Michael J. Brisson has over 30 years experience in analytical chemistry specializing in spectroscopy. His current work includes advisory support for industrial hygiene laboratories handling radioactive samples, and for the design of new nuclear laboratories. He is currently Chair of the Beryllium Health and Safety Committee (U.S. Departments of Energy and Defence) and Secretary of the ASTM International Committee on Air Quality. He is also the technical lead for three ASTM International Standards. He has organized numerous beryllium-related technical sessions at the American Chemical Society and the American Industrial Hygiene Association national meetings and was lead organizer of the Second Symposium on Beryllium Particulates and Their Detection in Salt Lake City, November 2005. He is author or co-author of eight peer-reviewed journal articles and guest edited a special issue of the Journal of Environmental Monitoring on beryllium sampling and analysis. Amy A. Ekechukwu is a senior Fellow Scientist with over 26 years experience in spectrophotometry, chromatography, electrochemical analysis and synthesis, liquid scintillation counting, gamma spectrophotometry, handling of radioactive material, and a variety of wet chemistry methods. She was profiled as International Woman of the Month for Women in Technology International, June 2000 and is currently a member of the Executive Board of the Beryllium Health and Safety Committee (U.S. Departments of Energy and Defence). She has chaired prominent sessions at four International Ion Chromatography Forums, organized numerous sessions at the American Chemical Society and the American Industrial Hygiene Association national meetings. She was lead organizer for the Third International Symposium on Beryllium Particulates and Their Detection in November 2008 in Albuquerque and has had eleven patents granted.

Beryllium

Environmental Analysis and Monitoring

By Michael J. Brisson, Amy A. Ekechukwu

The Royal Society of Chemistry

Copyright © 2009 Royal Society of Chemistry
All rights reserved.
ISBN: 978-1-84755-903-6

Contents

Chapter 1 Overview of Beryllium Sampling and Analysis: Occupational Hygiene and Environmental Applications Michael J. Brisson, 1,
Chapter 2 Air Sampling Martin Harper, 17,
Chapter 3 Surface Sampling: Successful Surface Sampling for Beryllium Glenn L. Rondeau, 68,
Chapter 4 Sample Dissolution Reagents for Beryllium: Applications in Occupational and Environmental Hygiene Kevin Ashley and Thomas J. Oatts, 89,
Chapter 5 Heating Sources for Beryllium Sample Preparation: Applications in Occupational and Environmental Hygiene T. Mark McCleskey, 102,
Chapter 6 Beryllium Analysis by Inductively Coupled Plasma Atomic Emission Spectrometry and Inductively Coupled Plasma Mass Spectrometry Melecita M. Archuleta and Brandy Duran, 113,
Chapter 7 Beryllium Analysis by Non-Plasma Based Methods Anoop Agrawal and Amy Ekechukwu, 131,
Chapter 8 Data Use, Quality, Reporting, and Communication Nancy E. Grams and Charles B. Davis, 147,
Chapter 9 Applications, Future Trends, and Opportunities Geoffrey Braybrooke and Paul F. Wambach, 182,
Subject Index, 194,

CHAPTER 1

Overview of Beryllium Sampling and Analysis

Occupational Hygiene and Environmental Applications

MICHAEL J. BRISSON

Senior Technical Advisor, Savannah River Nuclear Solutions, Analytical Laboratories, Savannah River Site, Aiken, SC 29808, USA

Abstract

Because of its unique properties as a lightweight metal with high tensile strength, beryllium is widely used in applications including cell phones, golf clubs, aerospace, and nuclear weapons. Beryllium is also encountered in industries such as aluminium manufacturing, and in environmental remediation projects. Workplace exposure to beryllium particulates is a growing concern, as exposure to minute quantities of anthropogenic forms of beryllium may lead to sensitization and to chronic beryllium disease, which can be fatal and for which no cure is currently known. Furthermore, there is no known exposure-response relationship with which to establish a “safe” maximum level of beryllium exposure. As a result, the current trend is toward ever lower occupational exposure limits, which in turn make exposure assessment, both in terms of sampling and analysis, more challenging. The problems are exacerbated by difficulties in sample preparation for refractory forms of beryllium, such as beryllium oxide, and by indications that some beryllium forms may be more toxic than others. This chapter provides an overview of sources and uses of beryllium, health risks, and occupational exposure limits. It also provides a general overview of sampling, analysis, and data evaluation issues that will be explored in greater depth in the remaining chapters. The goal of this book is to provide a comprehensive resource to aid personnel in a wide variety of disciplines in selecting sampling and analysis methods that will facilitate informed decision-making in workplace and environmental settings.

1.1 Introduction

Control of occupational exposure in the workplace, characterization of environments or legacy areas, and management of environmental or workplace remediation projects, all require careful planning and execution, including development of appropriate sampling plans, up-front understanding of laboratory capabilities, and proper evaluation of analytical data. This involves a number of disciplines, including industrial hygienists, laboratory personnel, statisticians, and line management. Even before a sampling plan is developed, additional disciplines such as medicine, immunology, toxicology, and epidemiology, are involved to tell us the health risks of the material we are trying to control. Additional disciplines, such as engineering, assist us with implementing the full hierarchy of controls, of which sampling and analysis are a part, to minimize exposure to toxic substances in workplace and environmental settings. All of these disciplines must work closely together, beginning with the design phases of a project or facility, through the end of a project’s lifecycle, to ensure an outcome that protects workers but also avoids unnecessary costs to the project.

Perhaps nowhere is this more true than with beryllium. Because beryllium exposure must be managed at ultra-trace levels (with the trend being toward even lower levels), the sampling and analytical challenges associated with measuring beryllium are greater than for most other metal or metalloid particulates. This includes workplaces actively using beryllium, legacy areas where beryllium was used in the past, and environmental remediation projects. New facilities where beryllium will be used need to be designed not only with appropriate engineering controls, but also with consideration of beryllium sampling and analytical requirements.

This book provides information on sampling and analysis techniques that have been developed to ensure that beryllium particulate (whether in natural or anthropogenic forms) can be effectively sampled and analyzed, and the resulting data properly evaluated for sound decision-making in workplace and environmental settings. This book is not intended to provide detailed medical or toxicological information, nor does it discuss engineering controls. It is focused primarily on the sampling and analytical state-of-the-art.

This chapter provides background information on beryllium sources, uses, health risks, and exposure limits. It then provides an overview of sampling and analysis issues to set the stage for the detailed discussion of these issues and techniques in the chapters to follow.

1.2 Goals of this Book

The primary goal of this book is to be a resource that can be used by all of the disciplines involved in beryllium health and safety management, to enable the best possible sampling and analytical decision-making so that workers are better protected from the risks of beryllium in the workplace. Its primary users would include industrial hygiene practitioners, analytical laboratory personnel, statisticians, and managers of projects or processes that either utilize beryllium or characterize beryllium in legacy or environmental settings. This book should help such users understand current capabilities and limitations in beryllium sampling and analysis, both in their own disciplines and in the others, and the need for good communication with other disciplines to assure success. It is also hoped that this book will be useful in academic, research and development settings to encourage additional research to address the many limitations in our current understanding and capabilities.

It is not the intention of this book to tell users to sample or analyze by some prescribed method(s). There is no “one size fits all” approach to beryllium sampling and analysis, but it is important that selected methods be fit for purpose and be defensible (as applicable) to customers, regulators, accrediting agencies, managers, and perhaps most importantly, to workers whose beryllium exposures are being characterized and managed.

1.3 Background

Beryllium (atomic number 4) is a lightweight metal (density 1.85) with a high melting point (1287 °C), stiffness (Young’s modulus 287 GPa) and thermal conductivity (190 W m-1 K-1). These properties make beryllium a highly desirable component for a wide variety of applications.

1.3.1 Beryllium Sources

Beryllium occurs naturally in some 30 different mineral species. In the Earth’s crust, beryllium content is estimated at 2–5 parts per million (ppm) overall, with specific rocks having up to 15 ppm. For the extraction of elemental beryllium, the species of importance are the beryllium alumino-silicate mineral beryl (Be3Al2Si6O18) and the beryllium silicate hydroxide mineral bertrandite [Be4Si2O7(OH)2], with bertrandite as the principal mineral mined in the United States, and beryl the principal mineral in other countries. Beryl is roasted with sodium hexafluorosilicate to form beryllium fluoride, which is water-soluble. From the fluoride, beryllium may be precipitated as beryllium hydroxide by adjusting the pH to 12, or may be obtained by reduction of the fluoride with magnesium. For bertrandite, the ore is leached with sulfuric acid; solvent extraction of the sulfate solutions ultimately produces beryllium hydroxide. In 2007, active mine production was principally in the United States, China, and Mozambique, with minor amounts elsewhere.

Beryllium also is found in bauxite ore used in the manufacture of aluminium. The amount of beryllium varies with the source of the bauxite. While bauxite is not a beryllium source for production purposes, aluminium smelter workers can be exposed to beryllium in pot emissions. Table 1.1 contains additional data on beryllium in a variety of materials based on information from the US Agency for Toxic Substances and Disease Registry (ATSDR).

1.3.2 Beryllium Uses

1.3.2.1 Beryllium metal

Beryllium metal is used in nuclear weapons, aircraft brake parts, spacecraft structures, navigation systems, X-ray windows, mirrors, and audio components. The metal is also a neutron reflector used in nuclear reactors.

1.3.2.2 Beryllium alloys

Beryllium alloys represent the largest use of beryllium. Copper–beryllium alloys typically have 0.15–2.0% beryllium content, and are widely used because they exhibit good conductivity, are resistant to corrosion, have high hardness, and are non-magnetic. Copper–beryllium alloys are used for applications such as coaxial connectors in cell phones, computers, aircraft bushings, non-sparking tools, automotive switches and sensors, and plastic injection molds. Aluminium– beryllium alloys, such as Brush-Wellman’s AlBeMets®, are used as optical substrates for night vision systems and avionics applications. Nickel–beryllium alloys have good spring characteristics and are used in applications such as thermostats and bellows.

1.3.2.3 Beryllium oxide

Beryllium oxide is used in a variety of ceramics applications such as medical laser bores, integrated circuits, electronic heat sinks and insulators, microwave oven components, gyroscopes, and thermocouple tubing.

1.3.3 Health Risks

The most noticeable adverse health effects from beryllium exposure are those affecting the respiratory system; however, effects on the lymph nodes, skin, and other target organs have been documented.

Acute beryllium disease is an inflammation of the entire respiratory tract caused by exposure to high levels of soluble beryllium. Symptoms may range from mild nasopharyngitis to severe pneumonitis, which could be fatal. These effects were reported in the US in the 1940s. All cases in the 1948 study involved exposures greater than 0.1 mg m-3. Imposition of exposure limits after 1950 all but eliminated acute beryllium disease.

At significantly lower levels, exposure to airborne beryllium particulate can cause an immune system response known as beryllium sensitization (BeS). Estimates of BeS range from 0.9% to 21.4% of those exposed, with some industrial processes having a higher prevalence of BeS than others. There is no established dose–response relationship, but BeS has been attributed in some studies to exposures below 0.2 [microg m-3 (mean daily lifetime weighted average). Studies are ongoing as to the mechanism by which sensitization occurs, but genetic susceptibility is believed to be a factor.

Sensitized individuals may go on to develop chronic beryllium disease (CBD), a debilitating and potentially fatal lung disease characterized by lesions in the lung known as granulomas. Because the mechanism of progression from exposure to BeS to CBD is not well understood, it is possible that once an individual is sensitized, a risk of developing CBD exists even if there is no further exposure to beryllium. Also, recent studies suggest that dermal exposure, in addition to causing contact dermatitis in some workers, may also be a pathway to BeS, although CBD appears to require some pulmonary exposure. Controlling workplace exposures to prevent BeS and/or CBD is the primary driver for the sampling and analysis activities described in this book.

Thus far, cases of CBD have involved exposure to anthropogenic forms of beryllium, i.e. metal, alloy, or oxide. Exposure to natural forms of beryllium (beryl or bertrandite) has not been shown to result in CBD, although BeS has been reported from such exposure.

Additionally, the International Agency for Research on Cancer (IARC) has determined that there is sufficient evidence that beryllium and compounds are human carcinogens. The US National Toxicology Program has reached a similar conclusion. Alternative conclusions have been presented in the literature, and discussion of the differing positions was ongoing at the time of writing.

1.3.4 Occupational Exposure Limits

In the US, initial exposure limits were established based on studies in the late 1940s by the Atomic Energy Commission. By this point, the existence of CBD and the need to protect against it, as well as acute beryllium disease, had been established. Additionally, instances of CBD were reported among residents near the beryllium plant in Lorain, Ohio. The initial proposal was for a peak exposure limit of 25 µg m-3, intended as protection against acute disease. Next, an ambient air limit of 0.01 µg m-3 was adopted for community protection. Finally, a limit value of 2 µg m-3 was proposed as an eight-hour time-weighted average to protect against CBD. This proposal was based on an extrapolation of the prevailing limit value for heavy metals such as arsenic and lead, accounting for the lower atomic weight of beryllium.

Within the US, two of the three original limits remain in place at the time of writing. The limit value of 2 µg m-3 (eight-hour time-weighted average) remains in place as the permissible exposure level (PEL) of the US Occupational Health and Safety Administration (OSHA). This limit value is also in use in many other countries, and until very recently, was also the threshold limit value (TLV®) of the American Conference of Governmental Industrial Hygienists (ACGIH®). The original ambient air quality standard of 0.01 mg m-3 also remains. In 1997, ACGIH® adopted a short-term exposure limit (STEL) of 10 mg m-3. Additional discussion on limit values in air can be found in Chapter 2.

A number of studies have established that an occupational exposure limit of 2 µg m-3, as well as the current STEL, are not adequately protective. As a result, proposals have been made to lower these limits. After issuing several notices of intended change (1999, 2005, 2006 and 2007), ACGIH® in early 2009 adopted a new TLV® of 0.05 mg m-3, but did not adopt a proposal to lower the STEL to 0.2 mg-3. OSHA has also begun the process to lower its PEL, possibly to as low as 0.1 mg m-3. A listing of occupational exposure limits for selected countries is provided in Table 1.2.

1.3.5 Impact of US Department of Energy Regulation

In 1999, the US Department of Energy (DOE) promulgated a regulation known formally as the Chronic Beryllium Disease Prevention Program (informally the Beryllium Rule), which established three action levels for DOE facilities:

(a) An airborne beryllium limit of 0.2 µg m-3

(b) A housekeeping limit of 3.0 µg per 100 cm2 for surfaces within beryllium work areas

(c) A limit of 0.2 µg per 100 cm2 for release of equipment to the public or to “non-beryllium” work areas

All of these action levels are empirical, as DOE recognized that the existing PEL was not adequately protective and, while wanting to take some steps to improve worker protection, did not have an exposure–response relationship on which to base any action levels.

At the time of writing, there is still no exposure–response relationship. DOE did not wait for such a relationship, and its action appears to be part of a trend toward lower empirical exposure limits and action levels. As noted previously, ACGIH® also acted in 1999, issuing the first of several notices of intended change. The 1999 proposal was in fact for a TLV® at the DOE action level of 0.2 µg m-3, with subsequent proposals even lower. In North America, the state of California and the province of Quebec have also lowered their workplace air exposure limits to 0.2 µg m-3 and 0.15 µg m-3, respectively. Finally, in OSHA’s report on its preliminary draft standard, options it has considered include essentially adopting the DOE Beryllium Rule.

The DOE Beryllium Rule is presently the only regulation with specific action levels for contaminated surfaces. However, others may soon follow. Studies of surface sampling have been performed in Quebec and at some US Department of Defense sites. OSHA has indicated that a surface PEL is a possible option for its new standard. Finally, a recent US National Academy of Sciences report commissioned by the US Air Force suggests that surface and skin contamination correlate with airborne contamination, and suggests that the Air Force perform surface sampling consistent with the DOE standard.

Thus, it is clear that the DOE Beryllium Rule has had appreciable impact within the US, and it appears reasonable, based on studies such as Day et al. and the National Academy of Sciences (NAS) report, to predict that both surface and dermal sampling for beryllium will increase, at least within the US. Even in the absence of specific numerical surface standards, some degree of surface sampling may be appropriate as part of an overall beryllium housekeeping program. Thus, the discussion in Chapter 3 of techniques for sampling and analysis of surfaces should be beneficial.

(Continues…)Excerpted from Beryllium by Michael J. Brisson, Amy A. Ekechukwu. Copyright © 2009 Royal Society of Chemistry. Excerpted by permission of The Royal Society of Chemistry.
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