Document 5LgVqLw0K75dkp00NgBjGGqER
FILE NAME: Asbestos Cement Pipe and Sheet (ACPS) DATE: 2016 DOC#: ACPS097
DOCUMENT DESCRIPTION: Unpublished Conference Presentation [Missing Pg. 62] - 20th Century Endorsements of Asbestos Filters and Pipe
R achel P. M aines, Ph.D .
H istorian of Technology
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A s Near Perfect as We are Likely to Get:"20th Century
Public Health Endorsements of Asbestos in Filters and Pipe
For ACI, A sbestos Claim s & Litigation, Chicago, 27 J u n e 2016
A bstract
Asbestos-'-cem ent pipe a n d a sb e sto s filters w ere only two of m an y h istorical uses of the m ineral th at were originally adopted by public health authorities in th e 20th c e n tu ry for th e ir then-perceived public h e a lth benefits, including workplace safety. The quotation in the title, for example, is from industrial h y g ien ists Philip D rinker a n d Theodore H a tc h 's 1954 Industrial D usts, in w hich the authors recom m ended crocidolite asbestos filters for workplace air, including for d u st m asks. A sbestos-cem ent pipe was approved in 1934 by the U.S. Public Service and the Am erican W ater W orks Association, and by OSHA in 1971. It rem ains an approved assem bly in 35 states and nearly all large U.S. cities, although International Association of Plum bing and M echanical Officials sta n d ard s adopted in 1975 prohibit cutting or grinding a-c pipe with power tools.
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Table of C ontents
A b stract............................................................................................................................ 1 "As Near P erfect a s We are L ikely to G et:" 2 0 th C entury Public H ealth
E n d o rsem en ts o f A sb esto s in F ilters and P ip e ....................................................... 7 A sb estos F ilters in th e 19th C en tu ry........ ............................................................8
Spontaneous G eneration and the Germ T h eo ry...................................... 8 The Gooch Crucible a n d Chemical F iltration..........................................12
A sb esto s F ilters 1 9 0 0 -1 9 4 5 ..................................................................................... 15 A sb esto s F ilters in th e Postw ar U .S..................................................................... 2 0
A sbestos-C em ent Water, Sewer and Vent Pipe in U.S. Plum bing and H eatin g C o d es.......................................................................................................................2 4 *
S ta n d a rd s a n d A pprovals fo r A sb esto s-C em en t W ater P ipe...............39 Standards and Approvals fo r Pressure, Process and Sew er Pipe.... 44 S ta n d a rd s a n d A pprovals fo r H eating Vent P ip e ...................................4 7 The PVC C o n tro versy.....................................................................................50
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N o t e s .................... ........................................................................................................................................................................... .....
Table of Figures
Figure 1 : P a s te u r's a p p a ra tu s for disconfirm ing th e th eo ry of sp o n ta n eo u s g en eratio n , 1862.......................................
Figure 2: The Gooch C rucible of 1884, still in u se in lab o rato ries today .. 14
Figure 3. H arvard professor of p ublic h e alth , Melvin W. F irst (1915-2011)
who served as a n advisor to the U.S. Army Chem ical W arfare Service and other
U.S. m ilitary a n d n u c le a r agencies concerned w ith filtration a n d a ir q u a lity .. 17
Figure 4:. Nobel la u re a te ch em ist Irving L angm uir (1 8 8 1 -1 9 5 7 ).................. 18
Figure 5: U.S. m ilitary gas m a sk c l 943. The cylindrical co m ponent in the
foreground co n tain ed th e a sb e sto s filter.........................................
lg .
Figure 6 : The U.S. Army gas m ask filter u n it of 1958, with pleated asbestos
p a p e r filter m a n u fa c tu re d by H ollingsw orth & V ose......................
21
Figure 7: Cost d a ta for sew er construction, from U nited S tates. Public
H ealth Service. Division of W ater Supply and Pollution Control. Sew er
Construction Cost Index, Construction Cost Trends Municipal Sewers. W ashington, 1964...............................
............................................................................ *......2o Figure 8: W ater pipe m ain break rates by pipe m aterial, from Folkman,
Steven. Water Main B reak R ates in the USA and Canada: A Comprehensive
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Survey. Logan UT: U tah S tate U niversity B uried S tru c tu re s Laboratory, 2012.
......................................................................................... ......................................................... 28 Figure 9: Aggregate Replacem ent Value of W ater Pipes by Pipe M aterial and
Utility Size (millions 2010 $s), from AWWA rep o rt B uried No L o n g er'2 0 1 2 ..... 29 Figure 10: W orld p ro d u ctio n of a sb esto s-c e m e n t pipe th ro u g h 1 9 3 5 ........30 Figure 1 1 : Leakage of sewage from cast iron pipe caused an epidemic of
amoebic dysentery in Chicago, Illinois, in 1933, in w hich 98 persons perished.
....................... : ...........................................................................................................................32 Figure 12: Electrolytic corrosion of u n d e rg ro u n d steel pipe. In th e 20th
century, asbestos-cem ent pipe w as often used in underground service because
it w as not subject to any of the three m ajor types of corrosion. Note caption in
original regarding rate of corrosion w ithout cathodic protection. From Wright,
J o h n E. Practical Corrosion Control M ethods fo r Gas Utility Piping. K ansas City,
Mo.: G as Service Co., 1981: 1.
22
Figure 13: C orrosion of m etal w ater pipes in Flint, M ichigan, 2015, from
Edw ards, Flint Water Study. A sbestos-cem ent pipe is highly resistan t to
chem ical c o rro sio n .................................................................................................
34
Figure 14: According to the Colorado Geological Survey, this c ast iron
w ater pipe required replacem ent after only 8 years in the ground, in an area of th e sta te w ith chem ically aggressive w ater a n d soil................................................. 34
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Figure 15: T u b ercu latio n of th e in terio r of ductile iron pipe. A sbestoscem ent pipe is not subject to this type of corrosion, although certain types of "soft" w a ters will w eaken it over tim e .......................................................................... 35
Figure 16: C orrosion of c arb o n steel w ater pipe after 20 y ears in service. 35 Figure 17: C orrosion of copper w ater pipe. Lead in jo in ts in th is assem bly leaches into drinking w ater if m easures are not tak en to control chloride levels in th e w a te r............................................................................................................................ ... Figure 18: T uberculation an d corrosion to failure of lead pipe, from h ttp ://w w w .te rz .c h /re s ta u r/z in n p e s t_ e .h tm ........................................... .................35 Figure 19: Vitrified clay pipe is approved only for w astew ater (sewage, storm w ater, and process w aste system s), as its bursting strength is under 50 psi. It is rarely used in diam eters under 6 inches. Advantages are veiy high re sistan c e to.chem icals, including acids, a n d long service life; d isad v an tag es include weak m ortar joints, brittle qualities in shear loading, seismic vulnerability, short lengths th at increase installation cost, and high purchase price, especially in the larger diam eters. The beaded stream s of water at bottom center are indications th a t this pipe is leaking at the joints. Image from T relleborg................................................................................................................................ ... Figure 20: Officially-approved asbestos-cem ent refuse disposal chutes in stalled in a p a rtm e n t com plex in Bondy (Seine), F rance, in 1964.....................38 Figure 21 : IAPMO Installation Standard for Asbestos cem ent pressure pipe for w ater service an d y a rd piping, 1 9 8 1 .........................................................................43
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Figure 22: B re n n a n a n d N em erow 's a sb e sto s cem en t pipe testin g a p p a ra tu s , S y racu se U niversity, 1963.......................................................................... 46
Figure 23: A sbestos-cem ent w ater h eater vent, from the 2009 Uniform Plumbing Code: 9 9 ................................................................................................................48
Figure 24: French specification for the finial tee of an asbestos-cem ent sm oke vent (conduit de fum e), from C harlent, Henri. Trait Pratique de Plomberie et d'installation Sanitaire: Comportant la Rglem entation des Installations d'Eau et de Gaz dans les Im m eubles d'Habitation. 1le d. m ise jour. ed. Paris: Garnier frres, Impr. Tardy-Quercy-Auvergne), 1972. A sbestos-cem ent was the only approved m aterial for this assem bly because of co n cern s a b o u t c arb o n m onoxide leak ag e................................................................... 49
Figure 25: IAPMO's notice of th e C alifornia E nvironm ental Im pact R eport on PVC, in th e 1985 edition of th e Uniform Plum bing Code....................................52
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"As Near P erfect as We are Likely to G et:" 20th C entury Public H ealth Endorsem ents of Asbestos in Filters and Pipe
Why discuss asbestos filters and asbestos-cem ent pipe in the sam e presentation? Because they have related uses historically in public and occupational health types of service, and because the consensus engineering standards for some historically approved assem blies of each included crocidolite asbestos. Both were included in the decision of the U.S. War D epartm ent (later Defense) decision to designate chrysotile a critical m aterial for w artim e emergency purposes, and crocidolite a strategic m aterial, the highest category for purposes of w artim e priority controls and postw ar defense stockpiling.1
W hat follows is the historical detail and docum entation behind the PowerPoint, w hich includes only a brief historical overview of both types of asbestos-containing assem bly. In th is longer version, I go into m ore detail on how each came to be approved by public and occupational health authorities.
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A sbestos F ilters in th e 19th C entury
A sbestos, a n expensive a n d ra re m aterial in th e early 19th cen tu ry , w as prized by scientists in Europe, Britain and the United States as a filtration m aterial because it is chem ically and electrically inert, and forms a fine m esh of fibers for separation of particles or m icroorganism s from fluids and gases.
Spontaneous Generation and the Germ Theory
In th e 19th c en tu ry , cities all over th e w orld suffered significant a n n u a l m ortality from w ater-vectored d ise ases, especially cholera a n d ty p h o id .2 Children and the elderly had the highest death rates from these ailm ents; the poor suffered disproportionately because they were the populations m ost likely to be living next to fecal-polluted bodies of w ater. There were two com peting d o m in a n t th eo ries of disease etiology betw een late 18th a n d late 19th century, m iasm atism and contagion.
M iasm atists, including, for example, Florence Nightengale, believed th at diseases were more prevalent in areas in which m iasm as, vapors rising from the ground, were unhealthy.3 Contagionists believed th at persons could be infected by contact w ith diseased persons, contam inated goods, and fecal-
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p o lluted w a te r.4 J o h n Snow 's (1813-1858) ex p erim en ts in 1854 w ith th e B road Street pum p in London lent increased credibility to the contagionist theory, as did the experiences of cities like Cincinnati, where cholera sickened riverbank com m unities in droves, b u t m ainly spared those on high ground like M ount Healthy, Ohio, w hich got its nam e during the cholera pandem ic of 1849-50.5 It was the end of the century, however, before the medical and public health
com m unity on both sides of the Atlantic arrived at consensus on the theory of
co ntagion .6
H ippocrates (460 BC -370 BC), who w rote of "Airs, W aters a n d P laces," suggested th at some locations were healthier th an others. Since this theory was compatible both with contagionism and m iasm atism , physicians could not agree on how to in te rp re t th e epidem iological d a ta from 18th a n d 19th c en tu ry epidemics and pandem ics. In part, however, the theory of m iasm atism rested on another theory, th at of spontaneous generation, which held th at disease agents could be generated spontaneously in w ater and air. Many physicians a n d sc ien tists, a lth o u g h th ey w ere aw are th a t sm all "a n im a c u le s" could be observed in w ater using a microscope (invented by Anton van Leeuwenhoek, 1632-1723), could not believe th a t su ch sm all entities could cause diseases th a t decim ated u rb a n p o p u latio n s.7
Louis P asteur w as able to show, in an 1859-62 series of w hat would now seem to be simple experim ents, b u t which were groundbreaking in his day, th a t filtered w ater a n d air, if k ep t sealed, did n o t pro d u ce th e "a n im a c u le s"
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visible in unfiltered water. He argued persuasively th at am ong these "a n im a c u le s" w ere th e h a rm fu l "germ s" of disease. Filtering th ro u g h asb esto s removed the m icroorganism s and purified the water, eliminating the w ater borne disease agents. P asteur had chosen asbestos paper as the filter m edium in his dem onstrations to other scientists, as he had found through experim entation th at the m ineral in filter form removed more organic m aterial from w ater th a n any other filtration m edium . In 1852, the cholera vibrio was identified by th e Italian Filippo Pacini (1812-83) a s one of th ese "germ s," a lth o u g h it w as n o t u n til well after Pacini's d e a th th a t his w ork w as recognized, after p u b licatio n of R obert Koch's (1843-1910) w ork on cholera in 1884.8 The typhoid bacterium was identified in the sam e decade.
Figure 1: P asteu r's apparatus for d isc o n tin u in g th e th eo ry o f spontaneous generation, 1862.
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In the United States, two m arker events brought about paradigm atic change in m edical and sanitary engineering policy for prevention and control of w aterb o rn e d ise a s e .9 The first w as th e em ploym ent of a co n tag io n ist strateg y by the City of New York in the cholera epidemic of 1866 (known to epidemiologists as the Fifth Pandem ic). The second was the disastrous typhoid epidemic of 1885 in Plymouth, Pennsylvania, in which more th an 1100 persons of a p o p u latio n of ab o u t 8 ,0 0 0 becam e ill a n d 114 d ie d .10
W hen th e U.S. Public H ealth Service (US PHS) a n d th e A m erican W ater W orks A ssociation (AWWA) jo in ed forces to co m bat w ater-vectored disease in th e U nited S ta te s in th e early 2 0 th cen tu ry , a sb e sto s filters, b o th in th e laboratory and in the field, formed p art of the arsenal of sanitation and disease prevention. Since P a s te u r's discoveries in 1859, experim ents in producing sa n ita ry w ater filters h a d been u n d e r way in G erm any a n d elsew h ere.11 By the 1920s, US PHS a n d AWWA w ere w orking w ith th e U.S. B u re au of S ta n d a rd s (U.S. D epartm en t of Commerce) to develop sta n d a rd s for all asp ects of w ater supply and sanitation, including filtration m ethods, pipe, plumbing, reservoirs, and sewage treatm ent and disposal. Many of these standards specified a sb e sto s in one form or a n o th e r.12
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The Gooch Crucible and Chemical Filtration
W hen Yale chem istry professor F rank A ustin Gooch (1852-1929) invented the sintered crucible and test m ethod th at still bears his nam e, asbestos was already, as we have seen, a well-known m aterial for chem ical, biological and m edical filtration. Dozens of test m ethods developed by the U.S. B ureau of S tandards and other laboratories employed the Gooch crucible, w hich came to be ro u tin ely specified in m eth o d s of te s t.13 In P rofessor's G ooch's m em orial article in th e N ational Academy of Sciences' Biographical Memoirs, his fellow chem ist Ralph Van Name characterizes the invention of the Gooch crucible as follows:
The -great value of th is device lay in the fact th a t the filtering m edium w as a m at of asbeslos fiber, introduced in suspension in w ater and com pacted by suction. Not only does this supply an efficient filtering surface unattacked by m ost acids and readily adaptable to the needs of precipitates of different degrees of fineness, b u t precipitates which could not be heated in contact with paper fiber w ithout undergoing decom position could be collected, ignited, and weighed, in the filtering crucible itself, th u s greatly simplifying the procedure. Criticised at first by some who attem pted to use it with asbestos of inferior quality, b u t vindicated by the overwhelming
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testim ony of others, this device soon becam e, and still is, one of the in d isp en sab le tools of th e an aly tical c h e m ist.14 U.S. Public H ealth Service sanitary engineers Jaco b Bloomfield (1897-1977) and Jo sep h M arius DallaValle (1906-1958), for example, co-authored a 1935 U.S. Public H ealth Service B ulletin now frequently cited in asbestos litigation, The Determination and Control o f Industrial D usts. The au th o rs, however, report the use of the m ineral themselves as a filtration agent in gravimetric an aly sis u sin g a Gooch crucible, on p .4 3 of th e B u lletin .15 The international m ovem ent for standardization of tests and m easurem ents h a d b eg u n in th e 19th cen tu ry , a n d h a d by 1916 re su lte d in th e U.S. in th e form ation of the American Standards Association, now the American National S ta n d a rd s In stitu te . ANSI's w ebsite describes th e org an izatio n 's h isto ry a s follows:
In 1916, the Am erican In stitu te of Electrical Engineers (now IEEE) invited th e A m erican Society of M echanical E ngineers (ASME), th e A m erican Society of Civil E ngineers (ASCE), th e A m erican In stitu te of M ining a n d M etallurgical E ngineers (AIME) a n d th e A m erican Society for T esting M aterials (now ASTM International) to join in establishing an im partial national body to coordinate standards development, approve national consensus standards, and h a lt u s e r confusion on acceptability. T hese five organizations, who were them selves core m em bers of the United Engineering Society
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(UES), su b seq u en tly invited the U.S. D epartm ents of W ar, Navy and Commerce to join them as founders. As consensus standards are developed in industrial democracies, test m ethods m ust be developed for them to determ ine w hether any given assem bly or p ro d u ct com plies w ith th e stan d ard . The ANSI (American N ational S tandards Institute) Due Process stan d ard , first, prom ulgated in 1919 and continuously revised since, requires th at every ANSI-accredited standard be testable by an approved standard test. Asbestos played a m ajor role in m any of these test m ethods, because it was chemically, electrically and therm ally in e rt.16 Som e types, especially crocidolite, h a d u n eq u alle d p ro p erties for filtratio n .17
Figure 2: The Gooch Crucible o f 1884, still in use in laboratories today
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Asbestos Filters 1900-1945
B etw een th e tim e of F ra n k Gooch a n d th e end of W orld W ar II, m an y new u se s for asbestos filters in chem istry, physics, m edicine, food science, and industrial filtration of liquids and gases were discovered in the Americas and E u ro p e .18 A sbestos filters were u s e d to rem ove im p u rities from textile dyestuffs, an d from the linseed oil u sed in wood finishing, as well as crude p etro leu m being p rep a red for sto ra g e .19 B last fu rn ac es gases w ere cleaned w ith asb esto s filters, as were boiler w ater contam inated w ith oil, an d the in te rm e d iate p ro d u c ts of su g a r refining.20
Most relevant to this discussion of the evolution of the Kent MicroniteTM filter w as the developm ent of gas m asks, with their requirem ent for highly so p h istica ted selective filtration of g a se s.21 For exam ple, th e gas m a sk filters u s e d in firefighting w ere req u ired to allow oxygen (O2) to e n te r th e lungs, b u t p rev en t th e p a ssa g e of c arb o n m onoxide (CO). T h at th is w as a scientific challenge m ay be judged by the fact th at neither hum an lungs nor our red blood co rp u scles c an m ake th is d istin ctio n betw een th e two gases. 22
After decades of m ilitary and civilian research and testing, crocidolite asbestos w as chosen by the U.S. Army Chem ical W arfare Service as the filter of choice for th e A m erican arm ed forces in W orld W ar II.23 Among th e scien tists
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who contributed to the project was Nobel prizewinning chem ist Irving Langmuir a n d H arvard sa n ita ry engineer a n d in d u stria l hygienist Melvin W. F irst.24 As
supplies of the m ineral from South Africa were uncertain due to enem y action and to diversion of B ritish shipping into m ilitary transport, m uch of the crocidolite u se d for th is p u rp o se in th e U.S. w as im ported from Bolivia.25 All asbestos was controlled during the w ar as a critical m aterial, but certain types of crocidolite h a d th e hig h er s ta tu s of "S trategic" before 1945. Of th is, U.S. . B ureau of Mines geologist Oliver Bowles wrote in 1959:
Long blue fibers are exceptionally well adapted for gas filters. Bolivian blue is preferred for this use. This is the only type of blue fiber th a t w as regarded a s strateg ic d u rin g World W ar II a n d th e early p o stw ar p erio d .26 Later in the sam e report, Bowles notes th a t
High-grade tremolite and anthophyllite varieties of amphibole asbestos are more resistant to chemical action th an chrysotile. Suitable fibers of these varieties are w ashed, thoroughly fiberized, and acid-treated to remove soluable im purities. The prepared fibers are used in Gooch crucibles or for other filtering processes employing stro n g acid s or a lk a lis.27 All a sb esto s w as controlled d u rin g th e w ar a s a critical m aterial; an d stockpiled afterw ard s by th e D e p artm en t of D efense well into th e 1980s.28 Of U.S. efforts to find s u b s titu te s for a sb esto s d u rin g W orld W ar II, A nn a n d
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M yron S u tto ii w rote in Science D igest in 1958 th a t "The tro u b le is th a t nothing else is like asbestos, and it th u s has specialized u ses for w hich no su bstitutes are available. It is a to u g h m in eral to d u p lic a te .."29
Figure 3: Harvard professor o f p ublic h ea lth , M elvin W. F irst (1 9 1 5 2011), w ho served as an advisor to th e U.S. Army C hem ical Warfare Service and other U.S. m ilitary and nuclear agencies concerned w ith
filtra tio n and air q u a lity .30
Dr. F irst, by th e n a t th e H arvard Air C leaning L aboratory in th e u n iv ersity 's School of Public H ealth, reported to the 1968 Atomic Energy Com m ission Air Cleaning Conference that:
It w as found th a t greatest efficiency could be achieved with either African or Bolivian blue crocidolite which can be reduced to very fine fibers of exceptional length by m echanical beating. ... In th e early days of W orld W ar II, th e B ritish se n t to th e
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U.S. Army Chem ical Corps Laboratories at Edgewood, M aryland, a piece of this paper th at had been removed from a captured German gas m ask canister. This was ju st w hat the Chemical Corps had been seeking for use as a gas m ask sm oke filter and they, together with the Naval Research Laboratory, proceeded to duplicate it and have it m anufactured in large quantities on conventional paper-m aking m achinery by the Hollingsworth and Vose Company. The first successful paper for the U.S. Navy, containing Bolivian crocidolite, w as called H-60. The U.S. Army paper, containing African crocidolite, w as designated H-64 and later was called Type 6 by th e Army C hem ical C o rp s.31
Figure 4: Nobel laureate ch em ist Irving Langmuir (1881-1957)
I m y 1Afnin.iu'- -- k^, >2a'h `'- w u s 1
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Figure 5: U.S. m ilitary gas m ask c l9 4 3 . The cylindrical com p on en t in the foreground contained the asbestos filter.
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A sbestos F ilters in th e Postw ar U.S.
In the decision environm ent of the early 1950s, crocidolite asbestos was highly regarded as a filtration m aterial for fluids and gases by a broad array of sc ien tists a n d safety p ro fessio n als.32 The Atomic E nergy C om m ission, for exam ple, in its 1952 H andbook on Air Cleaning: Particulate Removal, prepared by S h eldon K. F riedlander, Leslie Silverm an, Philip D rinker a n d Melvin W. F irst u n d e r th e a u sp ic e s of th e H arvard School of Public H ealth 's D e p artm en t of Industrial Hygiene, described its nuclear-facilities air filters for removal of "p o iso n o u s a n d radio-active d u s ts " (p.28) a s follows:
Cellulose-A sbestos Paper. At present, the AEC m akes great u se of CC-6 paper w hich w as originally developed by the Chem ical Corps [of the U.S. Army] for u se in gas m asks. It consists of fine asb esto s fibers mixed w ith coarser cellulose fibers to give m echanical stren g th an d act as a su p p o rt for the asbestos. The asbestos m esh does m ost of the filtering. Efficiency is initially high and increases w ith use. ... Cellulose asbestos paper is expensive a n d n o t available in large q u a n titie s .33 This assem bly was published as a m ilitary standard in 1954 and revised in ' 1955.34 In a 1958 article in th e A m erican Industrial H ygiene A ssociation Journal, Allan W est of the U.S. Army Chem ical W arfare Laboratories described th e developm ent of th e A rm y's gas m ask , inclu d in g its a sb esto s filters (see
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illu stra tio n below).35 The m ilitary specification for th is type of a sb esto s filter w as still in effect in 1969.36
Figure 6: The U.S. Army gas m ask filter unit o f 1958, w ith pleated asbestos paper filter m anufactured by Hollingsworth & Vose
Industrial Hygiene Journal
14d
Fjcurk 4. E4R5 gaa mask aerosol filter
In 1955, B ritish in d u stria l hygienist G. H. Vokes identified th e crocidolite/esparto grass filter then in use in gas m asks and radioactivep article p ro tectio n a s a n "ab so lu te filter," th e m o st effective available a t the tim e .37 The following y e a r H. E. Seifert a n d E. G. C allison d escribed th e u se of this type of filter m bacteriological hoods, used in the production of vaccines, to protect w orkers from th e pathogens from w hich both live- an d killed-virus vaccines w ere (and are) m a d e .38 H enry F. Allen M.D., a bacteriologist at
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H arvard Medical School, wrote in a 1959 issue of JAMA of the efficiency and effectiveness of pleated "g lass-asb esto s p a p e r" in rem oving b a cte ria from h o sp ital a ir .39
In a U.S. Public H ealth Service p u b licatio n in 1962, H erbert M. D ecker of the U.S. Army Chem ical Corps described the developm ent of crocidolite and e sp arto -g ra ss filters d u rin g W orld W ar II for "gas m a sk s a n d building filtration sy ste m s." He too c h aracterized th is filter assem b ly a s a n "a b so lu te filter," defined a s "th o se th a t have a n efficiency g reater th a n 99.99 per c en t for rem oving b acterial p articles having a d iam eter of one to five m ic ro n s."40
The Chemical Laboratory of the American Medical Association tested the effectiveness of the filters of both the first Kents .m anufactured in 1952 and a later (1953) modification with a more loosely-packed asbestos filter that improved draw, finding in their July 1953 report th at
The filter of B rand B -1 [the Kent MicroniteTM] is the m ost effective in removing nicotine and tars from the m ainstream smoke. However, the sam ple of later m anufacture, b ran d B-2, is m uch less effective as the filter is more loosely packed, apparently in an effort to improve th e sm oking q u a litie s.41 The Laboratory found that, while both Kent filters were considerably more effective th a n any of the com petitor filter assem blies, B -l removed 60 per cent of the nicotine and 55 per cent of the tar, b u t B-2 removed only 41 and 44 per cent respectively. Their tables of resu lts are reproduced below.
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Table 1: R e su lts o f AMA C h em ical Laboratory, "S tu d y o f C igarettes, Cigarette Sm oke, and F ilters," published in JAMA, 4 July 1954.
CollM
Brand A-l Brand A-2 Brand B-l Brand B-2 Brand C-i Brand C-2 Brand D
T able 1.--Moisture, Nicotine Content, and Physical Characteristics o f Four Brands o j Cigarettes
2
2
3
Type of Filter
P a p e r .......... ................ ...........
Fiber .........................................
Asbestos laminated with paper
Asbestos laminated with paper
Cotton ................... ..................
Cotton .....................................
No filte r.......
............. .
Date Sample Obtained
May, 1984 December, 1952 April, 1952
October, 1952 May, 1952 August, 1952 February,1953
Average Weight of Cigarette,
Gw.
1.005
1.123 1.053
1.011 1.047 1033
um
4
Average Weight of Filter-Tip,
Gm.
o.i 0.183 0.150 0.159 0.168 o m
5
Total Length of Cigarette,
Mm
76,9
6
Average Length of Filter-Tip,
Mm.
11.0
09.5
10.3
69,5
10.9
03.0
to.o
09.0
Hi.O
70.0
Average Ciremn-
Cigarette, Mm. *20.0
20,7 2tU 25 3 25.3 265
s
Tobacco, % 8.60 9.75 8.51 3.84 9.27
10.77 10.71
9 Nicotine io
Tobacco (Moisture-
Fiee %Basis),
13
1.94 2,54 2.44
2.02
Table 2,--Analysis o f Smoke from Four Brands of Cigarettes
Column
12
3
4
,
Weight of Average
Tobacco Volume of
Actually Mainstream
Smoked Smoke per
(Dry Weight), Cigarette,
Gm.
Ml,
BiaadA-1........................ 0.629
S40
Brand A-2........................ O.OSO
351
Brand B-l........................ 0 63
328
Brand B-2........................ 0.391
350
Brand 0-1........................ 0.681
461
Brand C-2........................ 0A55
5
Brand D ........................ 0.633
35
Weight of
Nicotine Pound in Mainstream Smoke per Cigarette, Mg, ,-- - ^ With
Filter-Tip With
Removed Filter-Tip
2*
20
2 *2
2 43
2.52
1,00
. 2 4!)
1.47
3.91
3.38
4.00
2.93
....
2.74*
5
0
7
Nicotine In
Tobacco Actually
Smoked Which is
Reduc
Transferred to
tion of Mainstream Smoke, %
Nicotine in r ..
---- -A. _ ---------
Mainstream With
Smoke, Filter-Tip With
%
Removed Filter-Tip
9
24
21
U
22
19
60
21
8
41
22
13
n
23
*20
27
25
18
21*
8
9
Weight of Tars Found In Mainstream Smoke
per Cigarette, Mg. f----- _ ..JN__--.
With Filter-Tip With Removed Filter-Tip
1..9
15.2
16 8
13.9
15,0
6.8
36,7
94
18 5
15.6
19.6
15.1
17.8*
10
Reduc tion o! Tars in Mainstream Smoke,
% 5 17 56 44 16 23
Placet! In this column lor comparison with full-length cigarettes.
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A sbestos-C em ent W ater, Sewer and V ent Pipe in U.S. Plumbing and Heating Codes
Asbestos cem ent pipe for carriage of potable w ater and w aterborne sewage was first considered for use in the United States in 1923, when the United S tates Public H ealth Service (US PHS) reported on the u se of EternitTM for w ater pipe in Italy .42 The U.S. se a rc h for reliable pipe m aterials received fresh im petus in 1933 from a serious outbreak of amoebic dysentery in Chicago, with
98 deaths, caused by the corrosion and leakage of cast iron sewage pipe into
th e potable w a te r d istrib u tio n system in two dow ntow n h o tels (see Figure 1 1 ).43
Unlike c a st-iro n a n d steel pipe, a sb esto s-ce m en t resisted th e "th re e dem ons of
electrolysis, tu b e rc u la tio n a n d corro sio n " (see figures below .)44 T h at corrosion
and leakage of c ast iron and lead w ater pipes are still public health issues is
evident from the current Flint, Michigan w ater crisis.
-
In Flint, the lead seals used historically in cast iron w ater m ains have been
steadily corroding since 2014, contributing to the very high lead levels leaching from corroding lead a n d co p p er d istrib u tio n p ip e s.45 The AWWA p red icts th a t Flint MI, J a c k s o n MS, a n d Ith a c a NY are only early exam ples of w h a t h a s been called a n epidem ic of co rrosion"*of w ater in fra stru c tu re , w hich will require a n a tio n al in v estm en t in pipe rep lacem en t of a b o u t $1.7 trillion by 2 0 5 0 .46 The
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figures below depict m ajor types of ferrous-m etal, copper, and lead pipe corrosion.
All m o d ern in d u stria l dem ocracies worldwide regulate w ater, sew er a n d fire suppression pipe assem blies, perm itting the installation of only those th at have been tested and approved by the authority having jurisdiction. In m ost of th e se n a tio n s, including th e U.S.', c o n se n su s engineering sta n d a rd s for construction were and are adopted and enforced by a variety of government agencies a t all th ree levels of governm ent: n atio n al, sta te , a n d local.47 Lower jurisdictions, such as counties and m unicipalities, may impose more restrictive local sta n d a rd s th a n th o se of hig h er o n e s .48 New York City, for exam ple, h a s more restrictive construction and public health standards than less urbanized areas of New York State because it is densely populated, w ith millions of lives, m any of them in high-rise stru ctu res, a t risk from fire, carbon monoxide poisoning, a n d infectious d ise a s e .49
Asbestos was specified in a broad range of assem blies in the first threeq u a rte rs of th e 2 0 th cen tu ry , approved in acco rd an ce w ith A m erican N ational S ta n d a rd s In stitu te (ANSI) d u e p ro cess req u ire m e n ts for s ta n d a rd s development, including b u t not limited to friction products, pipe, fiber reinforcem ent of plastics, protective clothing, electrical and therm al insulations, welding and cutting gear, filters, conduit, roofing, millboard, g ask ets, p ack in g a n d s e a ls .50 All w ere te ste d a n d approved by Federallyaccredited standards-developm ent organizations, including the U.S. B ureau of
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S ta n d a rd s (now NIST), th e N ational Fire P rotection A ssociation, th e Am erican Society for Testing and Materials* and the Am erican Society of M echanical Engineers. Assemblies in which asbestos was required by building laws before 1990 include cathodic w rap for underground steel gas pipe, hot-air register in su la tin g p ap er, a n d electrical in su la tio n for c o n d u cto rs in sw itc h b o ard s.51 Compliance with these standards was also required for obtaining the insurance n e c e ssa ry for m ortgage fin an cin g .52
A sb esto s-cem en t pipe w as in d em an d in in d u stria l n a tio n s in th e 20th century after 1934 because it was a tested and approved assem bly, supported by approvals from a wide range of governm ent agencies, independent engineering associations and non-governm ental organizations worldwide, including those concerned w ith public h ealth (see Figure 10' below). O ther . m aterials, including fiber glass, did not pass stan d ard engineering tests for fiber-reinforced cem ent pipe until engineers and scientists had spent m any decades seeking to overcome the chem ical and regulatory barriers to developing asb esto s-free pipe a sse m b lie s.53 M echanical engineers Reno King a n d S abin C rocker, w riting of a sb esto s-ce m en t pipe in th e 5th edition (1967) of th e Piping H andbook, describ ed its "A pplications" a s follows:
A sbestos-cem ent pipe is essentially im m une to corrosion in the ordinary sense. It is not subject to electrolysis or to attack in socalled `h o t" soils. It does no t tuberculate. This pipe will not cause
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discolored water. It is highly resistant to chem ical attack,
p a rticu la rly th a t en co u n tere d in su lfate so ils.54
The U.S. E n vironm ental Protection Agency's Office of W ater w rote of pipe
standards and approved assem blies in 2000 that:
Pipe m an u factu rers follow requirem ents set by the Am erican
Society of T esting M aterials (ASTM) or A m erican W ater W orks
A ssociation (AWWA) for specific pipe m aterials. Specification
standards cover the m anufacture of pipes and specify param eters
`
such as internal diam eter, loadings (classes), and wall thickness
(schedule). The m ethods of pipe construction vary greatly with the
pipe m a te ria ls.55
W hen King and Crocker evaluated asbestos-cem ent pipe in 1967, it was
considerably more expensive to purchase and install th an cast iron in
equivalent assem blies. The m aterials a n d in stalled-in-trench cost of A-C sewer
pipe in 1964, for example, was about 15% higher th a n th a t of cast iron, and
th e price differential w as a b o u t th e sam e for w ater p ip e .56 Due to its resistan c e
to corrosion, however, asbestos-cem ent pipe h as proved m uch less subject to
breakage over tim e in the ground, according to a study by U tah State
University B uried S tru ctu res Laboratory (see
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Figure 7, below).57 The A m erican W ater W orks A ssociation rep o rted in 2012 th a t replacerpent costs for all three types of iron pipe in u se in the U.S. will be h ig h er th a n for an y o th er type of*pipe a sse m b ly .58
Figure 7: Cost data for sew er construction , from United S tates. Public H ealth Service. D ivision o f Water Supply and Pollution Control. S ew er C onstruction Cost Index, Construction Cost Trends M unicipal Sewers.
W ashington, 1964.
Table IV, Material Goat Data for Category 7 "Pipe in Trench" of a Hypothetical $1 Million Sewer Construction Project
Type of material
feel ofpip Unit price Material price
Vitrified d a y ___ *___________ ____ Concrete............. ................. _......... Cast iro n ............................................... Asbeetoe eeBurnt___ __ __ ___ ___
T o ta ls.. _____ ___ .*__ _____
21, 316. 98 18, 332. 05 3,085. 96 3,187, 00
$1. 709 3. 688 2. 215 2. 5122
45, 921. 08 -------- --------
$36, 431 67, 609 6, 835 8, 000
118, 881
Figure 8: Water pipe m ain break rates by pipe m aterial, from Folkm an, Steven . W a ter M ain B rea k R a te s in th e USA a n d C anada: A
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C o m p re h e n siv e S u rv e y . Logan UT: U tah S ta te U n iversity Buried Structures Laboratory, 2012.
PIPE MATERIAL
Cl Dl PVC CPP Steel AC ' Other
TOTAL . :
LENGTH MILES 33611.0 33238 7 26840 3 2355.3 4300.1 13502.8 3755.3
117603.4
NUMBER OF
FAILURES
8204 1620 689 128 581 954 787
FAILURE RATE
#/(100mlV(Var1 24.4 49 26 5.4 135 7.1 21.0
11.0
Figure 9: Aggregate R eplacem ent Value o f Water Pipes by Pipe Material and U tility S ize (m illion s 2 0 1 0 $s), from AWWA report B u rie d No L onger,
2012.
! Region
Cl
CICL
Dl
N ortheast Large
48,958 8.995
5,050
N ortheast Medium & Small 66,357 61,755 28,777
N ortheast Very Small
14,491
15,992 10,661
Midwest Large
37,413
9,151
3,077
M idwest Medium & Small 74,65.4 92,106 51,577
Midwest Very Small
37,597
28,943 25,464
Southeast Large
30,425 28,980 29;569
South Medium & Small
54,772 98,608 140,079
South V ery Small
43,183
24,998 49,791
West Large .
15,448 16,055 28,949
W est Mecllum & Small
15,775
50,145
70.355
W est Very Small
16,344 11,199 17,910
Total
455,416 446,927 461,258
Ci. cast iron; C IC L : cast iron cem ent iined; Dl. ductile iron; A C
P C C P : prestressed concrete cylinder pipe
AC
PV
Steel PCCP
2 |0 8
1,875
335
0
26,007 16.084 5,533 6,899 '
7,281
7,937
329
482
2,504
1,098
784
512
37,248 30,506 8,682 11,152
12,428 19,720 601
828
21,229 14,936 9,337 7,227
103,659 102,804 21,394 17,160
34,529 47,823 1,461 1,244
14,774 14,723 7,443 6,215
50,541 48,885 12,276 9,806
13,166 17,245 545
453
325,674 323,637 68,719 61,957
asbestos
-
cem ent;
Pt/,
p o ly v in y l
chloride,
a
TOTAL
67,522 211,411 57,152 54,539 305,925 125,581 141,703 538,475 203,028 103,607 257,782 76,862 2,143,589
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Figure 10: World produ ction o f a sb esto s-cem en t pipe through 1935
WORLD PRODUCTION
CEMENT ASBESTOS 6 415 H LES 3 8 0 OOO DOLLARS (`us **
PIPE
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S ta n d a rd s developm ent organizations worldwide in th e 20th century,
in clu d in g AFNOR in F rance, th e B ritish S ta n d a rd s In stitu te in th e UK, a n d the
m em ber organizations of the American National S tandards Institute in the
U.S., formed technical com m ittees, w hich included state authorities,
academ ics, scientists from independent testing laboratories, public health
professionals, insurers, and m inority representation (limited to 30% of
m em bership) from m anufacturing industry, to consider and develop technical
stan d ard s th a t were adopted into national, state or departm ental, and local
la w s.59
.
Building and plum bing codes, and the engineering standards incorporated .
into them , were developed in W estern industrial nations for the purpose of
prev en tin g h a rm to citizens from defects in, or failures of, th e b u ilt
e n v iro n m en t.60 U ntil th e e n d of th e 2 0 th cen tu ry , a n d in som e cases beyond,
asbestos was specified and approved and in code-com pliant assem blies in the
U.S., Europe and elsewhere th a t passed inspections by the authorities having
ju risd ic tio n (AHJs).61 A sb esto s-cem en t pipe, h e atin g v en t a n d electrical-
conduit assem blies underw ent this process, in essence a form of peer review for
technology, in th e m id-20th cen tu ry , after a sb esto s-ce m en t pipe w as first
introduced from Europe in 1931, where asbestos-cem ent was already approved
for water, sewer and gas pipe, conduit, roof coverings, vents, and even garbage
ch u tes (see Figures an d captions below).
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Figure 11: Leakage o f sew age from cast iron pipe caused an epidem ic o f am oebic dysentery in Chicago, Illinois, in 1933, in w hich 98 persons
perished.
V*..*-. *. *,V **- *-
O fA fiK A M 6M 0W IN
POINTS or LEAKAGE FROM SEW ER OVER T H E CO O LED WATER TANK
iN
HOTEL "X*
1953
m,
epidemic this leakage was an important factor.
The m o r e important rea
sons are the large number of infections among guests
at hotel X on J une 8 and -29, and a relative lack of infections among guests at
hotel Z; also the excessive
rainfall on the evening ot the latter date which con tributed to flooding of the sewer system of hotel h which probably c a u s e d heavy pollution of this s p e c i a l drinking-water
system.
t
` The points of leakage
in the branch sewer over
tliis water tank are shown
in figure 2*2- They were
aroll nd n wooden plug in
a cleanout Y and holes in
the pipe due to corrosion,
particularly at threads.
Because of the insulating
pipe c o v e r i n g on this
sewer, the leaks due to
corrosion are not consid
ered to have been as seri
ous as the one around the
woodeirplug.
.
Apparently at some t tine
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Figure 12: E lec tro ly tic corrosion o f underground s te e l pipe. In th e 2 0 th century, asbestos-cem ent pipe was often used in underground service because it was not subject to any o f the three major types of corrosion. Note caption in original regarding rate of corrosion w ithout cathodic protection. From Wright, Joh n E. P ra c tic a l C orrosion C ontrol M ethods f o r G as U tility P ipin g. K ansas C ity, Mo.: Gas Service Co., 1981: 1.
CAHC0IC
FIGURE 1 -- One ampere of corrosion current flowing for one year will consume 20 lb of steel.
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Figure 13: Corrosion o f m etal water pipes in Flint, M ichigan, 2015, from Edwards, F lin t W ater S tu dy. A sbestos-cem ent pipe is highly
resistant to chem ical corrosion.
Figure 14: According to the Colorado G eological Survey, th is cast iron water pipe required replacem ent after only 8 years in the ground, in an
area of the state with chem ically aggressive water and soil.
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Figure 15: Tuberculation o f th e interior o f ductile iron pipe. Asbestoscem ent pipe is not subject to th is type o f corrosion, although certain ty p es o f "so ft" w aters w ill w eaken it over tim e.
Figure 16: Corrosion of carbon ste el water pipe after 20 years in service.
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Figure 17: Corrosion o f copper water pipe. Lead in join ts in this
assem bly leaches into drinking water if m easures are not taken to control
chloride levels in the water.
Figure 18: Tuberculation and corrosion to failure o f lead pipe, from http ://w w w .terz.ch/restaur/zinnpeste.htm .
fat i * * . 9* "
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Figure 19: Vitrified clay pipe is approved only for w astew ater (sewage, storm water, and process waste system s), as its bursting strength is under SO psi. It is rarely u sed in d ia m eters under 6 in c h e s. A dvantages are very
high resistan ce to chem icals, including acids, and long service life; disadvantages include weak mortar joints, brittle qualities in shear loading, seism ic vulnerability, short lengths that increase installation c o st, and h ig h p u rch ase price, e sp e c ia lly in th e larger d ia m eters.62 The beaded stream s o f water at bottom center are indications that th is pipe is
leaking at th e join ts. Image from Trelleborg.
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Figure 20: Officially-approved asb estos-cem ent refuse disposal chutes installed in apartm ent com plex in Bondy (Seine), France, in 1964.
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Standards and Approvals for Asbestos-Cement Water Pipe
The approvals process for asbestos-cem ent w ater pipe u n d er the British S tan d ard s system in the UK w as well u n d e r way by 1930, w ith B ritish and American sanitary engineers sharing experiences, test results, and engineering co n fig u ra tio n s.63 The A m erican W ater W orks A ssociation (AWWA) b eg an th e s ta n d a rd s developm ent process for a sb esto s-ce m en t w ater pipe in 1934, although the first adopted standard was not published until close to the completion of a long-term testing program , described below .64
D u rin g W orld W ar II, c a st-iro n pipe w as n o t available for expansion or repair of existing w ater and sewer system s, as both iron and steel were on the strateg ic m a teria ls lis t.65 A sb esto s-cem en t pipe w as therefore in d em an d , b u t as in all other w artim e m anufacturing in com batant nations, the m ilitary had priority over civilian u s e s of p ip e .66
M eanwhile, a num ber of real-life experim ents by both civilian and m ilitary authorities suggested th at asbestos-cem ent pipe and conduit had a variety of u s e s in peace a n d w a r.67 Sixty-two th o u s a n d feet of asb esto s-ce m en t w ater pipe, for example, were installed in the late 1930s in the cinder-filled (and therefore highly alkaline) salt m arsh know n as Flushing Meadow for the 1939 "W orld of Tom orrow " W orld's F air in New York City. T ests in 1942 by th e
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Borough of Q ueens engineer revealed th at the pipe rem ained uncorroded
d esp ite th e h a rs h u n d e rg ro u n d c o n d itio n s.68
A sb e sto s M agazine received rep o rts d u rin g th e w ar th a t "A sbestos-C em ent
pipe used in certain bom bed zones has shown little, if any breakage from
c o n c u ssio n ."69 To conserve strateg ic steel a n d iron in th e w ar y ears, a sb esto s-
cem ent sheet and pipe were used in tem porary structures in Britain, C anada
a n d th e U.S., in clu d in g in m ilitary train in g cam p c o n stru c tio n .70
The c o n stra in ts of th e G reat D epression a n d W orld W ar II prevented th e
form ation of a form al AWWA tech n ical com m ittee on A-C pipe u n til 1949, after
w hich the consensus process of developing, approving and publishing a
tentative standard for asbestos-cem ent w ater pipe moved rapidly to completion
by May 1953, w ith th e release of AWWA C 400-53T .71 Selection a n d in stallatio n
stan dard s for asbestos-cem ent w ater pipe, developed in cooperation with
IAPMO, US PHS, FHA, th e U.S. Navy, ASTM a n d ANSI, w ere approved a s
ten tativ e s ta n d a rd s in 1964 a n d a s ad o p ted s ta n d a rd s in 1965.72 M eanwhile,
in the four decades between 1930 and 1970, testing, approval and installation
of asbestos-cem ent pipe w as progressing in France, Germany, Argentina,
Holland, Brazil, C anada, A ustralia, New Zealand, Russia, Hungary, and
Sw eden a s well a s Italy a n d th e UK.73 An in stallatio n s ta n d a rd for a sb esto s-
c em en t pipe w as developed by AWWA a n d ASTM by 1964, w hich by 1978 h ad
been expanded into an AWWA-sponsored m an u al of safe work practices for
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a sb esto s-ce m en t, w hich, after 1975, in clu d ed IAPM0 In stallatio n S ta n d a rd 15 (see Figure 21 below ).74
Testing of underground pipe u n d er h u ndreds of different soil conditions had b e g u n a t th e U.S. N ational B u re a u of S ta n d a rd s in 1912.75 A new series of tests, including tests of asbestos-cem ent pipe, was initiated in 1937 in co n ju n ctio n w ith US PHS, th e Federal H ousing A dm inistration, a n d th e AWWA, w hich continued u n til 1957.TM The US PHS specified a n d approved asbestoscem ent pipe in the National Plum bing Codes of 1949 and 1962 as well as su b s e q u e n t e d itio n s.77
The stan dards for asbestos-cem ent water, sewer and pressure pipe in force in th e U.S. in the 1980s were as follows:
ASTM C 296 S ta n d a rd Specification for a sb esto s-ce m en t pressure pipe.
ASTM C 428 S ta n d a rd Specifications for asb esto scem ent nonpressure sewer pipe.
ASTM C 500 S ta n d a rd M ethods of testin g a sb esto s-ce m en t pipe. ASTM C 508 S ta n d a rd Specification for a sb esto s-ce m en t
perforated underdrain pipe. ASTM C 644 S ta n d a rd Specification for a sb esto s-ce m en t
small- diam eter nonpressure sewer pipe. AWWA C 401 S ta n d a rd practice for th e selection of asb esto s-cem en t
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"As Near P erfect as We are L ikely to G et"
d istrib u tio n pipe, 4 in th ro u g h 16 in. (100 m m th ro u g h 400 mm),
for w ater and other liquids.
AWWA C 402 S ta n d a rd for a sb esto s-ce m en t tra n sm issio n pipe, 18
in. through 42 in. (450 mm through 1050 mm), for potable w ater
and other liquids. ANSI/AWWA C603 S tan d ard for installation of asbestos
cem ent pressure pipe.
IAPMO IS 15 S ta n d ard for in stallation of asb esto s cem ent pipe,
w hich prohibits the u se of power tools in the field installation. Hand
tools only were approved for cutting and beveling of asbestos-cem ent
pipe. This standard was developed and adopted by the International
Association of Plum bing an d M echanical Officials in the early 1970s, and w as incorporated into the Uniform Plumbing Code in 1975. A page from th e 1981 edition of IS 15 is in clu d ed below a s Figure 2 1 .78
"H an d to o ls" have b een defined in Federal lab o r law since 1938 a s those w ith o u t a so u rce of pow er o th er th a n th a t of th e h u m a n u s e r s .79 It w as necessary to m ake this rule early on in Federal occupational safety regulation because w orkers u n d e r 18 years of age were and are prohibited from using m ost kinds of power tools, including power saws, cem ent mixers, m eat slicers a n d tr a s h c o m p a cto rs.80
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"As Near P erfect as We are L ikely to G et"
Figure 21: IAPMO In sta lla tio n Standard for A sb esto s c e m e n t pressure pipe for water service and yard piping, 1981.
ASBESTOS CEMENT PRESSURE PIPE FOR WATER SERVICE AND YARD PIPING
end of the pipe only, never to the rubber gasket or groove, unless specifically recommended otherwise by the
manufacturer.
an?-??
The end of the pipe and the coupling or fitting bell shall be assembled using a bar and wood block or a pipe puller, "Stabbing" or "popping" the pipe into the coupling (pipe is suspended and swung into the bell) is not recommended.
802,3
When a field cut is made, cut the pipe square, using hand pipe-cutters which use a cutting edge, or hand saws. To pro perly enter the rubber gasketed joint, the end of the pipe must be machined before insertion, using hand machining
tools.
1004 1004.1
1008
M aterials
.
Location. AC piping shall be installed only outside the foun dation of any building or structure or parts thereof, it shall be buried in the ground for its entire length with cover as provided in Sec. 317.1. It shall not be installed within or under any building or structure or mobile home or commer cial coach or parts thereof. The term "Building or structure or parts thereof" shall include structures such as porches and steps, roofed porte-cocheres, roofed patios, carports, covered walks, covered driveways and similar structures or
appurtenances.
Installation, Testing and Identification
1008.1 Installation
1008.1,1
Alignment and Deflection. Pipe and fittings shall be aligned
properly without strain. Pipe may be deflected tn accor
dance with the manufacturer's recommendations provided
that it shall not be permanently staked or blocked to mairv
tain this deflection. If soft soil conditions exist, deflected
joints may be permanently blocked or staked to maintain
the deflection. The amount of deflection shall be: f for
sizes4" (101.6 mm) through 12" (304.8 mm); 4 for 14 (355.6
mm) and 16" (406.4 mm); 3 1/* * for 18" (457.2 mm) through
24" (609.6 mm) for pipe belled on the job site. For factorybelled couplings, one half (Vi)the above deflections by size
shall be allowed.
.
1008.1.2 Working P ressure. Maximum working, pressure shall be as
follows:
MATERIALS. SIZES AND MAXIMUM WORKING PRESSURES
pipg
SIZES
MAXIMUM PRESSURE
C lass 00 4 *24* Irvd. (1016-8094 mm me!.)
100 pst (889 kPa)
Class 150 Class 200
4"-2<T Incl. (101,6-609*8 mm Incl.) 4"-?4" incl. (101.6-609-6 mmincl)
150 psM,!3l
|200 psi (1378 KPa>
1008.1.3 Laterals and Saddles. Installation of laterals, saddles or tapped couplings in AC piping shall be as required by their
listings.
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"As Near P erfect as We are L ikely to G et"
Standards and Approvals for Pressure, Process and Sewer Pipe
As the nam e implies, pressure pipe is intended for u se with liquid contents th a t are moved by the action of one or more pum ps, rath er th an th a t of gravity, w hich is th e m otive force of th e c o n te n ts of n o n p re ssu re p ip e.81 Process (industrial) and sewer pipe were (and, in som e nations, still are) m anufactured in both pressure and nonpressure assem blies. Both assem blies are made in Types I a n d II, in w hich th e la tte r h a s chem ical req u ire m e n ts th a t require a different c e m e n t/a s b e s to s fo rm u latio n from Type I.82 Type I a / c pipe m u st p a s s only th e four m ajor te s t a rra y s e n u m e ra te d in ASTM S ta n d a rd C 500, Standard M ethods o f Testing A sbestos-C em ent Pipe, for hydrostatic proof (resistance to leakage and weeping in service), flexure (resistance to transverse bending loads), straightness (deviation along the length of the pipe), and c ru sh in g s tre n g th (resistan ce to collapse u n d e r ex tern al loading).83
Type II a / c pipe m u st also p a ss a te s t for u n co m b in ed calcium hydroxide, w hich m e a su re s chem ical re s ista n c e .84 Over a period of several decad es of testin g in th e 2 0 th cen tu ry , chrysotile alone in P o rtlan d cem en t did no t p a ss this test; crocidolite, w hich is one of the m ost chem ically-resistant m aterials know n, w as ad d ed to th e Type II form ula in o rder to com ply w ith th e sta n d a rd
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"As Near P erfect as We are L ikely to G et"
of chem ical te s t.85 U.S. B u re a u of M ines m in eralo g ist Oliver Bowles (1877 1958), writing of this in a 1959 strategic defense survey of the m ineral, a sse rte d th a t "Crocidolite (blue asbestos), m ined in Africa a n d A ustralia, is regarded a s a n e c e ssa ry c o n stitu e n t of a sb esto s-c e m e n t p ip e."86 The chem ical aspects of this use of crocidolite are explained in detail in Professor-Dr.-Ing. K urt H iin erb erg 's m agisterial stu d y of a sb esto s-ce m en t pipe, p u b lish ed in G erm an in 1963, 1968 a n d 1977, in R u ssia n in 1968, a n d in F ren ch in 1971.87
Type II a sb esto s-c e m e n t pipe w as u s e d for u n d e rg ro u n d service in w hich corrosion by pipe contents (including sewage) a n d /o r by aggressive waters, salinity, or "h o t" (alkaline) soils are significant is s u e s .88 It w as also u se d extensively for electrical and telephone line conduit and heating equipm ent vents (see next section).
Maines for ACI June 2016
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"As Near P erfect as We are L ikely to G et"
Figure 22: B rennan and N em erow 's a sb e sto s c e m e n t pip e te s tin g apparatus, Syracuse University, 1963.
t u x ll S.h. ji} / ' i' ll H i ' Hi - H iiih '
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-Pi.aMu <!""*i'1'
Maines for ACI June 2016
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"As Near P erfect as We are L ikely to G et'*
Standards and Approvals for Heating Vent Pipe
A sbestos-cem ent vent pipe for heat-producing equipm ent w as and is
approved by the Uniform Plumbing Code, and by E uropean codes un til the mid-
to-late 19 90s.89 T hese assem b lies are still code-com pliant u n d e r th e c u rre n t
(2012) International Plumbing Code, the successor to the Uniform Plumbing
Code.
.
Historically, these assem blies were also com pliant with heating codes such
as those of the American Gas Association, th at of the former National Board of
Fire U nderw riters (now the Am erican Insurance Association), and th a t of
ASHVE/ASHRAE.90 The p u rp o se of th e a sb e sto s in a sb esto s-ce m en t h eatin g
equipm ent vents was to prevent therm al cracking of the cem ent, which would
have allowed leakage of carbon monoxide, produced by incom plete com bustion
of fuels, th ro u g h th e fissu re s into living s p a c e s .91 A sbestos fabric or rope seals
were u sed as vibration isolation connectors in heating duct system s for the
same reason.92
M aines for ACI J u n e 2 0 1 6 "As Near P erfect as We are L ikely to G et" Figure 23: A sbestos-cem ent water heater vent, from the 2009 Uniform
Plum bing Code: 99.
FIGURE G.l(e) Asbestos Cement type B or Single-Wall Metal Vent System Serving a Single DraftHood-Equipped Appliance.
Maines for ACI June 2016
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"As Near P erfect as We are L ikely to G et"
Figure 24: French sp ecification for th e finial tee of an asbestoscem en t sm oke v en t (c o n d u it d e fu m e), from Charlent, Henri. T rait
P ratique de Plom berie e t d'in stallation Sanitaire: C om portant la R glem en tation d es In sta lla tio n s d'Eau e t de G az d a n s les Im m eubles d'H abitation. I l e d. m ise jour. ed. Paris: Garnier frres, Impr. Tardy-
Quercy-Auvergne), 1972. A sbestos-cem ent was the only approved m aterial for th is assem bly because o f concerns about carbon m onoxide
leakage.
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"As Near P erfect as We are L ikely to G et"
The PVC Controversy
Polyvinyl chloride (PVC) for pipe is first a tte ste d in A m erican engineering literature in 1950, when Gas Age published an article about a recentlyin tro d u c ed an tico rro sio n PVC-film tap e for u n d e rg ro u n d p ip e .93 The Am erican Society for T esting M aterials (ASTM) w as, in th a t year, testin g v arious types of plastic pipe for possible u se in industrial processes involving hydrofluoric acid; sim ilar re se a rc h w as u n d e rta k e n in G erm any a n d rep o rted in 1951.94 T esting of PVC for w a ter a n d sew er pipe w as u n d erw ay in th e U.S., E urope an d elsew here by 1954, a n d co n tin u ed th ro u g h th e 1960s.95
B ritain approved PVC for cold w ater pipe in 1962, a n d revised th e s ta n d a rd in 1968.96 In-service a n d fire toxicity of PVC w ere explicitly ad d ressed in som e (but n o t all) of th ese testin g p ro g ra m s.97 The U.S. B u re a u of S ta n d ard s (D epartm ent of Com merce) p u b lish ed a s ta n d a rd for PVC "d rain , w aste an d vent pipe" in 1965, and the American W ater Works Association issued a s ta n d a rd for PVC p re ssu re pipe te n y ears la te r.98 Som e ju risd ic tio n s h a d approved the u se of PVC in a few types of process, w ater, an d sewer service by the time of publication of the International Association of Plumbing and M echanical Officials' (IAPMO) 1979 Uniform Plumbing C odelllustrated Training M anual.99
The adoption of PVC in th e 1980s, however, w as controversial. Donald
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51
"As Near P erfect as We are L ikely to G et"
G oodm an et a l rep o rted in 1987 on th e opposition to PVC in California th a t had resulted in the lim itation of state approvals:
In California, the plum bers union and others alleged th at plastic potable w a ter pipe (PVC, CPVC, a n d PB) poses h e a lth risk s. They have blocked the expanded use of plastic pipe by forcing an en v iro n m en tal im p act rep o rt (EIR) to be com pleted. The EIR is now in its seventh year, and the California D epartm ent of Housing and C om m unity D evelopm ent (CA DHCD) is actin g a s th e lead agency. As p a rt of th e EIR, S tanford R esearch In tern a tio n al (SRI) com pleted a literature survey in 1983 on the public health effects of plastic pipe on potable water. That report identified four issues which need to be addressed in the EIR process: leaching, perm eation, worker h e a lth a n d safety (exposure to solvent cem ents), a n d fire safety .100 Because the issue rem ained unresolved at the time of publication of the 1985 Uniform Plumbing Code, th e publisher, IAPMO, affixed a notice to the in sid e cover of th e code, show n below .101
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"As Near P erfect as We are L ikely to G et"
Figure 25: IAPMO's n o tic e o f th e C alifornia E n viron m en tal Im pact Report on PVC, in th e 1985 ed ition o f th e Uniform Plum bing Code.
W-.
NOTICE- For several years art environmental im pact fteport has oeen in the course 9 * preparation inCaiifofoia to determine whether ih M3>di CPVC,
m PVC, or PB plastic pipe for- transporting potable
y/tfier posa-s q cancer to pdbtfC. health tbeerv
virpom^nt. At the time of M e printing of the 1985 Edition of the Uniform Plumbing Code, the Califor
\ nia State Plumbing Code does not permit any ex
of pansion in the use such pip beyond those ap
plications permitted in the 1979 Edition of the Uniform Plumbing Code. For information on California restrictions, contact the State Housing Law Section of the California Housing and Community Development Depart ment
International Association ot Plumbing and Mechanical Officials
UNIFORM : PLUMBING
V.5.
UP Un Un UF .
DONTHOMPSONASSOCIATES, INC. 770 Tamalpais Dr,, Suit 206
Corl Madera, CA 94825
V
1985
E D IT IO N
Adopted at the Fifty-Fourth Annual Conference
SEPTEMBER 1983
INTERNATIONAL ASSOCIATION OF PLUMBING
`
AND MECHANICAL OFFICIALS
(A Non-Profit Organization!
As of 1987, the U nited Association of Journeym an and Apprentices of the Plum bing and Pipefitting Industry and the International Brotherhood of Electrical W orkers were still actively opposing plum bing and electrical code approvals of PVC pipe a n d cond u it on b o th environm ental a n d occupational h e a lth g ro u n d s .102 Som e ju risd ic tio n s, in clu d in g Chicago, h a d im posed b a n s on PVC pipe in re sp o n se to th e se cam p aig n s by organized la b o r.103
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"As Near P erfect as We are L ikely to G et"
By th e m id-1990s, however, PVC w as widely accepted a n d adopted for
w ater a n d sew er service by code a u th o ritie s w orldw ide.104 W riting of th is
transition from the 1950s in the Journal of ASTM International in 2011,
engineer Bob W alker observed that
As a su b stitu te for the w ell-established pipe m ainstays of th at
era--iron, steel reinforced concrete, asbestos cem ent, an d vitrified clay;
PVC pipe w as initially viewed as having insufficient stren g th an d
stiffness to be a viable contender. All th ese early views h a d to be
changed. ... th e q u estio n s a n d d o u b ts su rro u n d in g PVC p ip e's
perform ance capabilities w ere overcom e. PVC pipes now acco u n t for
the m ajority of all new w ater and sanitary sewer installations."
W alker goes on to a sse rt th a t "By 2004, PVC acco u n ted for 78 % of th e
com bined U.S. and C anadian buried w ater pipe m arket for pipe diam eter 4 in.
a n d la rg e r." 105
The PVC pipe controversy, u n su rp risin g ly , p a sse d in 1985 into th e h a n d s of
th e N ational S a n ita tio n F o u n d a tio n (NSF), a nonprofit testin g a n d s ta n d a rd s
developm ent organization th a t has, since 1944, worked closely with Federal
and state public health agencies to develop m aterials, equipm ent, and safe-
practices stan d ard s for food, w ater, and sanitation. After three years of
.
research and testing, the NSF published its revised S tandard 61 Drinking Water
System Components in 1988, w hich prom ulgated a list of m axim um allowable
co n tam in an t leachate levels from PVC a n d CPVC w ater system pipe an d its
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54
"As Near P erfect as We are L ikely to G et"
solvent cem ents, adhesives and sealants, and a battery of tests required for NSF certification, which was required for AHJ approval under the Uniform P lum bing C ode.106 More th a n 90 p o ten tial c o n ta m in a n ts of d rin k in g w ater are currently regulated u n d e r NSF stan d ard 61 an d U.S. E nvironm ental Protection Agency re g u la tio n s.107
Perform ance-in-service (as opposed to health) stan d ard s for plastic pipe were and are incorporated into revisions of NSF/ANSI S tandard 14 Plumbing S y ste m C om ponents.108
Maines for ACI June 2016
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"As Near P erfect a s We are L ikely to G et"
N otes
1 O n a sb e sto s a s a critical m ateria l in N orth A m erica d u rin g World W ar II,
see Bowles, Oliver, a n d K. G. W arner. "Asbestos." In M inerals Yearbook, edited
by H. H erbert H ughes, 1363-72. W ashington, D.C.: S u p e rin te n d e n t of
D ocum ents, 1940; Brom field, C. S., a n d A. F. Shride. Mineral R esources o f San
Carlos Indian Reservation, Arizona. 613-91. W ashington, DC, United States:
U nited S tates Geological Survey, 1956; R ansom , Ja y Ellis. "Arizona's Salt River
A sbestos." A sb e sto s 36, no. 3 (1954): 2-10; S tew art, L. A. "C hrysotile-A sbestos
D eposits of A rizona [1]." U.S. B ureau o f M ines Inform ation Circular 7706 (1955):
1-124; th e sam e a u th o r's "C hrysotile-A sbestos D eposits of A rizona [2]." U.S.
B ureau o f M ines Inform ation Circular 7745 (1956): 1-41; S tew art, L. A., a n d P.
S. H aury. "Arizona A sbestos D eposits, Gila C ounty, Ariz.". U.S Bureau o f Mines
Report o f Investigations 4100 (1947): 1-28; History o f Cork, A sbestos and
Fibrous Glass Division, War Production Board. W ashington DC: W ar Production
Board, 1945; Bowles, Oliver. "Asbestos, a Strategic Mineral; Has the United *
S tates A dequate Sources of Supply?" Mining & M etallurgy 19 (October 1938).
442-45; H olm es, H arry N. Strategic M aterials a n d National Strength. New York,:
M acm illan, 1942; Jo se p h so n , G. W., a n d F. M B arsigian. "Asbestos." In
M inerals Yearbook, edited by Allan F. M atthew s. W ashington, D.C.:
S u p e rin te n d e n t of D ocum ents, 1949: 139-149; Tim m , W. B. Industrial M inerals
and War Effort. M ontreal, C anada: C anadian Institute of Mining and
M etallurgy, 1942: 181-191; U nited States. Army and Navy M unitions Board.
The Strategic and Critical Materials. W ashington, 1940 an d 1945; U nited
S tates. C ongress. H ouse. Com m ittee on Arm ed Services. To A m end the A ct o f
July 23, 1946 (60 Stat. 596), Entitled "Strategic and Critical Materials Stock
Piling Act" (H.R. 4136). Mr. A n d re w s o f N ew York. W ashington: U.S. G.P.O.,
1947; United States. Congress. House. Committee on Banking and Currency.
A m e n d the R. F. C. Act, a s A m ended. H earings before the Comm ittee on B anking
and Currency, H ouse o f Representatives, Seventy-Seventh Congress, First
Session, on H.R. 5 6 6 7 (Superseding H.R. 5642), a Bill to E xem pt Strategic and
Critical Materials from C ustom s Duties in Certain Instances and fo r Other
Purposes. R evised S eptem ber 16,-1941. W ashington: U.S. Govt. P rint. Off.,
1941; United States. Congress. House. Committee on Interior and Insular
Affairs. Stock Piling o f Strategic and Critical M aterials and Metals. Hearings
'
before the Subcom m ittee on M ines and Mining o f the Committee on Public Lands,
House o f Representatives, Eightieth Congress, First Session. W ashington,: U.S.
Govt. Print. Off., 1947; U nited S tates. C ongress. H ouse. Com m ittee on Military
Affairs. Strategic and Critical R aw Materials. Hearings before the Committee on
Military Affairs, H ouse o f Representatives, Seventy-Sixth Congress, First Session,
on H.R. 2969, 3320, 2556, 2643, 1987, 987, and 4373, to Provide fo r the
Maines for ACI June 2016
56
"As Near P erfect as We are L ikely to G et"
Common D efense by Acquiring Stocks o f Strategic and Critical R a w Materials in Time o f National Emergency, and fo r Other Purposes. W ashington: U.S. Govt. P rint. Off., 1939; U nited S tates. C ongress. H ouse. C om m ittee on Naval Affairs. To Provide fo r the Naval D efsnse by Acquiring Stocks o f Strategic and Critical R a w Materials, Concentrates, a n d A lloys E ssential to the N eeds o f Industry fo r the M anufacture o f Supplies fo r the Naval Forces and the Civilian Population in Time o f a National Em ergency, a n d fo r Other P urposes (H.R. 3376). Mr. Vinson. W ashington: U.S. G.P.O., 1939; S. 572 A ct to Provide fo r the Common D efense . by Acquiring S to cks o f Strategic a n d Critical M aterials ... J u n e 7, 1939 (Public 117, 76th Congress, Chapter 190, 1st Session). 117; United States. Congress. Senate. Com m ittee on Military Affairs. Stock-Piling. Hearing before the Subcommittee on Surplus Property o f the Committee on Military Affairs, United S ta tes Senate, Seventy-N inth Congress, First Session, on S. 752 and S. 1481, Bills to A m en d the A ct o f J u n e 7, 1939 (53 Stat. 811), a s A m en d ed , Relating to the Acquisition o f Stocks o f Strategic and Critical Materials fo r National D efense Purposes, and S. 1522, a Bill to Regulate the Disposition o f Accum ulations o f Strategic and Critical Materials. October 30, 1945. W ashington: U.S. Govt. Print. Off., 1945; Strategic a nd Critical Materials. H earings before a Subcommittee o f the Committee on Military Affairs, United States Senate, S eventy-Seventh Congress, First Session, Relative to Strategic and Critical M aterials a n d M inerals M ay 15,19,21,26,J u n e 4,11,16, a n d J u ly 1, 1941. W ashington: U.S. Govt. Print. Off., 1941; U nited S tates. C ongress. Senate. Com mittee on M ilitary Affairs., an d E lbert D uncan Thom as. Strategic and Critical M aterials E ssen tia l to National D efense ... Report to A ccom pany S. 572. W ashington,: U. S. Govt, print, off., 1939; U nited S tates. Congress. Senate. Com mittee on Mines and Mining. Stock Piles o f Strategic Minerals. Hearings before a Subcom m ittee o f the Committee on Mines and Mining, United States Senate, Seventy-Eighth Congress, First Session, on S. 1160, a Bill to Stim ulate Production o f Strategic a n d Critical M inerals fo r the P resent War Effort a n d to A ssure an Adequate Supply o f Such Minerals fo r A ny Future Emergency by
Continuance, Intact, in the Post-War Period o f All Stock Piles Surviving the Present War and by N ecessary A ugm entation Thereof Primarily from Domestic Sources, and fo r Other Purposes. W ashington,: U.S. Govt. Print. Off., 1943; Stock Piles o f Strategic Minerals. Part 1 Hearings before the United States Senate Committee on M ines and Mining, Subcommittee on S. 1160, Seventy-Eighth Congress, First Session, on J u n e 24, Ju ly 1, 2, 1943. W ashington: U.S. G.P.O., 1943; Stock Piles o f Strategic Minerals. Part 2 Hearings before the United States Senate Committee on Mines and Mining, Seventy-Eighth Congress, First Session, on July 14, 1943. W ashington: U.S. G.P.O., 1943; Kennedy, D onald O., and J a m e s M. Foley. "Asbestos." In M inerals Yearbook, 199-209. W ashington DC: G.P.O., 1959; May, T im othy C. "Asbestos." In M inerals Yearbook. W ashington DC- GPO 1965: 201-211; Snyder, Gary. Stockpiling Strategic M aterials. S an Francisco, CA: C h an d ler, 1964: 140-149; U nited S tates. B u re a u of M ines., an d
Maines for ACI June 2016
57
"As Near P erfect as We are L ikely to G et"
U nited States. N ational Security R esources Board. M aterials Office. Materials Survey, Asbestos, 1950. W ashington: National Security Resources Board, 1952; United States. Congress. House. Committee on Armed Services. Subcom m ittee on Seapower and Strategic and Critical M aterials. Hearing on Shipbuilding Programs before the Seapow er and Strategic and Critical Materials Subcommittee o f the Committee on Armed Services, House o f Representatives, Ninety-Fifth Congress, First Session, M ay 25, 1977. W ashington: U.S. Govt. P rint. Off., 1977; U nited S tates. C ongress. S enate. C om m ittee on Arm ed Services. Inquiry into the Strategic and Critical Material Stockpiles o f the United States. Draft Report o f the National Stockpile and Naval Petroleum Reserves Subcom m ittee ... On the National Stockpile. W ashington: U.S. Govt. P rint. Off., 1963; Inquiry into the Strategic and Critical Material Stockpiles o f the United States. Hearings before the National Stockpile and Naval Petroleum Reserves Subcommittee o f the Committee on Arm ed Services, United States Senate, EightyS even th Congress, Second Session. W ashington: U.S. Govt. Print. Off., 1962, National Stockpile: Hearings before a Subcommittee o f the Committee on Armed Services, United S ta te s Senate, Eighty-Fifth Congress, First Sessio n ... Ju ly 24 and A u g u st 13, 1957. W ashington: U.S. G.P.O., 1957; United States. Congress. Senate. Com mittee on Interior an d In su lar Affairs. Accessibility o f Strategic and Critical M aterials to the United Sta tes in Time o f War and fo r Our E xpanding Econom y. W ashington,: U. S. Govt. Print. Off., 1954; E xtension o f Purchase Programs o f Strategic and Critical Minerals: Hearings before the Subcommittee on Minerals, Materials, and Fuels o f the Committee on Interior and Insular Affairs, United States Senate, Eighty-Fourth Congress, Second Session, on S. 2 8 7 6 [and Other] Bills to Encourage the Discovery, Development, and Production o f Tungsten, M anganese, Chromite, Mica, A sbestos, Beryl, Columbium-Tantalum-bearing Ore or Concentrate, Antim ony, Mercury, and Flourspar in the United States, Its Territories, and Possessions. W ashington: G.P.O., 1956; U nited S tates. Executive Office of th e President. Office of Em ergency Planning, an d U nited States. Office of Defense Mobilization. Stockpile Report to the Congress. W ashington: 1956; W est, J . M., a n d Victoria R. Schreck. "Asbestos." In Minerals Yearbook, 281-94. W ashington DC: GPO,
1961; a n d Knight, F., a n d L. A. Sm ith. "Arizona Low Iron Chrysotile A sbestos
Situation." A sbestos 42, no. 9 (1961). 2 On typhoid in the U nited States, see D ublin, Louis I., and Am erican
Public Health Association. Section on Vital Statistics. Typhoid Fever and Its Sequelae. New York: M etropolitan Life In su ra n c e , 1914; Gay, F rederick P. Typhoid Fever Considered a s a Problem o f Scientific Medicine. New York: M acm illan, 1918; a n d M cC arthy, M ichael P. Typhoid a n d the Politics o f Public Health in Nineteenth-Century Philadelphia. Memoirs of the American Philosophical Society. Philadelphia: American Philosophical Society, 1987. On cholera worldwide, see Kudlick, C atherine Jean . Cholera in post-revolutionary Paris: a cultural history. Berkeley, Calif.: University of California Press, 1996;
Maines for ACI June 2016
58
"As Near P erfect as We are L ikely to G et"
Rosenberg, C harles E. The cholera years, the United States in 1832, 1849, and 1866. Chicago: U niversity of Chicago P ress, 1962; C astro, A. F. P e sta n a de, W. F. Almeida, a n d ILSI Brazil. Cholera on the Am erican continents. W ashington, D.C.: ILSI P ress, 1993; a n d E chenberg, M yron J . Africa in the time o f cholera: a history o f pan d em ics fro m 1815 to the present. New York: C am bridge University
Press 2011. 3 Eyler, J o h n M. Victorian Social Medicine: The Id ea s a n d M ethods o f William
Farr. Baltim ore: J o h n s H opkins U niversity Press, 1979. 4 R utten, Thom as, an d M artina King. Contagionism and Contagious
Diseases: Medicine and Literature, 1880-1933. Spectrum Literaturw issenschaft
= Spectrum Literature,. Berlin ; Boston: De Gruyter, 2013. 5 Hempel, Sandra. The strange case o f the Broad Street pump: John Snow
and the m ystery o f cholera. Berkeley: University of California Press, 2007. 6 McGuire, Michael J. The Chlorine Revolution: Water Disinfection and the
Fight to Save Lives. Denver: A m erican W ater W orks A ssociation, 2013. 7 G est, Howard. Microbes: A n Invisible Universe. Rev. ed. W ashington, DC:
ASM Press, 2003.
.
8 Koch, Robert. Cholera and Its Bacillus. New York: New York Medical
Abstract, 1884. 9 Paradigm atic or K uhnian change is the historical framework accepted as
explanatory by the majority of m odern historians of science, technology and m edicine. The h y p o th esis w as first defined a n d d escribed in K uhn, T hom as S. The Structure o f Scientific Revolutions. Chicago: University of Chicago Press,
1964. 10 F ren ch , M orris S., a n d E dw ard O. S h ak esp eare. Report Upon the
Epidemic o f Typhoid Fever at Plymouth, Luzerne County, Pa. Philadelphia: Ledger jo b p rin t, 1885; Sedgwick, W. T. Principles o f Sanitary Science a n d the Public H ealth w ith Special R e ference to the C ausation a n d Prevention o f Infectious D iseases. New York: The M acm illan com pany; London, M acmillan a n d co., ltd., 1902; a n d W hipple, George C h an d ler, a n d W. T. Sedgwick. Typhoid Fever; Its Causation, Transm ission and Prevention. New York: J . Wiley
& Sons, 1908.
.
n "Breyvis' m icrom em brane filter," Journal f u r G asbeleuchtung und
W asserversorgung (1886): 412-416; "Piefke's filter," in th e sam e volum e of th is
journal, pp .781-788; "The G erm an Trials of W ater Filters," The British Medical
Journal 2, no. 1812 (1895): 725-26; W oodhead, G. Sim s, a n d G. E. C artw right
Wood. "An Inquiry into th e Relative Efficiency of W ater Filters in th e Prevention
of Infective Disease," The British Medical Journal 2, no. 1767 (1894): 1053-59;
a n d th e ir "An In q u iiy into th e Relative Efficiency of W ater F ilters in th e
Prevention of Infective Disease," The B ritish M edical Journal 1, no. 1934 (1898):
261-84. See also Zigerli, P. "Das "Z-Verfahren" Als N euer Beitrag Z ur
Abwasser-Reinigung," Schweizerische Bauzeitung 108, no. 6 (1936): 59-62, on
the use of asbestos filters for sewage treatm ent.
Maines for ACI June 2016
59
"As Near P erfect as We are Likely to G et"
12 Connolly, J . I. "The A pulian A queduct," Public H ealth Engineering
A bstracts, no. J-2 3 8 (13 O ctober 1923): 56-57; Uniform Plum bing Code
.
Com m ittee. Uniform Plumbing Code, Report. DC-13. W ashington: U.S. Govt.
P rint. Off., 1949; D esign a n d Construction o f General H ospitals. New York:
Dodge Corp., 1953; Jo in t Com m ittee on R ural S anitation (U.S.)., an d United
States. Public H ealth Service. Division of Engineering Services. Manual o f Septic
Tank Practice. Public H ealth Service Publication. W ashington: U.S. Dept, of
Health, E ducation and Welfare, Public H ealth Service, B ureau of State
Services, Division of Sanitary Engineering Services : For sale by the.Supt. of
D ocs., U.S. Govt. P rint. Off., 1959; General Standards o f Construction and Equipment: Nurses' Residence,
School o f Nursing, Public H ealth Center, State Public H ealth Laboratory,
Diagnostic or Treatm ent Center. H ospital and Medical Facilities Series (the Hill
B urton Program): Regulations; Public H ealth Service Regulations. W ashington,
D.C.: U.S. G.P.O., 1962; United States. Public H ealth Service. Technical
Com m ittee on Plum bing S tandards. Report o f Public H ealth Service Technical
Committee on Plumbing Standards: A Proposed Revision o f the National Plumbing
Code ASA A40. 8-1955. W ashington, D.C.: U.S. Dept, of H ealth, Education,
and Welfare, Public H ealth Service, 1962; and United States. Public Health
Service. Division of Environm ental Engineering and Food Protection. Manual of
Individual W ater Supply System s. Rev. ed. W ashington,: U. S. Dept, of Health, .
E ducation and Welfare, Public H ealth Service, Division of Environm ental
E ngineering 85 Food P rotection, 1962.
.
13 V an Nam e, R alph G. "B iographical M em oir of F ra n k A u stin Gooch 1852
1929, Presented to the Academy at the A nnual Meeting, 1931," National
A cadem y of Sciences Biographical Memoirs 15 (1931): 104-135.
14 V an Nam e, "G ooch," 114. 15 Bloomfield, J o h n Ja c o b , a n d Jo s e p h M arius DallaValle. The .
Determination and Control o f Industrial Dust. U nited States Public H ealth
Service Public H ealth B ulletin. W ashington: U.S. Govt, p rin t, off., 1935: 43.
16 See, for exam ple, C ain, J . R. The D eterm ination o f Chromium, a n d Its
Separation from Vanadium, in Steels. U.S. B ureau of S tandards. Technologic
P apers. W ashington: Govt. Print. Off., 1911; W esson, L aurence G oddard.
Combustion M ethod fo r the Direct Determination o f Rubber. U.S. B ureau of
S ta n d ard s. Technologic Papers. W ashington: Govt. Print. Off., 1914; and
Tuttle, Jo h n B., an d Louis Yurow. Direct Determination o f India Rubber by the
Nitrosite Method. United States B ureau of S tandards. Technologic Papers.
W ashington: Govt. Print. Off., 19J9.
17
Bowles, Oliver, a n d A. C. Petron. "Asbestos," in M inerals Yearbook, edited
by F. M. Shore. W a s h in g to n , D.C.: S u p e r in t e n d e n t of D o cu m en ts, 1941: 1427. .
is "New E quipm ent for Filtration Problem s: Utilising A sbestos Filtering
Films," Chemical A ge 27 (A ugust 27 1932): 195; .Belani, V. D. I. A sbest
K u n sth arz-M assen," K u n ststo ffe 22, no. 2 (1932): 30-31; K aspin, B. L.
Maines for ACI June 2016
60
"As Near P erfect as We are L ikely to G et"
"Preparing Asbestos for Filtering Mats," Industrial and Engineering Chemistry A nalytical Edition 12 (Sep 15 1940): 517; L angm uir, Irving. "Report on Sm okes a n d Filters, for th e U.S. Office of T echnical Services, OSRD R eport No. 865, 1942," in The Collected W orks o f Irving Langmuir; with Contributions in Memoriam, Including a Complete Bibliography o f His W orks, edited by C. Guy Suits. New York: Published w ith the editorial assistan ce of the General Electric Co. by Pergam on Press, 1942 (Reprint, 1960), v. 10: 394-436; Madall, E. "Separation betw een Liquids and Solids/ Separacao E ntre Solidos E Liquidos," Ordem d o s E ngenheiros --Boletim 4, no. 46 (1940): 377-403; P erruche, L. Filter Aids / Les A djuvants De Filtration." N ature (Paris), no. 3067 (1941): 70-72; S chepp, R. "D eterm ination of S u lp h u ric Acid in P resence of So2 in C alcining Gases / Bestim m ung Der Schwefelsaeure Neben So2 in Den Roestgasen. Papier-Fabrikant 36, no. 21 (1938): 178-80; an d Jaco b s, Morris B. War Gases, Their Identification a n d D econtam ination. New York, N.Y.: Interscience
Publishers Inc., 1942: 108. 19 Ju e rg e n , R. "Linseed-Oil Purification /Z u r Frage D er Leinoel-Veredelung."
Farben-Zeitung 34, no. 19 (1929): 1124-25; Raw son, C hristopher, W alter Myers G ard n er, a n d W. F. Laycock. A Dictionary o f D yes, M ordants, a n d Other C om pounds U sed in D yeing a n d Calico Printing. London: C. Griffin, T 918: 46, 188, 189, 191, 194-195, a n d 199; a n d Cozzens, F. R. "Improving C rude Oil."
A sbestos 23, no. 9 (1942): 810. 20 Kling, F. E. "Dry-Hot C leaning of B last F u rn a ce G as -- Revolution in G as
Cleaning," B last Furnace and Steel Plant 34, no. 10 (1946): 1257-64; Plum m er, I. L., a n d J . H. Peebles. "Low-Cost Filters Chase. Oil from C ondensate." Power 95 no. 5 (1951); Liu, T. "Asbestos a s Filter Aid in S u g ar Refining," Industrial a n d E ngineering C hem istry 38 (May 1946): 521-24; a n d Fee, R. G. "Improving F iltration of Beet S ugar Liquor," S u g a ry A zucar 53, no. 12 (1958): 25-27.
21 W est, Allan, L. Goldfield, a n d Jo s e p h M itchell Ja m e s . History o f R esearch and Development o f the Chemicat Warfare Service through 1945. Antigas Collective Protection E quipm ent [Report No: EA-SP-300-4]. Ft Belvoir Defense Technical Inform ation Center, 1969; and "Special Filter Paper Shows Excellent P erform ance in C leaning Air," Paper In d u stry 35, no. 8 (1953): 882-84.
22 J o h n s o n , Jo s e p h , E. P oinsett, a n d J a m e s Lynah. A n E xperim ental Inquiry into the Properties o f Carbonic Acid Gas or Fixed Air, Its Mode o f Operation, Use in D iseases, a n d M ost E ffectual M ethod o f Relieving A nim als A ffected by It. Being an Inaugural Thesis, Subm itted to the Exam ination o f the Rev. John Ewing, S.T.P. Provost; the Trustees and Medical Faculty o f the University o f Pennsylvania, on the 12th Day o f May, 1797. For the Degree o f Doctor o f Medicine. Philadelphia: Printed for th e a u th o r by S tephen C. Ustick, 1797; Downing, A. J ., George W illiam C u rtis, a n d F red rik a B rem er. "The Favorite poision of A m erica,''Rural E ssa y s. N e w York: G.A. Leavitt, 1869, Poisoning by Charcoal Fum es." Harper's N ew M onthly M agazine 43, no. 256 (Septem ber 1871): 627; C ailletet, L. "C arbon M onoxide a n d Oxygen." Com ptes R en d u s
Maines for ACI June 2016
61
"As Near P erfect as We are L ikely to G et"
hebdom adaires des Seances de VAcademie des Sciences 85 (1877): 1213+;
Haddon, J . "Poisoning by Coal Fum es and Smoke," British Medical Journal 1
(1890): 178'; H aldane, J o h n Scott. "The Action of C arbonic Oxide on Man,"
.
Journal o f Physiology 18 (1895): 430; "How G as Asphyxiates," N ew York Times
(Feb 20, 1904 1904): 8; Burrell, George A rthur, an d Alfred William Gauger.
Vitiation o f Garage Air by Automobile E xhaust Gases. W ashington: Govt, print,
off., 1919; a n d Callaway, H. R. "Deadly Monoxide," Power 37 (M arch 18 1913):
385-86. 23 B rophy, Leo P., W yndham D. Miles, a n d Rexm ond C. C ochrane. The
Chemical W arfare Service: From Laboratory to Field. U nited S tates Army in
World W ar II: The T echnical Services. W ashington: Office of th e C hief of
Military History, Dept, of the Army, 1959: 81. 24 L angm uir, Irving. "Report on Sm okes a n d Filters, for th e U.S. Office of
T echnical Services, OSRD R eport No. 865, 1942," in The Collected W orks o f
Irving Langmuir; with Contributions in Memoriam, Including a Complete
Bibliography o f His Works, edited by C. Guy Suits, 394-436. New York.:
P ublished w ith the editorial assistan ce of th e G eneral Electric Co. by Pergam on
Press, 1942. Reprint, 1960 edition of collected works. 25 "C arbon M onoxide G as Defied in Army M ask," The W ashington Post (Oct
7 1928): M16; "Special Filter Paper Shows Excellent Performance in Cleaning
Air," Paper In d u stry 35, no. 8 (1953): 882-84; B urrell, G. H. "Gas M ask,
Developed by B u re a u of M ines, A bsorbs C arbon M onoxide from In sp ired Air." .
Coal Age 20 (October 20 1921): 635-36; Katz, Sidney H. Bloomfield J. J ., and
Arno Carl Fieldner. The Universal and the Fireman's Gas M asks. W ashington:
Govt. Print. Off., 1923; K nappen, T heodore M. "Effective C arbon M onoxide Gas
M ask." Gas Age-Record 48, no. 23 (D ecem ber 24 1921): 841-44; K nudson, H.
W., a n d R. D. P arso n s. Filter Paper S tu d ies VIII: E ffect o f A sb e sto s Fiber
Treatm ent, Contract N7-ONR-430. U nited States: Office of Naval R esearch, 1952;
and National Safety Council. "Personal Protection," Industrial Supervisor 18, no.
1 (January 1950): 11. On the offshore sourcing concerns, see 26 Bowles, Oliver. M aterials Survey, A sb e sto s, 1950. W ashington: B u re a u of
M ines an d U nited S tates. N ational Security R esources Board. M aterials Office,
1952: 56. 27 Bowles, A sb e sto s, 1959: 61. 28 U nited S tates. C ongress. H ouse. C om m ittee on M ilitary Affairs. Strategic
and Critical R a w Materials. Hearings before the Committee on Military Affairs,
H ouse o f Representatives, Seventy-Sixth Congress, First Session, on H.R. 2969,
3320, 2556, 2643, 1987, 987, and 4373, to Provide fo r the Common D efense by
Acquiring Stocks o f Strategic and,Critical R aw Materials in Time o f National E m e r g e n c y , a n d f o r O t h e r P u r p o s e s . W a s h in g t o n : U.S. Govt. P r in t. Off., 1939;
U nited States. Army an d Navy M unitions Board. The Strategic and Critical
Materials. W ashington DC: U.S. G overnm ent Printing Office, 1940; U nited
States. C ongress. Senate. Com m ittee on M ilitary Affairs. Strategic and Critical
Maines for ACI June 2016
63
"As Near P erfect as We are L ikely to G et"
29 S u tto n , Ann, a n d M yron S u tto n . "Asbestos: M iracle Mineral," Science Digest 43 (January 1958): 10-14.
30 Leith, David, a n d S tep h en N. R udnick. "Melvin W. First, 1914-2011," Aerosol Science and Technology 46, no. 1 (2012): 124-25.
31 F irst, Melvin W. "Filters: Prefilters, High C apacity Filters, a n d 'High Efficiency Filters; Review an d Projection," in Tenth AEC Air Cleaning Conference, edited by U.S. Atomic Energy Com m ission. New York: AEC, 1968: 65-78. The quotations are from pp.66-67.
32 "The A bsolute Filter," Industrial B ulletin o f A rthur D. Little Inc. no. 265 (May 1950): 1; a n d "G anger Reveals Lorillard's R esearch on K ent Cigarette." United States Tobacco Journal (1952): 10 and 30.
33 F ried lan d er, Sheldon K., Leslie Silverm an, Philip D rinker, a n d Melvin W. First. H andbook on Air Cleaning; Particulate Removal, prepared by the Harvard School of Public Health, D epartm ent of Industrial Hygiene. W ashington: United S ta te s Atomic E nergy C om m ission, 1952: 36. See also Haxel, O. "Simple M ethod of M easuring Radioactive S u b stan ces C ontained in Air /E in e Einfache Methode Zur M essung Des Gehaltes Der Luft an Radioaktiven Substanzen," Z e itsch riftfu e r A n g ew a n d te P h ysik 5, no. 7 (1954): 241-42; a n d Palm er, J . H. "Developing F ire-R esistant High-Efficiency Air Filters," Fire Engineering 113,
no. 5 (1960): 397-98. 34 U.S. Army. Military Specification: Filter Material; MIL-F-13785a, 30
N ovem ber 1965, Superseding Mil-F-13785 o f MIL-F-13785 (CmlC) 12 November 1954. W ashington DC: G overm ent Printing Office, 1955.
35 W est, A. L. "R espiratory Protection E q u ip m en t D evelopm ents by th e U.S. Army Chem ical Corps," A m Ind H yg A ssoc J 19, no. 2 (Apr 1958): 140-8.
36 U.S. Army. Edgewood A rsenal. Military Specification: Filter M atenal; MILF -0013785b (MU), 24 N ovem ber 1969, U sed in Lieu o f MIL-F-13785a, 30 Novem ber 1955, FSC 4240. W ashington DC: G overm ent Printing Office, 1969.
37 Yokes, G. H. "Filtration of Very Fine D usts," Engineering 179, no. 4659