Coal Classification Industry approach to hazard classification under the revised MARPOL Convention and the IMSBC Code

Transcription

1 Coal Classification Industry approach to hazard classification under the revised MARPOL Convention and the IMSBC Code REPORT 2. ANALYSIS OF COAL COMPOSITION, ECOTOXICITY AND HUMAN HEALTH HAZARDS

2 World Coal Association The World Coal Association (WCA) is a global industry association formed of major international coal producers and stakeholders. The WCA works to demonstrate and gain acceptance for the fundamental role coal plays in achieving a sustainable and lower carbon energy future. Membership is open to companies and not-for-profit organisations with a stake in the future of coal from anywhere in the world, with member companies represented at Chief Executive level. The publication Coal Classification - Industry approach to hazard classification under the revised MARPOL Convention and the IMSBC Code was written by ARCHE, a Belgium-based consultancy specialising in environmental toxicology, under the oversight of the WCA Technical Working Group on Coal Classification and chaired by Dr. Sue Hubbard, Principal Adviser, HSEC Product Regulation & Information Support at Rio Tinto. ARCHE ARCHE is a Belgium-based consultancy founded in 2009 by experts with more than 15 years of experience in the field of environmental toxicology, exposure modelling and the preparation of risk assessment dossiers. The company is also recognised as a spin-off of Ghent University. The experts working at ARCHE have built up indepth knowledge on the preparation of Chemical Safety Assessments in the framework of the REACH regulation and chemical risk assessments under the predecessor of the REACH regulations (EU regulation 67/1488 on new and existing substances). One of the key areas of expertise is the preparation of risk assessments for inorganic substances such as metals, alloys, slags etc. ARCHE experts have been involved in the preparation of many guidance documents on these topics - for example Metal Risk Assessment Guidance (MERAG) and a widely used tool for metals classification - MECLAS. The scientific services of ARCHE have also been frequently consulted in the framework of the risk assessment of flame retardants and other organic chemicals. Any queries related to the publications which are part of this package should be addressed to the WCA Team at classification@worldcoal.org World Coal Association 5th Floor, Heddon House Regent Street London W1B 4JD, UK +44 (0) info@worldcoal.org ARCHE Stapelplein 70 box Gent, Belgium info@arche-consulting.be Published by the World Coal Association, London, UK Copyright World Coal Association All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, without the prior written permission of the copyright holder.

3 Coal Classification Industry Approach to Hazard Classification under the Revised MARPOL Convention and the IMSBC Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards BACKGROUND This report forms part of a package of reports - Coal Classification - Industry approach to hazard classification under the revised MARPOL Convention and the IMSBC Code. The aim of this publication is to help coal producers comply with the new coal classification requirements introduced by the International Maritime Organisation (IMO) under the International Convention for the Prevention of Pollution from Ships (MARPOL) and the International Maritime Solid Bulk Cargoes Code (IMSBC). The other two reports appearing in this series are: Report 1. New Compliance Requirements of the MARPOL Convention and the IMSBC Code Report 3: Coal Classification Guidance The reports were written by ARCHE, a specialist environmental toxicology consultancy, under the oversight of the World Coal Association Technical Working Group on Coal Classification, chaired by Dr. Sue Hubbard, Principal Adviser, HSEC Product Regulation & Information Support at Rio Tinto. This publication is available free of charge for all WCA Members. Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 1

4 TABLE OF CONTENTS 1. CHEMICAL COMPOSITION OF DIFFERENT TYPES OF COAL Coal general information Inorganic trace elements Mode of occurrence of trace elements Concentrations of trace elements in coal data in the public domain Concentration of trace elements in coal company-specific data Polycyclic aromatic hydrocarbons in coal Environmental hazard assessment of coal Hazard assessment of trace elements in coal Environmental hazard assessment of PAHs in coal Data provided by WCA members RESULTS OF ECOTOXICOLOGICAL EXPERIMENTS WITH COAL SAMPLES HUMAN HEALTH EFFECTS OF COAL AND COAL TRANSPORT: REVIEW OF LITERATURE Introduction Relevance of existing literature UN GHS criteria for classification Germ cell mutagenicity Carcinogenicity Reproductive toxicity Specific target organ toxicity repeated exposure Literature review Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

5 Route of exposure Human health effects of inhalation exposure to coal Germ cell mutagenicity Carcinogenicity Reproductive toxicity Specific target organ toxicity repeated exposure Summary and conclusion REFERENCES ANNEXES Annex I: Summary of the ASTM coal classification system Annex II: Mode of occurrence of metals in coal Annex III: Summary of Transformation/Dissolution Protocol (T/DP) test data for coal Annex IV: Human health hazards of crystalline silica (fine fraction) Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 3

6 GLOSSARY ACARP: Australian Coal Association Research Program ACIRL: Australian Coal Industries Research Laboratories AM: alveolar macrophages ASTM: American Society for Testing and Materials Btu/lb: British thermal unit/pound CCD: Coal Criteria Document CLP: classification, labelling and packaging COPD: chronic obstructive pulmonary disease CWP: coal workers pneumoconiosis DSD: Dangerous Substances Directive EPA: Environmental Protection Agency ERV: Ecotoxicity Reference Value GHS: Globally Harmonized System of Classification and Labelling of Chemicals IARC: International Agency for Research on Cancer IMDG: International Maritime Dangerous Goods IMSBC: International Maritime Solid Bulk Cargoes ISO: International Organization for Standardization MARPOL: International Convention for the Prevention of Pollution from Ships MeClas tool: Metals Classification tool MHB: materials hazardous only in bulk NIOSH: National Institute for Occupational Safety and Health PAH: polycyclic aromatic hydrocarbon PMF: progressive massive fibrosis HME: harmful to the marine environment STOT-RE: Specific Target Organ Toxicity Repeated Exposure T/DP: Transformation/Dissolution Protocol WCA: World Coal Association WHO: World Health Organization 4 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

7 1. CHEMICAL COMPOSITION OF DIFFERENT TYPES OF COAL 1.1. COAL GENERAL INFORMATION Coal originates from a mixture of vegetation that accumulates at the bottom of swamps where no oxidation occurs, and where the degradation of the organic material is determined by anaerobic bacterial populations. These swamps are also located in areas with very low erosion and runoff. This process takes place over millions of years until environmental conditions change; the layer of former plant material starts to lose part of its water content, gets covered by layers of sediment and a significant reduction of the layer thickness can be observed (80% reduction). Minerals in this material have different sources: present in the plant material associated to mineral particles that have undergone sedimentation during the formation process floods that occurred after the formation period ended (and which added, in general, multiple layers on top of this material). Several ranking systems for coal have been developed, each with their own specific parameters and criteria, advantages and disadvantages. In that respect, both the International Organization for Standardization (ISO) and American Society for Testing and Materials (ASTM) classification scheme (ASTM Standard D388-98a, ISO 11760) are commonly used for ranking different types of coals. The rank of a deposit of coal more or less depends on the pressure and heat acting on the plant debris as it sinks deeper over a period of millions of years, with each category having its typical chemical composition, its energy content and, ultimately, its end use. Lignite and sub-bituminous coals are typically softer, friable substances that have a dull, earthy appearance. Overall, they are characterized by high moisture levels and lower carbon content (and consequently a lower energy content). Lignite ( brown coal ) represents an early phase in the transformation process from plant to coal and is the least mature coal rank. It contains less carbon (40 60% fixed carbon) and Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 5

8 heating value (approx Btu/lb) when compared to other types of coal. It also contains long-chain hydrocarbons (aliphatic structures) with many hydroxic/carboxylic functional groups. Lignite is used for power generation (e.g. power stations constructed close to the mine). At this stage of the coal formation, the reduction of the layer thickness of former plant material is still limited, and therefore layers of lignite can have thicknesses of up to several hundred metres. Due to the limited reduction of the layer, trace metals are less concentrated when compared to later stages of the coal-formation process. When lignite is subjected to longer and deeper burial, it will be converted into the harder and darker sub-bituminous coal due to the rearrangement of the long-chain hydrocarbons into ring-structured aromatics. This more compact structure reduces the overall porosity of coal and, hence, its potential to leach some of its compounds. The fixed carbon content of sub-bituminous coal ranges between 46% and 60% and has a heating value of ,000 Btu/lb. Typically, sub-bituminous coal contains less sulfur, resulting in cleaner burning. Higher-ranked coals (bituminous coal, anthracite) are generally harder and stronger, and often have a black vitreous lustre. Compared to lignite and sub-bituminous coal, these coals have a higher aromaticity, fixed carbon content, a higher heating value and lower moisture content. In addition, as the aliphatic compounds are the most volatile fraction of coal, the percentage of volatile substances is low for higher-ranked coals (e.g. for anthracitic coals below 8%, up to 1% in extreme cases). Bituminous coal (or black coal) is the main fuel source in steam turbine-powered electric generating plants, and some of it has properties that make it suitable for conversion to coal used in steelmaking. Bituminous coal has a 46 86% fixed carbon content, and a heating value of 11,500 15,000 Btu/lb. Due to its compaction of both plant material and mineral matter, it is considered to be a sedimentary rock. Anthracite (also called blue coal, hard coal, stone coal) is a hard black coal with a fixed carbon content of 86 98%, and a heating value of 13,500 15,600 Btu/lb. It is a product of metamorphism (associated with metamorphic rock) and could be considered as a transition stage between bituminous coal and graphite. 6 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

9 Other important determinants of coal quality relate to its mineral content (sulfur, chlorine, phosphorus, trace metals). These chemical properties not only affect the behavior of a specific type of coal in its intended use, but also significantly determine its behavior in the environment. Based on the overall composition of coal, it can be concluded that the most critical fractions of coal that may be of concern for the aquatic environment are inorganic trace elements and organic aromatic compounds such as polycyclic aromatic hydrocarbons (PAHs). Both groups of substances are further discussed in more detail INORGANIC TRACE ELEMENTS MODE OF OCCURRENCE OF TRACE ELEMENTS Substantial information on the trace elements content of different types of coal is available. Each element is associated with one or more typical components in coal such as typical minerals, pyrite, clay material, carbonates, etc. Consequently, the relevance of each element in a specific type of coal is related to the presence and abundance of those compounds for that specific coal sample. Trace element levels are the sum of the fraction that is associated with organic matter and the fraction that is present in the mineral fraction. Depending on the type of coal, the total fraction of a specific element will be higher (enrichment) or lower (depletion) than the typical concentration in the Earth s crust. Enrichment suggests that the trace element is associated primarily with the organic matter, while depletion arises simple by the dilution effect of the mineral matter in the coal. Elements that enrich during coal formation are shown in Table 1. The most significant enrichment can be found for selenium. Elements depleted in coal are chromium, cobalt, fluorine, manganese, nickel, thorium, uranium, vanadium and zinc. Decaying plant material contains many (essential) trace elements that have an affinity to form chemical bonds with organic matter; these elements are found at elevated levels in coal (compared to the Earth s crust). In addition, some elements are enriched due to the co-crystallization with secondary minerals. The insoluble pyrite (FeS 2 ) can be formed in the anoxic environment of a coalforming swamp, and some trace elements are associated with this secondary mineral. Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 7

10 Table 1 Enrichment factors for trace elements in coal relative to the Earth s crust (1) Element Limited enrichment Moderate enrichment Significant enrichment Antimony 6 Arsenic 6 Boron 5 Cadmium 7 Lead 1.3 Mercury 2.3 Molybdenum 2.0 Selenium 82 (1) From US National Committee for Geochemistry, 1980 (Dale, 2009). Several authors reported on the likely mode of occurrence of trace elements in coal (data shown in Annex), This information has led to a summary overview where the most probable mode of occurrence is outlined, together with a confidence level (CL) for each specific element: antimony (CL: low): possibly associated with sulfides and organic arsenic (CL: medium): associated with sulfide, with minor organic and clay beryllium (CL: high): associated with clays boron (CL: high): associated with organics cadmium (CL: low): probably associated with sulfides chromium (CL: medium): associated with clays and minor organic association cobalt (CL: low): possibly associated with organic, clay, sulfide, carbonate copper (CL: medium): associated with sulfide and clay lead (CL: high): associated with sulfide manganese (CL: high): associated with carbonate mercury (CL: high): associated with sulfide, and possibly organic molybdenum (CL: high): associated with organic and sulfide nickel (CL: low): possibly associated with sulfide, carbonate, organic selenium (CL: high): associated with organic and sulfide thorium (CL: high): predominantly in clays uranium (CL: high): associated with clays, acid resistant minerals and organic 8 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

11 vanadium (CL: high): associated with clays and organic zinc (CL: high): associated with sulfide. This enumeration can be used for the identification of the most relevant trace elements for specific coal types. Identification of the modes of occurrence has been conducted in several ways: Column separation or heavy liquid separation has been used to separate the coaly matter from the mineral matter. The method also allows the separation of mineral phases with different density. Trace metal content is then determined for each phase. Sequential leaching procedures where each step releases the trace elements that are associated to a different mineral/organic fraction: loosely bound ions on clays and organic matter, bound to carbonates and monosulfides, bound onto disulfides (e.g. pyrite), bound to silicates, etc CONCENTRATIONS OF TRACE ELEMENTS IN COAL DATA IN THE PUBLIC DOMAIN The objective of this (and the following) section is to define representative ranges of different trace elements in various types of coal (where possible). Readily available information was brought together from different review reports. It should be noted that there are limitations to the global coverage of these ranges as not every region or type of coal is equally represented in the database. It should be stressed, however, that the main objective at this stage of the evaluation was not to determine exact ranges for each coal type but to get a good approximation of the order of magnitude (percent-wise) that an element may occur in one or more types of coal. In a next phase, the maximum values for each element are used to prioritize the most critical trace elements using an existing metal classification tool (MeClas tool, see further). Guidance on how to demonstrate that a coal sample should not be considered as a substance harmful to the marine environment (HME) will be based on the outcome of this prioritization process. Review data on coal trace element composition were collected from the Australian Coal Association Research Program (ACARP) report (Riley, 2005), Dale (2009) and Ahrens and Morrisey Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 9

12 (2005). The ACARP report (Riley, 2005) gives an overview of trace element concentrations in three types of coal: Australian export coal (predominantly bituminous coal with high calorific value) a limited selection of non-australian internationally traded coals Australian domestic coals (bituminous coal that is used in Australian power plants). Samples were analysed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) using standard methods accredited by Standards Australia (SA), the ASTM and the ISO. Many of the methods used were developed in work undertaken within ACARP. The analysis scheme used was according to AS Coal and coke analysis and testing, Part 10.0: Determination of trace elements Guide to the determination of trace elements (2002). The methods are based on modern instrumental techniques, including inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission spectrometry, hydride generation and cold vapour atomic fluorescence spectrometry, X-ray fluorescence spectrometry and proton-induced gamma emission. All are capable of accurately determining the concentrations of the trace elements at the levels normally present in thermal coal products. Average concentrations (plus range in parentheses) for each type of coal is provided in Table 2. The ACARP reports, however, did not specify whether the moisture content was taken into account when reporting concentration levels. It is assumed that values are expressed on a dry matter basis. One should be aware that the elemental ranges for non-australian traded coals in Table 2 only represent a very limited number of selected coal samples (approx. 60), and the relevance with regard to global non- Australian export coals is uncertain. Table 3 compares the average of trace elements in Australian export coals with concentrations (averages, minimum/maximum ranges) that were reported for other coal samples. The information on coal composition that is provided in Table 2 and Table 3 is predominantly relevant for coal that has been mined in Australia. The composition of coal, however, can vary significantly among different geographic areas. Several papers have compared the composition of coal samples that originate from other areas in the world. Dale (2009) has presented the composition of selected coal that was mined in China, Colombia, Indonesia, Poland, Russia, South Africa, Ukraine, 10 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

13 United States and Venezuela (Table 4). For most elements the reported min-max ranges are comparable, though it can be seen that sometimes the concentration of an element is somewhat higher for a specific country (e.g. Sb in Poland, B in Indonesia/Colombia, Cu in Poland/USA). However, as the amount of coals that are represented in each country-specific range is limited, no conclusions on regional differences should be drawn from these data sets. A second set of region-specific compositions of coal samples was identified in Ahrens and Morrisey (2005) (Table 5). Table 2 Trace element concentration in different types of coal (average and minmax range) (Riley, 2005) the ACARP report does not specify whether reported concentrations levels take the moisture content of the samples into account Element Australian export coals Australian domestic coals Limited selection of non-australian traded coals Antimony 0.39 ( ) Arsenic 1.05 ( ) Barium 180 ( ) Beryllium 0.9 ( ) Boron 19 (5 70) Cadmium 0.11 ( ) Chromium 10 (2 25) Cobalt 4 (1 14) Copper 15 (6 27) Lead 3 (2 14) Manganese 125 (5 700) Mercury 0.04 ( ) Approx. 100 samples, not specified per category (1) Approx. 60 samples (1) mg/kg 0.55 ( ) 1.6 ( ) 115 (15 250) 1.2 ( ) 32 (7 141) 0.15 ( ) 10 (2 23) 4 (1 12) 4 (1 12) 10 (3 18) 160 (19 430) 0.04 ( ) 0.33 ( ) 3.6 ( ) ( ) 72 (11 430) 0.08 ( ) 16 (1 35) 4 (>1 13) 9 (<1 23) 6 (<1 22) 40 (7 117) 0.09 ( ) Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 11

14 Molybdenum 0.8 ( ) Nickel 6 (4 23) Selenium 0.5 ( ) Thorium 2.8 ( ) Uranium 1.1 ( ) Vanadium 28 (7 75) Zinc 18 (3 26) (1) Amount of samples not specified for each element. Source: Riley, (< ) 1.2 ( ) 6 10 (2 18) (2 22) ( ) ( ) ( ) ( ) ( ) (< ) No sufficient data 19 (1 50) (< ) (4 23) 12 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

15 Table 3 Trace element concentration on different types of coal no specification whether reported concentrations levels are based on wet weight or dry weight (assumption: mg/kg DW ) Element Australian export coals (2005) ACIRL database (both export and domestic coals) Valcovic (mg/kg)v Dale, 2009 (compilation of Clark and Swaine, 1962; Swaine 1977, 1979) Coals in New South Wales and Queensland power stations Australian export coals (2009) (typical value) mg/kg Antimony 0.39 ( ) 0.33 (max: 1.69) (<0.1 2) 0.56 (0.05 1) 0.40 ( ) Arsenic 1.05 ( ) 0.62 (max: 3.2) (<0.1 55) 1.6 (0.2 7) 0.86 ( ) Barium 180 ( ) Beryllium 0.9 ( ) (<0.4 8) 0.9 ( ) 0.6 ( ) Boron 19 (5 70) 18.6 (max: 70) (2 300) 16 (<5 45) 17 (4 36) Cadmium 0.11 ( ) 0.04 (max: 0.14) ( ) 0.11 ( ) 0.07 ( ) Chromium 10 (2 25) 14.9 (max: 49) 10 9 (<2 56) 12 (3 25) 7 (2.9 24) Cobalt 4 (1 14) 4.3 (max: 14.2) 5 5 (<0.6 30) 5 (1 14) 3.0 (1.2 12) Copper 15 (6 27) 20.1 (max: 49) (3 40) 21 (7 35) 13 (6.2 32) Lead 3 (2 14) 6.93 (max: 21.6) (1.5 60) 8 (3 14) 5.6 (2.2 14) Manganese 125 (5 700) (3 900) 155 (1 570) 42 (4 700) Mercury 0.04 ( ) 0.07 (max: 0.241) ( ) ( ) ( ) Molybdenum 0.8 ( ) 0.87 (max: 2.6) (<0.3 6) 1 ( ) 0.66 ( ) Nickel 6 (4 23) 7.81 (max: 26.1) (1 70) 12 (4 23) 7.5 (1.4 31) Sulfur (%) 0.42% ( ) 0.47% ( ) Selenium 0.5 ( ) 0.77 (max: 2.94) ( ) 0.69 ( ) 0.42 ( ) Thorium 2.8 ( ) (<0.2 8) 3.5 ( ) 2.4 ( ) Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 13

16 Uranium 1.1 ( ) (0.28 5) 2.9 ( ) 0.82 ( ) Vanadium 28 (7 75) 25.1 (max: 61) (4 90) 32 (7 75) 22 (7 62) Zinc 18 (3 26) (max: 65) (6 500) 21 (3 125) 11 (4 51) 14 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

17 Table 4 Mean and maximum values for trace elements in a selected number of thermal coals from individual countries no specification whether reported concentrations levels are based on wet weight or dry weight (assumption: mg/kg DW ) Element South Africa n = 21 China n = 12 Poland n = 6 Indonesia n = 38 Colombia n = 18 Russia n = 5 Ukraine n = 3 USA n = 6 Venezuela n = 2 mg/kg Antimony Arsenic Beryllium Boron Cadmium Chromium Cobalt Copper Lead Manganese Mercury Molybdenum Nickel Sulfur (%) Selenium Thorium Uranium Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 15

18 Vanadium Zinc Source: Dale, Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

19 Table 5 Inorganic chemical properties of particulate coal; concentrations by dry weight Element UK Germany Canada Spain USA Australia New Zealand Rank (1) B L, B B SB, B B, SB SB, B SB, B mg/kg Silver < Arsenic <1 55 < Boron Barium < < Cadmium < Cobalt < < Chromium < Copper Fluor Iron , ,900 Gallium Germanium < Mercury Manganese Molybdenu m < < Nickel Phosphorus < < Lead Antimony < Selenium < Tin < Thorium Thallium <0.2 8 < Uranium Vanadium Zinc (1) L = lignite; SB = sub-bituminous; B = bituminous. Source: Ahrens and Morrissey, 2005 (data taken from: Francis, 1961; Swaine and Goodarzi, 1995; Querol et al., 1996; Gluskoter et al., 1977; Ward, 1984; Fendinger et al., 1989; Davis and Boegly, 1981; Swaine, 1977; Solid Energy New Zealand Ltd, 2002; Soong and Berrow, 1979; Sim, 1977; ANZECC, 2000) Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 17

20 The observed worst-case concentration for each element (i.e. highest reported concentration in Table 2 to Table 5) is summarized in Table 6. This table also provides the total amount of trace elements in 100 mg and 1 mg of coal as these amounts are relevant when implementing a bioavailability correction on the classification. Such correction is based on the outcome of Transformation/Dissolution Protocol (T/DP) tests (see further). Table 6 Worst-case concentration levels (mg/kg; %) of trace metals in coal; worst-case amount to be released at loadings 100 mg and 1 mg coal/l data assumed to be on a dry weight basis Element Worst-case concentration (mg/kg coal) % in coal Amount in 100 mg coal (= max release in a T/DP at this loading) (µg) Silver Antimony Arsenic Barium Beryllium Boron Cadmium Chromium Cobalt Copper Iron 33, Gallium Germanium Lead Manganese Mercury Molybdenum Nickel Selenium Tin Thorium Thallium Uranium Vanadium Zinc Amount in 1 mg coal (= max release in a T/DP at this loading) (µg) 18 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

21 CONCENTRATION OF TRACE ELEMENTS IN COAL COMPANY-SPECIFIC DATA Information on typical compositions of coal was requested from the members of the World Coal Association (WCA), and reports on several coal composition analyses were provided to ARCHE. It should be noted that agreement on a standardized method of analysis is essential when setting a global classification system for coal that is based on its composition. Huggins (2002), for instance, published a summary of analytical procedures for the analysis of coal for inorganic constituents. Riley et al (2005) developed a standard method (Australian Standard AS (R2013); Coal and coke analysis and testing Determination of trace elements Guide to the determination of trace elements; standard published by Standards Australia). This standard was adopted as ISO Standard (2008, revised 2013): Selection of methods for the determination of trace elements in coal. The ISO 23380:2013 provides guidance on the selection of methods used for the determination of environmentally relevant trace elements, including antimony, arsenic, beryllium, boron, cadmium, chlorine, chromium, cobalt, copper, fluorine, lead, manganese, mercury, molybdenum, nickel, selenium, thallium, vanadium, and zinc. The standard, however, does not prescribe the methods used for the determination of individual trace elements. The ASTM also published two standard test methods with regard to the determination of trace elements in coal: ASTM D : Standard Test Method for Trace Elements in Coal and Coke by Atomic Absorption ASTM D : Test Methods for Determination of Trace Elements in Coal, Coke, & Combustion Residues from Coal Utilization Processes by Inductively Coupled Plasma Atomic Emission, Inductively Coupled Plasma Mass, & Graphite Furnace Atomic Absorption Spectrometry. Four different companies provided trace element compositions for various coal samples. All reported concentration levels are based on dry weight analysis. 1 Companies and references to the mining sites have been anonymized for confidentiality reasons. In addition, the provided coal 1 Dry weight levels are higher than wet weight levels, and can therefore be considered as worst-case concentration levels. Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 19

22 sample compositions are grouped according to coal type (lignite, (sub-)bituminous, (semi-)anthracite, etc.), and not according to region or company, thus further anonymizing the information. Grouping was based on the ASTM ranking system (see Annex for more detailed information on this ranking system) as the provided properties of the different coal samples did not always allow a categorization according to the ISO ranking procedure, for example. All coal samples were categorized as either bituminous or sub-bituminous, and further distinction was made based on the reported British thermal unit (Btu) value (classification according to ASTM D388). Both ranks of coal represent the great majority of seaborne-traded coals. Table 7 compiles the trace element composition of seven high-volatile C bituminous coal samples (11,500 13,000 Btu/lb). The composition of four sub-bituminous A coals are given in Table 8. The trace element content of two sub-bituminous C coal samples is shown in Table 9. Table 10 presents the maximum concentration for each trace element for the different types of coal, and compares these with the maximum value that was found in the literature. This comparison demonstrates that the worst-case assumption that is based on literature data is sufficiently conservative as all maximum concentration levels in the coal samples that were provided by WCA members were below these maximum levels. Therefore, the literature-based worst-case values will be used to define the most critical elements that may drive the environmental classification of coal. 20 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

23 Table 7 Summary of high-volatile C bituminous coal samples (fixed carbon < 69%, Btu/lb 11,500 13,000) reported concentrations on a dry weight basis Element Sample #1 Sample #2 Sample #3 Sample #4 Sample #5 Sample #6 Sample #7 Max value mg/kg DW Antimony < Silver < Arsenic Boron Barium Beryllium Cadmium 2 < Cobalt Chromium Copper Iron Mercury < Manganese Molybdenum Nickel Lead Selenium < Tin <3 < Strontium Titanium Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 21

24 Thorium < Thallium < Uranium Vanadium Zinc Zirconium Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

25 Table 8 Summary of sub-bituminous A coal samples (fixed carbon < 69%, Btu/lb 10,500 11,500) reported concentrations on a dry weight basis Element Sample #1 Sample #2 Sample #3 Max value mg/kg DW Antimony <2 0,3 1.0 Silver <1 < Arsenic Boron Barium Beryllium Cadmium <0.3 < Cobalt Chromium Copper Iron Mercury Manganese Molybdenum 2 < Nickel Lead Selenium <3 < Tin < Strontium Titanium Thorium 1.5 Thallium <1 < Uranium Vanadium Zinc Zirconium Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 23

26 Table 9 Summary of sub-bituminous C coal samples (fixed carbon < 69%, Btu/lb ), a high-volatile B bituminous coal sample (Btu/lb 13,000 14,000) and a medium-volatile bituminous coal sample (Btu/lb > 14,000) reported concentrations on a dry weight basis Element Sample #1 Sample #2 Sample #3 Max value Sub-bituminous C High-volatile B bituminous mg/kg DW Antimony < Silver < Arsenic < Boron Barium Beryllium Cadmium < Cobalt Chromium Copper Iron Mercury Manganese Molybdenum < Nickel Lead < Selenium < Tin < Strontium Thallium < Uranium Vanadium Zinc Zirconium Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

27 Table 10 Maximum trace element concentration in different coal types (data provided by WCA members and literature data) reported concentrations on a dry weight basis Element Highvolatile B bituminous Highvolatile C bituminous Subbituminous A Subbituminous C Literature worst-case mg/kg DW Antimony Silver Arsenic Boron Barium Beryllium Cadmium Cobalt Chromium Copper Iron Mercury Manganese Molybdenum Nickel Lead Selenium Tin Strontium Titanium Thorium Thallium Uranium Vanadium Zinc Zirconium POLYCYCLIC AROMATIC HYDROCARBONS IN COAL Polycyclic aromatic hydrocarbons (PAHs) are composed of many carcinogenic substances that are ubiquitous in the environment. In addition to sorbed PAHs, once being exposed to the environment, original hard (unburnt) coal from the seam can contain PAHs up to hundreds and, in exceptional cases, thousands of mg/kg (Willsch and Radke, 1995; Stout and Emsbo-Mattingly, 2008). Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 25

28 Formation of PAHs is the result of the transformation of resistant plant biopolymers (e.g. lignin) into a highly aromatic, three-dimensional, network matrix under the influence of temperature and pressure (Taylor et al., 1998). In coals of low rank (e.g. lignite, sub-bituminous coal, brown coal), significantly lower PAH concentrations are detected (e.g. Püttmann, 1988). In theory, the native PAH content could pose a risk to the environment (and more specific soil and sediment); yet, no studies have clearly showed such a risk (Achten and Hofmann, 2009). Risks towards the water column are less likely to occur due to the hydrophobic properties of PAHs. Several authors demonstrated that non-native PAHs were effectively sorbed to simultaneously present coal particles, and this sorption was related to high sorption affinity and slow desorption kinetics (Kleineidam et al., 2002; Wang et al., 2007; Yang et al., 2008). Achten and Hofmann (2009) collected and summarized the PAH content of 39 types of coal (Table 11). Both the total and United States Environmental Protection Agency (EPA)-PAH concentration levels are included in this table, and are expressed as mg/kg coal and as weight/weight percentage (w/w %). The list of 16 EPA priority PAHs is often used as reference list for measurement and assessment of this group of compounds in the environment. A summary of the 16 EPA PAHs and their official classification under the Dangerous Substances Directive (DSD) and classification, labelling and packaging (CLP) is shown in Table 12. Acenaphthylene and indeno(1,2,3-cd)pyrene are the only two of the 16 EPA-PAHs that are not classified (no Annex VI classification; no self-classification). There are seven EPA-PAHs with an official classification of Aquatic Acute 1, Aquatic Chronic 1; only one of them (benzo(a)anthracene) has an additional M-factor of 100, indicating that the acute toxicity (ERV acute ) is situated between 1 µg/l and 10 µg/l. The Annex VI classification is based on acute data; therefore, no conclusions on the ERV chronic can be made. Assuming that a classification based on chronic ecotoxicity data would lead to a similar outcome (Aquatic Chronic 1, M-100), the ERV chronic for benzo(a)anthracene is situated between 0.1 µg/l and 1 µg 26 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

29 Table 11 Summary of total and 16 EPA polycyclic aromatic hydrocarbon concentrations in coals Type of coal Total PAHs EPA-PAHs mg/kg % mg/kg % High-volatile bituminous coal A, Elmsworth Gasfield, W6, Canada High-volatile bituminous coal A, Elmsworth Gasfield, W6, Canada Medium-volatile bituminous coal, Ruhr basin, Osterfeld, Germany Medium-volatile bituminous coal, Ruhr basin, Hugo, Germany Low-volatile bituminous coal, Ruhr basin, Westerholt, Germany Low-volatile bituminous coal, Ruhr basin, Blumenthal, Germany Low-volatile bituminous coal, Elmsworth Gasfield, W6, Canada Low-volatile bituminous coal, Ruhr basin, Haard, Germany High-volatile bituminous coal, Wealden Basin, Nesselberg, Germany High-volatile bituminous coal, Wealden Basin, Barsinghausen, Germany High-volatile bituminous coal, Saar, Ensdorf, Germany Medium-volatile bituminous coal, Germany Bituminous coal, Germany Lignite A, Northern Great Plains, Beulah, USA 8.5 < < Lignite A, Northern Great Plains, Pust, USA 6.5 < < Sub-bituminous coal C, Northern Great Plains, Smith-Roland, USA < Sub-bituminous coal C, Gulf Coast, Bottom, USA < Sub-bituminous coal B, Northern Great Plains, Dietz, USA < Sub-bituminous coal B, Northern Great Plains, Wyodak, USA 5.4 < < Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 27

30 Sub-bituminous coal A, Rocky Mountains, Deadman, USA < High-volatile bituminous coal C, Rocky Mountains, Blue, USA < High-volatile bituminous coal B, Eastern Coal, Ohio #4A, USA < High-volatile bituminous coal A, Rocky Mountains, Blind Canyon, USA < High-volatile bituminous coal A, Eastern Coal, Pittsburgh, USA Medium-volatile bituminous coal, Rocky Mountains, Coal Basin M, USA < Low-volatile bituminous coal, Eastern Coal, Pocahontas #3, USA < Semi-anthracite, Eastern Coal, PA Semi-Anth. C, USA 5.9 < < Anthracite, Eastern Coal, Lykens Valley #2, USA 0.2 < <0.1 < High-volatile bituminous coal, Blind Canyon, USA 78.3 High-volatile bituminous coal C-1, USA 7.5 < < High-volatile bituminous coal C-2, USA 3.4 < < High-volatile bituminous coal C-3, USA 2.4 < < High-volatile bituminous coal B-1, USA 1.6 < < High-volatile bituminous coal B-2, USA < High-volatile bituminous coal A-1, USA < High-volatile bituminous coal A-2, USA < Low-volatile bituminous coal, USA 1.2 < < Anthracite, China 2.5 < < Bituminous coal, Brazil Source: Achten and Hofmann, 2009 (data taken from Willsch and Radke, 1995; Radke et al., 1990; Pies et al., 2007; Stout and Emsbo-Mattingly, 2008; Stout et al., 2002; Zhao et al., 2000; Chen et al., 2004; Püttmann, 1988) 28 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

31 Table 12 Overview of the environmental classification of the most relevant PAH compounds 16 EPA-PAH Environmental classification under DSD/CLP compounds Naphthalene Aq.Acute 1, Aq.Chronic 1 Acenaphthylene No official classification, no environmental self-classification Acenaphthene No official classification; self-classification: Aq.Acute 1, Aq.Chronic 1 Fluorene No official classification; self-classification: Aq.Acute 1, Aq.Chronic 1 Phenanthrene No official classification; self-classification: Aq.Acute 1, Aq.Chronic 1 Anthracene No official classification; self-classification: Aq.Acute 1, Aq.Chronic 1 Fluoranthene No official classification; self-classification: Aq.Acute 1, Aq.Chronic 1 Pyrene No official classification; self-classification: Aq.Acute 1, Aq.Chronic 1 (M = 10) Benzo(a)anthracene Aq.Acute 1, Aq.Chronic 1 (M = 100) Chrysene Aq.Acute 1, Aq.Chronic 1 Benzo(b)fluoranthene Aq.Acute 1, Aq.Chronic 1 Benzo(k)fluoranthene Aq.Acute 1, Aq.Chronic 1 Benzo(a)pyrene Aq.Acute 1, Aq.Chronic 1 Dibenz(a,h)anthracene Aq.Acute 1, Aq.Chronic 1 Benzo(g,h,i)perylene No official classification; self-classification: Aq.Acute 1, Aq.Chronic 1 Indeno(1,2,3-c,d)pyrene No official classification; no environmental self-classification For the remaining seven EPA-PAHs there is no official classification, but the compounds were selfclassified under CLP (Aq.Acute1, Aq.Chronic1). An additional chronic M-factor of 10 was assigned to only one of these eight PAHs (pyrene). It can thus be concluded that for the majority of the EPA- PAHs, the ERV acute is situated between 100 µg/l and 1000 µg/l, and that the ERV chronic is situated between 10 µg/l and 100 µg/l ENVIRONMENTAL HAZARD ASSESSMENT OF COAL HAZARD ASSESSMENT OF TRACE ELEMENTS IN COAL The conservative worst-case concentration levels of trace metals in coal (see Table 6) are used as a starting point for the prioritization of the most critical trace elements that may trigger an environmental classification, resulting in the classification of coal as an HME. This assessment is conducted with the MeClas tool (Metals Classification tool). This tool uses the most up-to-date Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 29

32 information on metal toxicity and bioavailability of various metal compounds and minerals, and can be used for the derivation of a classification for a (multi)metallic complex material, hereby following the mixture rules that are outlined in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The use of this tool ensures that the derived classification is fully compliant with the principles, concepts and assumptions that are accepted by the various metal commodities (e.g. European Copper Institute, International Copper Association, Lead Development Association, etc.), and that the most recent toxicological and ecotoxicological data and principles (industry or legislation) are taken into account. Based on all information on trace elements in coal that is currently summarized (see Table 6), a worst case coal sample has been generated: for each trace element the highest available concentration in coal is taken forward in the composition. Table 6 also presents the fraction (in %) of each element in coal, and also determines the maximum amount of each trace metal in coal at a loading of 100 mg/l and 1 mg/l. It should be noted that the loading of 1 mg/l is relevant for Acute 1 and Chronic 1 classification purposes. Apart from iron, the highest percentage of a classified trace metal in coal was found for zinc and was 0.7%. With regard to the presence of a single classified substance in a mixture, the maximum allowed concentrations that would not trigger an Aq.Chronic1 or Aq.Chronic2 classification (i.e. classification criteria for an HME) can be summarized as follows: A substance with an Aq.Chronic2 classification will only trigger an Aq.Chronic2 classification in a mixture when present at concentration levels of 25% or higher (and no other substances with an Aq.Chronic1 or Aq.Chronic2 classification are present in the mixture). All worst-case trace metal concentrations are well below 1%; therefore, none of the metals with an Aq.Chronic.2 classification (e.g. Sn) will directly result in an Aq.Chronic2 classification for coal. A substance with an Aq.Chronic1 classification and M-factor 1 will only trigger an Aq.Chronic2 classification in a mixture when present at concentration levels of 2.5% or higher (and no other substances with an Aq.Chronic1 or Aq.Chronic2 classification are present in the mixture). All worst-case trace metal concentrations are well below 1%; therefore, none of the metals with a Aq.Chronic.1 classification and M-factor 1 (e.g. Zn, Cu) will directly result in an Aq.Chronic2 classification for coal. 30 Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards

33 A substance with an Aq.Chronic1 classification and M-factor 10 will only trigger an Aq.Chronic2 classification in a mixture when present at concentration levels of 0.25% or higher (and no other substances with an Aq.Chronic1 or Aq.Chronic2 classification are present in the mixture). Such a concentration level is only observed for Zn (0.7%), but as this metal does not have an M-factor of 10, it will not trigger an environmental classification. All elements with an M-factor of 10 are present at concentration levels below 0.25%, and will therefore not directly result in an Aq.Chronic2 classification for coal. A substance with an Aq.Chronic1 classification and M-factor 100 will only trigger an Aq.Chronic2 classification in a mixture when present at concentration levels of 0.025% or higher (and no other substances with an Aq.Chronic1 or Aq.Chronic2 classification are present in the mixture). An M-factor of 100 is relevant for Ag, Cd and Hg, but the highest worst-case concentration for these elements is %, % and 0.003%, respectively, i.e. well below the critical concentration level of 0;05%. As such, none of these three highly toxic elements will directly result in an Aq.Chronic2 classification for coal. The combined hazard classification of various elements, however, may trigger a classification, and this can be assessed with the output of the MeClas calculation. The output of this exercise is presented in Figure 1 and Table 13. Figure 1 shows the Tier-0 output of the MeClas calculation (relevant end points for environmental classification only). With the Tier-0 assumptions (100% bioavailability plus each element is present under its most toxic from), no Aq.Acute1 classification is derived. Under GHS, however, a worst-case coal sample would be classified as Aq.Acute2 (not relevant for the International Convention for the Prevention of Pollution from Ships (MARPOL)). Figure 1: MeClas output of the TIER-0 environmental classification of a worst-case coal sample Report 2. Analysis of Coal Composition, Ecotoxicity and Human Health Hazards 31