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( TOWARD A SUSTAINABLE CEMENT INDUSTRY )

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( ENVIRONMENT, HEALTH & SAFETY PERFORMANCE IMPROVEMENT )

. . . . . . . . . . . .

Toward a Sustainable Cement Industry

Substudy 10: Environment, Health &Safety Performance Improvement

December 2002

by

Ian Marlowe and David Mansfield

with contributions from

Neil Hurford, Alistair Bird, and Sue Wood

. . . . . . . . . . . .

An Independent Study Commissioned by:

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World Business Council for Sustainable DevelopmentThis substudy is one of 13 research investigations conducted as part of a larger project entitled,"Toward a Sustainable Cement Industry". The project was commissioned by the World BusinessCouncil for Sustainable Development as one of a series of member-sponsored projects aimed atconverting sustainable development concepts into action. The report represents the independentresearch efforts of AEA Technology to identify critical issues for the cement industry today, and

pathways forward toward a more sustainable future. While there has been considerable interactive

effort and exchange of ideas with many organizations within and outside the cement industryduring this project, the opinions and views expressed here are those of AEA Technology.

AEA Technology plcAEA Technology endeavors to produce work of the highest quality, consistent with our contractcommitments. However, because of the research nature of this work, the recipients of this reportshall undertake the sole responsibility for the consequence of their use or misuse of, or inability touse, any information, data or recommendation contained in this report and understand that AEATechnology makes no warranty or guarantee, express or implied, including without limitationwarranties of fitness for a particular purpose or merchantability, for the contents of this report.

The recommendations and actions toward sustainable development contained herein are based on

the results of research regarding the status and future opportunities for the cement industry as awhole. AEA Technology has consulted with a number of organizations and individuals within thecement industry to enhance the applicability of the results. Nothing in the recommendations ortheir potential supportive actions is intended to promote or lead to reduced competition withinthe industry.

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Foreword

Many companies around the globe are re-examining their business operations andrelationships in a fundamental way. They are exploring the concept ofSustainableDevelopment, seeking to integrate their pursuit of profitable growth with the assurance of

environmental protection and quality of life for present and future generations. Based onthis new perspective, some companies are beginning to make significant changes intheir policies, commitments and business strategies.

The study, of which this substudy is a part, represents an effort by ten major cementcompanies to explore how the cement industry as a whole can evolve over time to bettermeet the need for global sustainable development while enhancing shareholder value.The study findings include a variety of recommendations for the industry and itsstakeholders to improve the sustainability of cement production. Undertaking this type ofopen, self-critical effort carries risks. The participating companies believe that anindependent assessment of the cement industrys current status and future opportunitieswill yield long-term benefits that justify the risks. The intent of the study is to share

information that will help any cement company regardless of its size, location, orcurrent state of progress to work constructively toward a sustainable future. Thepursuit of a more sustainable cement industry requires that a number of technical,managerial, and operational issues be examined in depth. This substudy, one of 13conducted as a part of the project, provides the basis for assessing the current status orperformance and identifies areas for progress toward sustainability on a specific topic.The project report entitled Toward a Sustainable Cement Industrymay be found onthe project website: http://www.wbcsdcement.org/.

Study GroundrulesThis report was developed as part of a study managed by Battelle, and funded primarily by agroup of ten cement companies designated for this collaboration as the Working Group Cement

(WGC). By choice, the study boundaries were limited to activities primarily associated withcement production. Downstream activities, such as cement distribution, concrete production,and concrete products, were addressed only in a limited way. Battelle conducted this study asan independent research effort, drawing upon the knowledge and expertise of a large numberof organizations and individuals both inside and outside the cement industry. The cementindustry provided a large number of case studies to share practical experience. Battelleaccepted the information in these case studies and in public information sources used.

The WGC companies provided supporting information and advice to assure that the reportwould be credible with industry audiences. To assure objectivity, a number of additional stepswere taken to obtain external input and feedback.

A series of six dialogues was held with stakeholder groups around the world.

The World Business Council for Sustainable Development participated in all meetings and

monitored all communications between Battelle and the WGC.An Assurance Group, consisting of distinguished independent experts, reviewed both thequality and objectivity of the study findings.

External experts reviewed advanced drafts of technical substudy reports.

The geographic scope of the study was global, and the future time horizon considered was 20years. Much of the data for this particular substudy was drawn from US and UK sourcesbecause of their ease of access and the relatively long-term collection time frame. Regionaland local implementation of the study recommendations will need to be tailoredto the differing states of socioeconomic and technological development.

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List of Acronyms

B Belgium

BAT Best Available Techniques

BCA British Cement Association

BREF Best Available Techniques Reference Document

CH Switzerland

CIF Cement Industry Federation (Australia)

CKD Cement kiln dust

CSI Cement Sustainability Initiative

D Germany

EBRD European Bank for Reconstruction and Development, London

EIC Environmental Information Centre (India)

EIPPC European Integrated Pollution Prevention and Control Bureau, Seville

EMAS Eco-Management and Audit Scheme

HSE Health and Safety Executive (United Kingdom)

NAEI National Atmospheric Emissions Inventory (United Kingdom)

OSHA Occupational Safety and Health Administration (United States)

PEL Permissible Exposure Limit

RoW Rest of the World

S Sweden

SIC Standard Industrial Classification

TSP Total suspended particulates

UK United Kingdom

US United States

US EPA United States Environmental Protection Agency

USGS United States Geological Survey

VDZ German Cement Association

WGC Working Group Cement (ten core cement company sponsors)

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Glossary

By-Product Secondary product of an industrial process.

Cement A powdery product made from limestone and small amounts of other raw materials,heated to form clinker, which is then ground to a powder with small amounts of

gypsum and other additives.

Clinker A hard substance produced in cement kilns which is ground with gypsum and otheradditives to make cement.

Concrete A building material made from a mixture of sand and rocks bound together withcement.

Dioxins Informal term for the family of polychlorinated dibenzo dioxins and relatedpolychlorinated dibenzo furans.

Gypsum A naturally occurring mineral, hydrated calcium sulfate.

Limestone A naturally occurring rock, primarily composed of calcium carbonate, often containingtrace amounts of other minerals.

NOx Oxides of nitrogen: the sum of nitric oxide (NO) plus nitrogen dioxide (NO2).Although other oxides of nitrogen occur, such as nitrous oxide (N2O), they arenormally excluded from the definition of NOx.

PAHs Polyaromatic hydrocarbons.

PCBs Polychlorinated biphenyls.

SOx Oxides of sulfur: the sum of sulfur dioxide (SO2) and sulfur trioxide (SO3). Theformer substance predominates, and emissions of SOx are often reported as SO2equivalent.

Note that throughout this report, the unit t signifies metric tonnes; 1 tonne = 1000 kilograms.

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Executive Summary

This report assesses the past and current environment, health and safety performance of

the cement industry, and identifies key actions that will help drive the cement industry tocontribute to a more sustainable society.

Cement production is a key supplier to the concrete industry. The most importantenvironment, health and safety performance issues facing the cement industry are:

Greenhouse gas emissions (dealt with in other reports in this study); Atmospheric releases, primarily of NOx, SO2 and particulates; Stakeholder concerns over the potential for dioxin releases, particularly the perceived

association with use of alternative fuels;

Health and safety performance, in particular associated with accidents and workerexposure to dusts.

Recommendations to improve health and safety performance are:

1. In the short term, engagement of operators in industry safety initiatives andforums in order to share knowledge and good practices so that these become theindustry norm. The Cement Health & Safety Taskforce should be encouraged todevelop and publish information on key hazards and their control and safeworking practices.

2. Publish safety data using common metrics to encourage comparison and

benchmarking among companies.3. In the medium to long term, the industry should encourage the wider use of risk

assessment in plant design, plant modification and for key operational activities.

To improve environmental performance the key steps are:

4. Improve emission measurement and estimation by the development of industrywide protocols for NOX, SO2, particulates and dioxins.

5. An open approach to public reporting of performance by the industry as a wholeand by companies.

6. Adopt best practice in emission control measures and promulgate their use in all

countries of operation. Best practice can be broadly defined as a technique ormethodology that, through experience and research in an industrial sector, has

proven to reliably lead to a desired result.

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Table of Contents

1. Introduction 12. Overview of Health, Safety and Environmental Challenges 2

2.1 Health and Safety 2

2.2 Environment 23. Health and Safety Performance 6

3.1 Introduction 63.2 How the Cement Industry Compares 63.3 Key Risks and Control Measures 103.4 Improving Performance 143.5 Current Cement Industry Initiatives 153.6 Focus for the Future 163.7 Summary 17

4. Environmental Performance 194.1 Air Emissions 19

4.1.1 Oxides of Nitrogen (NOx) 20

4.1.2 Oxides of Sulfur (SOx) 224.1.3 Dust/Particulates 244.1.4 Oxides of Carbon: CO and CO2 294.1.5 Volatile Organic Compounds (VOCs) 294.1.6 Acid Gases 304.1.7 Metals 304.1.8 Organic Micropollutants 31

4.2 Alternative Fuels 354.3 Local Nuisance 38

4.3.1 Noise 384.3.2 Visual Impact 384.3.3 Dust/Haze 394.3.4 Odor 39

4.4 Monitoring, Managing and Reporting Releases 404.4.1 Monitoring 404.4.2 Environmental Management 404.4.3 Sectoral Guidelines 41

4.5 Summary 42Appendices 43

Appendix A: Further Reading 43Appendix B: References 43

List of Tables

Table 2-1. Key environmental aspects of cement production 4Table 3-1. Comparison of incidence rates 7Table 3-2. UK Fatal injury rate comparison for industries with the highest rates 8Table 3-3. UK Non-fatal major injury rate comparison for industries with the

highest rates9

Table 3-4. Breakdown of accident events by type 10Table 4-1. Major constituents of cement kiln exhaust gas 19Table 4-2. Emission ranges from European cement kilns 19Table 4-3. Emission Limit Values for particulate releases in different regions of the

world

28

Table 4-4. Dioxin emission estimates for Australian sources 33

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Table 4-5. The types of by-product most frequently used in Europe 35Table 4-6. International emissions data for cement production emissions of

dioxins36

Table 4-7. Emissions of micropollutants and VOCs from UK cement kilns in 2000,normalized to CO2 emissions

37

Table 4-8. World Bank guidelines on noise levels for cement plants 38

List of Figures

Figure 2-1. Global cement production in the year 2001 5Figure 3-1. Accident statistics for the workforce employed at the VDZ member

works in the years 1969 and 1998-200014

Figure 4-1. Trends in emissions of NOx 21Figure 4-2. Relative contributions of the cement, iron & steel and refineries sectors

to total UK NOx emissions in the years 1970 and 2000.21

Figure 4-3. Trends in emissions of SO2 23Figure 4-4. SO2 emissions from cement production as a proportion of total SO2

emissions23

Figure 4-5. Trends in emissions of PM10 27Figure 4-6. Relative contributions of the cement, iron & steel, refineries and

quarrying sectors to total UK PM10 emissions in the years 1970 and2000.

27

Figure 4-7. The composition of metals released from cement production in the UKin 2000 and the total emissions of heavy metals from cementproduction since 1970

30

Figure 4-8. Dioxin emission factors for cement production from national dioxininventories

32

Figure 4-9. Emissions of dioxins in the UK 34Figure 4-10. Cement kiln co-incineration market share in hazardous wasteincineration in France

36

Figure 4-11. Cumulative registrations to the EMAS scheme by cementmanufacturers in the European Union and Norway

40

List of Boxes

Box 3-1. Contractor passport systems 11Box 4-1. General primary measures for the manufacturing of cement 20

Box 4-2. Dust and particulates some definitions 26Box 4-3. Measurement and monitoring priorities for cement plants 41Box 4-4. Sectoral reporting guidelines for cement production 42

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1. Introduction

This substudy is one of 13 research investigations conducted as part of a larger projectentitled Toward a Sustainable Cement Industry. The project was commissioned fromBattelle Memorial Institute by the World Business Council for Sustainable Development

as one of a series of member-sponsored projects aimed at converting sustainabledevelopment concepts into action. This report contains data and information collected byAEA Technology and draws on earlier unpublished work by TNO1 andPricewaterhouseCoopers completed for Battelle.

The report aims to assess the environment, health and safety performance of the cementindustry. More specifically, the report aims to provide answers to the followingquestions:

What are the key health, safety and environmental aspects of cement production?

How does the performance of the cement industry compare with other sectors? How has performance changed historically, and what does a sustainable cementindustry look like?

What are the priorities for action?

The report is structured in 4 chapters. Following this introduction:

Chapter 2 overviews the challenges facing the cement industryChapter 3 considers the health and safety performance of the sectorChapter 4 looks in detail at the environmental performance.

1 A Dutch consultancy company.

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2. Overview of health, safety and environmentalchallenges

2.1 HEALTH AND SAFETY

The cement industry provides direct employment for an estimated 850,000 workersworldwide (ERM, 2002).

The cement manufacturing industry is labor intensive and uses large scale and potentiallyhazardous manufacturing processes. The industry experiences accident rates that are highcompared with some other manufacturing industries.

There are a number of hazards inherent to the cement production process. Someexamples for health are:

exposure to dust and high temperatures;

contact with allergic substances; and

noise exposure.

And some examples for safety:

falling / impact with objects;

hot surface burns; and

transportation.

These mainly impact on those working within the industry, although health hazards canalso impact on local communities.

For quarrying operations there are also hazards associated with blasting and rockhandling. Workers are also at risk from hazards common to many industrial workingenvironments: general slips, trips and falls, machinery hazards and electrical hazards.

2.2 ENVIRONMENT

Concrete is second only to water as the most consumed substance on earth, with nearlythree tonnes of the material used annually for each person on the planet.

Cement is the critical ingredient in concrete, locking together the sand and gravelconstituents in an inert matrix; it is the glue which holds together much of modernsocietys infrastructure.

To produce a tonne of cement2 uses approximately 1.5 tonnes of raw materials, 0.3tonnes of air and 6 gigajoules of fuel3; and releases 0.94 tonnes of carbon dioxide(Battelle, 2002a). The raw materials are primarily limestone together with clay, gypsum

2

Approximate material and energy flows in Ordinary Portland Cement production (dry process averageU.S. figures blended cements differ greatly)3 Includes energy to acquire and transport fuel

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and other materials which may include blast furnace slag and fly ash according to thedesired properties of the finished product.

Cement plants are often situated close to quarrying operations (the source of the rawmaterials) and to transportation outlets. Because of its weight, cement supply via land

transportation is expensive and generally limited to an area within 300 km of any oneplant site. Bulk export plants are normally situated on sea coasts or major inlandwaterways.

The main environmental issues associated with cement production are emissions to airand energy use. Waste water discharge is usually limited to surface run off and coolingwater only and causes no substantial contribution to water pollution (EIPPC, 2001).Quarrying activities associated with the cement industry impact land use and biodiversity.Land and landscape management issues are dealt with in the Substudy 11 Report(Battelle, 2002b).

The energy consumed by the cement industry is estimated at about 2% of the globalprimary energy consumption; 5% of global man-made carbon dioxide emissions originatefrom cement production (Hendriks et al., 1998). Carbon dioxide and other greenhousegas releases and related issues are dealt with extensively in the Substudy 8 ReportClimateChange (Battelle, 2002c) and are not discussed further in this report.

The Substudy 8 Report ClimateChange (Battelle, 2002c) notes the use of alternative rawmaterials such as fly ash, dust and gypsum from power generation as a cost effective wayto reduce carbon dioxide emissions. The availability of fly ash from coal-fired power

production is estimated to grow until 2020.

The fuels used for cement manufacture have traditionally been fossil fuels (principallycoal and heavy fuel oils). Using waste from other industries as fuel (for example wastesolvents, end of life tires or waste plastics) is a huge opportunity to reduce environmentalimpacts across a whole range of industries as well as from cement production. Wastescan be turned into valuable product; fossil fuel consumption can be reduced; and theenvironmental impacts of fossil fuel extraction, and raw material quarrying and miningoperations can be reduced. Western Europe currently uses the greatest percentage of non-traditional fuels i.e. fuels other than coal, oil, gas and heavy fuel oil, in their process at42%, compared to China that currently uses almost exclusively fossil fuels (Battelle,2002c).

Introducing alternative fuels into cement production also presents new challenges to thecement industry by potentially changing the nature of environmental releases. Releasesare highlighted in Table 2-1; a point to note is the possibility of dioxin formation wherechlorine-containing by-products are introduced into the cement kiln. Ever since theSeveso incident4 dioxins have gained an especially emotive reputation amongst thegeneral population and consequently the use of by-products in cement production hasattracted considerable attention from many groups. The situation may not be aided by thefact that although data on releases to the environment from the cement industry are

4 In 1976 a chemical plant at Seveso (Italy) manufacturing pesticides and herbicides released a vapor cloudcontaining tetrachlorodibenzoparadioxin from a reactor used for the production of trichlorophenol.

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widely available in the form of national inventories, it is not always organized in auniform manner at the individual plant performance level.

At a local level the environmental impacts of cement production relate to nuisanceissues mainly through emissions of dust, noise and/or vibration as well as visual impact

which, though not focused upon in this report, may be compounded by local quarryingoperations and traffic movements associated with transport of raw materials, fuel and

product.

Table 2-1. Key environmental aspects of cement

production

Air Emissions NOx, SOx, dust/particulates

Use of waste asfuel

Stakeholder concerns over releases ofdioxins, other chlorinated hydrocarbons

and heavy metals

Local nuisance Noise/vibration, dust, visual impact

Greenhousegases

CO2 (dealt with under Substudy 8 ClimateChange Battelle, 2002c)

Land use andbiodiversity

Primarily associated with quarryingactivities (dealt with under Substudy 11

Management of Land Use, Landscape andBiodiversity Battelle, 2002b)

In 2001 global cement production was approximately 1.65 billion tonnes (USGS, 2002 -estimate); as Figure 2-1 below shows, two thirds of global production was located in thetop 10 producing countries. China alone produced approximately one third of the globaltotal. Trends, challenges, and opportunities in Chinas cement industry are the subject ofa separate report (Battelle, 2002d). Though not explored within this report, the resourcedepletion associated with the extraction of raw materials this production demands may bean issue for the sustainable management of the industry it should be stressed that this

point only applies on a local basis, where limestone and other raw materials and/orenergy are in short supply.

Two basic variations for cement production are used around the world: a wet process anda dry process, distinguished by the amount of water present in feedstreams to the cementkiln. The dry process offers higher energy efficiency, and has replaced much, but not all,of the wet process plants. There are also two common kiln designs in use today: avertical shaft kiln, and a horizontal rotary kiln. The rotary kiln generally has highercapacity and better process and environmental controls. It is widely used. Vertical shaftkilns have largely disappeared from western countries, but still dominate the Chinesecement production. Present-day modern cement plants produce upwards of 2-4 milliontonnes annually. In contrast, China has only ten plants producing more than one milliontonnes annually, and the majority have capacities below 275,000 tonnes per year (as of

1995).

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5

0

100

200

300

400

500

600

700

China India USA Japan Korea,

Republic

of

Brazil Germany Italy Turkey Russia RoW

Milliontonnes

Figure 2-1. Global cement production in the year 2001 (USGS, 2002)

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3. Health and Safety Performance

3.1 INTRODUCTION

The cement production process can be divided into the two aspects of manufacturingprocesses and quarrying activities. As outlined in Section 2.1, the two aspects havedifferent profiles with respect to the health and safety performance of the cementindustry.

3.2 HOW THE CEMENT INDUSTRY COMPARES

The cement manufacturing industry is labor intensive. This, combined with the largescale and potentially hazardous nature of the manufacturing process, means that the

industry experiences accident rates that are high compared with many othermanufacturing industries.

This is illustrated in Table 3-1, which contains a comparison of incidence rates in theUSA in 1999. It is also evident from the table that it is possible to operate high hazardactivities more safely as is shown, for example, in the data for the chemical and oil andgas industries (note however that the data presented show only the incidence rate, not theseverity, of lost time incidents).

In the chemical industry for example, local companies and business units are centrallyrewarded for performing with zero accidents per million working hours. The better unitscould achieve accident rates of 0.5 or 1% (0.5 to 1 accidents per 100 employees per year)or less, performance that is currently only within reach for the front runners in the cementindustry (TNO and PricewaterhouseCoopers, 2002).

The lost workday case rate of 2.86 per 100 workers for hydraulic cement manufacturemay also be compared with the current average annual injury rate for the UKmanufacturing industry (includes major and 3 day lost time incidents). In 2000 this was1.2 per 100 employees for manufacturing and 0.7 per 100 employees averaged across allUK industry sectors (HSE, 2001).

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Table 3-1. Comparison of incidence rates5

Industry (SIC Code, US) Incidence

rate

Lost Workday

Cases(a)

Cement Hydraulic (324) 69 2.86Metal Mining (10) 58 2.70Concrete, gypsum and plaster products (227) 35 1.64Rubber & Miscellaneous Plastic Products(30)

30 5.19

Paper & Allied Products (26) 26 2.19General Building Contracts (15) 21 3.49Lumber & Wood Products (24) 19 2.48Coal Mining (12) 12 0.73Textile Mill Products (22) 7 1.49Chemical & Allied Products (28) 5 0.87Oil & Gas Extraction (13) 3 0.43(a)

annual cases per 100 workersLost Workday Case: A case that involves days away from work and/or days ofrestricted work activity

Incidence Rate: 200,000 times the number of injuries and/or illnesses or lostworkdays divided by the total hours worked by all employees during the calendaryear; (for an incidence calculator and comparison per SIC see:http://www.libertymutual.com/business/safety/risktool.html )

Similar comparisons can be drawn from the latest UK statistics (HSE, 2001), see Table 3-2 and Table 3-3.

These comparisons show that there is room for significant improvement in the cementmanufacturing industrys safety record. The fact that other industries viewed as highrisk, such as chemical manufacturing, perform better is a reflection of the level ofawareness and attention to health and safety in those industries. This shows how focusingthe attitudes and behaviors of workforce and management can bring about significanthealth and safety improvements. For example BOC Group (a speciality chemicalsmanufacturer) has instigated a five-year strategy to halve the Groups accident rate. Themain items underpinning the strategy are implementing, communicating, measuring andreporting best practice as well as training, competence and behavioral management

systems. Further information is provided on the BOC Group web site athttp://www.boc.com/socialResp/sub4.cfm?subcat_id=79&cat_id=94&sindex=1 .

5 Taken from unpublished research data collected by TNO

7
http://www.libertymutual.com/business/safety/risktool.htmlhttp://www.boc.com/socialResp/sub4.cfm?subcat_id=79&cat_id=94&sindex=1http://www.boc.com/socialResp/sub4.cfm?subcat_id=79&cat_id=94&sindex=1http://www.libertymutual.com/business/safety/risktool.html

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Table 3-2. UK Fatal Injury Rate Comparison for Industries with the Highest

Rates

Industry Sector

SIC92 UKIndustryClassification

Fatal Rate per100,000 Workers

Quarrying of stone, ore and clay 13-14 10.4Agriculture, hunting, forestry and fishing 01, 02, 05 9Extraction of coal, oil and gas 10-12 8.9Construction 45 4.8Manufacturing of basic metals andfabricated metal products 27/28 3.4Manufacturing of wood and wood products 20 3.2Manufacturing of other non-metallic mineral

products (includes cement) 26 2.7

Manufacturing not elsewhere classified 36/37 2.3Transport, storage and communication (a) 60-64 2.0Electricity, gas and water supply 40/41 1.6Manufacturing of rubber and plastic

products 25 1.6Total -All Industries (b) 0.9(a) Injuries arising from shore-based services only. Excludes incidents reported undermerchant shipping legislation.(b) Numbers and percentages do not sum to the total.

It is also interesting to note the relatively high accident rates associated with quarrying.Quarrying is a major activity associated with cement manufacture. If the cement industryas a whole is to improve, considerable effort is needed to tackle safety in its quarryoperations as well as in cement production plants. The different hazards and types ofactivities in quarrying as compared to cement production may mean that differentmanagement system priorities and approaches may be needed to improve safety andhealth performance in these two areas.

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Table 3-3. UK Non-Fatal Major Injury Rate Comparison for Industries with the

Highest Rates

Industry Sector

SIC92 UKIndustryClassification

Injury Rate per100,000 Workers

Quarrying of stone, ore and clay 13-14 449.7Manufacturing of wood and wood products 20 420.5Extraction of coal, oil and gas 10-12 392.6Construction 45 392.1Manufacturing of food products; beveragesand tobacco 15-16 306.9Manufacturing of other non-metallic mineral

products (a) 26 302.8Manufacturing of basic metals and

fabricated metal products 27/28 297.7Manufacturing of rubber and plasticproducts 25 274.4Transport, storage and communication (b) 60-64 258.9Agriculture, hunting, forestry and fishing 01,02, 05 01, 02, 05 212.2Total -All Industries (c) 112.8(a) Includes cement manufacture and other industries.(b) Injuries arising from shore-based services only. Excludes incidents reported undermerchant shipping legislation.

(c) Numbers and percentages do not sum to the total.

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3.3 KEY RISKS AND CONTROL MEASURES

Further analysis of the accident statistics reveals where the main risks arise. An analysisof recent accidents by a UK company (Table 3-4 is taken from an internal analysis of datafrom a UK cement manufacturing company) indicates the types of events that present

most risk. A recent review of worldwide fatal accident statistics by the Cement SafetyTaskforce identified vehicle impacts, falls from heights / falling objects, and contractorsworking on unfamiliar plant or unfamiliar with safe working practices as key issues.

Table 3-4. Breakdown of Accident Events by Type

Activity %

Manual handling 22Slips, trips and falls 17Falls from height 17Strike against fixed object 11

Struck by vehicle 6Other 27

Modern plant design, operational procedures and practices, mean that the risks fromroutine operations can be well controlled. Most handling operations are automated toavoid the need for manual intervention and for contact between workers and processmaterials. The worker groups most at risk are those involved in plant cleaning andmaintenance. Here the risk of contact with machinery, hazardous and hot substances ishigher.

Plant cleaning and maintenance activities frequently involve working at height or inawkward locations (for example confined spaces) presenting access and egressdifficulties and the handling of unusual or unfamiliar equipment, tools or situations. Thisis reflected in the percentage of incidents associated with manual handling and falls fromheight. Contractors are frequently used for cleaning and maintenance activities, especiallyduring major planned plant shutdowns, where additional workforce is required to meettight schedules. As a result, contractors can be exposed to some of the higher riskactivities, leading to a higher rate of accidents if the contractors are not fully trained andfamiliar with the plant and its hazards. Contractor safety awareness is improved throughinduction training addressing the specific hazards and control measures related to cementmanufacturing facilities. Schemes such as the contractor passport system (see Box 3-1)

can help ensure contractors remain up to date with safety awareness, standards and goodpractices.

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Box 3-1: Contractor Passport Systems

Contractor safety passport systems are widely used for both offshore and onshore operationsin the oil and gas industry worldwide. They provide a simple and practical means to ensurethat all contractors working on a companys site are competent, suitably briefed and trained inthe sites safety systems and minimum safety requirements. Safety passport systems vary informat and scope, but typically include the following:

Each contractor is issued with a signed and dated passport on satisfactorycompletion of the site safety induction training program and any competence orspecialist training checks

The passport typically has a limited validity both in terms of the type of work thecontractor can undertake (e.g. hot work) and the time the passport is valid for.

The passport system requires that refresher training at specified intervals is needed tokeep the passport valid Passport schemes may include different passports and requirements for workers and

supervisors The passport provides a simple means for both the contractor and the company

personnel to check if that person is trained and suitable to undertake a given task, andwhen retraining is required. If the passport is not valid, the contractor cannot do thework. This provides an incentive for contractors to ensure they have the right trainingand accreditation, and to keep their passport up-to-date

Safety passport training elements could includeo Introduction to Health and Safety Law

o Work Permitso Safe Working Practiceso Electrical Lock-out Procedureso Safe Access and Egresso Accident and First Aid Procedureso Hot works (welding and cutting) Procedureso Fire Precautions and Procedureso Hazardous substances handling and risks and Personnel Protective Equipmento Manual Handlingo Working with Cranes and Heavy Equipmento Excavationso Tool Box Talkso Risk Assessment

In some cases a number of companies operating similar facilities have got togetherand developed a common contractor safety passport system. This avoids the need forunnecessary and repetitive training were the contractor to need a different passportfor every site.

Slips, Trips and FallsSlips, trips and falls are another common cause of accidents in the industry. These can

arise from the uneven surfaces in the quarries and roads and from lapses in goodhousekeeping within the manufacturing plants.

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VehiclesCommon hazards associated with the heavy plant (e.g. dumper trucks, front loadingshovels, fork lift trucks) used in quarrying and bulk material transport include vehicleimpact and twisted ankles during embarking and disembarking. Vehicle impact has the

potential for particularly high severity incidents, both in quarries and on themanufacturing sites. When reporting and analyzing incidents, it is helpful to distinguish

between production, quarrying and general off-site transport activities. Incidents can bereduced by improved driver training, increasing awareness of the people workingalongside these vehicles, and by using dedicated routes and crossings to help keepvehicles and pedestrians apart. Modern vehicles also offer improved visibility, helpingfurther reduce the risks as the older equipment is replaced.

Working at HeightControls relating to working at height or in confined areas (e.g. Permit-to-work, task riskassessment) are effective in reducing accidents by raising awareness of the hazards and

ensuring the correct work methods are followed and that the proper precautions are taken.Mandatory use of safety equipment to properly tie off workers, posting permits, andregular inspections of the job site are commonly employed techniques.

BurnsIncidents and accidents resulting in burns arise from contact with hot clinker or cement

powder. Hazards are particularly associated with hot cement kiln dust (CKD), and duston preheater systems. Chemical (alkali) burns may also result from contact with CKD. Astudy in the cement industry in Egypt over the period 1991-1995 showed that 155 burnsaccidents occurred in a population of 3200 workers (El-Megeed et al., 1999). The totalnumber of working days lost was 4776 with a mean of 31 days per case. This studyemphasizes the need to ensure effective controls are put in place.

DustCement production carries with it an inherent capacity to produce high levels of dust,which without effective controls can lead to respiratory disease. Hospitalization andmorbidity due to cement dust is not higher than in comparable industries (TNO andPricewaterhouseCoopers, 2002).

A study in 1998 in the US reported that dust levels ranging from 26-114 mg/m havebeen recorded in quarries and cement works. This is an order of magnitude higher than

the U.S. Federal respirable dust standard exposure limit of 2.0 mg/m

3

for an 8-hourworking shift. In an individual case at a sieving operation, 384 mg/m was reported.

In cement factories using the wet process the upper short time values are occasionally 15-20 mg/m (Prodan & Bachofen, 1998). When the dust contains silica components (nottypical in most cement plants), regulations are stricter due to the known carcinogenic

properties of (crystalline) silica. In the USA a study showed that in the industries ofcement, concrete, gypsum and plaster products, 17.9% of the 252 samples exceed thePEL (Permissible Exposure Limit) of silica. Data for this group of industries suggestcaution on the subject of dust, especially dust containing (crystalline) silica.

In recent years, considerable attention has been directed at eliminating and controllingsources of dust, including extract systems and filters, and maintenance programs aimed at

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eliminating leak sources. As a result dust exposure during normal operations has beengreatly reduced see for example Figure 4-5 below which shows how releases of

particulates to the atmosphere have been reduced. More reliable equipment, improvedaccessibility, improved personal protective equipment and the use of vacuum systems for

plant cleaning have also reduced exposure to the more vulnerable maintenance and

cleaning worker groups.

Noise and VibrationThe main sources of noise are the milling plants used to grind the cement product.

Noise deflectors and improved sound insulation are now being used to reduce noiselevels: again it is the maintenance and cleaning personnel who are most at risk. Improvednoise personal protective equipment is also helping reduce the effects of exposure.

Whole body vibration is another issue that is creeping up the safety agenda. Workersdriving older heavy mobile equipment can be exposed to vibration, but the risks are smallcompared to that in other industries such as mining or construction, where vibrating

equipment (jack-hammers for example) are commonplace. Modern mobile equipmentcombine lower inherent vibration with damped seating and insulated cabins, reducing thehazard to insignificant levels.

Exposure to Hazardous SubstancesMany substances in industry are considered to be allergy-inducing. In the cementindustry, chromate components are raising concern because of their toxicity and knowncarcinogenic effect when the cement is used wet in downstream construction activities.When the chromate concentration of the product warrants it, ensuring that the chromiumVI component is chemically reduced and kept in the chromium III state is suggested as agood measure, as are improved awareness and safer handling campaigns aimed at users inthe construction industry. A minimum level of product stewardship is necessary toeducate users about proper handling precautions and necessary protective equipment.

Crystalline silica exposure is another well recognized issue, presenting an inhalation riskof silicosis. Silica can be present in some of the raw materials used in the cementmanufacturing process. The risks can be managed effectively by a combination of rawmaterial sampling and analysis to identify silica containing materials combined with airmonitoring and the use of suitable personal protective equipment where appropriate.Silica is more of a problem in the construction industry, where crystalline silicacontaining materials are handled routinely, with dust generating activities such as

grinding and cutting being commonplace.

Thallium is a highly toxic substance, which can be present in pyrite or iron oxide. Bothmaterials are used as a source of an iron additive. If thallium were identified in thesematerials, the cement plant would be advised to change its source of pyrite or iron oxide.Otherwise thallium might become a problem. This can be a particular problem wherecement kiln dust (CKD) is recycled, because of the potential to build up levels of thalliumin the recycle stream.

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3.4 IMPROVING PERFORMANCE

Many cement manufacturers are actively improving their health and safety performance,to come into line with other manufacturing sectors. There has been some success so far.Figure 3-1 shows accident data for the VDZ (German cement association) member

works. The recent data show a marked improvement over 1969 but a tendency to flattenout between 1988 and 2000 - suggesting that a different approach or new initiative isrequired to achieve further improvements.

B. Accident rate (accidents

per 1 million hours worked)

0

20

40

60

1969 1998 1999 2000

C. "100-men-rate" (accidents

per 100 employees)

0

5

10

1969 1998 1999 2000

E. Calender days lost per

accident

0

10

20

30

40

1969 1998 1999 2000

D. Working days lost per

employee

0

1

2

3

1969 1998 1999 2000

A. Cement production in

millions of tons

010

203040

1969 1998 1999 2000

Figures A to E show that althoughcement production has remained steadysince 1969, there has been a generalimprovement in accident statistics. Theonly area where there has not been animprovement is in the calendar days lost

per accident (Figure E), suggesting thatalthough the number of accidents isdecreasing, the lost work days perincident has increased.

Figure 3-1. Accident statistics for the workforce employed at the VDZ member

works in the years 1969 and 1998-2000 (VDZ, undated)

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Health and safety performance depends on a combination of:

engineered safeguards, largely those built in to the plant design, management systemsand arrangements such as procedures, and

the safety culture which is characterized by the levels of safety awareness and safe

behaviors and attitudes amongst the workforce.

Improvements can be made making changes in any of these areas. However, for manyexisting plants, the opportunity to improve the engineered safeguards is limited. The mainopportunities for improvement lie in the management systems and culture. For example:the Lonza Group (USA) incidents and near misses are recorded in the system. The recordcontains a description of the incident, the date the event is recorded, and the date(including time of day) the event took place. The type of incident is categorized from oneof eleven (11) possible types ranging from "process event" to "task observation" to"injury/illness". The name of the employee or contractor involved in the incident is alsorecorded. An Occupational Safety and Health Administration (OSHA) category is alsoselected from a drop-down list as well as the part of the body affected if it is an"injury/illness" incident.

3.5 CURRENT CEMENT INDUSTRY INITIATIVES

By bringing together ten of the worlds largest cement producers, the CementSustainability Initiative (CSI) under the World Business Council for SustainableDevelopment has begun to address a number of the health and safety issues noted above.In addition, several of the national cement associations (CIF Australia, BCA United

Kingdom) have begun taking a more active role in promoting workplace safety.

In general safety initiatives will aim to:

improve the effectiveness of the safety management system, and/or raise the level of health and safety awareness amongst staff and contractors, improve compliance with the management system

Effective target setting combined with incident monitoring is a commonly usedmechanism to focus management and workforce attention on safety improvements. As anexample, CEMEX in 1997 declared a target for their safety performance of 1% (1

accident per 100 employees per200,000 working hours). Over the period 1997-2000 theyreported a 63% decrease in cement plant accidents from 4.4% to 1.6%. This covers 40cement plants located in 10 countries. During 2000 operations in Costa Rica and Egyptwere brought up to CEMEX's standards and respectively decreased their accident rates by50% and 61%, in the latter half of the year compared with the first half. Of the 40cement plants, 4 facilities operated with zero accidents (Spain's Lloseta and Tenerife

plants, Colombia's Santa Rosa plant, and Venezuela's Guyana plant), while 12 otherachieved an accident rate of less than 1%.

Ciments Calcia, part of the Italcementi Group, has achieved a more than 50% decrease infrequency rate from 29.8 to 13.7 per million working hours over a period of 12 years

(1987 - 1999). For the last 6 years the figures are stable and no further improvement hasbeen achieved. The company has now formulated a safety program with an objective of a

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frequency rate below 10 for 2001. Ciments Calcia regards unsafe acts as the main causeof injuries. The company considers management responsible for the improvement of theworking conditions to avoid unsafe acts and conditions and responsible for thedevelopment of safety awareness of the employees.

3.6 FOCUS FOR THE FUTURE

The health and safety performance of the cement industry as a whole is lagging behindthat of other, more proactive, sectors of manufacturing industry. Within the sector, thereis a wide range of performances. The better companies have demonstrated that it is

possible to achieve accident rates similar to the average for the manufacturing industry.However even the best have room for further improvement. There is a particular need forthe industry to encourage and help those companies and plants that are significantlyunder-achieving to raise their safety standards to ensure a sustainable industry that meetssocial and employment expectations.

In the short term, the best ways to improve performance is to share knowledge and goodpractices so these can become the industry norm. The industry should find ways toengage operators from around the world in industry safety initiatives and forums such asthe CSI. The Health and Safety Taskforce should be encouraged to develop and publishinformation on key hazards and their control and safe working practices. Lack ofconsistent safety data and a common measurement framework have been a barrier tomonitoring and comparing safety performance between facilities and companies.

Specific priorities should include:

Contractor selection, training and control

Vehicle hazards and driver training

Maintenance and cleaning operations which involve possible contact with hazards

Working at height

Harmful contacts e.g. heat, hazardous substances

In the medium to long term, the industry should encourage the wider use of riskassessment in plant design, plant modification and for key operational activities. Thisleads both to better planning and improved awareness of hazards. Inherently saferapproaches to hazard management should be encouraged, with a hierarchy of safeguards

being adopted:

Inherent safety hazard avoidance, elimination, substitution or reduction at source

Preventative measures means to prevent hazards arising

Control measures means to control hazards before any harm can result

Mitigation measures means to control or limit the scale of accidents

Incident response arrangements intervention to limit the consequences of accidentsand deal with any harm arising

It is important that the industry continues and expands on its work to harmonize incident

reporting requirements so that data can be collected and analyzed to identify theunderlying causes of accidents and ill health. This will provide a better basis for industry

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benchmarking and enable health and safety improvements to be targeted where they willbe most effective. It will be useful to distinguish between quarry activities and cementproduction activities when reporting and analyzing accident statistics, since these havevery different risk profiles and safety issues. Health surveillance programs should also beencouraged as a means to monitor health effects and target improvements.

There is also an opportunity for the industry to work together to develop industry specificguidelines on heath, safety and environmental management systems. This should notnecessarily be taken as a means to harmonize systems, but as a mechanism to ensureeveryone is addressing the relevant aspects and to disseminate good practice.

Experience within the cement industry and with other industries suggests that the riskmanagement and management systems approach to safety can only go so far inimproving performance. Changing the culture, not just the organizational systems is avital part of moving toward a goal of zero accidents.

If, in the longer term, the industry as whole is to achieve health and safety performance inline with the best in manufacturing industry, it will need to address the safety culture as awhole and at all organizational levels. As a starting point, companies should consider theuse of safety culture climate surveys. These can identify and monitor:

attitudes and perceptions; good practices and barriers to good performance; and progress of initiatives to improve safety and safety culture.

At the working level, behavioral programs should also be considered to help develop and

implement safe behaviors during operation and maintenance. These programs need to beintroduced and implemented with the active participation of the workers themselves ifthey are to be effective. Some of the best cement manufacturing companies are alreadyactive in these areas, and reducing their accident rates to low levels (< 1 reportableaccident per 100 employees per year). An example of an industry-wide, integrated andcommitted initiative is the STEP initiative in the UK Offshore Oil and Gas Industry. TheDupont STOP program serves as an example of a company behavioral based safety

program (http://stop.dupont.com/).

3.7 SUMMARY

The most urgent priority is to gather good, consistent performance data from acrossthe sector. This is a precursor to effective targeting of initiatives to apply some of theexisting best practices to the worst performing areas of the sector.

This action will lead to a clearer understanding of safety incident causes, so thatcorrective action can be tailored to primary causes.

The cement manufacturing sector currently lags other, similar risk sectors in safetyperformance; some of the leading performers within the sector are demonstrating thatperformance in line with other sectors can be achieved.

Improvements can and will be made over time as a greater proportion of productioncomes from modern equipment with improved controls.

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Worker groups most at risk are those involved in non-routine operations such asmaintenance (and in some plant cleaning). Often this work is carried out bycontractors.

It is important that initiatives to improve health and safety management systems andto safety awareness and culture include non-routine activities and contractor

management issues.

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4. Environmental performance

4.1 AIR EMISSIONS

The main constituents of exhaust gases from a cement kiln are nitrogen, carbon dioxide,water, and oxygen. The exhaust gases also contain small quantities of dust, chlorides,fluorides, sulfur dioxide, NOx, carbon monoxide, and still smaller quantities of organiccompounds and heavy metals as shown in Table 4-1.

Table 4-1. Major constituents of

cement kiln exhaust gas (Cembureau,

1997).

Constituent %

Nitrogen 45-66CO2 11-29Water 10-39O2 3-10Remainder < 1

Table 4-2 reproduces emission ranges from European cement kilns published by EIPPC(2001).

Table 4-2. Measured emission ranges from European cement kilns (EIPPC,

2001).mg/Nm

3kg/tonne clinker tonnes/year

NOx (as NO2)

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EIPPC (2001) lists a number of general primary measures to minimize environmentalimpact, these are shown in Box 4-1.

Box 4-1

General primary measures for the manufacturing of cement

Management of the kiln process to achieve stable operating conditions, which maybe achieved by applying:- process control optimization, including computer-based automatic control

systems;- the use of modern, gravimetric solid fuel feed systems.

Minimizing fuel energy use by means of:- preheating and precalcination as far as possible, considering the existing kiln

system configuration;

- the use of modern clinker coolers enabling maximum heat recovery;- heat recovery from waste gas.

Minimizing electrical energy use by means of:- power management systems;- grinding equipment and other electricity based equipment with high energy

efficiency.

Careful selection and control of substances entering the kiln, to minimizeintroduction of sulfur, nitrogen, chlorine, metals and volatile organic compounds.

Each of the main groups of air pollutant are discussed in turn below. Where data are

available, long term trends (up to 30 years) are illustrated from the national inventory ofthe United Kingdom which may be taken as typical at least of western Europe and islikely to reflect the trends in other more developed countries. Trends and informationfrom the US, China and Australia are also presented.

Comparisons are drawn with two other energy-intensive industry sectors namely oilrefineries and the iron and steel sector. The main emphasis is placed on the key aspects

NOx, SOx and dust/particulates; and on dioxins which are a key stakeholder concern.

4.1.1 Oxides of Nitrogen (NOx)

NOx forms by the reaction of nitrogen with oxygen at the high temperatures generatedduring combustion of fuel.

Emissions of NOx are of concern as they can detrimentally affect air quality and humanhealth, an example of which is its role in the production of ground-level ozone, which canaggravate respiratory systems.

Trends in emissions for the UK and the US are shown in Figure 4-1. Features of the datato note are:

in developed countries, cement kilns are responsible for only a very small fraction ofthe total releases of NOx;

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21

the cement sector has made substantial improvements in emissions over the last 30years with the introduction of emission abatement techniques, though this may have

been countered by increased production in the US;

other sectors have also improved performance, as a result the relative contribution ofthe UK cement industry is much the same today as it was in 1970.

The latter finding is further illustrated by the pie charts in Figure 4-2.

0

50

100

150

200

250

1970 1975 1980 1985 1990 1995 2000

Emissionskt/yr

Cement (UK)

Iron & Steel (UK)

Refineries (UK)

Cement (US)

Figure 4-1. Trends in emissions of NOx (source: UK National Atmospheric

Emissions Inventory (NAEI, 2002) and the US National Emission Inventory (US

EPA, 2002).

1970

3%

Cement

Iron & Steel

Refineries

Other

2000

2%

Figure 4-2. Relative contributions of the cement, iron & steel and refineries sectorsto total UK NOx emissions in the years 1970 and 2000.

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According to EIPPC (2001), the best available techniques6 for reducing NOx emissionsare a combination of the general primary measures referred to earlier together with:

Primary measures to control NOx emissions:

- flame cooling;- low-NOx burner.

Staged combustion.

Selective non-catalytic reduction.

Achievable emission levels are in the range of 200-500 mg/m3 (but individual kilns mayhave less scope to achieve these levels) according to EIPPC (2001); or 600 mg/m3 (0.5 kg

per tonne of clinker) according to the World Bank Group (1998). Recent German cementindustry data show average emissions of approximately 400-800 mg/m3 (VDZ, 2002).

Conclusions regarding NOx:

The cement industry is a significant but not major source of atmospheric releases ofoxides of nitrogen or NOx.

The performance of the cement industry has improved over the last 30 years. A benchmark emission is in the region of 500-600 mg/m3 (0.5 kg per tonne of

clinker).

4.1.2 Oxides of Sulfur (SOx)

Emissions of oxides of sulfur are predominantly (99%) in the form of sulfur dioxide(SO2).

SO2 emissions arise from oxidation of volatile sulfur present in raw materials such asorganic sulfur, or inorganic sulfides. Some may also arise from sulfur in the fuels. If thevolatile sulfur content of the fuel and raw materials is low, SO2 emission can be very low.Much of the SO2 produced can potentially be captured within the process due to stronglyalkaline conditions.

Emissions of SOx are of concern as they can detrimentally affect air quality and humanhealth, some examples of which are the production of acid rain, reduced atmospheric

visibility (smog) and aggravation of respiratory systems.

Figure 4-3 shows the trend in UK and US emissions since 1970.

6 Note that best available technique has special meaning within European Union law, and in principlethat meaning is used by EIPPC (2001).

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0

100

200

300

400

500

600

700

1970 1975 1980 1985 1990 1995 2000

Emissionskt/yr

Cement (UK)

Iron & Steel (UK)

Refineries (UK)

Cement (US)

Figure 4-3. Trends in emissions of SO2 Source: UK National Atmospheric

Emissions Inventory (NAEI, 2002) and the US National Emission Inventory (US

EPA, 2002).

The cement industry is a minor source of SO2 emissions. Over the last few decades theindustry has seen some improvements in performance, shown in Figure 4-3 to be the case

for both the UK and the US. Other sources of emission, notably power stations, haveimproved substantially, consequently the cement industry has increased in relativeimportance as a source of SO2 see Figure 4-4.

0

10

20

30

40

50

60

1970 1975 1980 1985 1990 1995 2000

Emissions,

kt/

yr

0

0.5

1

1.5

2

2.5

Percent

Cement %

Cement kt/yr

Figure 4-4. SO2 emissions from cement production as a proportion of total SO2emissions Source: UK National Atmospheric Emissions Inventory (NAEI, 2002).

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A primary measure to avoid SO2 emissions is to minimize the volatile sulfur content ofthe raw materials. Concentrations of SO2 in the kiln exhaust gases may be reduced byenhancing capture within the process itself. The captured sulfur is thus incorporated intothe final cement product. Capture may be enhanced by:

improving the sulfur/alkali ratio by decreasing the sulfur feed or increasing the alkalifeed to the process;

increasing oxygen concentration in key zones of the process;

increasing the fineness of raw materials and solid fuels;

avoiding reducing conditions (lack of oxygen) at the kiln wall.

Scrubbers may be used to remove SO2 from exhaust gases.

According to EIPPC (2001), emission levels of 200-400 mg/m3 are achievable using bestavailable technologies. The World Bank Group (1998) recommends a maximumemission level of 400 mg/m3. German industry data for 2001 fall well within this range(VDZ, 2002).

Conclusions regarding SO2:

The cement industry is a significant but not major source of SO2 emissions. Despite improving performance over the last 30 years, the cement industry now

contributes a greater proportion of total emissions due to substantial gains in othersectors.

A key control measure is to minimize the volatile sulfur content in the kiln.

Mitigation techniques can achieve emission concentrations of 400 mg/m3

or less.

4.1.3 Dust/particulates

The principal sources of dust emissions are kilns, raw mills, clinker coolers and cementmills (EIPPC, 2001). Dust emissions also arise as a result of transport of raw materials tothe site, from stockpiles of raw materials, from hoppers and raw material transfer, and

pipework (EBRD, undated). Quarrying operations are also an important source of dust.

Cembureau (1997) indicates that dust emissions from European cement kilns in the year

1950 represented as much as 3.5% of the production but this had been reduced to afraction of a percent by 1970 and further reduced by 90% over the last 20 years.Emission levels below 10 mg/m3 are now achieved in some installations (EIPPC, 2001),although 50 mg/m3 is more typical for the majority of modern facilities. German industrydata show an average emissions level in 2001 for 55 kilns below 20 mg/m3 (VDZ, 2002).

Similar dramatic improvements have been seen in eastern Europe. For example inHungary it is estimated that the emission of solids amounted to 6-8% of the productionvolume until a modernization program commenced in 1963; the corresponding figure in1997 was 0.019% (Hungarian Cement Association, undated).

In contrast, ambient air levels of total suspended particulates (TSP) and sulfur dioxide(SO2) in Chinese cities are among the highest in the world. Particulate emissions remain

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as high as 2% of production and in 1998, cement plants were responsible for over 40 %of total industrial particulate emissions - data presented by Battelle, 2002d indicates that

particulate emissions in 1998 were 11 million tonnes; USGS, 2000 gives production inthe same year of 513.5 million tonnes. The figure of 40% is part of an upward trend from22% in 1991 (Battelle, 2002d). Of these emissions, medium and small plants are

responsible for the vast majority due to their obsolete equipment and production methods.The projected modernization programs described by Battelle (2002d) will reduce theseemissions substantially.

As an imperfect generalization, near-ground fugitive releases of dust impact primarily onthe local environment, whereas releases from high stacks may have an impact on airquality over a much larger area. Larger diameter grains or dust may give rise to localnuisance. However it is the finer sized particulates which give the greatest cause forconcern mainly because of impacts on human health (see section 3 and Box 4-2).

The production of cement kiln dust (CKD) and its disposal may have an impact on the

environment and human health. In 1995, 3.3 million metric tons of CKD was disposed ofby the US cement industry (US EPA, 1999a). When waste derived fuels comprise a partof the fuel source CKD may contain 200-2000 ppm lead and traces of other heavy metals(Ash Grove, 2000) and possibly dibenzodioxins and dibenzofurans. The issue is dealtwith by the implementation of management standards in the US (US EPA, 1999a).Management standards outline appropriate techniques to control releases to groundwaterfrom landfills through leaching, and the control of fugitive dust emissions in handling,storage and disposal areas from wind dispersal. Standards also cover the concentration ofvarious pollutants, including chlorinated dibenzodioxins and dibenzofurans in CKD usedfor agricultural purposes.

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Box 4-2

Dust and particulates some definitions

Total SuspendedParticulate (TSP)

The mass of particles collected on a filter.

Condensable Some material that is in the vapor phase at stack temperature(and which would therefore pass through a filter) maycondense to form particles as the plume disperses in theatmosphere and cools to ambient temperatures these are thecondensable particulates, in contrast to the filterable

particulates.

Inhalable or

Inspirable

When people breathe particle-laden air, particles with a

diameter greater than 10 micrometers (ten millionths of ameter) are usually stopped by the nose. Smaller particles canenter the respiratory system and are often called inhalable orinspirable.

Respirable Particles smaller than 10 micrometers but larger than 2.5micrometers can generally get as far as the larynx. Smaller

particles can penetrate into the lungs and are often calledrespirable.

PM10 Particulate matter with a diameter of less than or equal to 10

micrometers.

PM2.5 Particulate matter with a diameter of less than or equal to 2.5micrometers.

Figure 4-5 shows the 30-year trend in emissions of inhalable (PM10) emissions in the UKsince 1970. The equivalent figure for total particulates is similar.

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0

5

10

15

20

25

30

35

1970 1975 1980 1985 1990 1995 2000

Emissionskt/yr

Cement

Iron & Steel

Quarrying (All)

Refineries

Figure 4-5. Trends in emissions of PM10 Source: UK National AtmosphericEmissions Inventory (NAEI, 2002).

Points to note include:

Cement production is a small contributor to total particulate emissions. This is

typical of a developed country where there are other major sources of particulates,notably from powered transport. In China however, cement production is a majorcontributor to national emissions (Battelle, 2002d).

Quarrying operations are an important source, far larger than cement production.Note however that these UK data do not identify quarrying operations associatedsolely with providing raw materials for cement production.

The relative importance of quarrying activities as a contribution to total emissions hasgrown considerably, though still remains at just 12% of the total see also Figure 4-6.

19701% Cement

Iron & Steel

Refineries

Quarrying (All)

Other

20001%

Figure 4-6. Relative contributions of the cement, iron & steel, refineries andquarrying sectors to total UK PM10 emissions in the years 1970 and 2000.

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EIPPC (2001) describes a number of measures for reducing dust/particulate releases. Forexhaust stacks the two primary technologies are electrostatic precipitators and fabricfilters; both systems can achieve stack concentrations of 5 to 50 mg/m3 or specificreleases of 0.01 to 0.1 kg per tonne of clinker when installed as new technology. Forfugitive emissions the following techniques are indicated:

simple and linear site layout;

proper and complete maintenance of the installation;

use of automatic devices and control systems;

open pile wind protection;

water spray and chemical dust suppressors;

paving areas used by lorries, and wetting roads;

vacuum cleaning during maintenance operations or to handle spillages;

enclosure of all systems under negative pressure, with dedusting of air by fabric filter;

closed storage with automatic handling systems.

Many cement plants, including US plants, still employ older technology. The bestavailable technology in these cases is indicated by emission limit values as indicated inTable 4-3. Here as with new technology proper maintenance such as the emptying of bagfilters as part of a good management system is important in maintaining standards.

Table 4-3 Emission Limit Values for Particulate Releases in Different Regions of

the World.

Region Pollutant

Description

Emission Limit Value

European Union1 (forwaste burning cementkilns)

PM5 (totaldust)

30 mg/Nm3 10 vol% O2 dry

United States ofAmerica2 (for waste

burning cement kilns)

PM (general) 0.15 kg/Mg dry feed

India3 SuspendedParticulate

Material

50 mg/Nm3 (new plant)Existing plant:

150 mg/Nm3

(> 200 tpd6

, protected area)250 mg/Nm3 (< 200 tpd, protected area)250 mg/Nm3 (> 200 tpd, other areas)400 mg/Nm3 (< 200 tpd, other areas)

China4 PM Currently 150 mg/m3 exhaust gas, movingtoward 100 mg/m3

1 Taken from the Waste Incineration Directive 2000/76/EC (EU, 2000).2 Maximum Achievable Control Technology; US EPA, 1999b.3 EIC, undated.4 Battelle, 2002d.

5 PM = particulate matter.6 tpd = tons per day capacity

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Conclusions regarding dust/particulates:

Cement production is a significant but generally not major source of dust andparticulates, though in some countries it may be of national significance.

Quarrying is a significant and major source in developed countries.

Mitigation measures are available for dealing with stack emissions and fugitivereleases.

4.1.4 Oxides of carbon: CO and CO2

Cement production is a major source of emissions of the greenhouse gas carbon dioxide(CO2). As much as 5% of global carbon dioxide emissions originates from cement

production (Hendriks et al., 1998). This aspect is dealt with by the report on Substudy 8(Battelle, 2002c) and is not discussed further here.

The largest portion of greenhouse gas emissions from production of cement worldwide(about 50%) originates from the process reaction that converts limestone (CaCO3) tocalcium oxide (CaO), the primary precursor to cement. About 40% of the industrysemissions come from fossil fuel combustion at cement manufacturing operations withremaining emissions coming from transport of raw materials (about 5%) and combustionof fossil fuel required to produce the electricity consumed by cement manufacturingoperations (about 5%), (Batelle, 2002a).

Combustion conditions in cement kilns are managed so as to achieve optimum fueleconomy and maximum conversion of carbon to carbon dioxide. Only a small proportion

is converted to volatile organic compounds (see below) and a variable proportion tocarbon monoxide (CO). Carbon monoxide production may be of concern as it candetrimentally affect air quality and human health.

According to EIPPC (2001), good control of fuel feed rate is essential to maintainoptimal combustion conditions in the kiln.

4.1.5 Volatile Organic Compounds (VOCs)

VOCs are an ill-defined group of substances which are principally of concern in the

environment because of their role (together with oxides of nitrogen), under certainatmospheric conditions, in the formation of ground-level ozone and other photochemicaloxidants.

Emissions of VOCs arise from cement kilns as products of incomplete combustion.Under normal circumstances the VOC content of the exhaust gas is low, typically

between 10 and 100 mg/Nm3 (EIPPC, 2001). In developed countries cement productionis not a significant source of VOCs whose emissions are dominated by powered transport,together with organic solvent use, oil and chemical industry processes, and industrial anddomestic combustion.

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4.1.6 Acid gases

Cement production is a minor source of hydrogen chloride (HCl) and hydrogen fluoride(HF) arising from trace amounts of chlorine and fluorine present in feed materials.

4.1.7 Metals

Metals are present in raw materials and fuels, at widely variable concentrations. Thebehavior of the metals in a cement kiln depends on their volatility. Non-volatile metalsand metal compounds remain within the process and leave the kiln as part of the clinker.Semi-volatile metals are partly taken into the gas phase at sintering temperatures andcondense on the raw material in cooler parts of the kiln system. Volatile metals canexhibit similar behavior but may also be emitted with flue gas (EIPPC, 2001).

Dusts from cement production contain small amounts of a wide range of metals. Figure

4-7 illustrates the estimated composition of atmospheric releases of metals from cementproduction in the UK over the last 30 years.

As outlined in the earlier section on dust and particulates, when waste derived fuelscomprise a part of the fuel source the cement kiln dust (CKD) produced may contain 200-2000 ppm lead and traces of other heavy metals (Ash Grove, 2000), requiring propermanagement of this by-product, such as the lining of landfills to prevent leachatesreaching groundwater (US EPA, 1999a).

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

1970 1975 1980 1985 1990 1995 2000

Emissions,

kt/yr

2000As

Cu

Hg

Ni

SeV

CdCr

Mn

Pb

Zn

Figure 4-7. The composition of metals released from cement production in the UK

in 2000 (pie chart) and the total emissions of heavy metals from UK cement

production since 1970.Source: National Atmospheric Emissions Inventory (NAEI, 2002).

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In the UK vanadium is thought to have dominated the metal releases from cementproduction. This vanadium has mainly originated from fuel oil used as fuel in UKcement kilns.

4.1.8 Organic micropollutants

Cement kilns, in common with other combustion processes, are potential sources ofemissions of a number of semivolatile organic substances which are of concern becauseof their highly toxic properties:

polychlorinated dibenzodioxins and polychlorinated dibenzofurans collectivelyknown as dioxins;

polychlorinated biphenyls usually known as PCBs;

polyaromatic hydrocarbons known as PAHs.

These substances are sometimes collectively referred to as micropollutants as theabsolute mass of their releases from a given process is normally orders of magnitudelower than releases of VOCs or other air pollutants.

Dioxins and PCBs may be formed within the kiln if chlorine is introduced into the kiln asa constituent of the raw materials or fuels. Formation of dioxins occurs at relatively lowtemperatures most typically in exhaust gases from combustion processes as the gasescool through a temperature window of 450oC to 200oC. To minimize the possibility ofdioxin formation it is important that the kiln gases are cooled through the window of450oC to 200oC as quickly as possible (EIPPC, 2001).

The European Dioxin Inventory report (European Commission, 1997) has compiled theemission factors used for dioxin emissions from cement production in several nationalinventories of the EU; these are illustrated in Figure 4-8. With the exception of theBelgian emission factors, the values used are based on measurements.

Excluding the Belgian values which were based on literature estimates, the emissionfactors reported as typical (shown here as blue spots) span an order of magnitude from

0.015 g I-TEQ per tonne of production used in Germany, to 0.17 g I-TEQ per tonne ofproduction (average of Swiss range of 0.16 to 0.17 g I-TEQ/t). Similar levels ofuncertainty are to be found in data from other regions of the world. For example the

Australian Emissions Inventory (Environment Australia, 2002) notes a dioxin emissionfactor for Australia with a range spanning orders of magnitude from 0.0043 to 0.28 g I-TEQ/tonne clinker produced.

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0

0.2

0.4

0.6

0.8

1

1.2

B CH D S UK US Australia

Country

microgramI

-TEQ/tonne

28 g I-TEQ/t(see also Table 4.7)

20 g I-TEQ/t

Range of dataBest estimate

Figure 4-8. Dioxin emission factors for cement production from national dioxin

inventories. Source: European Dioxin Inventory (European Commission, 1997).

This illustrates the uncertainties in inventory data for dioxin releases from the cementindustry. The uncertainties arise from several factors, including variabilities in specificemissions from plant to plant according to the technology employed, the type andcomposition of fuel burnt, the sampling point, and the composition of raw materials. Theuncertainties in the emission factors also arise from uncertainties in dioxin measurements.In the EU, a measurement standard (EN 1948) has been established which is based onmanual extractive sampling of dioxins over 6-8 hour sampling periods. This gives asnap-shot view of the emissions. For example under Directive 2000/76/EC, cement kilnsco-incinerating waste should demonstrate compliance with a dioxin emission limit value

of 0.1 ng I-TEQ/m

3

at least twice per year using a measurement method compliant withthe EN 1948 standard. In Belgium (Flanders) in 1997 continuous dioxin samplers (whichcollect an integrated sample over a period of up to 6 weeks) were compared with EN1948 measurements on the main exhaust stacks of a number of municipal solid wasteincinerators. It was found that in this case the averaged dioxin stack concentrationsreported from the continuous samplers were higher than those found using the EN 1948method by a factor of 30 to 50 and were exceeding the Flemish emission limit valueallowed for such plants; as a result 5 of the plants were closed though 3 subsequentlyallowed to start up again (De Fr & Wevers, 1998). Despite the significantly differentresults obtained from the two techniques, no definitive answer is available as to whichmethod is the most likely to be correct.

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It is evident therefore that dioxin emission estimation is an evolving science, and theexact contribution of cement production or indeed any other industrial source may not yet

be fully understood. Nevertheless the broad picture which emerges from the EuropeanDioxin Inventory is that the major industrial emission sources in Europe (accounting forabout 62% of total dioxin air emissions) are probably:

incinerators for municipal waste;

iron ore sinter plants;

incinerators for clinical waste;

facilities of the non-ferrous metal industry.

The remaining 38% are partly due to other industrial sources but mainly come from non-industrial sources such as:

domestic heating facilities (particularly wood combustion);

accidental fires, e.g. forest and brush fires;traffic (mainly where petrol is used).

Cement manufacturing is identified as a dioxin emission source in studies performed inthe US, the UK and the Netherlands (Environment Australia, 2002). The overallmessage, however, is that although the cement industry is an emitter to air of dioxins andfurans, in the majority of cases it is not considered to be a significant source. The USdata do rank cement manufacture as third among significant sources, but here aselsewhere it is regarded as less significant than municipal and medical waste incineration(Table 4-4).

Australian data also support the European studies - see Table 4-5.

Table 4-5. Dioxin emission estimates for

Australian sources (Environment Australia, 2002)

Source Emission (g/year)

Fires prescribed burning 65-1300

Bushfires 7-400

Cement and Lime Production 0.31-0.60

Total 150-2100

Specifically for the cement sector, the European Dioxin Inventory concludes as follows:

In many cases cement production is of minor relevance for the totalemission of PCDD/F [dioxins as defined above] in Europe.

Nevertheless, from the data reported in the surveyed document follows

that there is still substantial uncertainty concerning dioxin emissions

Measurements may be recommended at some plants incinerating waste, inparticular hazardous waste with chlorinated compounds. In most other

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cases measurements at cement producing plants do not appear to be

necessary.

Figure 4-9 shows the trends in dioxin emissions in the UK. Unlike for other airpollutants, data are only available for the last 10 years.

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

Emission,g/yr

Cement

Iron & Steel

Refineries

0

10

20

30

40

50

60

70

80

90

Figure 4-9. Emissions of dioxins in the UK. Source National Atmospheric

Emissions Inventory (NAEI, 2002).

In Europe, cement kilns can mostly comply with an emission concentration of 0.1 ng I-TEQ/Nm3 (EIPPC, 2001), which is the limit value in the European legislation for wasteincineration (Parliament and Council Directive 2000/76/EC) and hazardous wasteincineration (Council Directive 94/67/EC).

Understanding of PCB and PAH formation mechanisms and emission characteristics isless well advanced than for dioxins, and there has not been international agreement on ameasurement standard for stack emissions of PCBs and PAHs. Initial information on theformation of PCBs indicates that the mechanisms are analogous to those for dioxins thisimplies that control techniques developed for dioxins, with suitable optimization, are

likely to reduce levels of PCB also (EIPPC, 2001).

PAHs are a product of incomplete combustion. As such they occur naturally in theenvironment as a result of forest fires. Important man-made combustion sources include:

transport (tailpipe emissions); power generation; industrial heaters and boilers; domestic combustion.

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Conclusions regarding organic micropollutants:

There are considerable uncertainties regarding emissions and emission factors fordioxins, and little data available for PCBs and PAHs. A number of emissionmeasurements have been made, although the measurement process is complex and

expensive. Kilns using chlorinated raw materials or chlorinated fuels need to take particular care

to satisfy their local communities that any releases of micropollutants are withinregulatory limits.

Burning by-products and alternative fuels is dealt with in the following section.

4.2 ALTERNATIVE FUELS

Because of the high combustion temperatures employed in cement production, cementkilns are capable of burning waste materials effectively, achieving almost completedestruction of organic wastes. As well as the organic component, inorganic constituentsof a wide variety of waste types are suitable for incorporation into the cement product.Consequently cement production is emerging as an effective way to recover and find anadditional worth for a wide range of industrial waste materials that might otherwisecreate problems if disposed of to landfill.

The types of waste most frequently used as fuels in Europe are listed in Table 4-6 (takenfrom EIPPC, 2001 source Cembureau). A similar mix of fuels is evident in theinventories of the United States and Australia (Environment Australia, 2002).

Table 4-6. The types of by-product most frequently used in Europe

Used tires Waste oils Sewage sludgeRubber Waste woods PlasticsPaper waste Paper sludg

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