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Home My WebLink AboutGlenn Cutler w rN� Centers or Disease Control and Prevention Miir" t�C k'iwlil rildtc! li � United es Department of Health and m n Se i ...�.�� http://www.cdc.govfTerriplatePackaagcw13.0/irysage s`mast.head_subpage,svg � Water FlUoriclatiori Additives Fact Sheet 'Types of Fluoride Additives wgrrMRtttjsty. ftL§y1ttiqrs in the United„Stater,use one of three,additNes for water tlwluor d att c)n.Decisions on which additive to use are teased on cast of product,prodauct-handling requirements,space availability,and equipment. 'fhe three additives are: [`_Lqgtosi fi6c_d�act w�raak r-based saa[ution us key„rny t gt w_ � tpa tie_,.in Unitfu „�t��rt_F9sacawfz obi ac acid is also referred to wad hydrpflea ro iiaate_w. car.u(dt . Sodium fluorosgicate:a dry additive,dissolved into a sotutic>n before being added to water. Sodiurn fluoride:a dry additive,typically used in small water systems,disc olvpd into a solution twfore teeing added to water. Sources of Fluoride Additives ?la t,t)aas ur uM arfcFattyg _ta pd to the United Sta ,a ,j§_p d�rra±ab pFacf p)oorTy(ta�,rpe m Phosphorite is mainly used for Manufacturing phosphate fertilizer. Phosphorite contains calcium phosphate mixed with limestone(calcium carbonates)minerals and apatite--a mineral with high phosphate and fluoride content. It is refluxed(heated)with sulfuric acid to produce a phosphoric acid-gypsum(calcium sulfate-CaSO4)slurry. The heating process releases hydrogen fluoride(HF)and silicon tetrafluoride(SiF4)gases,which are captured by vaouum evaporators.These gases are then condensed to a water-based solution of approximately 23%FSA, Approximately 95%of FSA used for water fluoridation cornes from this process.The remaining 5%of FSA is produced in manufacturing hydrogen fluoride or from the use of hydrogen fluoride to etch silicates and glasses when manufacturing solar panels and electronics. Since the early 1950s, FSA has been the main additive used for water fluoridation in the United States.The favorable cost and high purity of FSA make it a popular additive.Sodium fluorosilicate and sodium fluoride are dry additives that come from FSA. FSA can be partially neutralized by either table salt(sodium chloride)or caustic soda to get sodium fluorosilicate. If enough caustic soda is added to completely neutralize the fluorosilicate,the result is sodium fluoride.About 90%of the sodium fluoride used in the United States comes frorn FSA. Sodium fluoride is also produced by mixing caustic soda with hydrogen fluoride. Regulatory Scope on Additives F1°,gA�.S -;,nvwr rrwarentM Protc tiprr, a a c C:tl1 )_h°eta _ wrt farat'y<ay r ..:..aixtwaty w aamr mraa w:...Fg m wfw*r_hi the Safe; aa_u w�a Can the basis of the scientific study of potential harrnf'ud heafth effects frorn contaminated water,the EPA sks a Maximum Contaminant t..eveb (MCL)conc e.ntration allowed for various organisrras or substances, Although the EPA does riot specifically regulate tevets of"dire additives,”which are additNes addr-pct to water in the course of treatment,it dcres specify that the addition of chemicals as part of the treatment process should not tae rnorafc than the MCt.raoncer0ration for regulated substances. This MC,'k....lirnit includes the levels natural) occurring irr the source water, alas the contribution frorn direct additives. In ft�� t� o w.a e y .t� d g F ei tjoraaradyn.i of_L9radgr^ tandin,with the US,_Fools,data! r�rasaisFLTtror�:.L�r� )tc)gdF bdrsh an claru6y_w s.of.auQftg ty_in confrollata� ifs,.dc rtiv.p uart_w�runki%m water. FDA has regul�atcary oversight for food addifves,which includes botGed water,and EPA,phanar fGaftoty.,�q a rsam Fat 9�f di glLqdklj tr f (rr_dastFr @a OrinkirjjAgt rqVp aaWs. Because of the decision to transfer the additives prograarn to the puiv;.ate sector,EPA declared_f..rnoraFa minim irde1 c uj ur su Lie aN_adv farfr p1jinions on aftfivesr EPA awarded a g perprgr f �aarrrgeafv�rak lra sa r�rrrtar�.a�F sac�rlpro6aF.n¢arr � rwua r�arrk�l_cr rruz�aFion led.Zy�d,q atticsfa l Sa ni(aaborl oundrt4,iraL1j(4Sw[,jjn Y 94f2_dgq _Na darksarau tigLgc a kca_ata wra tgra rr ya_a ddr)rycr pre adrru'LFKgt yc r5_iat r t P nnoun t that the rardyr aatrcwru aY rawtdtrratr, a rwdaakrcaraF nerir, as Nationaai Standards Naw fift FF"�F� d ad ,kgEr sgLc.Q was iru.a��sd� ra. Information on drinking water treatment quality assurance practices of governmentar authorit es in vahous counlrries can be found in tp... fP Used tua rrrfl the Ovar'sklw of atiiarr�a/yin d.Mtersr�sVfa nil�artqdpPsr�t..+..nd 6t're�.c;raurrr�rRic(rgfr�aa.i.r."1.R._thr sse s �rrt;..C�J i a,r gu i grr,. Tr�ft,r�atrrrraiut_c:(ftirr kin t( )f°W w.l. ...i'idn�„d.']'his document discusses the Auneric"van aater yvcarks Association('AWWA)and NSF/ANSI standards and practices,which apply to water fluoridation in the United States, EPA Regalatory Criteria for Fluoride Additives additives a lyqt �fiqa A%AWA and NSF International.Both of these organizations are nonprofit, nongovernmental organizations. Fluoridated community water systems adjust fluoride to approximately 0.7 milligrams per Liter(mg/L). Because in some rare locations fluoride is ' naturally present in water at much higher levels,the EPA established a Maximum Contaminant Level(MCL)for fluoride of 4.0 mg/L(parts per | miUiun). -rhe EPA has not established an MCL for silicates,the second most prevalent substance in FSA, because there are no known health concerns, NSFIANSr Standard 60,however,has a Maximum Allowable Levei of 16 mgfL for sodium silicates as corrosion control agents.'Th��smaim`iyhu control turbidity—a measure of water clarity or how much the material suspended in water decreases light passing through the water. Studies have shown that silicofluorides achieve virtually complete dissolution and ionic disassociation at the concentrations used when they are added to the drinking water.The equilibrium reached at the pid,temperature, and fluoride concentration used in water fluoridation account for this. One study reported that no intermediates or other products were observed at pid levels as low as 3.5. (Finney WF,Wilson E,Callender A, Morris MD, Beck LW. EnvirnmS6 Terhncl2OO8;4O:82572). The studies that examined potential health effects from sodium fluoride additives in drinking water should also apply to FSA because they have the same results for ionic disassociation, AVVVVAStendorde The AWWA sets the minirnum requirements for the design, installation, performance, and manufacturing of fluoride products used for adjusting water content.The AWWA standards for fluoride additives are ANSI/AWWA B701 (sodium fluoride),ANSI/AWWA B702(sodium flUorosilicate), arid ANSI/AWWA B703(FSA).AWWA's standards are prepared by its Fluoride Standards Committee,with oversight by the Standards Council, concurrence by the AWWA Board of Directors, and concurrence by ANSI.AWWA standards are reviewed and updated at least every 5 years. AWWA standards stipulate product quality testing requirements and verification. NSF/ANSI Standards for Drinking Water Additives The NSF/ANS1 Standard 60 limris a chernical or product's Gontyibution of contaminants to drinking water applications.StantIgLgL[ _p It includes a detailed audit of the production of the additive products,yai�at�n test\ng of quafty,arid aud�nq of alt locations for iogistic handWq� There are also specific criteria for imported products from other countries,and in conjunction with NSF/ANSI Standard 223,there is conformity in quality controls regardless of where certification occurs or which entity performs the certification Forty-seven states have laws nrregulations requiring product compliance with Standard 0O, NSF/ANSI standards 8O and D1 (a related standard that applies m products that come in contact with water)were developed by consortium of associations, including NSF,AvVvVA`ANSI,the Asoouiabnnnf8toteD/inkingVVoterAdminiatmtnm. andtheCunfemnoeof8tateHea|thanUEnvimnmontn|Managem8tangardsOOand61ae accepted by the EPA as the requirements for controlling pntonUm|harmful effects from products added to water for its treatment.These standards replaced the fonnerEPA Additives Advisory Program.More information on Standard 6Qimposted on web*&e. Independent organizations,including NSF International and Qndepwfiters Lmbmnatonem,verify that fluoride additives meet the NSFIANSt standards.'T hese organizations test fluoride additives for regulated metai compounds and offier substances that have anEPA MCLForm fluoride additive product to meet certification staodands,regulated rnetal cormpmymda added by the water treatment process must have e oonoentomtionIess than 1V%mf Hie MCL A comprehensive assessment vfthe ANS|/NSF Standard 68 for more than 30sddMvas,was pmb}Ishedin2804. This peer-mviemrdassessment concluded that the process successfully met the stated goals m{prmwentim0punblernm with homacmntmminantsin@-S,water trmaunentaftfibes. Mpm information is available in the following afficle:Bnzwm.CmomweR.Mac',Phee. (Journal of the American Water Works Association 20O4;961211'l-123�) MeaSu[ed Levels of|mpmhfies Fluoride additives are analyzed for potential impurities indudinq ersen\c,lead,and rad\unuc"dey.Vwdfication ofcmn p\\mnomwith NGpx\NS1 Standard 6u must also hecertified, NSF hosts a detailed fact sheet mmUhe s,,i dir��U��Q�� 14.2KQ1).The fact sheet is based on separate product sampIes anMyzed from 2000 to 2011. Cpnswmersmey raise uonrmms about arsenic in drinking water and that fluoride edrktiwemmay contain some arsenic,'The EPA allowable m000rit for arsenic in drinking water is1Qparts per billion.NS q detectable�eveis of arsenic.For those samples that dp have sorne amount ofarsenrc,ffie acenic level that mn average cmnmwme,Would experience over an entire year of drinking water aua concentration ofl.2mg8 8uaride�sextreme�ycA�mmH—om@a&ovt 12%wfthe EPA eUuweb/oammunL Other impurities/nthe NSF International-certified fluoride prodmltesting were found t*be even[ower/ham tire arsenic levels,with only 111%-396 of fluoride products containing detectable levels oYneta�sT&m average exposure$ua typical uzns*me,would behess than 0.1"/6mY the EPA allowable levels. FDA Regulatory Criteria for Fluoride 'rh.e U.S.,Food and x Administration x qLgLte Ves used for cpmfetLq�fty Mnq s,g &,K its kjj However,because the FDA has authority over _j,concerns the safe bottled water osarmnsumar beverage(Federal Register,Volume 44,No. '141,July 20. 1978)'they dorequlate file in$enxmnai addition mf fluoride to bottled water and require labeling identifying the additive used.Bottlers lypicaVy rise NSF/ANSI Standard 8U-cedifiedOooddeproduct, In 2006,FDA announced that bottled water with fluoride levels greater than 0.6 arid mprot.0 rng/L_could bmlabeled with the following statement: | "Drinking fluoridated water may reduce the risk wf tooth decay.~CDC'sf act sheet,Soffied Water awJ F,[ provides adgdimmm|imfomnuuimnmn FDA requirements FDA also regulates fluoride in over-the-counter drug products,such as toothpaste and mouthwash, and inpresoip4ion items,such as pediatric � fluoride tablets and professional-strength gels arid 0muma. FDA does not have criteria mma|lowab�e irnpo�kiesi1sodionu fluoride mrflummsOfioate � Products. United States Pharmacopeia (USP) Grade Fiworide Products ! Sorne have SUggested that pharrnaceutical grade fluoride additives should be used far water fluo6dation, used jrLfL)Mg!ptlLjq pmmml�jt@ for wafer fluoridation additives,IfAppfio,j� itandaids could a it exceed the | The U.S. Pharmacopeia-National Formulary(USP-NF)publishes monographs on tests and acceptance criteria for substances and ingredients by manufacturers for pharmaceuticals,The USP 29 NF-24 monograph on sodium fluoride provides no independent monitoring or quality assurance testing. 'The USP does not include acceptance criteria for fluorosilicic acid or sodium fluorosilicate,As a result,the manufacturer is responsible for quality assurance and reporting. 'The USP does not provide specific protection levels for individoa)contaminants, brit establishes a relative maximum exposure level for a group uf related contaminants.Some potential impurities have nn restrictions by the USP. including � arsenic,onme heavy metals regulated hy the U.G. EPA,and radionuclides.Given the volumes of chemicals used in water fluoridation,a � pharmaceutical grade of sodium fluoride for fluoridation could potentially contain much higher levels of arsenic, radionuclides, and regulated heavy metals than an NSF/ANSI Standard 60-certified product3he USP does not provide specific protection levels for individual contaminants, but tries to establish a relative maximum exposure level of a group of related contaminants.The USP does not include acceptance criteriafor Ounmei|icic acid or sodium Muomsi|icate. In addition,AVVWA-grade sodium fluoride is preferred over USP-grade sodium fluoride for use in water treatment facilities because the granular AWWA product is less likely to result in exposure to fluoride dust by water plant operators than the more powder-like USP-grade sodium fluoride. FILloride Additives Are Not Different Frorfi Natural FILlodde Sorne consumers have questioned whether fluoride frorn natural groundwater sourceS,SUCh aS CarCrUrn fiLloride,is better than fluorides added ^mrtificio#y.~such amFSAorsodium fluoride.Two recent s6entifim studies,fttedbe�mm.derrimnmtrate that the same fiunriJe ion�s present in naturally Occurring fluoride o,in fluoride drinking water additives and that mminm:nTrmKhates*r other products eee observed a8pH Iewmlsmmlow as 3.5.In addition,the inetabolism of fluoride does not differ depending on the chernical compound used or whether the fluonda�s present naturally mr added to the water Supply. * Finney VYF.Wilson E.Callender A.Morris MD,Beck LW. Sci7echmg20S0;48�8:257Z * G.M.Whitford, F,C.3ampeio.C.3.Pinto,A.G.Mahs.\(E.S.Cardoso,M.A.R. Buzala[ effect of chemk.Zl(X)mpopo��.,Archives of Oral Bioliagy,53(2008) 1037--10411,