DOCSLIB.ORG

Measured Enthalpy and Derived Thermodynamic Properties of Solid and Liquid Lithium Tetrafluoroberyllate

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Measured Enthalpy and Derived Thermodynamic Properties of Solid and Liquid Lithium Tetrafluoroberyllate JOURNAL OF RESEARCH of the Notiona l Bureau of Standards-A. Ph ysics and Chemistry Vol. 73A, No.5, September- October 1969 Measured Enthalpy and Derived Thermodynamic Properties of Solid and Liquid Lithium Tetrafluoroberyllate, from 273 to 900 K 1 Thomas B. Douglas and William H. Payne 2 Institute for Basic Standards, National Bureau of Standards, Washington, D.C. 20234 (May 20, 1969) The enthalpy of a sampl e of lithium tetraAu oroberyllate, Li,BeF4 , of 98.6 percent purity was ?,easu. red re laLJ ve to 273 K a t eleven te mpe ratures from 323 to 873 K. Corrections we re appli ed fo r the Im purI li es and fo r ex t e n ~ lv e premelting below the m e lti~ g po int (745 K ). The e nthalpy and heat capacity, a nd the e ntropy a nd GIbbs free-energy functIOn rela LJ ve to the undetermined value of 5,°98 15 ' we re computed from empiri cal functIO ns of tem peratu re derived from the data and are tabuhied from 273 to 900 K. ' Key words: Drop calorimetry; enthalpy data; lithium beryllium Au oride; lithium te traAu orobe ryllate; premeltmg; th e rmodynamic properties. 1. Introduction The temperature-composition phase diagram of the condensed phases of the LiF-BeF 2 system has been As part of a long-term research program at the investigated in a number of laboratories. The version National Bureau of Standards on the thermodynamic in a fairly recent compilation of phase diagrams [3] is properties of the simpler li ght-element compounds, based on th e results of two groups of workers [4, 5]. the measure ments of hi gh-temperature enthalpy have Another composite di agram [6] is based on the results included several well-defin ed substances whi ch may of the above workers, as well as on those from two be regarded as double oxides or double fluorides of other publications [7 , 8] and additional work unpub­ lished at that time. A more recent version of the phase I two metals. S uch results have been published in two diagram, which is in essential agreement with the two papers for BeO · Ah03 (BeAh04) and BeO· 3Al2 0 3 already mentioned, is reproduced here as fi gure 1; it is (BeAlsO IO ) [1] ,3 are being obtained for 3LiF· AIF3 based largely on a comprehensive study at th e Oak (LiaAIF6 ), and are presente d in this paper for 2LiF · BeF2 Ridge National Laboratory [9]. One group of workers r (Li2 BeF4). The standard heats of formation and heat capacities of so me " double" compounds of this type [5] reported a compound LiF . 2BeF 2 not found in other are very nearly the same as the values calculated laboratories. There is general agreement, however, on additively from the parent binary compounds (in the the exi stence of the two solid compounds in the LiF­ same state), but in other cases there are considerable BeF 2 syste m indicated in fi gure 1. It will be noted that differences. Li2 BeF 4 , the compound of interest in this paper, is not The United States molten salt reactor program has quite congruent-melting, showing a peritectic point. , in recent years provided several notable demonstra­ The liquid fi eld is continuous, but when it has the tions of feasible examples. In nearly any foreseeable stoichiometric composition of LhBeF4 it may be thermal reactor of this type, the solvent for the fi ssile regarded as the liquid phase of this compound. Crystalline LhBeF4 exhibits an unusually small and/or fertile material is an LiF-BeF2 mixture of volume change when it melts (no more than 2 or 3 composition near that of Li2 BeF4 [2]. Accordingly, the percent [10]). This is attributed to the existence of thermodynamic properties of this compound are of two continuous void channels penetrating the unit cell great practical importance in this developing of the crystal, an unusual feature revealed by a recent y technology. quantitative structure determination [11]. A conse­ I Research sponsored by th e Advanced Researc h P rojects Agency, U.S. De partment of quence of this feature is that the crys tal density of Defense. un der ARPA Order No . 20 , and by the Ai r Force O ffi ce of Scie ntific Researc h _, Office of Aerospace Researc h, U.S. Air Force, un der AFOSR Contract No. ISSA 68-0004~ LhBeF4 is about 15 percent less than that computed 2 Present address: Science In fo rmat ion Ex change. 1730 M St. N. W., Washington, additively from the two component binary flu orides. D.C. 20036. 3 Figures in bracke ts indicate the li teratu re references at the end of thi s paper. An investi gation of the thermodynamic activities of 479 900 848 8 00 ~ I 700 ~ I 1 LiF + LlQUID u i ~ 600 \ -- \ 555 "" ---" 500 1\ ~ 458 V BeF2 (HIGH CUART Z TYPE ) .......... ' + :"" I QU ID 4 00 L -- ......... J -i--r- 360 L i F+ Li 2BeF4 "" I Li28 eF4 + BeF2 ( HIG H QUARTZ TYPE) --r--~. 300 --I 280 ,;:" I 1 m~ Li2~e F4 I L IBe F3 + BeF2 ( HIG H QUARTZ TYPE) ':;" .J L, Se F3 + 8eF2 ( LOW QUARTZ TY PE) ", 220 LiBe F3 CD I .J I 200 " L iF 10 20 30 4 0 50 60 70 80 90 oeF2 (mole %) FIGURE L The temperature-composition phase diagram of the LiF-BeF2 system (from ref [9])_ the components of the liquid LiF-BeF2 system has at about 400°C, in order to remove any volatile im­ recently been published [12]. purities that might have been produced by the acci­ Besides the above solid compounds in the LiF - BeF2 dental entrance of moisture during handling. The system, two gaseous compounds are known: from silver container was then sealed gas-tight by flame­ mass-spectrometric work the heats of formation at welding, and further enclosed within a container of 900 K of LiBeF3 (g) [13] and LizBeF4(g) [14] have been 80 Ni-20 Cr as a further precaution against escape of reported. The heat of formation of crystalline Li2BeF4 the toxic sample by volatilization or leakage during the at 298 K also has been reported [15]. subsequent enthalpy measurements. The measurements of enthalpy of Li2BeF4 reported After the completion of the enthalpy measurements, in this paper cover the temperature range 0 to 600°C. described in section 3, the sample was analyzed chemi­ Because the sampl~ was only 98.6 percent pure, there cally and spectrochemically in the Analytical Chemis­ was extensive "premelting" in the region 400-470 °C, try Division of the Bureau. The results of the chemical and the large corrections which this necessitated are analyses are given in table 1. The qualitative spectro­ sufficiently uncertain as to leave the derived heat of chemical analysis indicated the presence of the follow­ fusion much more uncertain than if the sample had ing additional elements in the ranges of abundance been highly pure. In addition, no low-temperature stated as weight percentages: 0.001-0.01 percent each 1 heat-capacity measurements on Li2BeF4 are available of Ag, AI, Cu, Fe, K, Mn, Na, Si, Ti, and Zr; 0.0001- to enable the calculation of values of absolute entropy 0.001 percent each of Ba, Ni, and Pb. (Thirty-five other from the data. elements were sought but not detected.) The deduction of the chemical composition of the 2. Sample sample was based entirely on table 1. It was assumed r that the metals were presen·t in their highest oxidation . The sample of lithium tetrafluoroberyllate was pre­ states, and the deficiency of fluorine in relation to the pared by the Oak Ridge National Laboratory, of Oak total equivalents of metal was assumed to be accounted Ridge, Tenn., by heating together in calculated propor­ for by oxygen, which was not analyzed for. Using the tions LiF and BeF2 to form a single liquid phase, mean analyses given in the last column of table 1, this followed by distillation of NHJIF2 from the material procedure accounted for 99.8 percent by weight of the in order to replace any oxygen present by fluorine. sample. However, the percentage of fluorine is obvi­ According to subsequent petrographic and x-ray exam­ ously the least precisely determined, so the percentage inations at ORNL, the colorless crystalline sample of this element was then taken to be 76.34 so that the consisted of a single phase within the detection limits percentages would add to exactly 100 percent. The of these methods. corresponding elemental composition of the sample After the sample was received, a portion of it (about then becomes the same as that of table 2, which was 3.3 g) was encased in a container of pure silver and used for correcting the thermal data to the basis of heated electrically in an efficient dry box for an hour pure Li2BeF4 in the manner described in section 4. 480 TABLE 1. Chemical analysis of the sample masses of parts of the container system, but not for impurities or premelting. For each furnace temperature the values are given in chronological order, although Element Individual analyses Mean the different furnace temperatures were run in some­ what random order. As always with this method, the Weight % Weight % times in the furnace adequate for reaching thermal Li a 13.87, a 13.85 b 13.85 equilibrium were predetermined from preliminary Be 9.36, 9.33 9.34 F 76.42,75.90, 75.56, 75.91 75.95 measurements at one temperature with deliberately Ca < 0.01 0.005 inadequate times.
Load more

Recommended publications
  • The Heat of Combustion of Beryllium in Fluorine*
    JOURNAL OF RESEARCH of the National Bureau of Standards -A. Physics and Chemistry Vol. 73A, No.3, May- June 1969 The Heat of Combustion of Beryllium in Fluorine* K. L. Churney and G. T. Armstrong Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234 (February 11, 1969) An expe rimental dete rmination of the e ne rgies of combustion in Auorine of polyte traAuoroethylene film and Q.o wder and of mixtures of beryllium with polytetraAuoroethyle ne gi ves for reacti on ( 1)f).H ~.or= - 1022.22 kJ 111 0 1- 1 (- 244.32 kcal mol - I) wit h a n ove ra ll precision of 0.96 kJ 111 0 1- 1 (0. 23 kcal 111 0 1- 1 ) at the 95 pe rce nt confid ence limit s. The tota l un cert a int y is estimated not to exceed ±3.2 kJ mol- I (±0.8 kcal mol - I). The measureme nts on polytetraflu oroeth yle ne giv e for reaction (2a) and reacti on (2 b) f).H ~. o c =- 10 369. 7 and - 10392.4 Jg- I, respective ly. Overall precisions e xpressed at the 95 pe rcent confide nce Ijmits are 3.3 and 6.0 Jg- I, respective ly. Be(c)+ F,(g) = BeF2(a morphous) (1) C,F.(polym e r powd er) + 2F2(g) = 2CF.(g) (2a) C2F.(polyme r film ) + 2F2 (g) = 2CF.(g) (2b) Be2C and Be metal were observed in a small carbonaceous residue from the co mbustion of the beryll iul11 -polytetraAuoroethylene mixtures.
    [Show full text]
  • Exposure Data
    BERYLLIUM AND BERYLLIUM eOMPOUNDS Beryllium and beryllium compounds were considered by previous Working Groups, In 1971,1979 and 1987 (lARe, 1972, 1980, 1987a). New data have since become available, and these are included in the present monograph and have been taken into consideration In the evaluation. The agents considered herein Include (a) metallic beryllium, (b) beryllium- aluminium and -copper alloys and (c) some beryllum compounds. 1. Exposure Data 1.1 Chemical and physical data and analysis 1.1.1 Synonyms, trade names and molecular formulae Synonyms, trade names and molecular formulae for beryllium, beryllum-aluminium and -copper alloys and certain beryllium compounds are presented in Thble 1. The list is not exhaustive, nor does it comprise necessarily the most commercially important beryllum- containing substances; rather, it indicates the range of beryllum compounds available. 1. 1.2 Chemical and physical properties of the pure substances Selected chemical and physical properties of beryllium, beryllum-aluminium and -copper alloys and the beryllium compounds covered in this monograph are presented in Thble 2. The French chemist Vauquelin discovered beryllium in 1798 as the oxide, while analysing emerald to prove an analogous composition (Newland, 1984). The metallc element was first isolated in independent experiments by Wöhler (1828) and Bussy (1828), who called it 'glucinium' owing to the sweet taste of its salts; that name is stil used in the French chemical literature. Wöhler's name 'beryllum' was offcially recognized by IUPAe in 1957 (WHO, 1990). The atomic weight and corn mon valence of beryllum were originally the subject of much controversy but were correctly predicted by Mendeleev to be 9 and + 2, respectively (Everest, 1973).
    [Show full text]
  • United States Patent Office Patented Jan
    2,732,410 United States Patent Office Patented Jan. 24, 1956 2 The process can be carried out in various ways. Thus, 2,732,410 the vaporized halogen fluoride can be passed, if desired PROCESS FOR PREPARNG TETRAFLUORO with an inert carrier gas such as nitrogen, argon or helium, ETHYLENE BY REACTING CARBON AND through a column of carbon heated at a temperature of A BINARY HALOGEN FLUORDE at least 1500 C. in a suitable reactor, e. g., a graphite Mark W. Farlow, Holly Oak, and Earl L. Muetterties, tube placed inside a resistance furnace or an induction Hockessin, Dei, assignors to E. I. du Post de Neois's furnace. The gaseous reaction products are then imme and Company, Wilmington, Del, a corporation of Dela diately treated, as described below, to remove any un Ware reacted halogen fluoride and any free chlorine or bromine, 0 in order to minimize or eliminate the possibility of their No Drawing. Application January 12, 1955, reacting with the tetrafluoroethylene present in the re Serial No. 481,482 action product. A preferred mode of operation consists in 4 Claims. (C. 260-653) reacting the halogen fluoride with the carbon electrodes of a carbon arc, where the temperature is estimated to be in This invention relates to a new process of preparing 15 the range of 2500 to 3500-4000 C., and again immediate compounds containing only carbon and fluorine, or car ly removing from the effluent gas any halogen fluoride and bon, fluorine and another halogen, such compounds be free reactive halogen which may be present.
    [Show full text]
  • Sulfur Hexafluoride Hazard Summary Identification
    Common Name: SULFUR HEXAFLUORIDE CAS Number: 2551-62-4 RTK Substance number: 1760 DOT Number: UN 1080 Date: April 2002 ------------------------------------------------------------------------- ------------------------------------------------------------------------- HAZARD SUMMARY * Sulfur Hexafluoride can affect you when breathed in. * If you think you are experiencing any work-related health * Sulfur Hexafluoride can irritate the skin causing a rash or problems, see a doctor trained to recognize occupational burning feeling on contact. Direct skin contact can cause diseases. Take this Fact Sheet with you. frostbite. * Exposure to hazardous substances should be routinely * Sulfur Hexafluoride may cause severe eye burns leading evaluated. This may include collecting personal and area to permanent damage. air samples. You can obtain copies of sampling results * Breathing Sulfur Hexafluoride can irritate the nose and from your employer. You have a legal right to this throat. information under OSHA 1910.1020. * Breathing Sulfur Hexafluoride may irritate the lungs causing coughing and/or shortness of breath. Higher WORKPLACE EXPOSURE LIMITS exposures can cause a build-up of fluid in the lungs OSHA: The legal airborne permissible exposure limit (pulmonary edema), a medical emergency, with severe (PEL) is 1,000 ppm averaged over an 8-hour shortness of breath. workshift. * High exposure can cause headache, confusion, dizziness, suffocation, fainting, seizures and coma. NIOSH: The recommended airborne exposure limit is * Sulfur Hexafluoride may damage the liver and kidneys. 1,000 ppm averaged over a 10-hour workshift. * Repeated high exposure can cause deposits of Fluorides in the bones and teeth, a condition called “Fluorosis.” This ACGIH: The recommended airborne exposure limit is may cause pain, disability and mottling of the teeth.
    [Show full text]
  • Patent Office
    Patented Mar. 12, 1940 2,193,364 UNITED STATES PATENT OFFICE 2,193,364 PROCESS FOR OBTANING BEEY UMAND BERYLUMAL LOYS Carlo Adamoli, Milan, Italy, assignor to Perosa Corporation, Wilmington, Oel, a corporation of Delaware No Drawing. Application April 17, 1939, Serial No. 268,385. a tally June 6, 1936 16 Claims. (C. 5-84) The present application relates to a process ical method for the production of beryllium and for directly obtaining in a single operation start its alloys by treatment with a decomposing bi ing from halogenated compounds containing be valent metal such as magnesium, of a fluorine ryllium, beryllium as such or in the state of alloys containing compound of beryllium, that is a 5 with one or more alloyed elements capable of double fluoride of beryllium and an alkali metal 5 alloying with beryllium, and is a continuation-in (sodium) less rich in sodium fluoride than the part of my prior application Ser. No. 144,411 filed normal double fluoride BeFa2NaF. on May 24, 1937. The practical impossibility in fact has been In my said prior application, I have disclosed established which is met with in operating with 0 a process for directly obtaining in a single oper the normal double fluoride according to the re o ation beryllium or beryllium alloys starting from action: simple beryllium fluoride anhydrous and free or Substantially free from oxide. The present in which is rendered explosive by reason of the lib vention relates more particularly to a process eration of sodium and this is the reason in par s 5 of manufacture of beryllium or beryllium alloys ticular why instead of the normal double fluo starting from normal double fluoride of beryllium ride BeF2.2NaF the complex fluoride BeFa.NaF and an alkali-metal, the term “normal' being in is treated according to the reaction: tended to designate double fluorides containing ! 2BeFaNaF.--Mg-Be--MgF2--BeF2,2NaF two molecules of alkali fluoride for one molecule 20 of beryllium fluoride.
    [Show full text]
  • Effects of Fluoride and Other Halogen Ions on the External Stress Corrosion Cracking of Type 304 Austenitic Stainless Steel
    NUREG/CR-6539 _ Effects of Fluoride and Other Halogen Ions on the External Stress Corrosion Cracking of Type 304 Austenitic Stainless Steel M low, F. B. Ilutto, Jr. Tutco Scientific Corporation Prepared for U.S. Nuclear Regulatory Commission pfo)D'' ~%, 1 a- ! '% .. lill|Il||# lilllll:[ll[Ill]Ol|Ill E M 72A8A!8 * 7 * CR-6539 R PDR __ . - . .-- I | ! ' AVAILABILITY NOTICE Availabilny of Reference Matenals Cited in NRC Pubhcations Most documents cited in NRC publications will be available from one of the following sources: 1. The NRC Public Document Room, 2120 L Street, NW., Lower Level. Washington, DC 20555-0001 i | 2. The Superintendent of Documents, U.S. Government Pnnting Office, P. O. Box 37082. Washington, DC 20402-9328 l 3. The National Technical information Service Springfield, VA 22161-0002 Although the listing that follows represents the majority of documents cited in NRC publications, it is not in- tended to be exhaustive. Referenced documents available for inspection and copylng for a fee from the NRC Public Document Room include NRC correspondence and internal NRC memoranda; NRC bulletins, circulars, information notices, in- spection and investigation notices; licensee event reports; vendor reports and correspondence; Commissen papers; and applicant and licensee documents and correspondence. The following documents in the NUREG series are aves slo for purchase from the Government Printing Office: formal NRC staff and contractor reports, NRC-sponsored conference proceedings, internatior,al agreement reports, grantee reports, and NRC booklets and brochures. Also available are regulatory guides NRC regula- tions in the Code of Federal Regulations, and Nuclear Regulatory Commission issuances.
    [Show full text]
  • 68854 Federal Register / Vol
    68854 Federal Register / Vol. 64, No. 235 / Wednesday, December 8, 1999 / Rules and Regulations DEPARTMENT OF ENERGY H. Review Under Small Business as nuclear reactor moderators or Regulatory Enforcement Fairness Act of reflectors, and as nuclear reactor fuel 10 CFR Part 850 1996 element cladding. At DOE, beryllium Appendix A to the PreambleÐReferences operations have historically included Appendix B to the PreambleÐQuestions and [Docket No. EH±RM±98±BRYLM] Answers Concerning the Beryllium melting, casting, grinding, and machine Induced Lymphocyte Proliferation Test tooling of parts. (Be±LPT), Medical Records, and the Inhalation of beryllium dust or RIN 1901±AA75 Department of Energy (DOE) Beryllium particles can cause chronic beryllium disease (CBD) or beryllium Chronic Beryllium Disease Prevention Registry sensitization. CBD is a chronic, often Program I. Introduction debilitating, and sometimes fatal lung AGENCY: Office of Environment, Safety This final rule implements a chronic condition. Beryllium sensitization is a and Health, Department of Energy. beryllium disease prevention program condition in which a person's immune (CBDPP) for the Department of Energy system becomes highly responsive ACTION: Final rule. (DOE or the Department). This program (allergic) to the presence of beryllium in will reduce the number of workers the body. There has long been scientific SUMMARY: The Department of Energy currently exposed to beryllium at DOE consensus that exposure to airborne (DOE) is today publishing a final rule to facilities managed by
    [Show full text]
  • Ammonium Fluoride Product Stewardship Summary February 2012
    Ammonium Fluoride Product Stewardship Summary February 2012 (NH4)F Chemical Name: Ammonium Fluoride Chemical Category (if applicable): Inorganic neutral halide Synonyms: Neutral ammonium fluoride; Commercial ammonium fluoride; and (NH4)F CAS Number: 12125-01-8 CAS Name: Ammonium fluoride EC (EINECS) Number: 235-185-9 Other identifier (Please specify): GPS0050 Honeywell manufactures ammonium fluoride that is used by industry in the manufacture of electronic materials. Exposure can occur at either an ammonium fluoride manufacturing facility or at other manufacturing, packaging or storage facilities that handle ammonium fluoride. Persons involved in maintenance, sampling and testing activities, or in the loading and unloading of packages containing ammonium fluoride are at risk of exposure, but worker exposure can be controlled with the use of proper general mechanical ventilation and personal protective equipment. Workplace exposure limits for fluoride ion have been established for use in worksite safety programs. When ammonium fluoride is a component of consumer products, users should follow manufacturer’s use and/or label instructions. Ammonium fluoride dusts released to the atmosphere and deposited in soil or surface water in the vicinity of production sites have negligible impact on the environment. Please see the MSDS for additional information. Ammonium fluoride is a nonflammable solid that is stable under normal conditions. Ammonium fluoride is corrosive to metals and glass. It can react with acids to liberate hydrogen fluoride and bases to liberate ammonia. When heated to decomposition, it will release toxic hydrogen fluoride gas and ammonia. Contact of ammonium fluoride with water or extended skin contact under moist conditions can produce hydrofluoric acid (HF), a very dangerous acid that can cause burns of the skin and eyes.
    [Show full text]
  • Reaction of Potassium Fluoride with Organic Halogen Compounds. I
    Reaction of Potassium Fluoride with Organic Halogen Compounds. I) Reactions of Potassium Fluoride with Organic Halides, Acids, aad Esters in presence ef Dimethyl Formamide and their Pyrolytic Decaboxylation in presence of Potassium Fluoride By You Sun Kim Atomic Energy Research Institute, Korea 有機 할로겐 化合物과 弗化加里의 反應 （第1報） 有機 할라어드, 酸 및 에스테르와 弗化加里의 디메칠 호쁨아마이드 溶蝶系 反應 및 高混■■脫炭酸-熱分解反應 金 裕 *善 （1963. 6. 19 受理） Abstract Reactions between potassium fluride with organic halogen-containning carboxylic acids in dimethyl formamide solvent gave a decarboxylation reaction for the case of fluoro carboxylic acids of the type of CF3 COOH, C3F7COOH, and C2F5COOH, whereas an additional partial fluorination together with dimeri­ zation reaction occured for the chlorine containning acids of the type of CH2CICOOH, CH3CHCICOOH, CHCI2COOH and o-Cl-CeHi-COOH. The phenyl halides showed no reactivity, but the halides with two electron attracting substituents on the benzene ring gave mainly dimerization reaction. The esters and alcohols gave an usual fluorination reaction. The same reactions in absence of the solvent at the elevated temperature increase the yield of the dimerized product and gave the cyclized product, fluorenone, in case of o-chlorobenzoic acid. It was found that the fluorination usually precede the decarboxylation reaction by checking the stiochemical sequence of reaction. Catalytic influence of potassium fluoride were discussed and the mechanism of the reaction was considered. 耍 約 「디메望호름아마이드」溶媒系에서 有機含할로겐化合物을 弗化加里와 反應시켜 본 結果 CFsCOOH, CsF’COOH, CzFQOOH 와 같은 含弗素有機酸에서는 脫炭酸反應이 일어나며, 含鹽素有機酸, CH2C1COOH. CH3CHC1COOH, CHC12- COOH 및 o-CK사LCOOH 은 一部 弗化反應이 일어 나고 雙合어imerization) 反應이 隨伴된다는 것을 究明하였다.
    [Show full text]
  • ADA Fluoridation Facts 2018
    Fluoridation Facts Dedication This 2018 edition of Fluoridation Facts is dedicated to Dr. Ernest Newbrun, respected researcher, esteemed educator, inspiring mentor and tireless advocate for community water fluoridation. About Fluoridation Facts Fluoridation Facts contains answers to frequently asked questions regarding community water fluoridation. A number of these questions are responses to myths and misconceptions advanced by a small faction opposed to water fluoridation. The answers to the questions that appear in Fluoridation Facts are based on generally accepted, peer-reviewed, scientific evidence. They are offered to assist policy makers and the general public in making informed decisions. The answers are supported by over 400 credible scientific articles, as referenced within the document. It is hoped that decision makers will make sound choices based on this body of generally accepted, peer-reviewed science. Acknowledgments This publication was developed by the National Fluoridation Advisory Committee (NFAC) of the American Dental Association (ADA) Council on Advocacy for Access and Prevention (CAAP). NFAC members participating in the development of the publication included Valerie Peckosh, DMD, chair; Robert Crawford, DDS; Jay Kumar, DDS, MPH; Steven Levy, DDS, MPH; E. Angeles Martinez Mier, DDS, MSD, PhD; Howard Pollick, BDS, MPH; Brittany Seymour, DDS, MPH and Leon Stanislav, DDS. Principal CAAP staff contributions to this edition of Fluoridation Facts were made by: Jane S. McGinley, RDH, MBA, Manager, Fluoridation and Preventive Health Activities; Sharon (Sharee) R. Clough, RDH, MS Ed Manager, Preventive Health Activities and Carlos Jones, Coordinator, Action for Dental Health. Other significant staff contributors included Paul O’Connor, Senior Legislative Liaison, Department of State Government Affairs.
    [Show full text]
  • 2. Relevance to Public Health
    FLUORIDES, HYDROGEN FLUORIDE, AND FLUORINE 15 2. RELEVANCE TO PUBLIC HEALTH 2.1 BACKGROUND AND ENVIRONMENTAL EXPOSURES TO FLUORIDES, HYDROGEN FLUORIDE, AND FLUORINE IN THE UNITED STATES Fluorine is the most electronegative and reactive of all elements; fluoride is the ionic form of fluorine. Fluorine and anhydrous hydrogen fluoride are naturally occurring gases that have a variety of industrial uses including the production of fluorine-containing chemicals, pharmaceuticals, high octane gasoline, and fluorescent light bulbs; aqueous hydrofluoric acid is a liquid used for stainless steel pickling, glass etching, and metal coatings. The general population is typically exposed to very low levels of gaseous fluoride (primarily as hydrogen fluoride); in the United States and Canada, the levels ranged from 0.01 to 1.65 µg/m3. Populations living near industrial sources of hydrogen fluoride, including coal burning facilities, may be exposed to higher levels of hydrogen fluoride in the air. Additionally, vegetables and fruits grown near these sources may contain higher levels of fluoride, particularly from fluoride- containing dust settling on the plants. Fluoride salts, generically referred to as fluorides, are naturally occurring components of rocks and soil. One of the more commonly used fluoride salt is sodium fluoride; its principal use is for the prevention of dental caries. Sodium fluoride and other fluoride compounds, such as fluorosilicic acid and sodium hexafluorisilicate, are used in the fluoridation of public water. Sodium monofluorophosphate and stanneous fluoride are commonly used in dentifrices such as toothpaste. The general population can be exposed to fluoride through the consumption of fluoridated drinking water, food, and dentifrices.
    [Show full text]
  • SDS US 2945 Version #: 02 Revision Date: 03-17-2021 Issue Date: 01-21-2020 1 / 10 Precautionary Statement Prevention Obtain Special Instructions Before Use
    SAFETY DATA SHEET 1. Identification Product identifier Lithium Beryllium Fluoride Other means of identification SDS number M47 Synonyms FLiBe Manufacturer/Importer/Supplier/Distributor information Manufacturer Company name Materion Brush Inc. Address 6070 Parkland Boulevard Mayfield Heights, OH 44124 United States Telephone 1.800.862.4118 Website www.materion.com E-mail [email protected] Contact person Theodore Knudson Emergency phone number 1.800.862.4118 2. Hazard(s) identification Physical hazards Not classified. Health hazards Acute toxicity, oral Category 3 Acute toxicity, inhalation Category 2 Skin corrosion/irritation Category 2 Serious eye damage/eye irritation Category 2 Sensitization, skin Category 1 Carcinogenicity Category 1B Specific target organ toxicity, single exposure Category 3 respiratory tract irritation Specific target organ toxicity, repeated Category 1 exposure Environmental hazards Hazardous to the aquatic environment, Category 2 long-term hazard OSHA defined hazards Not classified. Label elements Signal word Danger Hazard statement Toxic if swallowed. Causes skin irritation. May cause an allergic skin reaction. Causes serious eye irritation. Fatal if inhaled. May cause respiratory irritation. May cause cancer. Causes damage to organs (respiratory system) through prolonged or repeated exposure by inhalation. Toxic to aquatic life with long lasting effects. Material name: Lithium Beryllium Fluoride SDS US 2945 Version #: 02 Revision date: 03-17-2021 Issue date: 01-21-2020 1 / 10 Precautionary statement Prevention Obtain special instructions before use. Do not handle until all safety precautions have been read and understood. Do not breathe dust. Wash thoroughly after handling. Do not eat, drink or smoke when using this product. Use only outdoors or in a well-ventilated area.
    [Show full text]