat protection strategies
Next, implementers should assess the costs of potential valve seat
protection strategies if these are indicated. (See Section 3.1.1 for
some ways to protect valve seats.)
4. Evaluate net costs and savings for the vehicle fleet
The resulting net benefits or costs should then be calculated as
functions of time for each of the lead phaseout strategies consid-
ered, in order to compare them with the other costs and benefits.
3.1 Lead's Role In The Engine
During the 1960s and 1970s, many technical papers discussed the effects of lead
additives and unleaded fuels on engines. Weaver (1986) reviewed the literature
through 1984, as well as a number of unpublished results of fleet experience
using unleaded gasoline. The results of his review were cited in the EPAs 1985
cost-benefit study of lead phaseout, and provided the technical basis for its
conclusion that the vehicle maintenance savings would outweigh the costs. The
remainder of this section summarizes the results of that study.
3.1.1 Valve Seat Recession
The exhaust valves and valve seats of modern gasoline engines operate at high
temperatures and under great mechanical stresses. When it closes, the valve
strikes the seat with great force thousands of times per minute. Under high-speed
and high-power output conditions, small "warts" of iron oxide may form on the
valve. This results from segments of the valve seat welding to the valve upon
impact, and then being torn loose when the valve opens. When these "warts"
repeatedly strike against the valve seat, it causes deformation, cracking, and
flaking of the seat, while the presence of hard iron oxide particles being scrubbed
across the valve face causes abrasive wear. The resulting rapid wear of the valve
seat can lead to a loss of compression and require major repairs to the engine in
less than 10,000km.
The presence of lead deposits on the valve seat appears to prevent the initial
adhesion and welding that leads to valve seat recession. Only a small amount of
lead is required to provide this protection: 0.02 grams per liter has been found
40 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
to be effective in laboratory tests. A similar protective effect is obtained from
deposits of other elements such as manganese (from MMT), phosphorus, zinc,
and calcium (from engine oil). Valve seat recession can also be prevented by heat-
treating the valve seat area to harden it, or by using valve seat inserts made of
hard material. A hardness of approximately 30 on the Rockwell C scale is
adequate to prevent valve seat recession.
Nearly all gasoline engines and replacement cylinder heads now produced in the
world have hardened valve seats, and thus are not subject to valve seat recession.
This applies generally to U.S. vehicles made after 1970, and European vehicles
beginning in the early 1980s. Some older engines still in service may have soft
valve seats, however, and could potentially experience valve seat recession.
Although valve seat recession can readily be produced in the engine laboratory,
practical experience and a number of specific studies have shown that it is very
uncommon in actual use. This is apparently because few gasoline vehicles (espe-
cially old ones) experience long periods of uninterrupted operation at high speeds
and loads. There appears to be a threshold effect — a certain period of high-
speed operation is required to wear through the deposit layer on the valve seat
before recession can begin. Interrupting this period of high-speed operation with
periods of lighter use may allow the deposit layer to re-form, prolonging engine
life.
McArragher et al. (1993) reviewed a number of later studies and assessed the
potential for valve seat recession due to lead phaseout in Europe. Like the EPA
study, McArragher and his colleagues concluded that valve seat recession was
likely only where vulnerable engines were subject to prolonged high-speed
operation. They noted, however, that this was more likely in Europe, due to the
smaller engines common there and the high speeds reached on autobahns and
similar motorways. They also concluded that a minimum of 0.05 g/Iiter of lead
would provide complete protection to the most vulnerable engines, even under
the most extreme conditions. A potassium additive was found that gave com-
plete valve seat protection at high concentrations and good protection at lower
concentrations.
The McArragher team projected the fraction of surviving cars in Europe with
soft seat valves potentially vulnerable to recession. This percentage was projected
to drop from around 40 percent in 1990 to less than 20 percent by 1997. They
pointed out as well that many of the "soft" seats were actually hard enough to be
unlikely to suffer valve seat recession except under extreme conditions, so that
the number of vehicles actually vulnerable to valve seat recession would be even
less than what they projected.
In the minority of vehicles that experience valve seat recession, the problem can
be corrected and kept from recurring. This is done either by replacing the
cylinder head with a new one having hardened valve seats, or by machining out
the valve seats in the old cylinder head and replacing them with hardened inserts.
The cost of this operation is about US $500 in the United States, and is ex-
pected to be considerably less in most developing countries, which have lower
labor costs.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
Valve seat recess/on
can occur in some
older vehicles when
they are subjected to
prolonged high-speed
operation, but the
hardened valve seats
manufactured after
1970 in the United
States and the early
1980s in Europe
protect against this
problem.
In the minority of
vehicles that
experience valve seat
recession, the
problem can be
corrected and kept
from recurring.
-------
Studies carried out for
EPA found that using
unleaded gasoline
greatly reduces the
number of valve-
related repairs needed,
more than offsetting
any increase in repairs
due to valve seat
recession.
Unleaded gasoline can
extend engine life by
reducing engine rust
and the corrosive wear
of piston rings and
cylinder walls.
Cars using leaded
gasoline need spark
plug replacements
twice as often as those
running on unleaded
gasoline.
3.1.2 Valve Corrosion And Guttering
Although lead deposits protect valve seats from accelerated wear, they can reduce
the life of exhaust valves. At high temperatures, the lead oxide layer on the seat
can attack the protective oxide layer on the valve, causing corrosion. This
weakens the metal and can eventually cause "guttering" — the formation of a
channel on the valve surface. Hot combustion gases escaping through this
channel rapidly enlarge it, causing the valve to fail. A similar effect can occur
when lead deposits build up too thickly on the valve seat. When these deposits
flake, they can create a path for hot gases past the valve face.
Measures to prevent lead deposit buildup were designed into engines intended
for use with leaded gasoline. These include the use of valve rotators, greater
spring loadings, and steeper valve seat angles. U.S. experience and a number of
fleet studies have shown that the use of unleaded gasoline greatly reduces the
number of valve-related repairs needed, more than offsetting any increase in
repairs due to valve seat recession.
3.1.3 Oil Changes And Engine Life
Before unleaded gasoline was used, engine rusting was an important and widely
studied problem. To prevent the excess buildup of lead deposits, leaded gasoline
includes ethylene dichloride and ethylene dibromide to serve as "scavengers." The
bromine and chlorine atoms introduced to the combustion chamber combine
with the lead, forming compounds that are more easily removed. Unfortunately,
chlorine and bromine also form corrosive hydrochloric and hydrobromic acids,
respectively. Some of these acids get into the engine oil, where they will readily
combine with any water that may be present to cause internal corrosion and rust.
To delay this phenomenon, engine oils contain special basic additives diat react
with the acids to neutralize them. Since the reaction consumes the additives, the
oil must be changed at intervals to supply fresh additive. Reducing the lead
content of the fuel reduces the corrosive burden on the lubricating oil, and allows
oil change intervals to be extended.
The lead scavengers used with leaded gasoline also contribute to corrosive wear
inside the cylinder, especially wear of the piston rings. For example, taxi studies
in the 1970s showed that corrosive wear of the piston rings and cylinder walls
was 70 to 150 percent greater with leaded than unleaded fuel (Carey et al., 1978,
Gergel and Sheahan, 1976). Switching to unleaded gasoline can thus be expected
to extend engine life significantly.
3.1.4 Spark Plug Fouling And Replacement Frequency
Lead deposits can foul spark plugs and contribute to chemical corrosion. The
spark plugs used with leaded gasoline can suffer serious corrosion and require
replacement generally within 20,000 km, while those used with unleaded fuel can
go 40,000 km or more without replacement. As a result, the costs for spark plug
replacement and servicing are much lower for vehicles using unleaded fuel. A
study in Canada (Hickling Partners, 1981) concluded that spark plug mainte-
nance costs would be reduced by about 49 percent with unleaded fuel.
42
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
3.1.5 Exhaust System Corrosion
Vehicle exhaust systems can corrode from both the inside and the outside. From
the inside, the primary corrosion process is cold corrosion, which occurs when
water condenses inside the exhaust system. Where leaded gasoline is used, this
water is contaminated with hydrochloric and hydrobromic acids. Exhaust gas
condensates in engines burning leaded gasoline typically have pH values in the
range of 2.2 to 2.6, which is highly corrosive. The pH values of unleaded
gasoline condensates are around 3.5 to 4.2.
Fleet tests comparing leaded and unleaded fuel show that vehicles using leaded
gasoline require four to ten times as many replacements of exhaust system
components. In warm climates, where road salt is not used, exhaust systems used
with unleaded gasoline can be expected to last the life of the vehicle, while those
used with leaded fuel require replacement about every 50,000 km.
3.2 U.S. Fleet Experience
As the preceding review has shown, the use of unleaded gasoline offers many
advantages in terms of vehicle life and maintenance costs. However, these
advantages are counterbalanced by a potential major disadvantage in engines not
equipped with hardened valve seats: valve seat recession. For this reason,
proposals to eliminate leaded gasoline have caused public concern.
The likelihood that valve seat recession will occur, and the consequences if it
does occur, have often been exaggerated. The great body of in-use experience
with unleaded gasoline, including its widespread use in vehicles without hardened
valve seats, shows that the likelihood of valve seat damage due to unleaded fuel
use is very small, while the overall savings in maintenance costs are generally
substantial.
A number of controlled fleet studies were carried out in the 1960s to compare
maintenance costs of vehicles running on leaded and unleaded gasoline. A study
financed by Ethyl Corporation, a major lead additive supplier, showed that over
a. 5-year period, 4 out of 64 vehicles using unleaded gasoline required cylinder
head replacement (1 vehicle required 2 replacements), compared to 1 out of 64
vehicles using leaded gasoline (Wintringham et al., 1972). However, the un-
leaded gasoline group required only 6 valve repairs, compared to 16 among the
vehicles using leaded gasoline. Other studies conducted in the same time period
showed that overall maintenance costs were lower with unleaded than leaded
gasoline.
Engines in heavy-duty gasoline vehicles are more likely to undergo severe service
than those in passenger cars, and thus might be expected to show an increased
incidence of valve seat recession. This has not been the case, however. A major
test conducted by the U.S. Army involved switching all of the vehicle fleets of
three army posts to unleaded gasoline. This included some 7,600 vehicles (some
dating from the 1940s), as well as many items of power equipment. The results
of this test were definitively negative: no untoward maintenance problems were
experienced that could be attributed to the effects of unleaded gasoline. The U.S.
Army subsequently converted its entire establishment to unleaded gasoline
without ill effects.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 43
YIPAC^S On
Vehicles run on leaded
gasoline need four to
ten times as many
replacements of
exhaust system
components as those
running on unleaded
gasoline.
-------
Analyses of 42 months of maintenance data for heavy-duty gasoline trucks
used by the U.S. Postal Service (during which the trucks averaged 280,000
kilometers of service) showed that 4.2 percent of the trucks suffered valve
failures and 1.2 percent suffered valve seat failures during that period
(Weaver et al., 1986). The valve seat failure rate was comparable to that
expected when using leaded gasoline, while the valve failure rate was signifi-
cantly lower. Experience in numerous public utility truck fleets during the
1970s also showed no increase in valve- or valve seat-related problems with
the use of unleaded fuel.
3.3 Worldwide In-Use Experience
In recent years, the use of leaded gasoline has been eliminated in a number of
developing countries, including Brazil, Colombia, Egypt, Thailand, Guatemala,
Costa Rica, and Argentina. Increased seat valve problems have not been observed
in any of these countries.
The case of Brazil is especially important, given the size of its vehicle fleet. With
the inclusion of 22 percent ethanol by volume in gasoline as part of the Proalcool
program, lead additives were no longer needed, and Brazil began eliminating
gasoline lead in 1979. It completed its lead phase-out in 1991 (Faiz et al., 1996).
Despite the presence of large numbers of vehicles with soft valve seats, no
significant or widespread problems have been experienced with valve seat reces-
sion.
3.4 Monetizing Maintenance Costs And Savings
An evaluation of the costs and benefits of phasing out lead in gasoline should
include an estimate of the maintenance savings to vehicle owners. Table 7 shows
a hypothetical example of such a calculation. The assumptions used in this
example are outlined below.
Spark plug life. Here, the assumptions were that:
• The vehicle's useful life is 200,000 kilometers.
• The average interval between spark plug changes with leaded gasoline is
15,000 kilometers (if available, actual data on the average spark plug change
interval in the area under consideration should be substituted instead).
• The average spark plug change interval will be doubled with unleaded
gasoline, and extended by two-thirds using low-lead fuel (0.1 gram of lead
per liter).
The lifetime costs are then the cost of a single spark plug change (estimated at
US $20), multiplied by the number of spark plug change intervals over the
vehicles life, minus one (since the vehicle comes equipped with one set of plugs).
Engine overhauls. The number of engine overhauls required during the vehicle's
lifetime was estimated at 1.0 with leaded gasoline, and 0.8 with low-lead or
unleaded fuel. This is based on the much lower rates of piston ring wear, rusting,
and corrosion with low- and zero-lead fuel.
44 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
Exhaust system replacements. The numbers of exhaust system replacements
and valve repairs are based on the data of Wintringham et al., extrapolated to
the full engine life. The number of exhaust system replacements with low-
lead gasoline is assumed to be similar to that with high-lead fuel, as the
critical factor is considered to be the presence of acids formed by the lead
scavengers in the exhaust pipe, and not the amount of the acid present.
Cylinder head replacements. The number of cylinder head replacements is also
based on the data of Wintringham et al., and reflects a pessimistic assumption
that 20 percent of the vehicle fleet will suffer valve seat recession at some point
during their useful lives when using unleaded gasoline. This is considerably
higher than the observed rate of occurrence of this problem in the countries that
have already phased out leaded gasoline.
Net maintenance savings. Adding up the total maintenance costs and savings in
this hypothetical case suggests that the use of low-lead gasoline would result in
savings of about US $557 over the life of a car, equivalent to about $0.033 per
liter of gasoline used. For unleaded fuel, total savings would be $783, or about
$0.047 per liter. These costs can be compared directly to the additional costs of
producing the low-lead and unleaded fuels in a cost-benefit evaluation.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
45
-------
Table 7: Hypothetical Maintenance Cost
Savings With Low-Lead And Unleaded Gasoline
Maintenance Item
Vehicle life (km)
Spark Plugs
Change interval
Change cost
Lifetime cost
OH Change
Change interval
Change cost
Lifetime cost
Engine Overhaul
Total overhauls
Overhaul cost
Lifetime cost
Total replacements
Replacement cost
Lifetime cost
Valve Repairs
Total number
Cost/repair
Lifetime cost
Cylinder Head Replacements
Total number
Cost/repair
Lifetime cost
Total lifetime cost
Saving compared to leaded
Total fuel used (1)
Saving per liter
Gasoline Type
High Lead
200,000
15,000
$20
$247
4,000
$12
$588
1.0
$500
$500
3
$80
$240
0.5
$500
$250
0.1
$300
$30
$1,855
16,667
Low Lead
200,000
25,000
$20
$140
6,000
$12
$388
0.8
$500
$400
3
$80
$240
0.2
$500
$100
0.1
$300
$30
$1,298
$557
16,667
$0.033
Unleaded
200,000
30,000
$20
$113
8,000
$12
$288
0.8
$500
$400
1
$80
$80
0.2
$500
$100
0.3
$300
$90
$1,071
$783
16,667
$0.047
46
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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4. ASSESSING LEAD PHASEOUT
EFFECTS ON VEHICLE EMISSIONS
AND AIR QUALITY
Phasing out lead will entail changes in gasoline composition, and these changes
will affect the emissions of lead and other pollutants from gasoline-powered
vehicles. For instance, increasing the aromatic hydrocarbon content of gasoline
may increase emissions of benzene and other aromatics in exhaust and evapora-
tive emissions. Changes in gasoline composition may also affect the photochemi-
cal reactivity of volatile organic compound (VOC) emissions, and thus affect the
formation of ground-level ozone (photochemical smog).
In a number of cases, public concerns over these secondary effects have delayed
lead phaseout programs. It is thus important that the potential secondary effects
of lead phaseout be assessed and quantified as part of the phaseout plan, and that
- where necessary - measures be taken to mitigate any adverse impacts. Such
measures might include setting limits on or taxing the benzene, aromatic, and/or
olefin content of fuels, and limiting vapor pressure to minimize evaporative
emissions.
Lead phaseout also provides an opportunity for a more general review of emis-
sion control policies related to vehicles and fuels, such as the adoption of cata-
lytic converters and/or evaporative emission controls, and limits on gasoline
sulfur content. To the extent that such policies require changes in either the
composition or the market shares of different fuels, they will affect investment
plans in the refining and fuel distribution sectors. To avoid waste and confusion,
it is best that they be adopted as an integrated package with the lead phaseout
policy, rather than one at a time.
This chapter first examines the effects of vehicle emission
control technology on CO, HC, and NOx emissions. It then
discusses the emission standards in effect in North America and
Europe, which implementers should consider incorporating in
their own countries' lead phaseout strategies.
Next, the studies examining the differences in emissions
between leaded and unleaded gasoline in vehicles without
catalytic converters are examined. The chapter concludes with a
discussion of the rationale for considering the inclusion of
regulations that reduce sulfur, fuel volatility, olefins, aromatics
and benzene when establishing a lead phaseout program.
4.1 Emission Control Technologies For Gasoline Vehicles
In addition to lead emissions from leaded gasoline, gasoline engines in cars, light-
duty trucks, and motorcycles are responsible for more than 90 percent of the
carbon monoxide (CO) emissions and substantial fractions of the emissions of
unburned hydrocarbons (HC) and oxides of nitrogen (NOx) in most large cities.
Carbon monoxide is a poisonous gas, and exposure to it may increase the risk of
heart attack in persons with existing cardiovascular disease. HC emissions
include cancer-causing organic chemicals such as benzene and 1,3 butadiene. HC
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
The changes in
gasoline composition
resulting from phasing
out lead will affect the
emissions of lead and
other pollutants from
gasoline-powered
vehicles.
47
-------
Modern technologies
can reduce CO, HC,
and NOx emissions
from new gasoline
vehicles by more than
90 percent compared
to those of vehicles
without emission
controls.
The benefits of
phasing out lead in
gasoline do not
depend on whether
catalyst-forcing
emission standards are
adopted or not. The
decision to phase out
lead in gasoline should
not be delayed while
this question is
debated.
The Steps In Assessing Lead Phaseout Effects
On Vehicle Emissions And Air Quality
1. Assess gasoline composition effects on emissions and air
quality
Implementers should assess and quantify the potential secondary
effects of lead phaseout on emissions and air quality.
2. Assess the need for policies affecting gasoline composition
Where necessary, implementers should specify measures to mitigate
any adverse impacts resulting from changes in gasoline composition.
Such measures might include setting limits on or taxing the benzene,
aromatic, and/or olefin content of fuels, and limiting vapor pressure to
minimize evaporative emissions.
3. Consider vehicle emission control policy
Implementers should conduct a general review of emission control
policies for vehicles and fuels, such as the adoption of catalytic
converters and/or evaporative emission controls, and limits on
gasoline sulfur content.
and NOx also react in the presence of sunlight to form ozone and other photo-
chemical oxidants, the main ingredients in photochemical smog. Ozone is an
irritant gas with effects that include increased risk of asthma attacks, respiratory
illness, and death. Most large cities worldwide exhibit unhealthy levels of carbon
monoxide, ozone, or both.
With modern emission control technology, emissions of CO, HC, and NOx
from new gasoline vehicles can be reduced by more than 90 percent compared to
the levels typical for vehicles without emission controls. The emission control
system used to achieve this reduction has three main components: a three-way
catalytic converter, an electronic fuel injection system, and an electronic engine
control system incorporating a lambda sensor (air-fuel ratio sensor) for feedback
control of the air-fuel ratio.
Both catalytic converters and lambda sensors depend on catalytic reactions, and
both require the use of unleaded gasoline. Otherwise, lead compounds in the
exhaust will rapidly coat the active surface of the catalyst, blocking contact
between the catalyst and the exhaust gas. This was the original reason for
mandating the sale of unleaded gasoline in the United States in 1975, and
subsequently in other countries. At that time, the health dangers of lead aerosol
contamination were not as well understood as they are today.
The decision to phase out lead in gasoline is fully justifiable on health grounds,
whether or not a government also chooses to adopt emission standards for HC,
CO and NOx emissions that require the use of catalytic converters. Once the
decision is taken to phase out lead, however, it removes a major roadblock to
adopting such standards. The decision on whether to adopt strict emission limits
for HC, CO, and NOx can then be considered on its own merits, taking into
account both the costs and the benefits of such controls. Proper evaluation of the
costs, benefits, and feasible schedule for implementing vehicle emission controls
can be time consuming. It is important to emphasize, therefore, that the benefits
48
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
of phasing out lead in gasoline do not depend on whether catalyst-forcing
emission standards are adopted or not, and the decision to phase out lead in
gasoline should not be delayed while this question is debated.
4.2 Systems Of Emission Standards
If a nation or other jurisdiction does decide to require gasoline vehicles to meet
emission standards, it will have to face the question of what emission standards
to adopt. It is very costly and time consuming for vehicle manufacturers to
develop unique emission control systems. Therefore, considerations of economies
of scale, the lead-time required, the cost to vehicle manufacturers to develop
unique emission control systems, and the cost to governments of establishing
and enforcing unique standards all argue for adopting one of the sets of interna-
tional emission standards and test procedures already in wide use.
The main international systems of vehicle emission standards and test procedures
are those of North America and Europe. North American emission standards and
test procedures were originally adopted by the United States, which was the first
country to set emission standards for vehicles. Under the North American Free
Trade Agreement, these standards have also been adopted by Canada and Mexico.
Other countries and jurisdictions that have adopted U.S. standards and/or test
procedures include Argentina, Brazil, Chile, Taiwan, Hong Kong, Australia, the
Republic of Korea, and Singapore (for motorcycles only). The standards and test
procedures established by the United Nations Economic Commission for Europe
are used in the European Union, a number of former Eastern bloc countries, and
some Asian nations. Japan has also established a set of emission standards and
testing procedures that have been adopted by some East Asian countries as
supplementary standards.
U.S. and European emission standards and test procedures are described by Faiz
et al. (1996) in a publication by the World Bank. Updated information as of
mid-1998 was included in another report prepared under contract to the U.S.
Agency for International Development (Chan and Weaver, 1998). Generally,
gasoline passenger cars and light-duty trucks in Europe and North America use
very similar technologies, and are certified to similar emission levels. Vehicles
meeting each set of standards (and sometimes both) are readily available on the
world market.
With this in mind, countries may wish to maximize their access to international
automotive markets by allowing vehicles to comply with either North American
or European emission standards. Thus, vehicles could be allowed if they were
certified either to the current European emission standards for passenger cars and
light-commercial vehicles (contained in EU directive number 96/69/EC) or to
U.S. Tier 1 emission standards as defined in the U.S. Code of Federal Regula-
tions (40 CFR 86, Part B). The cost of meeting either of these sets of emission
standards is estimated to be on the order of US $ 1,000 per vehicle compared to
a vehicle without emission controls. This cost would be partly offset by an
improvement in fuel economy of approximately 10 percent due to the use of
electronic fuel injection with electronic management of air-fuel ratio and spark
timing.
Incorporating emission control technologies and new-vehicle emission standards
into vehicle production is a necessary, but not a sufficient, condition for achiev-
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 49
Economies of scale,
the costs to
governments and
vehicle manufacturers,
and other factors
argue for adopting a
set of international
emission standards
and test procedures,
rather than developing
standards and test
procedures that are
unique to one country.
The incremental cost
of meeting inter-
national emission
standards can be partly
offset by improve-
ments in fuel economy
from electronic fuel
injection with
electronic manage-
ment.
-------
EFFECTS ON
AIR
Studies have found
that using unleaded
gasoline reduces
hydrocarbon emis-
sions by 5 to 17
percent over leaded
fuel.
ing low emissions. Measures are also required to ensure the durability and
reliability of emission controls throughout the vehicle's lifetime. Low vehicle
emissions at the time of production do little good if low emissions are not
maintained in service. To ensure that vehicle emission control systems are durable
and reliable, countries such as the United States have programs to test vehicles in
service, and recall those that do not meet emission standards. Vehicle emission
warranty requirements have also been adopted to protect consumers. It is
recommended that countries seek the advice of specialists in this field to aid
them in designing effective and cost-effective emission control programs. The
International Activities Branch of the U.S. EPA's Office of Mobile Sources,
located in Ann Arbor, Michigan, USA, may be able to offer advice in this area.
4.3 Effect Of Leaded Vs. Unleaded Gasoline
A number of studies examined the differences in emissions between leaded and
unleaded gasoline in vehicles without catalytic converters. Existing studies were
summarized by the Coordinating Research Council (1970) and by Weaver
(1986). The Council's summary found that stabilized HC emissions were
reduced by 5 to 17 percent using unleaded gasoline compared to leaded fuel in
consumer-type driving tests, and by an even larger fraction in accelerated mileage
accumulation schedules.
Weaver (1986) describes the reason for these differences. With leaded gasoline,
lead deposits in the combustion chamber develop over time. These take longer to
develop with low-lead gasoline, but eventually build up to the same level. The
unburned fuel-air mixture trapped in this deposit layer does not burn, and later
contributes to HC emissions when it is swept into the exhaust along with the
burned charge. With unleaded fuel, deposits consist of carbon rather than lead,
and are much more variable. A period of high-load operation can reduce deposit
levels considerably, and overall deposit levels are lower, on average. These lower
deposit levels result in lower hydrocarbon emissions.
The presence of tetra-ethyl lead acts as a combustion inhibitor, and this may also
contribute to increasing hydrocarbon emissions. For example, in studies by the
Institute Mexicano del Petroleo (1994), the average of 28 vehicles tested in back-
to-back tests on leaded, low-lead, and unleaded gasoline showed lower HC
emissions as gasoline lead content was reduced (Table 8). Benzene and 1,3
butadiene emissions using low-lead and unleaded fuel were less than with leaded
gasoline, despite slightly higher benzene and aromatic content in the unleaded
fuel. Tests by CSIRO in Australia (Duffy et al., 1998) also showed that emissions
of benzene and 1,3 butadiene were reduced using unleaded gasoline (Table 9).
In actual consumer use, the difference in HC emissions between vehicles using
leaded and unleaded fuel is likely to be much greater than in these controlled
studies. This is due to the effect of lead on spark plug replacement requirements.
All of the controlled studies included routine maintenance, which would have
included timely spark plug changes. In the real world, however, spark plug
replacement is often delayed until misfire develops. Since spark plugs require
changing at much shorter intervals when leaded gasoline is used, vehicles using
leaded gasoline are more likely to be operating with one or more cylinders
misfiring due to fouled plugs. The increase in HC emissions due to misfire is
very large compared to the typical emissions from properly functioning vehicles.
50 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
Table 8: Comparison Of Pollutant Emissions Using Leaded, Low-Lead,
And Unleaded Gasoline In Vehicles Without Catalytic Converters
RON
MON
Composition
Paraffins
Olefins
Naphthenes
Aromatics
Benzene
MTBE
TELg/l
Emissions (g/km)
CO
HC
NOx
Toxic Air Contaminants (mg/km)
1 ,3 Butadiene
Benzene
Formaldehyde
Baseline
81.7
57.3%
10.0%
10.2%
18.1%
1.4%
5.0%
0.37
31.7
2.95
1.50
87.56
82.61
78.72
Ref.Nova
81.1
77.2
56.4%
7.9%
11.4%
17.3%
1.3%
7.0%
0.19
30.4
2.9
1.53
85.45
76.4
85.1
Nova A
81.5
77.3
54.4%
8.8%
11.4%
18.4%
1.3%
7.0%
0.0
30.0
2.8
1.52
81.50
79.7
83.0
Source: Institute Mexicano de Petroleo (1994).
Table 9: Toxic Air Contaminant Emissions
Using Leaded And Unleaded Gasoline
RON
Composition
Paraffins + naphthenes
Olefins
Aromatics
Benzene
TELg/l
Toxic Air Contaminants (mg/km)
1 ,3 Butadiene
Benzene
Leaded
91.3
43.7%
5.2%
42.8%
5.7%
0.37
15.5
146.6
Unloaded
96
45.0%
6.8%
40.5%
5.0%
0.0
14.00
122.8
4.4 Effect Of Gasoline Properties And Composition on
Emissions
In establishing programs to phase out lead in gasoline, implementers may also
want to consider the desirability of other regulations on gasoline composition
and properties. The potential reduction in HC and CO emissions due to the
inclusion of oxygenated compounds such as MTBE and ethanol was discussed in
Section 2.5. Other gasoline properties that may be of interest for pollution
reduction purposes include its sulfur content, the content of benzene and other
aromatic hydrocarbons, olefin content, and volatility, as measured by Reid vapor
pressure.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 51
EFFECTS ON
AIR QUALITY
When establishing
lead phaseout
programs, imple-
menters should
consider developing
other regulations on
gasoline composition
and properties.
-------
4.4.1 SulfUr
Sulfur in gasoline is undesirable for several reasons. The most important of these
is that, in vehicles with catalytic converters, sulfur binds to the precious metal
catalyst under rich conditions, temporarily poisoning it. Although this poisoning
is reversible, the efficiency of the catalyst is reduced while operating on high-
sulfur fuel. A 1981 study by General Motors (Furey and Monroe, 1981) showed
emissions reductions of 16.2 percent for HC, 13.0 percent for CO, and 13.9
percent for NO^with aged catalysts in going from fuel containing 0.09 percent
sulfur to 0.01 percent. An even larger percentage reduction was seen in vehicles
with relatively new catalysts.
Similar results have been reported from modern fuel-injected vehicles with three-
way catalysts, tested as part of the Auto/Oil Cooperative Study in the United
States (1992). This study showed that reducing fuel sulfur content can contrib-
ute directly to reductions in mass emissions (HC, CO, and NOx), toxic emis-
sions (benzene, 1,3-butadiene, formaldehyde, and acetaldehyde), and potential
ozone formation. The Auto/Oil sulfur reduction study used test fuels with
nominal fuel sulfur levels of 50, 150, 250, 350, and 450 ppm in 10 late-model
vehicles. Reductions in HC, NMHC, CO, and NO were 18, 17, 19, and 8
X
percent, respectively, when fuel sulfur level was dropped from 450 ppm to 50
ppm. Reducing the fuel sulfur level also reduced benzene emissions by 21 percent
and acetaldehyde emissions by 35 percent. Formaldehyde emissions were in-
creased by 45 percent, while 1,3-butadiene changes were insignificant.
In addition to its effects on catalyst efficiency, sulfur in gasoline contributes
directly to SO2, sulfate, and H2S emissions, and indirectly to the formation of
sulfate particles in the atmosphere. These particles are a significant contributor to
ambient concentrations of fine particulate matter (PM2.5), which has recently
been shown to have strong links to human health and mortality. Under lean
conditions, fuel sulfur forms particulate sulfates and sulfuric acid in catalytic
converters. Under rich conditions, hydrogen sulfide is formed by the reduction
of SO, and sulfates stored on the catalyst substrate. The strong offensive odor of
H,S in the exhaust contributes to a public perception that catalysts "don't work,"
and may lead to increased tampering with emission controls.
4.4.2 Volatility
Fuel volatility, as measured by Reid vapor pressure (RVP), has a marked effect on
evaporative emissions from gasoline vehicles, both with and without evaporative
emission controls. In tests performed on European vehicles without evaporative
emission controls, it was found that increasing the fuel RVP from 62 to 82
kilopascals (kPa) roughly doubled evaporative emissions (McArragher et al.,
1988). The percentage effect is even greater in controlled vehicles. In going from
62 to 81 kPa RVP fuel, average diurnal emissions in vehicles with evaporative
controls increased by more than 5 times, and average hot-soak emissions by 25-
100 percent (U.S. EPA, 1987). The large increase in diurnal emissions from
controlled vehicles is due to saturation of the charcoal canister, which allows
subsequent vapors to escape to the air. Vehicle refueling emissions are also
strongly affected by fuel volatility. In a comparative test on the same vehicles
(Braddock, 1988), fuel with 79 kPa RVP produced 30 percent greater refueling
emissions than gasoline with 64 kPa RVP (1.45 vs. 1.89 g/litre dispensed).
52 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
In response to data such as these, EPA has established nationwide summertime
RVP limits for gasoline. These limits are 7.8 pounds per square inch (PSI) (4
kPa) in warm-climate areas and 9.0 PSI (62 kPa) in cooler regions. Still lower
RVP levels will be required in "reformulated" gasoline sold in areas with serious
air pollution problems.
An important advantage of gasoline volatility controls is that they can affect
emissions from vehicles already produced and in use, and from the gasoline
distribution system. Unlike new-vehicle emissions standards, it is not necessary
to wait for the fleet to turn over before they take effect. The emissions benefits
and cost-effectiveness of lower volatility are greatest where few of the vehicles in
use are equipped with evaporative controls. Even where evaporative controls are
in common use, as in the United States, the control of volatility may still be
beneficial to prevent in-use volatility levels from exceeding those for which the
controls were designed.
In its analysis of the RVP regulation, EPA (1987) estimated that the long-term
refining costs of meeting a 62 kPa RVP limit throughout the United States
would be approximately US $0.0038 per liter, assuming crude oil at $20 per
barrel. These costs were largely offset by credits for improved fuel economy and
reduced fuel loss through evaporation, so that the net cost to the consumer was
estimated at only $0.0012 per liter.
Gasoline volatility reductions are limited by the need to maintain adequate fuel
volatility for good vaporization under cold conditions. Otherwise, engines will
be difficult to start. Volatility reductions below about 58 kPa have been shown
to impair cold starting and driveability, and increase exhaust VOC emissions
somewhat, especially at lower temperatures. For this reason, volatility limits are
normally restricted to the warm months, in which evaporative emissions are
most significant. The range of ambient temperatures encountered must also be
considered in setting gasoline volatility limits.
4.4.3 Olefins
Olefins, or alkenes, are a class of hydrocarbons that have one or more double
bonds in their carbon structure. Examples include ethylene, propylene, butene,
and 1,3 butadiene - a powerful carcinogen. Olefins in gasoline are usually created
by the refining process of cracking naphthas or other petroleum fractions at high
temperatures. Olefins are also created by partial combustion of paraffinic hydro-
carbons in the engine. Compared to paraffins, olefins have extremely high ozone
reactivity. Because of their higher carbon content, they also have a slightly higher
flame temperature than paraffins, and thus NOx emissions may be increased
somewhat. It has been shown (Duffy et al., 1998) that the evaporation of 1,3
butadiene in gasoline contributes to ambient levels of this toxic air contaminant.
The Auto/Oil study in the United States examined the impacts of reducing
olefins in gasoline from 20 percent to 5 percent by volume (Hochhauser and
others, 1991). The results show that while there tends to be a slight reduction in
NOx emissions from both current and older catalyst-equipped vehicles, VOC
emissions tend to rise in both vehicle classes. This was ascribed to the fact that a
reduction in olefin content implies an increase in the paraffins. The olefins react
much more readily in a catalytic converter than do paraffins. Increasing the
paraffin content of the fuel therefore tends to reduce the overall VOC efficiency
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 53
An important
advantage of gasoline
volatility controls is
that they can affect
emissions from
vehicles that are
already in use and
from the gasoline
distribution system.
-------
r" t~ f"*
c I* r
cfT*; ON
UK, « I **« %.» < W \,t/ I Tl
A i 13 r> i S A 5 I TV
M! i \ *^, \J f*t ;„ I i *
It is recommended that
appropriate limits on
the benzene and
aromatic content of
gasoline be adopted at
the same time as the
lead phasedown
program.
of the catalytic converter. The result of this change is higher paraffinic VOC
emissions (which have substantially reduced reactivity in comparison to olefinic
VOC emissions) and an associated reduction in vehicle exhaust reactivity.
4.4.4 Aromatics And Benzene
Aromatic hydrocarbons are hydrocarbons that contain one or more benzene rings
in their molecular structure. In order to meet octane specifications, unleaded
gasoline normally contains about 30-50 percent aromatic hydrocarbons. Aromat-
ics, because of their high carbon content, have slightly higher flame temperatures
than paraffins, and are therefore thought to contribute to higher engine-out NOx
emissions. Aromatics in the engine exhaust also raise the reactivity of the exhaust
VOC because of the high reactivity of the alkyl aromatic species such as xylenes
and alkyl benzenes. Reducing the content of aromatic hydrocarbons in gasoline
has been shown to reduce NOx emissions, exhaust reactivity, and benzene
emissions.
An EPA study of toxic air contaminant emissions from mobile sources (EPA,
1993) gives a regression equation relating the fraction of benzene in the exhaust
hydrocarbons to the benzene and aromatic content of the fuel. For vehicles
without catalytic converters, this fraction is given as
Benzene as % of total HC =
0.86 (vol % benzene) + 0.12 x (vol % aromatics) - 1.16
Evaporative and exhaust emissions of benzene are of significant public concern
because benzene is a probable (albeit fairly weak) human carcinogen. In a number
of cases, exaggerated concerns of supposed increases in benzene emissions due to
lead phaseout have been allowed to delay lead phaseout programs. As Chapter 5
will demonstrate, the risks of even a very large increase in vehicular benzene
emissions would be much less than the risks from lead. Even the relatively small
risks due to benzene may be worth mitigating, however, if only to reduce public
anxiety and potential delays in the lead phaseout program. Implementers may
thus wish to consider establishing limits on both the benzene and total aromatic
concentrations in gasoline.
As discussed in Chapter 2, increasing the aromatic content of gasoline by
catalytic reforming is one of the most important octane-enhancing processes in
the refinery. With advance planning, however, the increase in aromatic content
due to lead phaseout can be minimized by emphasizing other octane-enhancing
processes such as isomerization, alkylation, and blending of ethers. In addition,
the benzene content of the aromatic fraction can be reduced considerably by
using special reformer catalysts tailored to produce other aromatics, and by
processes that either remove the benzene for sale as a petrochemical or chemically
destroy it by converting it to non-toxic compounds such as cyclohexane. In
order to minimize the cost impact on refiners, it is important that these consid-
erations be taken into account at the time the refinery is upgraded to increase its
octane capacity. Thus, it is recommended that appropriate limits on the benzene
and aromatic content of gasoline be adopted at the same time as the lead
phasedown program.
54 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
5. ASSESSING THE HEALTH BENEFITS
OF LEAD PHASEOUT
Reducing or eliminating lead aerosol emissions through the use of unleaded
gasoline can be expected to decrease lead concentrations in ambient air, dust, and
other media. This, in turn, will lessen human exposure to lead and the resulting
adverse health effects.
This chapter presents data and a methodology for estimating
the reduction in the average lead concentrations in human
blood to be expected as a result of reducing or eliminating lead
in gasoline.
Given this information, dose-response relationships derived
from epidemiological data can be used to estimate the change in
the incidence of high blood pressure, cardiovascular illness, and
other health outcomes due to a given lead phaseout scenario.
Examples of these calculations are also presented in this chapter.
Finally, this chapter presents an approach for calculating the
monetary value attributable to these benefits.
In comparing the costs of reducing lead in gasoline with the resulting health
benefits, it is often useful to express the health benefits in monetary terms. The
value to society of preventing a case of lead-related illness or premature death can
be estimated based on treatment exists, lost productivity, and people's willingness
to pay to reduce the risk of such consequences as premature death. This chapter
presents the bases for developing such estimates.
ASSESSING
HEALTH
BENEFITS
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
55
-------
The Steps In Assessing The Health Benefits
Of Lead Phaseout
1. Estimate the air quality impact of lead and lead alternatives
To assess the health benefits of reducing or eliminating lead emis-
sions, the implementer should estimate how the distribution of lead
concentrations in ambient air and in human blood will change in
response to changes in gasoline lead concentrations. To relieve
public concerns about these issues, the implementer should also
estimate the effect of the resulting changes in gasoline composition
on emissions of toxic air contaminants such as benzene and 1,3
butadiene.
2. Conduct a risk assessment for lead and lead alternatives
Given the estimated change in lead concentrations, coefficients
derived from epidemiological studies of health outcomes as functions
of blood lead concentration can be used to estimate the change in the
risks of hypertension, impacts on children's health, cardiovascular
illness, neurodevelopmental problems, and premature death due to a
given reduction in lead emissions. Similarly, published factors on unit
risk can be used to estimate the potential change in cancer incidence
due to changes in toxic air contaminant emissions.
3. Assess the public health benefits of phasing out lead
The change in individual risk is multiplied by the population affected
to give the total public health impacts of a given lead phaseout
scenario.
4. Conduct an economic valuation of public health benefits
In comparing the health benefits with the costs of reducing lead in
gasoline, it is often useful to express the health benefits in monetary
terms. The value to society of preventing a case of lead-related
illness or premature death can be estimated based on treatment
costs, lost productivity, and people's willingness to pay to reduce the
risk of premature death and other adverse consequences.
56 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
5.1 Emissions Vs. Ambient Concentrations
Ambient lead concentrations resulting from lead emissions in a given area such as
a city are proportional to the quantity of leaded gasoline consumed in that area.
The resulting ambient lead concentrations will depend on the:
• Quantity of leaded gasoline consumed.
• Proximity of the particular monitoring site to heavy concentrations of road
traffic.
• Local meteorological conditions, which will determine the rate and extent of
dispersion of the lead aerosol.
Table 10 compares the estimated lead emissions for seven of the world's
megacities with their average lead concentrations. As this figure shows, the ratio
of average lead concentrations to emissions is remarkably constant, averaging
about 0.002 ug/m3 per ton of lead emitted in the urban area per year. Surpris-
ingly, this ratio does not appear to be much affected by variations in the size of
the urban area, possibly because (except for London) heavy traffic concentrations
and lead monitoring sites may tend to be concentrated in a much smaller region.
Table 10: Lead Emissions Vs. Ambient Concentration
For A Selection Of World Megacities
City
Mexico City
Bangkok
Delhi
Cairo
London
Manila
Jakarta
Date
1988
1993
1990
1992
1993
1994
1995
1996
1992
Lead
Emissions
(tons/year)
1400
210
598
182
160
110
75
25
600
1200
525
689
520
Avg. Leada
Cone, (pg/m )
2.8
0.6
1.245
0.44
0.33
0.185
0.16
0.08
0.52
2.5
0.3
1.45
1.1
Ratio
0.0020
0.0029
0.0021
0.0024
0.0021
0.0017
0.0021
0.0032
0.0009
0.0021
0.0006
0.0021
0.0021
Sources: Wangwongwatana (1998), WHO (1992), Romieu (1995).
In the absence of a significant industrial source such as a primary or secondary
lead smelter or a steel mill, more than 90 percent of the ambient lead aerosol
measured is likely to be attributable to leaded gasoline combustion. Reducing the
total mass of lead used in gasoline will likely produce a nearly proportional
reduction in lead aerosol concentrations in the atmosphere.
To estimate the change in ambient lead concentration that would result from
reducing or eliminating lead in gasoline, it is best to rely on local monitoring
data, if available. If measurements of ambient lead concentration are not avail-
able, then the data shown in Table 10 can be used to develop a first approxima-
tion. Multiplying the lead content of gasoline (in grams per liter) by annual
leaded gasoline consumption in an urban area (in millions of liters) will give the
If a large industrial
source of lead is not
located in the area
being monitored, it is
likely that over 90
percent of lead aerosol
in the atmosphere is
coming from leaded
gasoline combustion.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 57
-------
Lead can be absorbed
by the body directly
through inhalation or
indirectly through lead
aerosol settling on
floors, cooking
utensils, and other
surfaces.
annual lead emissions in tons. Multiplying this value by 0.002 ug/m3-ton will
give an order-of-magnitude estimate of the lead aerosol concentration caused by
leaded gasoline use.
5.2 Ambient Concentration Vs. Blood Lead Concentration
A number of studies and reviews have examined the relationship between changes
in the lead concentration in ambient air and the resulting change in average
blood lead concentrations in children and adults. These include studies by the
World Health Organization (WHO, 1995), the U.S. Environmental Protection
Agency (1986), and the California Office of Environmental Health Hazard
Assessment (OEHHA) (Ostro et al., 1997). These reviews generally concur in
finding that this relationship is non-linear; it has a relatively high slope at low
ambient lead levels, and a decreasing slope as the lead concentration increases.
Most of the available data linking blood lead concentrations to lead concentra-
tions in ambient air are based on studies in developed nations with temperate
climates (such as the United States, United Kingdom, the Netherlands, and
Australia) and where ambient lead concentrations were between 0.5 and 10 ug/
m3. The lead concentration in most urban atmospheres lies toward the lower end
of this range. Although individual studies have shown a wide range of relation-
ships, the WHO, EPA, and OEHHA reviews concur that - for the range of lead
concentrations typical of non-occupational exposures — the relationship of
blood lead to lead in ambient air can be approximated as a linear function. For
adults, the slope of this function is approximately 2 ug/dl of lead in blood per
ug/m3 of lead in ambient air. For children, the slope lies between 3 and 5 ug/dl
of lead in blood per ug/m3 of lead in ambient air, with a best estimate value of
approximately 4. Thus, a reduction in average ambient lead concentration of 1.0
ug/m3 can be expected to produce a reduction in the average blood lead concen-
tration of 2 ug/dl for adults and 4 ug/dl for children. The half-life of lead in
blood is about 36 days (WHO, 1995), so that average blood lead concentrations
can be expected to respond to changes in ambient lead levels within two months.
The blood lead/air lead relationships shown in Figure 10 account both for lead
absorbed directly (as a result of inhalation) and indirectly (as a result of lead
aerosol settling on floors and other surfaces, cooking and eating utensils, etc.).
Based on direct inhalation alone, the blood lead to air lead ratio would be around
1.6 for adults and 2.0 for children. Young children are subject to much greater
indirect exposure than adults because of their tendency to play on the floor, and
to put their hands and other things in their mouths. Boys also tend to exhibit
higher blood lead concentrations than girls, possibly because they spend more
time playing outside.
Implementers should bear in mind that the average blood lead concentration in a
given population is a function not only of the lead concentration in ambient air,
but also of total lead exposure through other media such as food, water, and dust
or chips from lead paint. Where lead exposure through other media is high, the
incremental lead absorption due to lead in the air is likely to be less. Conversely,
where people are less exposed to lead through other media, their blood lead
concentrations may be more sensitive to lead concentrations in the air.
58 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
Figure 10: Expected Change In Average Blood Lead Concentration
Due To A Change In Lead Concentration In Ambient Air
-5 -4 -3 -2
Change in Avg. Lead In
These blood lead/air lead relationships are based on population studies conducted
mostly in developed nations with relatively cold climates, in which people tend
to spend most of their time indoors, where there is relatively little interchange
between indoor and outdoor air, where children are unlikely to spend much time
on or near busy streets, and where anemia and malnutrition are uncommon.
Each of these factors would tend to reduce the slope of the blood lead/air lead
relationship. It is therefore very likely that the factors given here substantially
underestimate the slope of the blood lead/air lead relationship in many develop-
ing countries, where people are likely to spend more time outdoors on busy
streets, and where there is more interchange between indoor and outdoor air.
It is also important to note that these blood lead/air lead relationships reflect
only the short-term effects of reducing ambient lead concentrations, and not the
reduction in the long-term accumulation of lead in soil and croplands due to
reducing overall lead emissions. Again, this means that these calculations will
tend to understate the long-term benefit of reducing lead emissions, as they do
not account for the long-term reduction in lead concentrations, and thus lead
from food and soil due to reducing lead emissions to the air.
5.3 Estimating The Reduction In Blood Lead Due To Lead
Phaseout
To estimate the reduction in blood lead concentrations from phasing out lead in
gasoline, one must first calculate total lead emissions, and then relate these to
ambient air monitoring data. Gasoline lead emissions (in tons) are equal to the
product of leaded gasoline consumption (in millions of liters) and the lead
concentration in leaded gasoline (in grams per liter).
Table 11 shows a hypothetical example. Leaded gasoline sales are 1000 million
liters per year, with a lead concentration of 0.7 grams per liter, resulting in lead
emissions of 700 tons per year. The ambient lead concentration is 1.4 ug/m3.
Reducing the lead content to 0.15 gram per liter would reduce annual lead
emissions by 550 tons, and would be expected to reduce the average ambient
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 59
When people have
high exposure to other
sources of lead (for
example, indirect
exposure or exposure
through food or lead
paint), their absorption
of lead in the air is
likely to be less. And
when they are less
exposed through other
media, their blood
lead concentrations
may be more sensitive
to lead in the air.
Most of the studies
done on the blood
lead/air lead
relationship were
conducted in
developed countries,
where people tend to
spend less time
outdoors. For this and
other reasons, the
blood lead/air lead
relationship's slope
may be higher in
developing nations.
These studies also do
not account for the
long-term effects of
reducing lead in soils,
and may thus
understate the long-
term benefits of
reducing lead.
-------
lead concentration proportionally (assuming that there are no other significant
sources of lead aerosol emissions). The resulting reduction in lead concentration
would be 1.1 ug/m3.
As shown in Section 5.2, the slope of the short-term relationship between blood
lead and lead in air is approximately 2 for adults and 4 for children. Thus, the
expected short-term change in average blood lead concentrations for adults is two
times the change in ambient concentration, or 2.2 ug/dl. For children, similarly,
it is 4.4 ug/dl.
Table 1 1 : Reduction In Blood Lead Concentrations Due
To Reducing Lead In Gasoline: A Hypothetical Example
Leaded gasoline sales
Lead concentration in gasoline
Annual lead emissions
Avg. lead concentration in air
Effect of reducing lead to 0.15 g/liter
Annual lead emissions
Change in lead concentration in air
Change in blood lead: adults
Change in blood lead: children
Values
1,000
0.7
700
1.4
-550
-1.1
-2.2
-4.4
Units
million liters per year
grams per liter
tons Pb per year
grams per cubic meter
tons Pb per year
grams per cubic meter
microgram per deciliter
micrograms per deciliter
Figure 11: Blood Lead Concentration In Children Vs.
Quarterly Sales Of Lead In Gasoline, Chicago, USA
24 U
23
22
£ 20
I 19-
18 -
17 -
16
0.27 0.30 0.33 0.36 0.39 0.42 0.45 0.48 0.51 0.54
0.15 0.18 0.21 0.24
Gasoline Lead (billions of grams per calendar-quarter)
Source: Schwartz et al. (1985).
In a number of U.S. cities, average blood lead concentrations have been related
directly to changes in total consumption of lead in gasoline. In Chicago (Figure
11), a reduction of 300 tons per quarter in gasoline lead (1200 tons per year)
resulted in a reduction of 5 ug/dl in the average blood lead concentration of
children in a lead screening program. In New York City (Figure 12), a reduction
of 550 tons per quarter gave an average reduction of 7 ug/mjin children's blood
lead concentration.
60 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
Figure 12: Blood Lead Concentration In Children Vs.
Quarterly Sales Of Lead In Gasoline, New York City, USA
1
TJ
a
24 r-
23
22
20
19
m 18
17
16
15
0.20 0.25 0.30
~I 1 1
0.65 0.70 0.75
0.35 0.40 0.45 0.50 0.55 0.60
Gasoline Lead (billions of grams per calendar-quarter)
0.80
Source: Schwartz et al. (1985).
5.4 Assessing The Health Benefits Of Lead Phaseout
Numerous studies have documented the effects of lead on human health.
Major reviews of these studies have been carried out by the U.S. EPA
(1986), World Health Organization (1995), and the California Office of
Health Hazard Assessment (Ostro et al., 1997). The main adverse health
effects associated with lead exposure in children are neurodevelopmental
damage, resulting in lowered intelligence, increased incidence of behavioral
problems, increased risk of learning disabilities, increased risk of hearing loss,
and increased risk of failure in school. In adults, lead exposure is linked to
increased blood pressure, leading to increases in the incidence of hyperten-
sion, cardiovascular illness, stroke, and premature death. Lead and the lead
scavengers ethylene dichloride and ethylene dibromide are also considered
possible human carcinogens, but the risk of cancer from emissions associated
with lead in gasoline is much less than the risk of cardiovascular mortality
due to hypertension.
5.4.1 Lead And Neurodevelopmental Effects In Children
All of the recent reviews of lead and its health effects agree in concluding that
children with blood lead concentrations exceeding the "level of concern" of about
10 ug/dl can suffer impairments in the development of their central nervous
system and other organs, impairments in cognitive function, and increased risk
of behavioral problems. The impairment in cognitive function is most readily
measured by comparing results on standardized intelligence tests. Performance on
these tests has been shown to be a good predictor of later achievement in school,
and to be correlated with lifetime earnings (Schwartz et al., 1985).
Schwartz (1994a) conducted an extensive meta-analysis of the studies linking
lead in blood with children's IQ. He concluded that there is a highly significant
association between blood lead levels and IQ in children, and that this associa-
tion was robust to changes in model formulation, study type, and potential
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 61
The main effects of
lead in children are
neurodevelopmental
damage, and in adults
increased blood
pressure.
Other things being
equal, a child with 20
ug/dl of lead in his or
her blood will score
about 2.6 points lower
in IQ than one with 10
ug/dl. To put this in
perspective, U.S. child-
ren today average less
than 5 ug/dl of blood
lead, compared to
around 15-20 ug/dl in
the United States in
the early 1970s or in
many developing
countries today. This is
equivalent to around 4
IQ points - a signi-
ficant difference.
-------
Data suggest that the
damaging effects of
lead on IQ extend to
blood lead levels as
low as 1 jjg/deciliter.
In addition to its
health effects, lead in
the blood can affect
children's lifetime
earnings.
confounding factors. For an increase in blood lead concentration from 10 to 20
ug/deciliter, the meta-analysis predicted a decrease in mean IQ of 2.57 +/- 0.41
points, or 0.256 IQ points per ug/dl.
Schwartz also found that the results do not support the potential existence of a
blood lead "threshold" below which no significant harm occurs. To the contrary,
the data suggest that the damaging effects of lead on IQ extend to blood lead
levels as low as lug/deciliter, and that the slope of the lead/IQ curve may even be
higher at low levels of lead exposure. If correct, this would imply that there is no
acceptable level of lead exposure, and that every effort should be made to reduce
even low levels of ambient lead.
Accepting Schwartz's analysis, a 1 ug/dl change in the mean blood lead concentra-
tion of preschool children would be expected to shift the mean IQof the same
children by 0.256 points. It is not clear to what extent this effect is reversible:
that is, whether it is possible to improve the mental performance of children
exposed to high blood lead concentrations during the critical early childhood
years by reducing their lead exposure later in life. There is some reason to believe
that a significant part of the damage is permanent: that is, that children exposed
to high blood lead concentrations from birth to age six years are unlikely to
recover their full mental function, even if this exposure is subsequently reduced.
While the effect of blood lead on IQis too small to be measurable in any
individual child, the implications for the population of children as a whole
may be significant. In particular, a shift in the mean of the intelligence
distribution may have a disproportionately large impact on the numbers of
children classified as learning-disabled (with IQs less than 80) or gifted
(with IQs exceeding 120).
Schwartz (1994a) also estimated the effects of lead exposure on schooling and
lifetime earnings of children in the United States. For people of near-normal
intelligence, the effect of IQon earnings was estimated at approximately a 0.5
percent change in lifetime earnings per one point change in IQ. However, lead
exposure in children also reduces the chance of successfully completing school,
which tends to reduce both wages and the probability of employment. Taking
these effects into account, the present value of the total loss in earnings per ug/dl
of lead in blood was calculated at approximately 0.6 percent of the total expected
value of lifetime earnings.
The change in the number of learning-disabled and gifted children due to a lead-
induced shift in mean IQcan also be calculated. Ostro (1997) indicates that IQ
is normally distributed, with a mean of 100 and a standard deviation of 16.
Figure 13 shows the projected effects of changes in blood lead concentration on
mean IQ, and on the percentage of learning-disabled and gifted children, based
on this distribution function.
62
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
Figure 13: Effect Of Changing Average Blood Lead Level
On Percentage Of Learning-Disabled And Gifted Children
£U7b •
1ft°/ -
Percent ^/Q
Below 80
Percent
Above 20 Q0/
OO/ _
no/. _
X.
^x
^
^^^
"X
^x^
x.
^\
- QQ
- QQ
- Q7
- Qfi
Qd
Q1
on
012345678 910 15 20
Average Blood Level (M9/dl)
25
Mean IQ
5.4.2 Lead And Blood Pressure In Adults
Numerous studies (Schwartz et al., 1985; EPA, 1990; WHO, 1995; Ostro
et al., 1997) have shown a correlation between blood lead concentrations in
adults (especially males aged 40 to 59) and blood pressure. The general
relationship is that a doubling of blood lead concentration (e.g., from 5 to
10 ug/dl, or from 10 to 20) is associated with an increase in diastolic blood
pressure of 1.9 mm of mercury (Hg). This directly increases the probability
of hypertension (defined as diastolic blood pressure exceeding 90 mm Hg), and
indirectly increases the chance of stroke, heart attack, and premature death. Since
both the relations between lead and blood pressure and those between blood
pressure and the different health outcomes are nonlinear, calculating the change
in the incidence of each outcome is complicated. Ostro et al. (1997) give the
following equation for hypertension:
AH = (1 + exp-(-2.74+b (In PbBl)))-' - (1 + exp-(-2.74+b (In PbB2)))
(1)
where
AH is the change in the probability of hypertension due to lead phaseout
PbBl is the present mean blood lead concentration
PbB2 is the mean blood lead concentration expected after lead phaseout
b is a regression coefficient, equal to 0.79 +/- 0.48 (95% confidence interval).
The change in blood pressure due to a change in blood lead concentration is
given by Ostro et al. (1997) as:
A DBF = 2.74 (In PbBl - In PbB2) (2)
where
ADBP is the change in diastolic blood pressure due to lead phaseout
PbBl and PbB2 are the lead concentrations in the blood before and after lead
phaseout.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
63
-------
The effects of
increased lead blood
levels are about twice
as great in men as
women.
The probability that a middle-aged man will die during the next 12 years is
affected by his diastolic blood pressure. For white males in the United States,
aged 40 to 59, this probability is given by Ostro et al. (1997) as:
AM = (1 + exp-(-5.32 + b(DBPl)))-' — (1 + exp-(-5.32 + b(DBPl)))-'
(3)
where
AM is change in the probability of death (from all causes) during the next 12
years
DBP1 = diastolic blood pressure associated with present lead exposure
DBP2 = diastolic blood pressure after lead phaseout, equal to DBP2 + A DBF
b = regression coefficient, equal to 0.035 +/- 0.14.
For women aged 40 to 59, they estimate that the effect will be half that for
men.
Table 12 shows how this calculation would be done for the hypothetical case
outlined in Table 11. The average blood lead concentration among adults in
this case is assumed to be 10 ug/dl, and the mean diastolic blood pressure is
assumed to be 85 mm Hg (a more accurate calculation would consider the
actual distribution of blood pressure levels among the population). The
phaseout of leaded gasoline would reduce the mean blood lead concentration
by about 2.2 ug/dl. The resulting change in blood pressure is then calculated
from Equation 2. Equation 3 is then used to calculate the probability that a man
aged 40 to 59 will die within the next 12 years, based on this blood pressure
level. Finally, the total change in annual mortality is calculated by dividing this
value by 12. For women, the change is assumed to be half as much (Ostro et al.,
1997).
Table 12: Calculating The Reduction In Mortality Due
To A Hypothetical Reduction In Blood Lead Concentration
Current Blood Lead Level (ug/dl)
Current Mean Blood Pressure (mmHg)
Proj. 12 Year Mortality
New Blood Lead Level (ug/dl)
New Mean Blood Pressure (mmHg)
Proj. 12 Year Mortality
Avoided Deaths/Million Persons/Year
Males 40-59
Females 40-59
10.0
85.0
8.75%
7.8
84.3
8.56%
157
78
5.4.3 Lead And Cancer
A number of the compounds associated with leaded gasoline and its emis-
sions are classed as known or potential carcinogens. These include lead itself,
the lead scavengers ethylene dibromide and ethylene dichloride, and such com-
bustion products as 1,3 butadiene, benzene, formaldehyde, and acetaldehyde.
Table 13 lists these compounds, along with the estimated carcinogenic potency
of each. Although benzene and formaldehyde have received more attention, 1,3
butadiene is actually much more important in terms of cancer risk, accounting
64
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
for two-thirds of the estimated cancer cases due to toxic air contaminants from
gasoline vehicles in the United States (U.S. EPA, 1993).
Overall, the cancer risk due to motor vehicle emissions is low relative to the
risk of non-cancer health effects. For the United States, the total number of
cancer cases due to gasoline-related mobile source emissions, based on
upper-bound limits on carcinogenic potency, was calculated at 459 per year,
with 1,3 butadiene accounting for 304 of these. For non-catalyst vehicles,
the relative importance of 1,3 butadiene is even greater.
The arguments of lead additive suppliers, among others, have created public
concern over a purported increase in cancer risk due to increased benzene
emissions with unleaded gasoline. These arguments are invalid for several
reasons.
• Increasing benzene and other aromatic compounds is
only one of several options for making up the difference
in gasoline octane due to the elimination of lead (see
Chapter 2).
• Benzene emissions from motor vehicles would be unlikely
to increase even if unleaded gasoline contained more
benzene and aromatics. This is because total hydrocarbon
emissions tend to be lower with unleaded gasoline (see
Chapter 8).
• Most important, overall cancer risk would be reduced due to
the reduction in other carcinogenic compounds, especially
1,3 butadiene and lead.
There is also some evidence that MTBE, a gasoline additive often used as a
substitute for lead, may be weakly carcinogenic, although a formal determination
of its carcinogenicity has not been made. Relatively little MTBE survives the
combustion process, however. In emission measurements on non-catalyst
Mexican vehicles using fuel with 7 percent MTBE by volume, MTBE made up
only about 2.7 percent of the exhaust hydrocarbons (IMP, 1994). Because
blending MTBE reduces benzene and 1,3 butadiene emissions, it is estimated to
create a net reduction in cancer risk (California EPA, 1998).
Table 13: Carcinogenic Compounds Associated
With Gasoline Combustion
Compound
1 ,3 Butadiene
Benzene
Formaldehyde
Acetaldehyde
Inorganic lead
Ethylene dibromide
Ethylene dichloride
Unit Risk
95% U.S.
2.80E-04
8.30E-06
1.35E-05
2.20E-06
1 .20E-05
7.10E-05
2.20E-05
Cancer
Class
A
B2
B1
B2
B2
Est Cases
In U.S.*
304
70
44
5.3
Typical Non-Catalyst Emissions*
mg/km benzene eq.
88 2,954
83 83
79 128
NA NA
48 69
NA NA
NA NA
Average of 19 non-catalyst vehicles in Mexico (IMP, 1994). Fuel was 1.4% benzene, 18%
aromatics, and 10% olefins.
' U.S. EW (1993).
To calculate the potential change in cancer incidence due to gasoline composition
changes resulting from lead phaseout, it is necessary to know the existing levels
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 65
Overall, the cancer risk
due to toxic
contaminants from
gasoline motor vehicle
emissions is low
relative to the risk of
non-cancer health
effects. 1,3 butadiene
accounts for two-thirds
of the estimated cancer
cases caused by these
emissions in the United
States.
-------
of exposure to gasoline-derived carcinogens. This can be estimated by air disper-
sion modeling or by directly measuring ambient concentrations. A procedure for
making such measurements is given by EPA (1997).
Unless a major non-gasoline emission source is present, such as a chemical
plant, gasoline combustion is the main contributor to lead, benzene, and 1,3
butadiene in the urban atmosphere (EPA, 1993). As a first approximation,
therefore, one can estimate the effects of a change in gasoline composition by
multiplying the measured or estimated ambient concentrations of benzene
and 1,3 butadiene in the atmosphere by the percentage change in these
emissions from gasoline vehicles. To the extent that other sources contribute
to these pollutants, this will overestimate the impact of the change in
gasoline composition.
Ambient benzene concentrations in urban areas of the United States range
from about 4 to 7 ug/m3, while 1,3 butadiene concentrations range from 0.12 to
0.56 ug/m3. In Bangkok, a risk assessment by the U.S. Agency for International
Development estimated ambient concentrations at 3-14 ug/m3 for benzene and 2
ug/m3 for 1,3 butadiene. In Australia, the average ratio of 1,3 butadiene to
benzene concentrations in a traffic tunnel was 0.21. To illustrate the potential
impacts of a change in gasoline composition, initial concentrations of 10 ug/m3
for benzene, 2 ug/m3 for 1,3 butadiene, and 1.4 ug/m3 for lead were assumed. As
an extreme example, it was assumed that the changes in gasoline formulation due
to lead phaseout increase benzene emissions by 50 percent, while reducing 1,3
butadiene emissions by 7 percent and lead emissions by 100 percent. It was
further assumed that MTBE concentrations increase from zero to 15 ug/m3 as a
result of the lead phaseout. The total population of this hypothetical city, 5
million persons, is assumed to be exposed to these changed concentrations.
Table 14 shows the resulting change in cancer risk. In this case, the small
increase in cancer risk due to the higher benzene concentration is more than
offset by the reductions in 1,3 butadiene and lead, resulting in a net reduc-
tion in the 95 percent upper-bound risk of cancer of 0.8 cancer cases per
year out of 5 million persons exposed. Compared with the changes in lead-
related non-cancer mortality calculated in Section 5.4, these impacts are negli-
gible.
Table 14: Example Of Change In Cancer Risk
Due To Lead Phaseout
Compound
1 ,3 Butadiene
Benzene
Inorganic Lead
MTBE
Total
Unit Risk*
95% Upper
Bound
2.80E-04
8.30E-06
1 .20E-05
1 .70E-07
Concentration (M9/m )
Before
2.0
10.0
1.4
0.0
After
1.86
15.00
0.00
15.00
Cancer Incidence (cases/year)*
Before
40.0
5.9
1.2
0.0
47.1
After
37.2
8.9
0.0
0.2
46.3
95% upper bound estimate of the risk of acquiring cancer due to exposure to 1 ug/m concentra-
tion over a 70-year human lifetime
* Unit risk x concentration x 5,000,000 exposed population / 70 years
66
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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5.5 Economic Value Of Reducing Adverse Health
Impacts
As outlined earlier, reducing lead emissions can be expected to result in
quantifiable reductions in hypertension, stroke, heart attacks, and premature
death in adults; an increase in the average intelligence and improvements in the
learning performance of children born in the future; and a future reduction in the
number of mentally handicapped children. In order to compare these benefits
with the costs of phasing out lead in gasoline, it is useful to express these benefits
in monetary terms. In other words, it is necessary to place an economic value on
such intangibles as death and disability, or at least on the avoidance of these
problems.
A lower bound for the economic value to society of avoiding premature
death, disability, or illness can be established by considering the directly
measurable costs of medical treatment for illness and compensatory educa-
tion to overcome learning disabilities, as well as the calculable costs of lost wages
or reduced earning power. However, these directly calculable economic losses are
only a small part of the entire picture, as they fail to account for the inherent
value that people place on their lives and those of their loved ones, or for the
harm suffered to people's enjoyment of life due to disease or disability.
A fundamental tenet of economics is that the value of anything is determined by
what people will pay for it. Although money is certainly not an adequate
measure of the grief and loss suffered by someone who is crippled or the family
of someone who dies prematurely due to stroke or heart attack brought on by
hypertension, or of a mentally handicapped child, it is possible to measure the
amounts that people are willing to pay to reduce their risk of suffering such
hazards (or, alternatively, the amounts that they are willing to accept as compen-
sation for bearing an increased risk). By assessing this "willingness to pay"
(WTP) to reduce risk, or the compensation demanded to accept an increased
risk, it is possible to assess the value that people place on reducing their risks of
death or illness.
Most of the available WTP studies have focused on the value to be imputed to
reducing the risk of premature death, as this is generally the dominant factor in
the calculation of health benefits. Maddison et al. (1997), in a study for the
World Bank, reviewed the literature on the WTP to reduce the risk of death, and
have adapted the results to the conditions common in developing countries. In
developed countries such as the United States, the imputed value of a statistical
life saved (VOSL) has been estimated at around US $3.6 million. This should
not be interpreted as the "value" of saving any one individual life — a quantity
that involves both theoretical and moral problems. Instead, it should be inter-
preted as the value imputed to reducing the risk of premature death by a small
increment for a large population — for example, the value of reducing by one
chance in a million the risk experienced by one million persons. Maddison et al.
suggest that this value should be reduced to $3.2 million for pollution-related
deaths in the United States, because the people at greatest risk are generally older,
with fewer years of life remaining than those dying as a result of traffic accidents
or industrial hazards.
People's willingness to pay to reduce risks depends on their income — countries
with higher incomes are generally willing to pay more. For this reason, VOSL
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 67
To quantify the benefits
of phasing out lead in
gasoline, it is necessary
to place values on such
things as death and
disability, or on the
avoidance of these
problems.
In economics, the
value of anything is
determined by what
people will pay for it.
By assessing people's
"willingness to pay" to
reduce risk or what
they are "willing to
accept" as compen-
sation for an increased
risk, it is possible to
assess the value that
people place on
reducing their risks of
death or illness.
-------
Most of the calculable
economic benefits due
to lead phaseout result
from the reduced risk
of premature mortality
for adults, and the
improvement in
educational perfor-
mance and future
productivity and
earnings of children.
One researcher found
that the benefits of
reducing blood level
concentrations in U.S.
children by 1 ug/dl
would have a net
present value of nearly
$7 billion. For adults,
this figure exceeds $10
billion.
estimates for developing nations tend to be lower than those for the United
States. In their work for the World Bank, Maddison and coworkers derived
VOSL values for cities representing a range of middle-income and lower-income
countries. These included Santiago de Chile, Shanghai, Manila, and Mumbai.
Other VOSL estimates have been developed by Conte Grand (1998) for Buenos
Aires, and Shetty et al. (1994) for Bangkok.
Most of the calculable economic benefits due to lead phaseout result from
the reduced risk of premature mortality for adults, and the improvement in
educational performance and future productivity and earnings of children.
Schwartz (1994b) reviewed all of the main health effects of lead in an
attempt to quantify the societal benefits of reducing lead emissions in the
United States. With respect to the economic impacts of neurobehavioral
problems in children, Schwartz calculated the combined effects of lower IQ,
reduced probability of completing school, and reduced participation in the
workforce due to a 1 ug/dl increase in blood lead concentration as a reduction of
US $1300 (0.6 percent) in the net present value of lifetime earnings for a child
turning 6 years of age.
Table 15 summarizes the results of Schwartz's calculations. As this table shows,
Schwartz calculated the net present value of increased earnings due to reducing
blood lead concentrations in U.S. children by 1 ug/dl to be more than US $5.0
billion per year. Total benefits to children were calculated at $6.9 billion, with
reduced infant mortality accounting for more than $1.1 billion, and reductions
in the costs of medical care and compensatory education accounting for $0.8
billion. For adults, Schwartz valued the total benefits at $10.6 billion, of which
$9.9 billion is attributed to reduced mortality, $0.6 billion to medical cost
savings, and $0.1 billion to lost wages due to illness. Thus, these two main
effects account for more than 85 percent of the total benefit. In calculating these
values, Schwartz used a VOSL estimate for the United States of $3.0 million for
both infants and adults, which is toward the low end of the range of recent
VOSL estimates.
Table 15: Estimated Benefits Of Reducing Blood Lead
Concentrations In The United States By 1 .0 ug/dl
Nationwide Benefits (millions of USS)
Adults
Premature mortality
Medical costs
Hypertension
Heart attacks
Strokes
Lost wages
Hypertension
Heart attacks
Strokes
Total adults
9,900
399
141
39
50
67
19
10,615
Children
Medical costs
Compensatory education
Lifetime earnings
Infant mortality
Neonatal care
Total children
Combined population
189
481
5,060
1,140
67
6,937
17,552
Source: Schwartz (1994b).
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6. CONDUCTING A COST-BENEFIT
ANALYSIS
The selection of a lead phaseout strategy should take into account the costs
and benefits of the different alternatives, and such considerations as techni-
cal and political feasibility, the legal basis for the strategy, equity among
various social sectors, and acceptability to political decision makers and the
public. Ideally, the strategy selected should be the one with the greatest net
benefits among those strategies that are technically feasible, legally viable,
equitable, and acceptable.
This chapter first explains the purpose of a cost-benefit
analysis and describes the main components of a lead phaseout
cost-benefit analysis.
Next, it discusses the specific lead phaseout strategies
implementers should consider in their cost-benefit analyses,
stressing the inclusion of a strategy where lead content is
reduced as much and as quickly as possible.
Last, this chapter shows how the benefits and costs of lead
phaseout are calculated under two hypothetical strategies: a
near-term strategy that seeks to reduce the lead content of
gasoline as quickly as possible, and a longer-term strategy
that delays lead phaseout until new refinery process units
can be constructed.
The Steps In Selecting A Lead Phaseout Strategy
1. Identify alternative phaseout strategies
First, implementers should identify a number of alternative phaseout
strategies that are technically feasible and legally viable.
2. Assess net costs to the public and the public health benefits of
each strategy
In this step, Implementers should seek to quantify, to the extent pos-
sible, the social costs and benefits of each strategy.
3. Select preferred phaseout strategy
Last, implementers should assess the strategies to determine which of
them are technically feasible, legally viable, equitable, and acceptable
to decision makers and the public, and from them, select the strategy
with the greatest net benefits.
6.1 Cost- Benefit Analysis And Strategy Selection
Cost-benefit analysis is a technique for comparing the costs and the benefits
of alternative courses of action, considered from the viewpoint of the society
as a whole. (For the purposes of cost-benefit analysis, "society" can be
considered to comprise the entire human population affected positively or
negatively by a given decision — for instance, the entire national population
if a decision is of national importance.)
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 69
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Cost-benefit analysis
helps implementers to
determine the course
of action that will result
in the greatest net
benefits (total benefits
minus costs) for the
society affected by a
decision. This is an
important technique in
environmental decision
making, where the
costs can be quite
large and the benefits
difficult to quantify.
The cost-benefit
analysis performed to
assess the proposed
lead phaseout in the
United States was
instrumental in creating
a strong consensus for
action and in reversing
policies that had
weakened controls on
leaded gasoline.
The purpose of cost-benefit analysis is to determine the course of action that will
result in the greatest net benefits (that is, total benefits minus costs) for the
society in question. While not infallible, a rigorous cost-benefit analysis can help
government leaders and legislators to avoid costly errors and to make the best use
of limited resources. Cost-benefit analysis is especially useful in setting priorities
and making decisions in the environmental field. Such decisions often involve
significant economic costs, while the benefits of improved health and well-being
may be more difficult to quantify. While cost-benefit analysis cannot substitute
for value judgments or moral decisions, it can often help to clarify such judg-
ments and the stakes involved in such decisions.
By providing a clear quantification and comparison of the costs and benefits
of a given decision, cost-benefit analysis can also help to resolve controversies,
overcome opposition, and secure public and political support for policies
that are clearly justifiable on cost-benefit grounds. For example, the rigorous
cost-benefit analysis performed for the proposed phaseout of leaded gasoline
in the United States (Schwartz et al., 1985) created a strong consensus for
immediate action, and led to a sharp reversal in the existing policy, which
had previously been to weaken controls on leaded gasoline. Such a consensus
would have been very difficult to develop in the absence of the clear conclu-
sions derived from the cost-benefit analysis.
6.2 Cost-Benefit Comparison Of Alternative Strategies
A cost-benefit analysis of alternative lead phaseout strategies should begin
with a definition of the different strategies under consideration. The analyst
should then seek to quantify, to the extent possible, the social costs and
benefits of each strategy.
In evaluating social costs, cost-benefit analysts normally focus on the actual
consumption of resources (labor, goods, and services) available to society,
excluding from consideration the effect of transfer payments. These payments
shift resources from one economic actor to another, but do not directly
reduce the overall stock of goods and services available.
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Social Costs Vs. Transfer Payments
The social cost of a liter of gasoline in the refinery or in the
port is generally evaluated as equal to the amount that a
country would have to pay to purchase it from abroad (in
the case of importing nations) or would receive from selling
it abroad instead of using it at home (in the case of export-
ers). In both cases, this amount is the international price of
gasoline, adjusted for applicable transport costs.
The transportation, distribution, and retail marketing of
gasoline also involve the consumption or exclusive utilization
of social resources such as labor, transport, buildings, and
land, resulting in real social costs that must be taken into
account in the cost-benefit analysis, where applicable. In
contrast, a government tax on gasoline does not result in the
consumption of resources, but only transfers them from the
consumer paying the tax to the government. It is thus a
transfer payment, not a cost.
In the case of lead phaseout, the principal social cost will be the increase in
the cost of producing gasoline of a specified octane quality, while the princi-
pal benefits will be the reductions in the adverse health effects due to lead
exposure and the savings on automotive maintenance costs experienced by
vehicle owners. Methods for estimating the change in refining costs due to
lead phaseout were discussed in Section 2.7, while a method for quantifying
the maintenance benefits was demonstrated in Section 3.4. Because both
refining costs and maintenance benefits are expressed in monetary terms,
their quantification is relatively straightforward, and does not depend on
questions of values (however, because of the complexity of the refining sector,
considerable effort may be required to arrive at an accurate estimate of
refining cost changes).
Quantifying the health benefits of lead phaseout is more complicated, as
these benefits are very much linked to human values. As outlined in Chapter
5, the main identifiable health benefits due to lead phaseout are the reduc-
tions in the incidence of hypertension, stroke, heart attack, and premature
mortality due to lower blood lead concentrations in adults; in children, they
include reductions in the loss of IQ points (and associated earning power)
and decreased incidence of developmental disabilities. Of these, the changes
in adult mortality and children's average IQ account for most of the benefits
that can be quantified and expressed in monetary terms. In the interest of
saving analytical time, the analyst may wish to confine his or her attention to
these factors. While omitting other, smaller health benefits from consider-
ation will tend to bias the overall estimate downwards, this is unlikely to
affect the ultimate conclusions, as even very conservative estimates of the
benefits of lead phaseout have generally exceeded the costs by a factor of 10
or more.
30-: PNG
ANALYSIS
In lead phaseout, the
principal social cost will
be the increase in the
cost of producing
gasoline of a specified
octane quality. The
principal benefits will
be reductions in
adverse health effects
and savings on
automotive
maintenance costs.
Even very conservative
estimates have found
that the benefits of lead
phaseout generally
exceed the costs by a
factor of ten or more.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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In their cost-benefit
analyses, imple-
menters should
consider at least one
strategy in which the
lead content in existing
leaded gasoline
grades is reduced as
much as possible and
as quickly as possible.
6.3 Potential Lead Phaseout Strategies
Potential strategies for lead phaseout were discussed in Section 2.7. In
general, it is recommended that the cost-benefit analyst consider several
different lead phaseout strategies involving different generic approaches to
meeting the octane deficit due to removing lead. The additional refining
costs involved in each strategy, as well as any incremental costs for fuel
transportation, distribution, and marketing, should be taken into account.
These should then be compared with the benefits of reduced automotive
maintenance costs, reduced mortality in adults, and improved intelligence in
children. If adequate analytical resources are available, other benefits can also
be included. These include the savings in medical costs due to reduced
incidence of hypertension, stroke, and heart disease; reductions in the cost of
remedial education for children; and reductions in the cost of medical
treatment for lead toxicity.
The specific lead phaseout strategies to be considered in each case will
depend on each country's situation: its gasoline consumption levels, gasoline
sources (especially the degree of reliance on local refining), the equipment
already installed at local refineries, pipeline and port capacity, and related
issues. It is strongly recommended, however, that the set of lead phaseout
strategies considered include at least one strategy in which the lead content
of existing leaded gasoline grades is reduced as quickly as possible, and by as
much as possible - using measures such as the blending of imported MTBE,
alkylate or other high-octane blendstocks, revamping of catalytic reformers,
and other steps as necessary to achieve the greatest possible lead reduction in
the shortest time. Although this rapid phaseout approach will often result in
higher gasoline production costs than a slower approach based on upgrading
refinery processing equipment, the benefits of earlier reduction in lead emissions
usually outweigh the additional costs.
6.4 Example Of Cost-Benefit Comparison
This section presents an example of a cost-benefit comparison for the hypo-
thetical case and two hypothetical strategies developed in previous chapters.
Hypothetical case. Chapter 5 estimated the probable reductions in ambient
lead levels and average blood lead concentrations due to a given reduction in
total lead emissions in a hypothetical city.
Hypothetical strategies. Section 2.7 developed costs for two hypothetical lead
phaseout strategies:
• A near-term strategy using MTBE and imported high-octane blending
components, along with increased reformer severity and some upgrading
of reformer catalyst, to reduce the lead content of regular gasoline to 0.1
g/liter while eliminating lead entirely from premium gasoline.
• A longer-term strategy to achieve higher octane levels by adding new
refinery process units such as isomerization, alkylation, and catalytic
reforming.
72 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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Below, these two hypothetical strategies are applied to this hypothetical case.
Existing gasoline sales under the status quo are assumed to comprise 500
million liters of regular and 500 million liters of premium per year, with
lead contents of 0.7 g/liter in each case.
In the first, or slow phaseout strategy, refiners begin planning and building new
process units in Year 1, in order to be able to eliminate the need for lead
additives beginning in Year 4. In the second, quick phaseout strategy, refiners
also begin planning and building process units in Year 1 to eliminate all
need for lead in Year 4. In the meantime, however, they carry out the near-
term strategy outlined in Section 2.7 - blending MTBE and imported high-
octane components into both regular and premium grades, thus reducing
annual lead emissions in the hypothetical city from 700 tons to 50 tons.
Table 16 shows the effect of each strategy on ambient lead concentrations
and average blood lead levels among adults and children.
Table 16: Effect Of Lead Phaseout Strategies On
Blood Lead Concentrations: Hypothetical Case
Leaded gasoline sales
Lead concentration in gasoline
Annual lead emissions
Avg. lead concentration in air
Values
1,000
0.7
700
1.4
Units
million liters per year
grams per liter
tons Pb per year
grams per cubic meter
Effect of Low-Lead Regular with Unleaded Premium
Annual lead emissions
Avg. lead concentration in air
Avg. lead in blood: adults
Avg. lead in blood: children
-650
-1.3
-2.6
-5.2
tons Pb per year
grams per cubic meter
micrograms per deciliter
micrograms per deciliter
Effect of Eliminating Lead
Annual lead emissions
Avg. lead concentration in air
Avg. lead in blood: adults
Avg. lead in blood: children
-700
-1.4
-2.8
-5.6
tons Pb per year
grams per cubic meter
micrograms per deciliter
micrograms per deciliter
To complete the benefits assessment, it is necessary to estimate the effect of
the change in blood lead concentrations among adults on the mortality rate,
and thus to calculate the number of premature deaths avoided under each
strategy.
Table 17 shows the results of this calculation. The reduction in mortality
among adults aged 40 to 59 can then be multiplied by the number of
people in that age cohort to calculate the change in the total number of
deaths.
Calculating the benefits to adults. In order to express the benefit of this
mortality reduction in monetary terms, the change in the number of deaths
per year must be multiplied by an estimate of the value of a statistical life
(VOSL). For this hypothetical case, it was assumed that the total size of the
cohort aged 40 to 59 is 500,000 persons. For conservatism, a relatively low
value for VOSL of US $200,000 was assumed. This is the value suggested
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 73
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for Shanghai, Manila, and Mumbai by Maddison et al. (1997). The benefits
calculated in this way amount to about US $ 30 million per year, as shown
in Table 18.
Table 17: Effect Of Changes In Adult Blood Lead
Concentrations On Mortality: Hypothetical Case
Current blood lead level (ug/dl)
Current mean blood pressure (mmHg)
Proj. 12 year mortality
New blood lead level (ug/dl)
New mean blood pressure (mmHg)
Proj. 12 year mortality
Avoided deaths/million persons/year
Males 40-59
Females 40-59
Low Lead
10.0
85.0
8.75%
7.4
84.2
8.52%
190
95
Zero Lead
10.0
85.0
8.75%
7.2
84.1
8.50%
207
103
Table 18: Calculation Of Population-Wide
Health Benefits: Hypothetical Case
Change in lead emissions
Change in adult blood lead
Adults 40-59 affected
Change in mortality 40-59
Assumed value of statistical life
Monetized adult benefit
Change in child blood lead
Change in avg. child IQ
Change in avg. lifetime earnings
Monetized benefit/child
Children affected
Total child IQ benefit
Total health benefits
Low Lead
-650
-2.6
500,000
142
$200,000
$28
-5.2
1.33
3.12%
$1 ,248
100,000
$125
$153
Zero Lead
-700
-2.8
500,000
155
$200,000
$31
-5.6
1.43
3.36%
$1,344
100,000
$134
$165
Unite
tons per year
micrograms per deciliter
persons
deaths /year
US$
million US$
micrograms per deciliter
IQ points
US$
persons
million US$
million U8$
Calculating the benefits to children. Table 18 also shows how to calculate the
benefits of reduced blood lead in children. Here, the main effect is the
increase in average IQ, and thus the increase in the present value of lifetime
earnings. Schwartz (1994b) calculated this benefit as 0.6 percent of lifetime
earnings per ug/dl of blood lead at age six. The net present value of lifetime
earnings was assumed to be US $40,000 in this case: about one-sixth of the
estimate developed by Schwartz for the United States. This is consistent with
the assumption of a relatively low income level, as in Shanghai or Manila.
The resulting change in lifetime earnings is somewhat more than 3 percent,
for a total of around $ 1300 per six-year old child. Here, it was assumed that
100,000 children turn 6 years old each year, giving a net benefit in the
neighborhood of $130 million. The benefits are slightly less for the low-lead
strategy, and slightly more for the zero-lead strategy.
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IMPLEMENJER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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Results. Table 19 compares the overall costs and benefits of each strategy. To
simplify the calculation, the costs of the refinery investment are assumed to
be included in the cost of the fuel (from Table 6), and are not accounted for
separately. As this table shows, the slow phaseout strategy results in no
difference in fuel cost or lead emissions during the first three years, and thus
no difference in the costs or benefits compared to the status quo. Once the
lead phaseout takes effect in Year 4, however, the net benefits amount to US
$206 million per year.
In this hypothetical case, the change in gasoline costs is very small compared
to the health benefits, or even to the reduction in vehicle maintenance costs
alone. Although the quick phaseout strategy results in higher near-term costs
of gasoline production, the benefits of rapidly reducing lead emissions are
more than 14 times greater than these costs, resulting in net benefits of US
$180 million per year. The difference in the total net present value of
benefits, compared to the slow phaseout scenario, is $447 million.
Table 19: Cost-Benefit Comparison Of Lead
Phaseout Strategies: Hypothetical Case
Yr.1
Yr.2
Yr.3
Yr.4
Yr.5
5-yr. NPV
Status Quo
Added gasoline costs (million US$)
Vehicle maint. saving (million US$)
Lead emissions (t/y)
Health benefits (million US$)
0
0
700
0
0
0
700
0
0
0
700
0
0
0
700
0
0
0
700
0
$0
$0
$0
Slow Phaseout
Added gasoline costs (million US$)
Vehicle maint. saving (million US$)
Lead emissions (t/y)
Health benefits (million US$)
Total benefits compared to status quo
0
0
700
0
0
0
0
700
0
0
0
0
700
0
0
0
0
700
165
206
6.2
47
0
165
206
$8
$61
$216
$269
Quick Phaseout
Added gasoline costs (million US$)
Vehicle maint. saving (million US$)
Lead emissions (t/y)
Health benefits (million US$)
Total benefits compared to status quo
Total benefits compared to slow phaseout
13.6
40
50
153
180
180
13.6
40
50
153
180
180
13.6
40
50
153
180
180
6.2
47
0
165
206
0
6.2
47
0
165
206
0
$42
$161
$597
$716
$447
A
BENEFIT
ANALYSIS
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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7. CHOOSING POLICY INSTRUMENTS
The policy instruments available for implementing a lead phaseout strategy
depend on the legal system, the ownership structure of any existing refiner-
ies, and the policy and/or regulatory framework governing motor vehicle
fuels and their distribution.
Examples of instruments. Some of the most important instruments available
for lead phaseout include:
• Direct action. Governments can take direct action when they own or
control the refinery, or when they purchase fuel for the country's own
use. Examples of direct action might include directing a state-owned
refinery to reduce its use of lead, or specifying low-lead or unleaded
gasoline for government purchases.
• Regulatory "command and control" measures. Examples of these
instruments include limiting the maximum lead content of gasoline, or
prohibiting imports of lead additives and gasoline containing them.
• Market-based incentives. Examples of these instruments might include a
tax on lead additive imports, on leaded gasoline, or (preferably) on the
lead content of gasoline.
• Public information measures. These instruments, which are discussed in
Chapters 10 and 11, include such actions as requiring gasoline lead content
to be posted at the service station, publicizing the adverse health impacts of
lead from gasoline, and making consumers aware of the savings in
maintenance costs possible with low-lead or unleaded fuel.
Where legally feasible, market-based measures are generally preferable to
command-and-control regulations. The decision to add lead to gasoline is an
economic one on the part of the refiner - lead is the cheapest way of achiev-
ing the necessary octane level. By changing market conditions so that this is
no longer true, refiners can be induced to reduce, and ultimately eliminate, lead
use as quickly as possible. The flexibility of market-based incentives also helps to
reduce the chances of a regulatory mistake - allowing too little time for the
necessary changes (and thus disrupting the gasoline market) or allowing too
much time, and thus allowing the health damages due to leaded gasoline to
continue longer than necessary.
Where legally feasible,
market-based
measures are generally
preferable to
command-and-control
regulations.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
77
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r
After discussing the issues that surround the ownership
structure of a country's refining sector, this chapter compares
two important policy instruments that can be used in a lead
phaseout strategy:
• Command-and-control instruments, which involve the
government mandating the actions of industries or individu-
als.
• Market-based incentives, which allow industries or individu-
als more flexibility in their decisions, but provide incentives
and disincentives for particular decisions.
It then reviews the lessons learned from employing these
policy instruments in the United States.
Ownership structure considerations. Where petroleum refining and distribu-
tion are carried out by the private sector, the main concerns are generally to
define the quickest phaseout schedule achievable without disrupting the
gasoline market, and to incorporate sufficient flexibility in the regulations to
accommodate legitimate differences in the time periods required for different
refineries to comply. The monitoring and enforcement of compliance with
the schedule should also receive careful attention, and it may be necessary to
overcome political opposition from refinery owners. Where petroleum
refineries are owned by the government, these issues are generally less
difficult, but the mobilization of adequate funds for refinery investments
may present a significant problem.
The Steps In Choosing Policy Instruments
1. Identify legal authority
Implementers should first identify the legal authority or authorities
available as a basis for policy instruments.
2. Assess available policy instruments
Next, they should assess the types of instruments that are legally
permissible under the authority(ies) identified. For example, govern-
ment agencies often have the authority to limit or prohibit the emission
of toxic substances, but may require new legislation in order to
change the tax rates on fuel.
3. Evaluate the "fit" between strategy and instruments
Implementers should then assess the compatibility between the
strategy chosen and the instruments available. They should carefully
review existing regulations and legislation to ensure that these do not
present a barrier to the changes required. For example, gasoline
quality regulations sometimes specify minimum as well as maximum
lead content, or they may fix maximum limits on ethers or other
components at lower levels than necessary.
4. Select "best" combination of instruments
Last, implementers should select the best combination of instruments,
considering their effectiveness, costs and benefits, timing, flexibility,
and political acceptance.
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7.1 Cornmand-And-Control Instruments
In most countries, government agencies already have been granted authority
to set and enforce quality and composition standards for motor fuels. They
will often have the authority to limit or prohibit the use of harmful additives
such as TEL, The legal basis for such limitations might be found either in
the demonstrable damage to human health due to lead emissions, or,
alternatively, in the harmful effects of lead and lead scavengers on engines.
The transition from leaded to unleaded gasoline cannot occur overnight.
Thus, command-and-control regulations must allow enough time for the
refining industry to adjust to the phaseout requirements. The amount of
time required will vary depending on the situation in each country, includ-
ing the availability of excess domestic octane-producing capacity, the avail-
ability and cost of imported octane enhancers such as MTBE and high-
octane gasoline blendstocks, and the capacity of ports and transportation
systems to handle imports of these materials.
It is important that the amount of time allowed for industry to comply not
be too short, as this may result in disruptions of the gasoline market, which
in turn are likely to lead to a reversal of the lead phaseout decision on
political grounds. On the other hand, the grace period allowed for compli-
ance should not be longer than necessary, in order to minimize the adverse
impacts on human health and the environment.
The example of Egypt shows that lead phaseout can proceed very quickly -
within a few months — given favorable circumstances and adequate availabil-
ity of high-octane blending components such as MTBE. The refining
industry will generally argue for a longer grace period. Unless the agency
involved has such expertise in-house, it is generally advisable to seek the
advice of expert consultants in determining the length of any grace period
allowed, and the maximum lead levels to be allowed in gasoline during the
interim.
In most countries,
government agencies
already have been
granted authority to set
and enforce quality and
composition standards
for motor fuels.
Because it takes time to
make the transition
from leaded to
unleaded gasoline,
command-and-control
regulations must allow
enough time for the
refining industry to
adjust to the phaseout
requirements.
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79
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Ideally, the rate of tax
on lead used in
gasoline would be
equal to the economic
disbenefits imposed by
its use. In practice,
however, implementers
must consider the
negative effects on the
market if a high tax is
suddenly imposed.
The trading of "lead
rights" may provide an
alternative mechanism
for introducing
flexibility into the lead
phaseout process.
In the United States,
the allowable lead
content in leaded
gasoline was reduced
to 1.1 gram per gallon
by 1982 and to 0.1
gram per gallon in
1986. By 1995, sales of
leaded gasoline were
banned.
82
lead used, which is readily monitored both at the port (for imports of TEL)
and in the finished gasoline.
Ideally, the rate of tax on lead used in gasoline would be equal to the eco-
nomic disbenefits (costs) imposed by its use. For example, in the hypotheti-
cal case outlined in the preceding chapter, total lead emissions of 700
million grams per year resulted in health damages equivalent to US $165
million. This would justify a tax rate of $0.236 per gram of lead ($165
million/700 million grams). In practice, such a high tax rate would likely
disrupt the gasoline market if it were imposed suddenly. Even a much lower
tax rate, on the order of $0.10 per gram, would more than offset the saving in
refining costs due to lead use, and would serve as a strong incentive to
refiners to reduce their lead use as quickly as possible. At the same time, the
funds mobilized by the tax could be used to set up an effective monitoring
and enforcement program, to fund publicity campaigns, and for other
purposes in connection with the phaseout of lead in gasoline. If necessary,
some of the funds raised in this manner could be used to finance the needed
investments in refinery process units.
Lead "rights trading." If a Pigouvian tax on lead is not feasible, the trading of
"lead rights" may provide an alternative mechanism for introducing flexibil-
ity into the lead phaseout process. In this approach, regulators fix a limit on
the average lead content of each refinery's gasoline production. If a refinery
produces gasoline with a lower lead concentration than the maximum, it can
sell to another refinery the right to produce gasoline containing a corre-
sponding amount of lead in excess of the maximum. To guard against abuses,
such trading requires careful safeguards and effective verification mecha-
nisms. If properly implemented, however, lead rights trading can make it
possible to achieve much faster reductions in lead use than would be possible
if all gasoline producers had to meet the same lead limits without trading.
The lead rights trading approach was used by the EPA as part of its lead phaseout
plan in the 1980s. The experience with lead rights trading in the United States is
summarized in the next section.
7.3 Lessons From The U.S. Experience
The U.S. experience in phasing out leaded gasoline is described by Nichols
(undated). In the 1970s, average lead concentrations measured in U.S. cities
often exceeded EPA's 3-month average air quality standard of 1.5 ug/m3 (today,
it is recognized that even this standard is insufficiently protective of human
health). The mandatory sale of unleaded gasoline was introduced in 1974, in
order to meet the needs of cars equipped with catalytic converters. At that time,
leaded gasoline contained an average of 2.4 grams of lead per gallon (0.63 g/liter),
and average blood lead concentrations among children in major cities were
around 20 ug/dl.
Through a phased program, the allowable lead concentration in leaded
gasoline was reduced to 1.1 gram per gallon (0.29 g/1) by 1982. This rule
also introduced the trading of lead rights between refineries, so that a
refinery that was able to produce gasoline containing less than 1.1 gram per
gallon could sell the excess "lead rights" to another refinery that needed
them. By 1984, about half of the refineries in the United States were partici-
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
-------
pacing in this market, with the larger, more complex refineries generally selling
lead rights to smaller refineries that had less capability to produce high-octane
gasoline through process changes (Nichols, undated).
In 1984, EPA carried out a major cost-benefit evaluation of further lead
reductions (Schwartz et al, 1985). This study concluded that the benefits of
further reducing lead use in gasoline greatly outweighed the costs, and that
allowable lead concentrations should be reduced to a minimum as quickly as
possible. A final rule was promulgated in March 1985, reducing the allow-
able lead concentration to 0.5 gram per gallon in July 1985 and to 0.1 gram
per gallon (0.026 g/1) on January 1, 1996. The decision to reduce the
allowable lead content to 0.1 gram per gallon instead of zero was due to
widespread public concern (fomented by the lead industry) over the poten-
tial for damaging valve seat recession to occur in older engines. The allowable
concentration was retained at this level until leaded gasoline sale was finally
banned in 1995, pursuant to the 1990 revisions to the Clean Air Act.
An important feature of the 1985 regulation was the provision allowing
refiners to "bank" unused lead rights for later sale or use. At the time the rule
was promulgated, many refineries had the capacity to produce gasoline
containing substantially less than 1.1 gram per gallon. By reducing their
lead use in advance of the legal limit, they were able to store up lead rights
for the future, when they would be more valuable. As discussed in Chapter
2, the nonlinear relationship between lead and octane means that the benefit
of going from 0.1 to 0.2 grams of lead per gallon is much greater than the
octane loss due to going from 1.1 to 1.0 gram per gallon. Thus, lead rights
saved when the maximum limit was 1.1 g/gallon became much more
valuable when it dropped to 0.1 gram/gallon.
EPA estimated that the trading and banking of lead rights would save
between US $173 and $226 million between 1985 and 1988, or about 10
percent of the total cost of complying with the rule during that period
(Nichols, undated). In fact, the actual use of lead banking was even greater
than projected by EPA's analysis, and it seems likely that the overall costs
were lower as a result. More importantly, the incorporation of lead trading
and banking provisions made it feasible for small, simple refineries to comply
with the phasedown rule by buying lead rights from larger refineries. Had
this not been allowed, the prospect that some small refineries would be
driven out of business would likely have resulted either in a delay in the
phasedown, or a special exemption for small refineries that would have
allowed them to continue to produce high-lead gasoline for some time.
The incorporation of
lead trading and
banking provisions in
EPA's rule allowed small
refineries to stay in
business without
delaying the phase-
down or permitting
them to continue to
produce high-lead
gasoline.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
83
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84 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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8. MONITORING COMPLIANCE
Sampling and checks, which confirm that the gasoline sold actually complies
with the lead limits and quality specifications in effect, are an integral part of
a lead phaseout strategy. A statistical sampling procedure should be set up
that is adequate to ensure that any significant cheating or noncompliance is
detected. To guard against adulteration or smuggling, gasoline samples
should be collected for analysis at retail service stations as well as at the
refinery and/or port of importation. As an additional check on lead additive
use during the lead phaseout process, authorities may wish to establish
special procedures for monitoring the importation and use of lead additives.
Since only a few chemical companies produce these extremely hazardous
compounds, monitoring lead additive shipments should not be difficult.
This chapter presents information on standard sampling and
analytical procedures for lead, gasoline octane, and gasoline
properties and composition, together with information on the
laboratory equipment required and their costs.
The Steps In Monitoring Compliance
1. Identify monitoring needs
The monitoring requirements implementers should identify include the
number of samples and the types of locations to be sampled to
ensure adequate coverage. This will involve a tradeoff between
enforcement costs and adequacy of control.
2. Identify legal authority/requirements for monitoring gasoline
composition
Implementers should identify the legal authority that will monitor fuel
composition, including any ongoing monitoring efforts.
3. Identify Institutional and physical requirements for monitoring
In this step, implementers should identify the equipment and person-
nel required for the monitoring program and the sources of financing
for any new equipment or personnel needed.
4. Identify responsibilities for monitoring and enforcement
Here, implementers should identify the institutional responsibilities of
the personnel identified in Step 3.
5. Plan and implement gasoline monitoring and enforcement
program
Based on the information developed, the implementer should work
with the organizations responsible for enforcement to prepare a
detailed plan for the enforcement program, obtain any necessary
authorizations or approvals, and implement the program.
6. Identify and prosecute violators
The program should include provisions for identifying and prosecuting
individuals who are violating the lead phasedown requirements.
7. Follow up to ensure program effectiveness
Once the program is underway, the implementer should follow up to
confirm that monitoring is being done according to the plan.
*\*{" "*•>•/ " '*, »4' **".
u- *H > I
Sampling and checks
on the importation and
use of lead additives
are used to detect
cheating or non-
compliance with a lead
program, and to guard
against the adulter-
ation or smuggling of
gasoline.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
85
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8.1 Gasoline Sampling
The samples collected must be truly representative of the gasoline in question. A
detailed description of the procedures for obtaining representative samples of
gasoline for Reid vapor pressure measurements can be found in the U.S. Code of
Federal Regulations (CFR 40, Part 80, Appendix D). The CFR can be accessed
on the World Wide Web at www.access.gpo.gov. Gasoline samples obtained by
these procedures can also be analyzed for other properties of interest.
Recently, EPA proposed to modify Appendix D to allow the use of sampling
procedures developed by the American Society for Testing and Materials
(ASTM). The main standard for gasoline sampling is ASTM D-4057-95
(Standard for Sampling Petroleum and Petroleum Products). The other
ASTM standards involved include: D-4177-82 (Standard for Automatic
Sampling), D-5842-95 (Standard Practice for Sampling and Handling of
Fuels for Volatility Measurement), and D-5854-96 (Standard Practice for
Mixing and Handling Liquid Samples of Petroleum and Petroleum Prod-
ucts).
8.1.1 Sampling Precautions
Numerous precautions are required to ensure that the character of the
samples is representative. These depend upon the tank, carrier, container or
line from which the sample is being obtained, the type and cleanliness of the
sample container, and the sampling procedure that is to be used. A summary
of the sampling procedures and their application is presented in Table 20.
Each procedure is suitable for sampling a material under definite storage,
transportation, or container conditions. The basic principle of each proce-
dure is to obtain a sample in such manner and from such locations in the
tank or other container that the sample will be truly representative of the
gasoline.
Table 20: Summary Of Gasoline Sampling
Procedures And Applicability
Type of Container
Procedure
Storage tanks, ship and barge tanks, tank
cars, tank trucks
Storage tanks with taps
Pipes and lines
Retail outlet and wholesale purchaser-
consumer facility storage tanks
Bottle sampling
Tap sampling
Continuous line sampling
Nozzle sampling
8.1.2 Sampling Terms
A description of terms shows the complexity involved in sampling:
• Average sample is one that consists of proportionate parts from all sections
of the container.
• All-levels sample is one obtained by submerging a stoppered beaker or
bottle to a point as near as possible to the draw-off level, then opening
the sampler and raising it at a rate such that it is 70-85 percent full as it
emerges from the liquid. An all-levels sample is not necessarily an average
86
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sample because the tank volume may not be proportional to the depth and
because the operator may not be able to raise the sampler at the variable rate
required for proportionate filling. The rate of filling is proportional to the
square root of the depth of immersion.
• Running sample is one obtained by lowering an unstoppered beaker or
bottle from the top of the gasoline to the level of the bottom of the
outlet connection or swing line, and returning it to the top of the
gasoline at a uniform rate of speed such that the beaker or bottle is 70-
85 percent full when withdrawn from the gasoline.
• Spot sample is one obtained at some specific location in the tank by
means of a thief bottle or beaker.
• Top sample is a spot sample obtained 6 inches (150 mm) below the top
surface of the liquid.
• Upper sample is a spot sample taken at the mid-point of the upper third
of the tank contents.
• Middle sample is a spot sample obtained from the middle of the tank
contents.
• Lower sample is a spot sample obtained at the level of the fixed tank
outlet or the swing line outlet.
• Clearance sample is a spot sample taken 4 inches (100 mm) below the
level of the tank outlet.
• Bottom sample is one obtained from the material on the bottom surface of
the tank, container, or line at its lowest point.
• Drain sample is one obtained from the draw-off or discharge valve.
Occasionally, a drain sample may be the same as a bottom sample, as in
the case of a tank car.
• Continuous sample is one obtained from a pipeline in such a manner that
it gives a representative average of a moving stream.
• Mixed sample is one obtained after mixing or vigorously stirring the
contents of the original container, and then pouring out or drawing off
the quantity desired,
• Nozzle sample is one obtained from a gasoline pump nozzle which dispenses
gasoline from a storage tank at a retail outlet or a wholesale purchaser-
consumer facility.
Other important aspects to be considered are sample containers (including
cleaning procedure), sampling apparatus, time and place of sampling,
handling, shipping, labeling, and testing procedures.
The directions for sampling cannot be made explicit enough to cover all
cases. Extreme care and good judgment are necessary to ensure samples that
represent the general character and average condition of the material. Clean
hands are important. Clean gloves may be worn but only when absolutely
necessary, such as in cold weather, when handling materials at high tempera-
ture, or for reasons of safety. Select wiping cloths so that lint is not introduced,
contaminating samples.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 87
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8.2 Measuring Lead In Gasoline
EPA has approved three methods for measuring lead in gasoline. For details
on any of these methods, consult The United States Code of Federal Regula-
tions Title 40 Part 80, Appendix B. This document can be downloaded from
the World Wide Web at: 1) http://www.legal.gsa.gov, or 2) http://
www.epa.gov/docs/epacfr40/chapt-I.info/.
In using any of the three methods, care should be taken to collect and store
samples in containers that will protect them from changes in the lead
content of the gasoline such as from loss of volatile fractions of the gasoline
by evaporation or leaching of the lead into the container or cap. Since metal
cans are sometimes sealed with lead solder, it is preferable to collect samples
in glass bottles. If samples have been refrigerated, they should be brought to
room temperature (25° Celsius) prior to analysis.
Also, gasoline is extremely flammable and should be handled cautiously and
with adequate ventilation. The vapors are harmful if inhaled, and a pro-
longed breathing of vapors should be avoided. Skin contact should be
minimized.
8.2.1 Standard Method Test By Atomic Absorption Spectrometry
This method determines the total lead content of gasoline. The method
compensates for variations in gasoline composition and is independent of
lead alkyl type. The gasoline sample is diluted with methyl isobutyl ketone
(MIBK) and the alkyl lead compounds are stabilized by reaction with iodine
and a quarternary ammonium salt. The lead content of the sample is then
determined by atomic absorption flame Spectrometry at 2833 A, using
standards prepared from reagent-grade lead chloride. Using this treatment,
all alkyl lead compounds give an identical response.
The equipment needed to perform this method includes an atomic absorp-
tion spectrometer, volumetric flasks, pipettes, and micropipettes. This
method is now rarely used, since automatic equipment for lead determina-
tion is readily available.
8.2.2 Automated Method Test By Atomic Absorption Spectrometry
This method is very similar to the one above, and has largely replaced it in
practice. The main difference is that an automated system is used to perform
the diluting and the chemical reactions, and to feed the products to the atomic
absorption spectrometer. This method requires an auto-analyzer system and an
atomic absorption spectroscopy detector system
8.2.3 X-Ray Spectrometry
As with the other two methods, this determines the total lead content of
gasoline. It is insensitive to variations in gasoline composition, and is inde-
pendent of lead alkyl type.
A portion of the gasoline sample is placed in an appropriate holder and
loaded into an X-ray spectrometer. The ratio of the net X-ray intensity of the
lead L alpha radiation to the net intensity of the incoherently scattered tungsten
88 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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L alpha radiation is measured. The lead content is determined by reference to a
linear calibration equation that relates the lead content to the measured ratio.
The incoherently scattered tungsten radiation is used to compensate for varia-
tions in gasoline samples.
The primary apparatus needed for using this method is an X-ray spectrometer. It
is recommended that the optical path in the spectrometer be helium instead of
air. The use of air produces ozone, and could also pose flammability problems if a
container with a sample of gasoline ruptures.
8.3 Octane Measurements
There are two ASTM methods for measuring the antiknock quality in
gasoline: ASTM D 2699 (Test for Knock Characteristics of Motor Fuels by
the Research Method), and ASTM D 2700 (Test for Knock Characteristics
of Motor and Aviation-Type Fuels by the Motor Method). Both methods
require the use of a special single-cylinder laboratory engine with a variable
compression ratio, known as a CFR engine. The Research Method (which
results in the RON) simulates driving under mild conditions, while the
Motor Method (which results in the MON) simulates more severe condi-
tions, as well as operation under load or at high speeds. Both methods relate
the knocking characteristics of the test gasoline to that of two pure fuels: iso-
octane (2,2,4 tri-methyl pentane) and n-heptane. These are defined to have
octane numbers of 100 and zero, respectively.
The octane number of a gasoline is measured by determining the compres-
sion setting on the laboratory engine at which the knock begins to occur
when operating on the test gasoline. This is then compared to the compres-
sion settings at which known mixtures of iso-octane and n-heptane begin to
knock. The octane value is equal to the percentage of octane in the mixture.
Thus, a gasoline blend that knocks at the same compression setting as a
mixture of 80 percent iso-octane and 20 percent n-heptane would have an
octane rating of 80.
8.4 Gasoline Composition
This section summarizes the measurement of the reformulated gasoline fuel
parameters followed by EPA. The entire document is the United States Code
of Federal Regulations (CFR) Title 40 Part 80, including appendixes A
through G. This document is available through the World-Wide Web at the
following addresses (other addresses are also available):
http://www.legal.gsa.gov, or
http://www.epa.gov/docs/epacfr40/chapt-I.info/
ASTM documents can be obtained through the American Society for Testing
and Materials. ASTM can be contacted via the World-Wide Web at the
following address: http://www.astm.org, or at their physical address: ASTM,
100 Barr Harbor Drive, West Conshohocken, Pennsylvania USA 19428-
2959.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 89
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8.4.1 Sulfur
Sulfur content is determined using ASTM standard method D—2622—92,
entitled "Standard Test Method for Sulfur in Petroleum Products by X-Ray
Spectrometry."
8.4.2 Olefins
Olefin content is determined using ASTM standard method D-1319-93,
entitled "Standard Test Method for Hydrocarbon Types in Liquid Petroleum
Products by Fluorescent Indicator Adsorption." The gas chromatographic
method described below for aromatics can also be used to determine olefin
content.
8.4.3 Reid Vapor Pressure (RVP)
Reid vapor pressure is determined using the procedure described in the U.S.
CFR Title 40 Part 80, Appendix E, Method 3 (Evacuated Chamber
Method), in which a known volume of air-saturated fuel at 32-40° F (0-4.4° C)
is introduced into an evacuated, thermostatically controlled test chamber, the
internal volume of which is or becomes five times that of the total test specimen
introduced into the test chamber. After the injection, the test specimen is
allowed to reach thermal equilibrium at the test temperature, 100° F (37.8° C).
The resulting pressure increase is measured with an absolute pressure measuring
device whose volume is included in the total of the test chamber volume. The
measured pressure is the sum of the partial pressures of the sample and die
dissolved air. The total measured pressure is converted to Reid vapor pressure by
use of a correlation equation.
8.4.4 Distillation
Distillation parameters are determined using ASTM standard method D-
86-90, entitled "Standard Test Method for Distillation of Petroleum
Products." EPA has determined, however, that the figures for repeatability
and reproducibility given in degrees Fahrenheit in Table 9 in the ASTM
method are incorrect, and are not to be used.
8.4.5 Benzene
Benzene content is determined using ASTM standard method D-3606-92,
entitled "Standard Test Method for Determination of Benzene and Toluene
in Finished Motor and Aviation Gasoline by Gas Chromatography"; except
that instrument parameters must be adjusted to ensure complete resolution
of the benzene, ethanol and methanol peaks because ethanol and methanol
may cause interference with ASTM standard method D-3606-92, when
present.
8.4.6 Aromatics
Aromatics content is determined by gas chromatography identifying and
quantifying each aromatic compound as set forth in either of the two methods
described in the U.S. CFR Title 40, Part 80.46. The equipment used is an
atomic gas mass spectrometer detector.
90 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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The first method for determining aromatic content involves developing a three-
component internal standard, where a curve is developed using calibration points
for each level of a particular peak in the instrument's calibration table. The
response of the compound in a sample is divided by the response of the internal
standard to provide a response ratio for that compound in the sample. A cor-
rected amount ratio for the unknown is calculated using the curve fit equation
determined earlier. Finally, the amount of the aromatic compound is equal to the
corrected amount ratio times the amount of the internal standard. The total
aromatics in the sample is the sum of the amounts of the individual aromatic
compounds in the sample.
The second method uses a percent normalized format to determine the
concentration of the individual compounds. No internal standard is used in
this method. The calculation of the aromatic compounds is done by develop-
ing calibration curves for each compound using the type fit and origin
handling specified in the instrument's calibration table. The percent normal-
ized amount of a compound is calculated using an equation, where the total
aromatics is the sum of all the percent normalized aromatic amounts in the
sample.
This method allows the quantification of non-aromatic compounds in the
sample. Correct quantification can only be achieved, however, if the
instrument's calibration table can identify the compounds that are respon-
sible for at least 95 volume percent of the sample.
Last, there is an alternative test method (allowed by EPA prior to September
01, 1998): ASTM standard method D-1319-93, entitled "Standard Test
Method for Hydrocarbon Types in Liquid Petroleum Products by Fluores-
cent Indicator Absorption." This method, which is still used by EPA for
determining olefin content, is considerably less expensive, but less accurate
in identifying aromatic compounds.
8.4.7 Oxygen And Oxygenate Content Analysis
Oxygen and oxygenate content are determined by gas chromatography,
using an oxygenate flame ionization detector (GC-OFID) as set out in U.S.
CFR Title 40, Part 80.46. The equipment needed for performing this
method includes: a gas chromatograph equipped with an oxygenate flame
ionization detector, an autosampler (highly recommended), a non-polar
capillary gas chromatograph column (J&W DB-1 or equivalent), an integra-
tor to process the gas chromatograph signal, and a positive displacement
pipet.
This method is a single-column, direct-injection gas chromatographic
technique for quantifying the oxygenate content of gasoline, where a sample
of gasoline is spiked to introduce an internal standard, mixed, and injected
into a gas chromatograph (GC) equipped with an oxygenate flame ionization
detector (OFID). After chromatographic resolution, the sample components
enter a cracker reactor in which they are stoichiometrically converted to
carbon monoxide (in the case of oxygenates), elemental carbon, and hydro-
gen. The carbon monoxide then enters a methanizer reactor for conversion to
water and methane. Finally, the methane generated is determined by a flame
ionization detector (FID).
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 91
IVIQN1TOR!NG
-------
Because gasoline is
extremely flammable
and its vapors are
harmful if inhaled, it
must be handled
cautiously and only in
areas with adequate
ventilation.
Special care should be taken when collecting and handling gasoline samples.
Samples must be collected and stored in containers which will protect them from
changes in the oxygenated component contents of the gasoline, such as loss of
volatile fractions of the gasoline by evaporation. If samples have been refriger-
ated, they must be brought to room temperature (25° dC) prior to analysis.
Also, gasoline is extremely flammable and should be handled cautiously and with
adequate ventilation. The vapors are harmful if inhaled and prolonged breathing
of vapors should be avoided. Skin contact should be minimized.
8.5 Laboratory Equipment And Costs
Table 21 lists the laboratory equipment most commonly used in lead
sampling and the average prices of the equipment.
Table 21: Prices For Analytical Equipment
Equipment
Lead
Method 1 (manual)
Atomic absorption spectrometer
Method 2 (automatic)
Atomic absorption spectrometer system
Method 3 (can measure sulfur too)
X-ray spectrometer (helium optical path)
Sulfur (can measure lead too)
X-ray spectrometer
Oleflns
Fluorescent indicator adsorption
Reid Vapor Pressure
Grabner
Distillation
Special distillation apparatus (manual)
(automatic)
Benzene and Oxygenates
Gas chromatograpft + OFID
Aromatics
Gas mass spectrometer
Cost ($US)
N/A
$20,000
$110,000 - $200,000
$80,000 • $200,000
$200
$15,000
$12,000
$15,000 - $20,000
$50,000
$80,000
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9. CONDUCTING FOLLOW-UP
EVALUATION AND REPORTING
Followup monitoring and evaluation are needed to ensure that the lead
phaseout program achieves its goals, and to demonstrate to decision makers
and the public that these goals have been achieved.
This chapter reviews the procedures available for measuring lead
concentrations in human blood and ambient air.
The Steps In Fotlow-Up Evaluation And Monitoring
1. Monitor trends in ambient lead and other air pollutants
In addition to monitoring changes in the lead content of gasoline,
implementers should assess the changes in concentrations of lead
and other pollutants in ambient air.
2. Monitor trends in human exposure to lead
Implementers should also assess the changes in the distribution of
blood lead concentrations among the exposed population, particularly
children, that result from the phaseout program.
3. Evaluate the effectiveness of the phaseout program
Implementers should measure the effectiveness of the program in
terms of declines in lead concentrations in both air and human blood.
4. Identify the cause of any problems found
In most cases, the followup evaluation will demonstrate that lead
concentrations in air and human blood have declined significantly.
Should the monitoring show that lead concentrations in either the air or
the exposed population have not declined as expected, it may indicate
that other sources of lead exist and need to be identified.
5. Communicate results to the public, politicians, and legal
authorities
The information on declining levels of lead concentrations in air and
human blood should be communicated to decision makers and the
public in order to maintain their support for the phaseout program.
9.1 Measuring Lead Concentrations In Blood
Measuring blood lead concentrations can help to track the reduction in
average blood lead concentrations due to the phaseout of lead in gasoline. In
addition, these tests can identify individuals — especially children — who are
at risk of health damage due to abnormally high blood lead concentrations.
Such concentrations may result either from excessive exposure to airborne
lead, or exposure to other sources such as lead-based paint, improperly
glazed pottery, or lead water pipes. Once these high-risk individuals are
identified, they or their parents can be counseled to reduce their exposure,
and medical treatment can be initiated if the blood lead concentrations
indicate that treatment is warranted.
Recommendations for blood lead screening have been given by the American
Academy of Pediatrics (1998). The standard procedure for blood lead
measurement requires a blood sample collected by venipuncture. With
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 93
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FOllOW-UP
EVALUATION
'O
Blood lead laboratories
should establish careful
procedures to ensure
that their blood
samples are accurate.
suitable precautions, capillary (fmgerstick) blood samples can also be used, but
these carry a greater risk of contamination by environmental lead that may be
present on the skin (Parsons et al., 1997). The glassware, needles, and chemical
reagents used for collecting and storing blood must be lead-free, and each batch
should preferably be checked for lead contamination before use. Suitable supplies
are available from a number of commercial medical suppliers.
Because of the ubiquity of lead in the environment, the contamination of
blood lead samples is a common problem, and careful quality assurance and
quality control procedures are essential. These should include analyses of
blank samples to identify contamination in the sampling and analysis
process. Blood lead laboratories should establish careful procedures, and
participate in routine proficiency testing to verify the accuracy and precision
of their blood lead measurements. The U.S. Centers for Disease Control
operates a blood lead level laboratory reference system; it provides blood
samples having accurately known lead concentrations to more than 250
laboratories around the world (CDC, 1998). These can be used to verify
calibrations and as reference samples for quality control purposes. A list of
blood lead laboratories certified by the U.S. Occupational Safety and Health
Administration is available on the World-Wide Web at www.osha-slc.gov/OCIS/
toc_bloodlead.html.
The World Health Organization has summarized analytical techniques for
lead in blood (WHO, 1995). Commonly used techniques include atomic
absorption spectrometry, graphite-furnace atomic absorption spectrometry,
anode-stripping voltimetry, and inductively-coupled plasma atomic emission
spectrometry. X-ray fluorescence spectroscopy can also be used. The Na-
tional Institute of Standards and Technology uses isotope-dilution mass
spectrometry to establish accurate target values for its blood lead reference
materials. The U.S. Centers for Disease Control uses a similar method -
inductively coupled plasma isotope-dilution mass spectrometry (U.S. CDC,
1998).
9.2 Measuring Lead In Ambient Air
Lead concentrations in ambient air are measured by collecting total sus-
pended particulate matter on a glass-fiber filter for 24 hours using a high-
volume air sampler, and then analyzing the collected particulate matter for
lead. The analysis of the 24-hour samples may be performed either for
individual samples or composites of the samples collected over a calendar
month or quarter. Lead in the particulate matter is solubilized by extraction
with nitric acid (HNO3), facilitated by heat or by a mixture of HNO} and
hydrochloric acid (HC1) facilitated by ultrasonication. The lead content of
the sample is analyzed by atomic absorption spectrometry. The ultra-
sonication extraction with HNO3/HC1 will extract metals other than lead
from ambient particulate matter. For a complete description of this method,
refer to the United States Code of Federal Regulations Part 50, Appendix G.
The typical range of lead concentrations that can be analyzed using this
method is 0.07 to 7.5 ug Pb/m3, and the typical sensitivity (for a 1 percent
change in absorption) is 0.2 and 0.5 ug Pb/ml for the 217.0 and 283.3
nanometer lines, respectively. A typical lowest detectable level is
0.07 ug Pb/m3.
94 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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10. CONDUCTING PUBLIC
EDUCATION
If a lead phaseout strategy is to be successful, it must gain the public's under-
standing and acceptance. For this reason, implementers commonly include
public education programs as part of their lead phaseout strategies. These
programs consist of efforts to generate public interest in, and understanding of,
a particular message. They can be designed and conducted by the government
alone or in cooperation with non-governmental organizations (NGOs) and/or
the private sector. While they are often developed for a broad audience, they
can also include media communications targeted to a range of differing public
opinions. More specific outreach and training programs can be targeted to
auto mechanics and service station attendants (Lovei, 1998).
This chapter describes how to establish goals and develop
specific strategies for implementing a public education program
for lead phaseout. It also reviews media and other techniques
for public communication.
The Steps In A Public Education Program
1. Define public education goals
An effective public education program will help assure public support for
the lead phaseout policy. The program goals ("the desired results")
should include: 1) increasing awareness and understanding of the health
and developmental problems caused by exposure to lead and 2) chang-
ing public perceptions about the ability of older vehicles to use unleaded
gasoline and the maintenance benefits of reducing or eliminating lead.
2. Develop public education strategy
Once the goals are established, implementers must devise specific
strategies for achieving these goals. Because strategies are likely to differ
for different audiences, it is important to categorize "the public" so that
messages can be tailored to the specific needs and concerns of different
groups (e.g., parents, taxi cab drivers, service station operators).
3. Identify potential communication media
Next, implementers should identify appropriate communication media,
choosing the most effective media for each audience they want to reach.
4. Assign responsibilities for communication and public education
In this step, implementers assign responsibilities for communication and
public education to the appropriate organization. The organization(s) can
include government agencies, NGOs, public relations firms, and others.
5. Follow up to assess the program's effectiveness
During and after the public education process, followup studies should
be conducted. These should assess the effort's effectiveness and
determine whether further public education efforts are required.
6. Begin public education activities
To obtain the best results, implementers should initiate these activities
well in advance of the actual lead phaseout program.
The success of a lead
phaseout strategy
hinges on public
acceptance.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
95
-------
A public education
strategy can both build
public support for
phasing out lead in
gasoline and reduce
opposition to the
phaseout strategy.
Before spending large
sums on a public
outreach effort,
implementers should
evaluate the public's
general awareness
about lead's adverse
health effects and their
concerns and
misperceptions.
10.1 Defining The Goals Of The Public Education
Strategy
The public's understanding of a lead phaseout strategy's policies and programs is
important in building political support for the strategy and educating consumers
to change their fueling and auto maintenance habits. Public education programs
for lead phaseout generally have two important goals:
• Increasing awareness of the health risks associated with using leaded
gasoline and the significant social benefits of policy measures to phase
out lead from gasoline.
• Changing public perceptions that unleaded fuel will adversely affect
vehicle performance and reduce gas mileage.
It is recommended that implementers evaluate the public's general level of
awareness of lead's adverse health effects as well as the level of concern and
misperception about the effects of unleaded fuel before significant resources
are spent on the lead phaseout program itself as well as related public
outreach efforts. Because resources are typically limited for outreach activi-
ties, it is important to understand the audience's level of awareness and
understanding as fully as possible before committing to a specific strategy or
approach. For example, if it is determined that opposition to unleaded fuel is
less than anticipated, then relatively fewer dollars will need to be devoted to
dispelling the myths related to poor performance.
Several tools exist for gauging public awareness and attitudes, including
public opinion surveys and focus groups.
Public opinion surveys. These can be expensive and time consuming, but
offer a systematic way to assess widespread public attitudes as well as to
evaluate the reactions of different segments of the public to proposed policies
or programs. A formal effort involves administering a survey to a sample of
people through a written questionnaire or through in-person or telephone
interviews. The sampling method is carefully chosen to be statistically
representative of the public, and the survey results require statistical analysis.
The results can be used to identify public concerns, gather information on
the likely level of public acceptance of a policy or program, and also to
develop effective messages for public information materials and a media
strategy. When public opinion surveys are repeated over time, they can help
keep the government informed of changes in public knowledge of a policy or
program, as well as any accompanying changes in public preferences.
An informal survey is less expensive and can also be useful in identifying
public attitudes. However, its results may not be statistically valid.
Focus groups (small group discussions with professional facilitators who
gather opinions or perspectives) are an effective way of gathering information
on public opinions and concerns regarding broad policy or program goals
and impacts. They can be especially useful for obtaining more detailed
information when designing a media strategy or strategies for specific groups
(see Section 8.2). Focus groups are not a suitable method for wide public
participation or to disseminate information.
96 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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10.2 Developing A Public Education Strategy
Once implementers articulate the goals and develop a sound understanding
of the public's current level of awareness, they can begin to develop ap-
proaches to increase awareness and understanding.
The audiences. For a strategy to be most effective, it is useful to break up the
general public into different groups or "audiences," defined on the basis of
their specific concerns, driving or vehicle use patterns, and access to informa-
tion. Implementers should also review who is affected by the lead phaseout
strategy indirectly, as well as those social groups or businesses that may be
difficult to reach.
The table below characterizes the types of audiences that should be targeted
in the public education program. Each audience segment has different
concerns or issues, and each plays a different role in the overall success of the
lead phaseout program.
<»**
i
Audience Segment
General Public
Parents
Motorists
Service Station Operators
Fleet Owners and Operators
(e.g., taxi cab drivers,
government agencies)
Specific Concerns or
Issues
Doesn't perceive lead as a
health threat
Concerned about their
childrens' health and welfare
Concerned about keeping
gasoline prices low
Concerned about changes
that would adversely affect
vehicle performance or gas
mileage
Concerned that the need to
supply unleaded gasoline
will disrupt normal opera-
tions and increase costs of
doing business
Particularly concerned about
keeping operating costs low,
vehicle performance, and
access to supplies
Potential Role
Can be a powerful force
lobbying for change
Can be instrumental in
pushing for lead
phaseout
Account for major share
of gasoline consumption
as well as new/used car
purchases, and demand
for vehicles and
maintenance services
Because of role in the
supply chain, can be key
to delivering public
education messages and
to the overall program's
success
Can represent a significant
portion of the driving
public
The message. Public education efforts should inform the general public and
specific audience segments about the serious health risks from human exposure
to lead. Education efforts should also inform the public that leaded gasoline is
the main source of lead in the environment. Information about the neurotoxic
impacts of lead in gasoline, especially its impacts on the IQ development of
children, can be very powerful in influencing public opinion and consumer
behavior. Increased public understanding of the significant social benefits
expected from a phaseout strategy, in terms of greatly reduced health and devel-
opmental problems from exposure to lead, can influence consumer behavior and
also alleviate public concerns.
r** i | r% i
*«,* I s fH* 5
!U€A"
ION
Public education
messages should stress
both the negative
health effects of lead in
gasoline and the
positive benefits
society can realize from
phasing it out. They
should also address
public concerns about
automobile perfor-
mance and the
economic impacts of a
lead phaseout strategy.
'".'PLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
97
-------
Sample Messages On Lead's Health Risks And The Expected
Social Benefits From A Lead Phaseout Strategy
• Lead exposure in children results in neurodevelopmental
damage, resulting in lower intelligence, increased inci-
dence of behavioral problems, increased risk of learning
disabilities, and increased risk of failure in school.
• The damaging effects of lead on the cognitive function of
children begin to occur at very low levels of lead exposure.
• Reducing the adverse health impacts of lead exposure in
children can be expected to result in an increase in
average intelligence and improvements in the learning
performance of future children, thus improving their
lifetime productivity.
• Lead exposure in adults is linked to increased blood
pressure, leading to increases in the incidence of hyper-
tension, cardiovascular illness, stroke, and premature
death.
A public education strategy should also identify and address public concerns
about automobile performance and the economic impacts of a lead phaseout
strategy. Many of the public's concerns may have been exaggerated by vested
interests in continuing the sale of leaded gasoline, or by an initial lack of
practical or scientific information to support the phaseout strategy.
Sample Messages On The Effects Of Unleaded
Gasoline On Vehicle Performance
Unleaded gasoline does not adversely affect an engines
performance, and generally reduces maintenance costs.
Even older engines with soft valve seats are unlikely to suffer
adverse effects unless they are driven continuously at high
speeds for long distances. For the few engines that do suffer
valve seat problems, replacing the cylinder head or valve seats
will correct the problem and keep it from recurring.
Catalytic converters are not necessary for a vehicle to use
unleaded gasoline.
Vehicles using unleaded gasoline require far less frequent
spark plug changes.
Price and supply information can help allay concerns that
unleaded gasoline will be too expensive or unavailable.
Training. Last, targeted training programs for auto mechanics and service station
operators can be an effective way to assist consumers in reducing the sensitivity
of old cars to the use of unleaded gasoline. Such training can facilitate the proper
engine modifications and maintenance of older cars with engines not designed for
unleaded gasoline. Mechanics and service station operators can also help dissemi-
nate information to consumers about proper fueling practices.
98 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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10.3 Media And Other Techniques For Public
Communication
A wide variety of media and other techniques are available to communicate
with the public, as well as specific groups, and deliver public education
strategies. Agencies should develop attractive public information materials
that convey the appropriate messages or information in a fast, concise, and
clear way. The wider availability of desktop publishing and increasingly
accessible communication technologies offer government agencies more
varied ways to capture the publics interest effectively and educate them
about policies and programs.
Some Of The Techniques Available
For Public Education Programs
Newspaper inserts and articles
Public service announcements and media advertising
Brochures, fliers, and fact sheets
Posters and billboards
Information hotlines
Special techniques
Public information materials are often designed to reach a broad public
beyond those who are directly affected. An emphasis on concise, informative,
visual presentations makes it easier to reach people who have only a few
moments to catch the message. Technical information and issues should be
translated into terms that the public can easily understand. In countries
where language may be a political issue, using multilingual materials can
demonstrate that the government is trying to reach out to all social groups.
In other instances, the wide distribution of public information materials is
impractical. The government can make some materials (e.g., summaries of
reports, videos, exhibits) available upon request. Other materials, such as
point-of-sale information for service stations, can be targeted and customized
for distribution to specific groups such as motorists.
Agencies are encouraged to seek professional assistance in crafting effective
messages and completing the design and artwork needed to convey messages
in the most powerful and effective manner.
All outreach materials should provide contact information so that individuals
with additional questions can call for more information or assistance. More
detailed descriptions of the various techniques are provided below.
Newspaper inserts and articles can be extremely effective in reaching the general
public as well as specific groups. They are also an inexpensive way to disseminate
information. By providing factual information in press releases, a government
agency can help reporters assemble articles or news stories that can counteract
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 99
PUBLIC
EDUCATION
Agencies should
develop attractive
public information
materials that convey
the messages quickly,
concisely, and clearly.
Technical information
should be presented in
terms that people can
easily understand.
-------
CONDUCTING
PUBLIC
EDUCATION
Media coverage
creates opportunities
for public education,
but can also be used
by vested interests or
political opposition to
seize on and distort
issues related to a lead
phaseout strategy.
misleading information put forward by special interest groups that may be
opposed to lead phaseout.6 Although government agencies have little control over
news stories before they are published or broadcast, they may be able to avoid
spending valuable resources explaining a message or trying to reshape public
opinion if they hold events targeted at the media or issue press releases with easy-
to-understand information.
Public service announcements. In addition to providing detailed information
that can be used as "news" in articles, government agencies can place ads or
public service announcements in newspapers and other media. Unlike
articles, the ads would provide broad, simple messages on the benefits of lead
phaseout or the specifics of the governments lead phaseout strategy (e.g.,
price information, location of service stations offering unleaded gasoline).
Often, the news media will allow the government to place ads free of charge
or at a discount. More elaborate media advertising schemes can to be expen-
sive and must be used carefully and efficiently. A minimum media strategy
would include a central message via a public service announcement. A more
high-profile media campaign would involve a series of radio and television
ads during prime time. As consensus builds for the lead phaseout strategy,
stakeholders and government agencies can cooperate in a media strategy to
inform and educate the public through features and ads on television and radio,
and in newspapers
Brochures, fliers and fact sheets can be effective education tools and are
usually targeted at a specific group. For example, fact sheets explaining the
adverse effects of lead on the development of children can be prepared and
distributed at schools, health clinics, daycare facilities and other locations
serving the needs of parents and children. Brochures providing detailed
information related to vehicle performance should be targeted at motorists
and are best distributed at gasoline stations or to companies or agencies
operating vehicle fleets.
Posters and billboards are also extremely good mechanisms for spreading the
main themes of the phaseout strategy: positive effects on the neurological
development of children, minimal effects on vehicle performance, etc.
Messages must be presented in a simple, clear, concise form, and their
effectiveness can be greatly enhanced by the use of color and artwork, or
linkages to popular themes or personalities.
Posters can be widely distributed and effectively displayed in service stations,
public buildings, buses and other mass transit, schools, and places of worship.
Information hotlines can be very useful, especially in the early days of the lead
phaseout strategy's implementation. By providing a number motorists can call for
information on everything from sales locations, price differentials, and timing, to
engine performance, government agencies can reduce opposition to the program
caused by uncertainty or lack of knowledge. However, it is extremely important
700
Government agencies should be aware of the opportunities that media coverage creates for public
education, but also of the dangers if vested interests or political opposition seize on and distort issues
related to a lead phaseouc strategy and discredit the program in the eyes of the public. For example, in
some countries, myths about engine damage from the use of unleaded gasoline have been fostered or
promoted in the media by organizations with vested interests in the sale of leaded gasoline.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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for information hotlines to be fully operational during the stated hours of
operation and staffed by competent, knowledgeable individuals.
Special techniques, including hands-on-demonstrations, videos and other
devices, can be effective for workshops and targeted outreach efforts. For
example, workshops or training courses may be the most effective method of
educating service station operators and mechanics on the effects of unleaded
fuel on engine performance. Videos or hands-on demonstrations could
instruct mechanics on how to perform vehicle maintenance to improve engine
performance. Educational videos on the effects of lead on air quality and human
health could be developed for use in schools or with parent groups. These
techniques are generally more expensive, but are likely to be the most effective in
increasing the awareness and building the support of such influential groups as
service station operators and mechanics.
10.4 Assigning Responsibility For Public Education
The agency responsible for implementing lead phaseout should also retain
overall responsibility for the public education program to ensure that the
outreach activities and messages support the technical strategy, both in terms of
the timing of specific messages and activities, and the content of these messages.
However, the responsible agency should seek the assistance of relevant public
affairs agencies, non-governmental organizations, industry associations, and the
communications departments of universities. These groups typically have access
to particular audience segments as well as expertise in managing public education
programs or media campaigns. They can be useful, as well as inexpensive, sources
of assistance to government agencies, which often lack the technical expertise and
resources to carry out elaborate public outreach programs.
The responsible agency should consider setting up a special "public educa-
tion committee" consisting of senior representatives from the various groups
listed above. This committee would oversee the development of the outreach
strategy and manage the activities carried out by individual group members.
10.5 Tracking Progress And Measuring Effectiveness
It is important to evaluate the programs effectiveness so that activities can be
reshaped or revised as necessary over the course of the program.
A number of methods can be used to monitor progress and measure the
programs effectiveness. Certainly, purchases of unleaded gasoline may be a direct
measure of the program's effectiveness. If an outreach program is successful (and
the overall phaseout strategy is logical and effectively addresses key pricing and
supply issues), then purchases of unleaded gasoline should increase over an initial
start-up period, while the total consumption of lead additives should decline.
The government also may want to conduct additional public opinion surveys six
months to one year after the start of the public outreach program to determine
the programs effect on public attitudes and awareness. If an initial survey was
conducted, the agency can use the same survey instrument to evaluate effective-
ness.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 101
CONDUCTING
PUBLIC
EDUCATION
Telephone hotlines can
be very useful in
reducing opposition to
a lead phaseout
program, but they must
be fully operational
during their stated
hours of operation and
staffed by competent,
knowledgeable
individuals.
-------
CONDUCTING
PUBLIC
EDUCATION
Public education efforts
should begin well
before the implemen-
tation of the lead
phaseout program
starts.
10.6 The Timing Of Public Education Activities
It is recommended that agencies begin public education efforts as early as
possible - well before actual implementation of the lead phaseout program,
so that the public is informed in advance of the changes that will take place,
has time to adjust to these changes, and can accept them as improvements
and benefits rather than needless inconveniences or, worse, expensive bur-
dens to be avoided. Even the best phaseout program can be a total failure if
it comes as a surprise to the general public.
Ideally the outreach program should evolve in concert with the development
of the lead phaseout strategy itself so that the public is kept informed of the
strategy's key elements. Over time, the outreach program should incorporate
more and more information on the specifics of the phaseout strategy itself
and the basis for the decisions that are made. Preferably, these decisions will be
based on input from key stakeholders (see Chapter 11), which will reduce public
opposition.
General education effort can start with the use of broad messages conveyed
through public service announcements, posters and billboards that are
widely distributed. These messages should convey the broad themes —
improved childrens' health and welfare; and no adverse effects on vehicle
performance. These broad messages can be supported by more detailed press
articles that provide the rationale for phaseout, the benefits, the timing, and
descriptions of the program (timing, availability, price, etc.).
By the time the phaseout strategy is put in place, the education program
should be focusing on providing information that enhances implementation
(e.g., providing locations where unleaded fuel is being sold, providing price
information) and monitoring effectiveness.
702
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11. INVOLVING KEY STAKEHOLDERS
IN THE DEVELOPMENT OF A
LEAD PHASEOUT STRATEGY
Stakeholder involvement is an essential part of a lead phaseout strategy, and
should be incorporated into the process from the very beginning. Although
stakeholder involvement is closely linked to public education and outreach
(see Chapter 10), it differs in that it seeks to involve key parties in the
decision making process. Public education and outreach, on the other hand,
seek to inform the public and key groups about the need for the program
and how it will work.
Many of the key stakeholder groups are the same as the audiences identified
in the previous chapter and include parties that are most interested in, and
affected by, a lead phaseout program, including government agencies,
gasoline refiners and distributors, service stations owners and operators, and
non-government organizations (NGOs). Gaining the support of these
stakeholders is critical to the successful development and implementation of
a lead phaseout strategy. By consulting these parties and involving them in
the decision-making process, stakeholders will feel that they "own" both the
process and its outcomes, and are less likely to oppose the program once it is
implemented.
This chapter summarizes stakeholder involvement strategies,
which include both stakeholder identification and outreach
components.
The Steps In Stakeholder Consultation And Involvement
1. Identify stakeholders
Here, implementers should identify the program's stakeholders: the indi-
viduals and organizations whose interests will be most affected.
2. Identify strategy for stakeholder involvement
Implementers should next design a process for including the program's
stakeholders in the strategy's development and implementation.
3. Communicate risk assessment and benefit estimates
Education is a key component of stakeholder involvement. Stakeholders
must understand the need for the program, its benefits and its costs.
4. Communicate/consult on alternative phaseout strategies
Ideally, implementers should be willing to consider alternative phaseout
strategies that address stakeholder concerns and constraints.
11.1 Stakeholder Identification
A first step in developing a stakeholder involvement program is to identify
the various stakeholders whose interests will be affected by a lead phaseout
strategy. Often, the key stakeholders are the same organizations or people as
the key audiences identified for a public education strategy (see Chapter 10). The
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE 103
Gaining the concensus
of the stakeholders in a
lead phaseout program
is critical to the
program's success.
-------
INVOLVING
KEY
The key stakeholders
for a lead phaseout
program are often the
same as the audience
for the program's public
education strategy
(Chapter 10).
focus here, however, is engaging key stakeholders in a collaborative decision-
making process. Potential stakeholders include:
• Government agencies and ministries (e.g., energy, environment, health,
industry, transportation, finance, trade).
• Petroleum refiners.
• Automobile manufacturers and importers.
• Gasoline distributors and retailers.
• Fleet owners and operators.
• Non-government organizations.
• Motorists.
Each group is described briefly below.
Government agencies. Typically, many government agencies and ministries —
both at the national and local levels - play a role in the phaseout of leaded
gasoline. These include agencies that set and control tax policies, environ-
mental programs, vehicle registration, vehicle inspection and maintenance
programs, and tariffs and duties on vehicle imports and fuel imports, and
regulate refiners. These agencies need to be involved in the process so that
they understand what implications (if any) a phaseout program will have on
their programs and vested interests.
Petroleum refiners. Oil refiners have a large stake in the decision making
process for a lead phaseout strategy. It is important to involve such powerful
stakeholders in the consensus building process to reduce their opposition to
a lead phaseout strategy. Timing as well as the technical aspects of the
phaseout options considered are significant issues for oil refiners because
converting from leaded to unleaded fuel can have enormous cost implications
for them. Implementers should be sensitive to their issues and be willing to
consider various incentive schemes or schedules to facilitate the conversion
process.
Automobile manufacturers and importers. Auto manufacturers are not likely
to be affected much by lead phaseout per se. However, many countries may
decide to take advantage of the opportunity presented by lead phaseout to
introduce vehicle emission standards that are strict enough to require
catalytic converters. In this case, auto manufacturers will be very much
affected, and it will be critical to obtain the support (or at least the acquies-
cence) of this stakeholder group. Working with automobile manufacturers to
devise a practical schedule for incorporating emissions controls in their automo-
bile designs can promote broad support and reduce the potential for opposition
from certain segments (those less able to quickly add controls or increase imports
of vehicles so equipped). Auto manufacturers can actually support a phaseout
strategy by endorsing the use of unleaded gasoline.
Gasoline distributors and retailers. These groups provide an important link in
the supply chain and their support can greatly enhance the operation of a lead
704 IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
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phasedown program. Retailers also play an important role in the public education
process because of their direct access to motorists, so their issues should be
carefully considered in the development of a strategy. Retail service station
owners and operators should be involved in the consensus building process
because gaining their support for a lead phaseout strategy can assist in securing
support from vehicle owners and operators. Service station attendants or me-
chanics can assist with the public education strategy by disseminating informa-
tion to motorists when they purchase gasoline or auto maintenance services.
Fleet owners and operators, particularly government vehicle fleets, can play a
key role in a lead phaseout program by implementing measures first and
demonstrating their effectiveness.
Non-government organizations (NGOs), such as medical or public health
associations, educational or teachers' associations, or environmental organiza-
tions, can facilitate consensus building. Working with concerned members of
the public, NGOs generally will support the significant social benefits of
policies and programs to phase out lead from gasoline. They can help explain
the health risks associated with using leaded gasoline and build political
support for a lead phaseout strategy.
Motorists are also key stakeholders. They must pay any price differentials or
bear any service inconvenience that result from the strategy. Motorists (or
groups of motorists such as taxi cab drivers) may be represented by an NGO
or association. If so, representatives of these groups should be invited to
participate in the decision making process.
11.2 Stakeholder Involvement Strategies
After stakeholders are identified, implementers should design a process for
disseminating information to them and involving them in the decision
making process for the lead phaseout strategy. The nature and extent of
stakeholder involvement will vary depending on the institutional arrange-
ments and industry practices in each country.
The stakeholder involvement strategy should be closely linked with the
public education strategy (see Chapter 10) to ensure a consistent and
effective message. The inputs stakeholders provide may, in some cases,
identify the need for more public education, but also may identify real
problems that must be addressed in designing a lead phaseout strategy.
Examples of issues where stakeholder involvement may help in building
consensus for a lead phaseout strategy are:
• Identifying the best technical options for phasing out lead in gasoline.
• Evaluating the timing for implementing selected technical options.
• Assessing the economic and behavioral impacts of pricing decisions and
incentive policies.
• Evaluating the "fit" between technical options and policy instruments.
• Identifying monitoring, compliance and enforcement needs.
INVOLVING
KEY
STAKEHOLDERS
The nature and extent
of stakeholder
involvement will vary
depending on the
institutional
arrangements and
industry practices in
each country.
IMPLEMENTER'S GUIDE TO PHASING OUT LEAD IN GASOLINE
105
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INVOLV'NG
Public meetings are
more effective if they
are held early in the
decision making
process.
Good organization and well-planned outreach are necessary for a stakeholder
involvement program because they can help produce inputs that the government
can use in decision making as well as facilitate consensus building. Implementers
should identify specific strategies to gain the participation of stakeholders.
Several methods are available to bring stakeholders together, provide them with
information, and establish effective communications. Selected examples are
summarized in this section.
Advisory groups. An advisory group is a way to bring together a core group of
stakeholders who have a strong interest in a lead phaseout strategy. An
advisory group should be composed of representatives from each of the key
stakeholder groups (each should be given equal status in presenting and
deliberating their ideas), along with representatives from government
agencies. Advisory groups provide a forum for the government to present
proposed policies and programs, and bring stakeholder feedback and ideas
into the process.
Advisory groups usually meet regularly to discuss issues of concern and to
reach agreement on recommendations as input to implementers. Advisory
group meetings can serve to educate stakeholders on technical issues, update
them on progress or new issues identified, and provide an organized way for
the government to learn and understand the positions of different groups.
An advisory group can also assist in outreach efforts to broaden a stakeholder
involvement program.
Public meetings and hearings. Implementers can use these vehicles to present
information to stakeholders and the public, and obtain input from partici-
pants. They can be tailored to specific issues or organized for specific groups
of stakeholders with an interest in a lead phaseout strategy. While public
meetings are useful for exchanging information, public hearings typically are
more formal events held prior to a specific decision point in developing
policies and programs. Public meetings are more effective if they are held
early in the decision making process and if the government makes clear the
link between the meetings' input and decision making. If held too late in the
process and not accompanied by other stakeholder involvement opportuni-
ties, stakeholders and the public may feel that their ideas and concerns will
not be addressed. A media strategy is important for effective public meetings
to attract the widest possible audience. Public education materials (see
Chapter 10) can be distributed at a public meeting.
Workshops. These are designed as special meetings to inform stakeholders
and seek input on a specific policy issue or program. They usually involve a
relatively small group of people, require advance registration or invitation,
and provide an opportunity for people to participate intensively. Typically,
participants work on specific issues or concerns and are usually sent materials
in advance to prepare for the workshop. They can be very useful for educating
groups on technical issues to enhance their ability to make informed decisions.
Input from workshops can be integrated into the larger stakeholder involvement
process.
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The Role Of Public Awareness In Slovakia's Lead Phaseout
Slovakia's successful phaseout of leaded gasoline was due to
the use of an incentive policy, which was later combined
with a rapid phaseout approach to influence consumer
behavior and to smooth the transition. Different programs
were put in place to combine the incentive policy with
regulations to ensure the reduction of lead content in
gasoline, and to support the use and import of cars with
improved pollution characteristics. Slovakia only has one
refinery (Slovnaft), which facilitated the transition from the
production of leaded to unleaded gasoline.
At the beginning of the phaseout program in 1988, Slovnaft
introduced a lubricant additive ANABEX* 99, which helped
ease the transition and achieve lead levels of 0.15 g/1 by 1989
(down from 0.25 g/1). Beginning in 1993, the Slovakian
government enforced and made catalytic converters mandatory
for bodi imported and domestic cars. And beginning in 1995,
only unleaded gasoline was sold at service stations. These
policies were accompanied by registration standards for new and
imported vehicles that included the:
• Capability to use unleaded gasoline without the use of
lubricating additives.
• Presence of a three-way catalytic converter.
• Age of imported vehicles: manufactured in 1985 or later.
These initiatives were supported by strong information
campaigns that informed and influenced consumers' behav-
ior, and involved them in the lead phasedown process. This
rigorous, multi-faceted approach helped to overcome the
problem of old vehicle fleets (most of which were over 15 years
old) and the respective low turnover rates, thus giving the
public an incentive to buy cars with catalytic converters (REC,
1998).
INVOLVING
KEY
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