DOCSLIB.ORG

Antimony Trioxide October 2018

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Antimony Trioxide October 2018 Report on Carcinogens Monograph on Antimony Trioxide October 2018 Report on Carcinogens Monograph on Antimony Trioxide October 19, 2018 Office of the Report on Carcinogens Division of the National Toxicology Program National Institute of Environmental Health Sciences U.S. Department of Health and Human Services RoC Monograph on Antimony Trioxide 10/19/18 Foreword The National Toxicology Program (NTP) is an interagency program within the Public Health Service (PHS) of the Department of Health and Human Services (HHS) and is headquartered at the National Institute of Environmental Health Sciences of the National Institutes of Health (NIEHS/NIH). Three agencies contribute resources to the program: NIEHS/NIH, the National Institute for Occupational Safety and Health of the Centers for Disease Control and Prevention (NIOSH/CDC), and the National Center for Toxicological Research of the Food and Drug Administration (NCTR/FDA). Established in 1978, the NTP is charged with coordinating toxicological testing activities, strengthening the science base in toxicology, developing and validating improved testing methods, and providing information about potentially toxic substances to health regulatory and research agencies, scientific and medical communities, and the public. The Report on Carcinogens (RoC) is prepared in response to Section 301 of the Public Health Service Act as amended. The RoC contains a list of identified substances (i) that either are known to be human carcinogens or are reasonably anticipated to be human carcinogens and (ii) to which a significant number of persons residing in the United States are exposed. The NTP, with assistance from other Federal health and regulatory agencies and nongovernmental institutions, prepares the report for the Secretary, Department of HHS. The most recent RoC, the 14th Edition (2016), is available at http://ntp.niehs.nih.gov/go/roc. Nominations for (1) listing a new substance, (2) reclassifying the listing status for a substance already listed, or (3) removing a substance already listed in the RoC are evaluated in a scientific review process (http://ntp.niehs.nih.gov/go/rocprocess) with multiple opportunities for scientific and public input and using established listing criteria (http://ntp.niehs.nih.gov/go/15209). A list of candidate substances under consideration for listing in (or delisting from) the RoC can be obtained by accessing http://ntp.niehs.nih.gov/go/37893. i RoC Monograph on Antimony Trioxide 10/19/18 Abstract Background and Objective: Antimony trioxide (Sb2O3) is a synergist in flame retardants, a catalyst in polyethylene terephthalate (PET) production, and a material used in various industrial process and consumer goods. Antimony trioxide is a potential public health concern because of occupational exposure and a suggested association with cancer based on animal studies. The National Toxicology Program (NTP) conducted a cancer hazard assessment of Sb2O3 for possible listing in the Report on Carcinogens (RoC), a document mandated by the U.S. Congress to provide information on cancer hazards for people residing in the United States. Methods: Using a systematic review approach, NTP evaluated evidences on human exposure, cancer studies in humans and experimental animals, mechanisms, and other relevant information. Studies identified via a systematic literature search of three databases were selected using pre- defined inclusion and exclusion criteria. Using a structured framework, multiple reviewers assessed human and animal cancer studies for the study quality (potential biases and study sensitivity) and utility of informing Sb2O3 carcinogenicity. NTP also evaluated mechanistic data, using the 10 key characteristics of carcinogens as a guide, and reviewed other relevant data, such as metabolism and toxicokinetic studies. Because Sb2O3 may exert its effects through released trivalent antimony ions, biological effects observed with other compounds containing trivalent antimony were also considered. Conclusions on the level of evidence (e.g., sufficient, limited, or inadequate) of the carcinogencity of antimony trioxide from cancer studies in experimental animals and humans, and the final listing recommendation (not to list, known or reasonably anticipated to be a human carcinogen) were reached by applying the RoC listing criteria to the body of evidence. Results and Discussion: Among over 5,500 references identified, 256 references were cited in the monograph. This included an evaluation of 5 cancer studies in experimental animals and 4 human cancer studies of independent populations. Antimony trioxide administered by inhalation caused lung tumors (i.e., malignant tumors and/or combined benign and malignant tumors) in rats and mice of both sexes and tumors at several other tissue sites (adrenal gland in female rats, skin in male mice, and lymphatic system in female mice). All studies, except one study in which the high dose was too low, reported increase in tumors. In human cancer studies, elevated mortality of lung cancer was seen in all three cohort studies of antimony-exposed smelter workers; however, it is unclear whether the increased risk was due to exposure to antimony or concurrent exposure to other lung carcinogens. An increased risk of stomach cancer was found in one case-control study and only one of two antimony smelter cohort studies. Evidence for antimony-induced biological effects potentially contributing to carcinogenicity include oxidative stress (and consequently oxidative damage) seen in cultured cells treated with Sb2O3 or other antimony compounds, and inhibition of DNA repair seen in cultured cells treated with antimony trichloride. Furthermore, trivalent antimony inhibits cell differentiation in cultured skin cells treated with antimony trichloride or ii RoC Monograph on Antimony Trioxide 10/19/18 antimony potassium tartrate, which also contains trivalent antimony, and consequently increase the potential for tumor development. Conclusions: NTP recommends that antimony trioxide is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals and supporting evidence from mechanistic studies. The data available from studies in humans are inadequate to evaluate the relationship between human cancer and exposure specifically to Sb2O3 or antimony in general. iii RoC Monograph on Antimony Trioxide 10/19/18 Collaborators, Contributors and Acknowledgments Collaborators Role Collaborator Affiliation Project lead Responsible for execution and H.S. Amy Wang, PhD NIEHS, DNTP* coordination of project activities, including conception, design, planning, conduct, and technical review of cancer hazard evaluation RoC Evaluation Team Contributed to the coordination of project Ruth M. Lunn, DrPH NIEHS, DNTP* activities, conception, design, conduct, technical review, and interpretation of studies for the cancer hazard evaluation Contributed to design, conduct, technical Sanford C. Garner, PhD ILS review, and interpretation of studies for the Joanne Trgovcich, PhD ICF cancer hazard evaluation Suril S. Mehta, MPH NIEHS, DNTP* Andrew D. Ewens, PhD ILS Alton F. Peters, MS ILS Kristine L. Witt, MS NIEHS, DNTP Contributors Role Contributor Affiliation Provided scientific input or technical Gloria D. Jahnke, DVM NIEHS, DNTP* assistance with the monograph preparation Jui-Hua Hsieh, PhD NIEHS, DNTP Melanie C. Buser, MPH ATSDR Kristina M. Hatlelid, PhD, MPH CPSC Linda M. Sargent, PhD CDC Yin-tak Woo, PhD EPA Whitney D. Arroyave, PhD ILS NIEHS internal review committee Provided critical review of the monograph Stephen S. Ferguson, PhD NIEHS, DNTP Gordon P. Flake†, MD NIEHS, DNTP Michelle J. Hooth, PhD NIEHS, DNTP B. Alex Merrick, PhD (Chair) NIEHS, DNTP Daniel L. Morgan, PhD NIEHS, DNTP Arun K.R. Pandiri, BVSc, MS, PhD NIEHS, DNTP Matthew D. Stout, PhD NIEHS, DNTP Kyla W. Taylor, PhD NIEHS, DNTP Erik J. Tokar, PhD NIEHS, DNTP Suramya Waidyanatha, PhD NIEHS, DNTP iv RoC Monograph on Antimony Trioxide 10/19/18 Acknowledgements Role Participant Affiliation Provided technical input or review Michael A. Babich, PhD CPSC Alison H. Harrill, PhD NIEHS, DNTP Sharon L. Oxendine, PhD EPA Nisha S. Sipes, PhD NIEHS, DNTP Stanley T. Atwood, MS ILS Organized the peer review of the Mary S. Wolfe, PhD NIEHS, DNTP monograph Developed a web-based database Andy J. Shapiro, MS NIEHS, DNTP (formerly) Provided editorial assistance Susan Dakin, PhD Independent consultant Provided administrative assistance Ella J. Darden, BS ILS Tracy L. Saunders, BS ILS Designed and performed literature Jessica A. Geter, MSLS ILS (formerly) searches Lara Handler, MSLS ILS Provided logistical support for the peer- F. Louise Assem, PhD ICF review meeting Susan Blaine, BA ICF Canden N. Byrd, BS ICF Anna N. Stamatogiannakis, BS ICF *Members of the Office of the Report on Carcinogens (ORoC). †Deceased July 30, 2018. ICF = ICF Incorporated, LLC (Support provided through NIEHS Contract Number GS00Q14OADU417/HHSN273201600015U). ILS = Integrated Laboratory Systems, Inc. (Support provided through subcontract number 16EDBO0078 with ICF). DNTP = Division of National Toxicology Program. NIEHS = National Institute of Environmental Health Sciences. v RoC Monograph on Antimony Trioxide 10/19/18 Peer Review Peer review of the Draft RoC Monograph on Antimony Trioxide was conducted by an ad hoc expert panel at a public meeting held on January 24 2018, in the Rodbell Auditorium at the National Institute of Environmental Health Sciences, David P. Rall Building, Research
Load more

Recommended publications
  • Citing Data Using ACS Style
    Sciences and Technology Library Citing Data using ACS Style ACS Style Guidelines for Citing Data The examples below are suggested formats for citing data such as physical property data or spectra obtained from various types of resources. The ACS Style Guide provides a few examples for citing data but does not include examples of the wide variety of online sources that are available. The purpose of the citation is to provide sufficient detail so that someone else can locate the data. Page numbers may not exist when citing online sources of data and therefore it may be necessary to indicate information like the CAS Registry Number or the entry name so that someone else can locate the exact information that was cited. For more information consult the ACS Style Guide: Effective Communication of Scientific Communication, 3rd edition (Sciences and Technology Library Reference QD 8.5 A25 2006). Citation Examples for Citing Data Web Sites Web sites can be government sites, organization sites, course web sites or personal home pages. Some websites are considered databases and should be cited as a database. See the information on databases listed below. Databases include a reference number or other identifying information along with one or more search options. General Features of Web Sites: accessible on the Internet no page numbers information cited is located at the URL provided – no additional searching is required Where to Find Citation Information: Look at the About Us links, Contact Us links, Copyright link, copyright information at the bottom of the search screen, links with the word Citation or Cite.
    [Show full text]
  • Transport of Dangerous Goods
    ST/SG/AC.10/1/Rev.16 (Vol.I) Recommendations on the TRANSPORT OF DANGEROUS GOODS Model Regulations Volume I Sixteenth revised edition UNITED NATIONS New York and Geneva, 2009 NOTE The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. ST/SG/AC.10/1/Rev.16 (Vol.I) Copyright © United Nations, 2009 All rights reserved. No part of this publication may, for sales purposes, be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, electrostatic, magnetic tape, mechanical, photocopying or otherwise, without prior permission in writing from the United Nations. UNITED NATIONS Sales No. E.09.VIII.2 ISBN 978-92-1-139136-7 (complete set of two volumes) ISSN 1014-5753 Volumes I and II not to be sold separately FOREWORD The Recommendations on the Transport of Dangerous Goods are addressed to governments and to the international organizations concerned with safety in the transport of dangerous goods. The first version, prepared by the United Nations Economic and Social Council's Committee of Experts on the Transport of Dangerous Goods, was published in 1956 (ST/ECA/43-E/CN.2/170). In response to developments in technology and the changing needs of users, they have been regularly amended and updated at succeeding sessions of the Committee of Experts pursuant to Resolution 645 G (XXIII) of 26 April 1957 of the Economic and Social Council and subsequent resolutions.
    [Show full text]
  • An Investigation of the Crystal Growth of Heavy Sulfides in Supercritical
    AN ABSTRACT OF THE THESIS OF LEROY CRAWFORD LEWIS for the Ph. D. (Name) (Degree) in CHEMISTRY presented on (Major) (Date) Title: AN INVESTIGATION OF THE CRYSTAL GROWTH OF HEAVY SULFIDES IN SUPERCRITICAL HYDROGEN SULFIDE Abstract approved Redacted for privacy Dr. WilliarriIJ. Fredericks Solubility studies on the heavy metal sulfides in liquid hydrogen sulfide at room temperature were carried out using the isopiestic method. The results were compared with earlier work and with a theoretical result based on Raoult's Law. A relative order for the solubilities of sulfur and the sulfides of tin, lead, mercury, iron, zinc, antimony, arsenic, silver, and cadmium was determined and found to agree with the theoretical result. Hydrogen sulfide is a strong enough oxidizing agent to oxidize stannous sulfide to stannic sulfide in neutral or basic solution (with triethylamine added). In basic solution antimony trisulfide is oxi- dized to antimony pentasulfide. In basic solution cadmium sulfide apparently forms a bisulfide complex in which three moles of bisul- fide ion are bonded to one mole of cadmium sulfide. Measurements were made extending the range over which the volumetric properties of hydrogen sulfide have been investigated to 220 °C and 2000 atm. A virial expression in density was used to represent the data. Good agreement, over the entire range investi- gated, between the virial expressions, earlier work, and the theorem of corresponding states was found. Electrical measurements were made on supercritical hydro- gen sulfide over the density range of 10 -24 moles per liter and at temperatures from the critical temperature to 220 °C. Dielectric constant measurements were represented by a dielectric virial ex- pression.
    [Show full text]
  • General Listing Background Document for the Inorganic Chemical Listing Determination
    GENERAL LISTING BACKGROUND DOCUMENT FOR THE INORGANIC CHEMICAL LISTING DETERMINATION August, 2000 U.S. ENVIRONMENTAL PROTECTION AGENCY ARIEL RIOS BUILDING 1200 PENNSYLVANIA AVENUE, N.W. WASHINGTON, D.C. 20460 TABLE OF CONTENTS Page LIST OF TABLES .............................................................ii LIST OF FIGURES ............................................................ii LIST OF APPENDICES .........................................................ii 1. INTRODUCTION .......................................................1 1.1 BACKGROUND ...................................................1 1.2 EXISTING INORGANIC CHEMICAL LISTINGS ........................2 1.3 OTHER EPA REGULATORY PROGRAMS AFFECTING THE INORGANIC CHEMICAL INDUSTRY ............................................3 2. INDUSTRY DESCRIPTION .........................................5 2.1 INDUSTRY PROFILE ..............................................5 2.2 INDUSTRY SECTORS .............................................5 2.2.1 Antimony Oxide ..............................................8 2.2.2 Barium Carbonate ............................................8 2.2.3 Boric Acid ..................................................8 2.2.4 Cadmium Pigments ............................................8 2.2.5 Inorganic Hydrogen Cyanide ....................................8 2.2.6 Phenyl Mercuric Acetate .......................................8 2.2.7 Dry Process Phosphoric Acid ....................................8 2.2.8 Phosphorous Pentasulfide .......................................8
    [Show full text]
  • Preparation of Aromatic Carbonyl Compounds
    ~" ' MM II II II Ml I III II II I Ml II I II J European Patent Office © Publication number: 0 178 184 B1 Office_„. europeen- desj brevets^ » © EUROPEAN PATENT SPECIFICATION © Date of publication of patent specification: 28.04.93 © Int. CI.5: C07C 45/45, C07C 49/76, C07C 51/58 © Application number: 85307320.3 @ Date of filing: 11.10.85 © Preparation of aromatic carbonyl compounds. © Priority: 11.10.84 US 659598 (73) Proprietor: RAYCHEM CORPORATION (a Dela- ware corporation) @ Date of publication of application: 300 Constitution Drive 16.04.86 Bulletin 86/16 Menlo Park, California 94025(US) © Publication of the grant of the patent: @ Inventor: Horner, Patrick James 28.04.93 Bulletin 93/17 139 Buckthorn Way Menlo Park California 94025(US) © Designated Contracting States: Inventor: Jansons, Vlktors AT BE CH DE FR GB IT LI NL SE 123 New York Avenue Los Gatos California 95030(US) References cited: Inventor: Gors, Helnrlch Carl EP-A- 0 024 286 EP-A- 0 069 598 2508 Mardell Way DE-A- 2 014 514 GB-A- 1 420 506 Mountain View California, 94043(US) GB-A- 2 103 604 US-A- 1 874 580 US-A- 3 282 989 Representative: Jay, Anthony William et al Raychem Limited Intellectual Property Law Department Faraday Road Dorcan Swindon Wiltshire (GB) 00 00 00 Note: Within nine months from the publication of the mention of the grant of the European patent, any person ® may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition CL shall be filed in a written reasoned statement.
    [Show full text]
  • Generation of Carbon Dioxide and Mobilization of Antimony Trioxide by Fungal Decomposition of Building Materials John D
    University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School 3-25-2005 Generation of Carbon Dioxide and Mobilization of Antimony Trioxide by Fungal Decomposition of Building Materials John D. Krause University of South Florida Follow this and additional works at: https://scholarcommons.usf.edu/etd Part of the American Studies Commons Scholar Commons Citation Krause, John D., "Generation of Carbon Dioxide and Mobilization of Antimony Trioxide by Fungal Decomposition of Building Materials" (2005). Graduate Theses and Dissertations. https://scholarcommons.usf.edu/etd/730 This Dissertation is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Generation of Carbon Dioxide and Mobilization of Antimony Trioxide by Fungal Decomposition of Building Materials by John D. Krause A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Environmental and Occupational Health College of Public Health University of South Florida Major Professor: Yehia Y. Hammad, Sc.D. Noreen D. Poor, Ph.D. Ann C. Debaldo, Ph.D. Diane Te Strake, Ph.D. Date of Approval: March 25, 2005 Keywords: mold, mould, carbon dioxide, antimony trioxide, flame retardant © Copyright 2005, John D. Krause Dedication For their love, support, patience and understanding throughout this endeavor, I dedicate this work to my family, daughter, and most of all, my loving wife. Acknowledgements I would like to acknowledge the following individuals and companies for their assistance in this research.
    [Show full text]
  • Landolt-Börnstein Indexes of Organic Compounds Subvolumes A-I by V
    Landolt-Börnstein Indexes of Organic Compounds Subvolumes A-I By V. Vill, C. Bauhofer, G. Peters, H. Sajus, P. Weigner, LCI-Publisher and Chemistry Department of the University of Hamburg All printed index material has been used to build up the comprehensive Scidex database index developed by LCI Publisher GmbH, Hamburg For further information please visit www.lci-publisher.com From this database a CD-ROM and two online versions were derived. The first is attached to each of the printed subvolumes and the latter are offered for free use at the following addresses: Scidex Database online with graphical structure search on http://lb.chemie.uni-hamburg.de/ Or the easy to use html version on http://lb.chemie.uni-hamburg.de/static/ Landolt-Börnstein Numerical Data and Functional Relationships in Science and Technology New Series / Editor in Chief: W. Martienssen Index of Organic Compounds Subvolume A Compounds with 1 to 7 Carbon Atoms Editor: V. Vill Authors: V. Vill, G. Peters, H. Sajus 1 3 ISBN 3-540-66203-0 Springer-Verlag Berlin Heidelberg New York Library of Congress Cataloging in Publication Data Zahlenwerte und Funktionen aus Naturwissenschaften und Technik, Neue Serie Editor in Chief: W. Martienssen Index of Organic Compounds A: Editor: V. Vill At head of title: Landolt-Börnstein. Added t.p.: Numerical data and functional relationships in science and technology. Tables chiefly in English. Intended to supersede the Physikalisch-chemische Tabellen by H. Landolt and R. Börnstein of which the 6th ed. began publication in 1950 under title: Zahlenwerte und Funktionen aus Physik, Chemie, Astronomie, Geophysik und Technik.
    [Show full text]
  • Financial Statements and Trustees' Report 2017
    Royal Society of Chemistry Financial Statements and Trustees’ Report 2017 About us Contents We are the professional body for chemists in the Welcome from our president 1 UK with a global community of more than 50,000 Our strategy: shaping the future of the chemical sciences 2 members in 125 countries, and an internationally Chemistry changes the world 2 renowned publisher of high quality chemical Chemistry is changing 2 science knowledge. We can enable that change 3 As a not-for-profit organisation, we invest our We have a plan to enable that change 3 surplus income to achieve our charitable objectives Champion the chemistry profession 3 in support of the chemical science community Disseminate chemical knowledge 3 and advancing chemistry. We are the largest non- Use our voice for chemistry 3 governmental investor in chemistry education in We will change how we work 3 the UK. Delivering our core roles: successes in 2017 4 We connect our community by holding scientific Champion for the chemistry profession 4 conferences, symposia, workshops and webinars. Set and maintain professional standards 5 We partner globally for the benefit of the chemical Support and bring together practising chemists 6 sciences. We support people teaching and practising Improve and enrich the teaching and learning of chemistry 6 chemistry in schools, colleges, universities and industry. And we are an influential voice for the Provider of high quality chemical science knowledge 8 chemical sciences. Maintain high publishing standards 8 Promote and enable the exchange of ideas 9 Our global community spans hundreds of thousands Facilitate collaboration across disciplines, sectors and borders 9 of scientists, librarians, teachers, students, pupils and Influential voice for the chemical sciences 10 people who love chemistry.
    [Show full text]
  • Gsaüiiveiwibte
    'C or GSAÜIIVEIWIBTE CUflIIITIIIi MïtiTHI AJIAlfïïf ,7 -' y/ . •'• .'7. 's -i, . \ STELLINGEN BEHORENDE BIJ HEJ FROEFSCHRIffT VAN R. FURLER 1. De episoomtheorie over het ontstaan van het mitochon- drion is weinig plausibel. R.A, Ratt and H.R. Mahler, Science 221 O972),575 2, Doordat S. Cirendini et al. de dragergassnelheid aan 'aet einde van een chromatografische kolom gebruiken, ontstaat een geflatteerd beeld van de weergegeven re- sultaten. Tevens is het niet mogelijk een dragergas- snelheid te berekenen zonder dat men de interstitiële porositeit kent» S, Cirendini, J. Vermont, J.C. Gressin and CL. Guilleain , J. Chromat. 84 (1973),24 3. De in de mode zijnde bepaling van RNA-moleculair ge- wichten door metingen aan formaldehyde behandelde RNA's berust op dubieuze aannamen. J.M. Kaper and M.E. v/aterworth,Virology 51 (1973),183 T.O. Diener and D.R. Smith, Virology *£ (^973), 359 M.M. El Manna and G. Bruening, Virology 56 (1973),198 4, Op grond van de zeer grote verschillen in stralingska- rakteristiek van de isotopen 1-131 en 1-123 is het streven van isotopenproducenten om een zo 'schoon' mogelijk 1-123 voor diagnostische doeleinden te leve- ren in strijd met de volksgezondheid, doordat de ver- tragingen#die dit oplevert onnodige stralingsbelasting voor patiënten veroorzaakt. H. ïlishiyama et al. J.Nucl.Med. 1£ (1974),261 5« De analogie die Gilbert et al. opmerken tussen de "exchange peak" in de kolom vloaistofchromatografie met behulp van ionenwisselaar en de luchtpi.ek bij gaschromatografie is twijfelachtig. T.W. Gilbert and R.A, Dobbs, Analyt.Chem. 45 (1>73), 1390.
    [Show full text]
  • Beitrag Zur Chemie Des Galliums the Synthesis and Some Properties of Gallium Ethoxide
    52 4 R. REINMANN UND A. TANNER Beitrag zur Chemie des Galliums The Synthesis and some Properties of Gallium Ethoxide R . R e in m a n n u n d A . T anner Forschungsinstitut der Schweizerischen Aluminium A.G., Neuhausen am Rheinfall/Schweiz (Z. Naturforsdig. 20 b, 524—525 [1965] ; eingegangen am 6. März 1965) Experimental amounts in the range of 50 g each of gallium triethoxide have been prepared by reacting gallium trichloride with freshly prepared sodium ethoxide in absolute alcohol. Chloride, always present in the raw product, can be eliminated by precipitation with silver nitrate. Gallium triethoxide crystallizes in colourless needles, melting at 144.5 °C. The density of the very hygro­ scopic product is 1.23 g/cc. It is volatile at elevated temperature in vacuum. By alcohol interchange, the ethoxide can easily be transformed to the isopropoxide. Although many of the various alkoxides are Sodium metal is carefully freed from its superficial described in the literature, those of gallium were crust in a glove box under dry nitrogen, weighed, and lacking until recently. dissolved in ethanol under reflux. The stoichiometric amount of gallium trichloride, dissolved in cooled etha­ The purpose of this investigation was to find a nol, is added dropwise to the sodium ethoxide solution. suitable method for the preparation of gallium The mixture is finally heated to ebullition for about ethoxide, and to evaluate also some properties of 30 minutes. After cooling, when the NaCl and the the new compound. major part of the Gallium ethoxide are precipitated, benzene is added to about 30 — 40% of the final When writing this manuscript, we came across the mixture.
    [Show full text]
  • Circular of the Bureau of Standards No. 539 Volume 10: Standard X-Ray
    :ationa.u d H.W. BIS <T be Libra.ry, Reisrence book not to 1965 JVPR 1 6 from ibe lib s ary. taken NBS C | RCULAR 539 VOLUME 10 Standard X-ray Diffraction Powder Patterns UNITED STATES DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS THE NATIONAL BUREAU OF STANDARDS Functions and Activities The Functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agencies on scientific and technical problems; in- vention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic and applied research, development, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. Research projects are also performed for other government agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau’s unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover. Publications The results of the Bureau’s work take the form of either actual equipment and devices or pub- lished papers. These papers appear either in the Bureau’s own series of publications or in the journals of professional and scientific societies.
    [Show full text]
  • 4. Inorganic Flame Retardants. Plastics Can Be Given Flame Retardant Characteristics by Introducing Elements of Organic, Inorganic and Halogen Origin
    4. Inorganic Flame Retardants. Plastics can be given flame retardant characteristics by introducing elements of organic, inorganic and halogen origin. Such elements include magnesium, aluminium, phosphorous, molybdenum, antimony, tin, chlorine and bromine. Flame retardants are added in either the manufacturing step of the polymer or the compounding step of the polymeric article. Phosphorous bromine and chlorine are usually included as some organic compound. Inorganic flame retardants are usually added together with other flame retardants to provide a more efficient flame retardant action through synergism. Halogen flame retardants usually need an addition of about 40% in order to be effective, and this affects the properties of the polymer quite negatively. Structural integrity of the polymer article is often very important, and a drastic decrease in strength and other mechanical properties is simply not acceptable. The efficiency of halogen flame retardants is often enhanced by the addition of inorganic flame retardants. A smaller mass percentage halogen flame retardant is now needed, so the adverse effect on the polymer properties is also reduced (Touval, 1993) . 4.1 Antimony Compounds The antimony compounds used for flame retardancy include antimony trioxide, antimony pentoxide and antimony-metal compounds. In 1990 in the United States alone, the use of antimony trioxide amounted to 20 000 metric tons just for the flame retardancy of plastics. Antimony oxide is readily found in nature but in very impure form. This is not suitable for 29 direct use as flame retardant, so antimony oxide is often rather produced from antimony metal. There are therefore many different grades of antimony oxide that can be used for flame retardants.
    [Show full text]