Document XRQm8jKbq3yab9v200MM9wG9J

/** N Transactions of THIRTEENTH ANNUAL MEETING INDUSTRIAL HYGIENE FOUNDATION OF AMERICA, Inc November 18, 1948 ( SA-107 INDUSTRIAL HYGIENE CODES AND REGULATIONS W. P. VAHT, Se.D. KnM *J iMoit ft MIh tAd Attlkant ( I | Connotation Mini tile suggested iiu|ltfMtitntH of a subject arc un avoidable element* of very im|Mir|aut ihllucnco on a person's thinking. When dcutiug with industrial hygiene it is, therefore, nreesKsvy to M(iitlifion the mind. by deriding whether one is to think of A code in the strictly legal ami rcpulutnry sense of being "u body of luw established by the legislative authority of the stale, ami designed to regulate completely, mi far as statutes may, the subject to which it relates."--or whether one is thinking about codes in the ordinary ami none voluntary sense of being "a system of |irinei|iles, rules, nr regulations relating to one subject, or a formal statement of them." .The preference of the speaker is the more common nod volmitary sense with a minimum of regulatory provisions. There is much evi- ileuee that a desire for a concept of a uiuxiimiiii permissible freedom in the rules of life is shared by many pentuua. It ia Imped that this will be a eoulinually increasing dominant iullucuce in the formnlu- tioii and adminifilrtlioit of ill codes. The real usefulness of codes ia inherent in their compilation of good knowledge and description of good praclicca pertinent to a par ticular auhjeet, tlioir contribution to education and understanding, the basis they provide for measuring and comparing the results of endeavor, am) their effect, whether voluntary or legul, iu attaining good practice. Codes, Isilli written and unwritten, have always been an essential factor in (lie progress of civilization, and are mi less so In industrial hygiene. Development of Industrial Hygiene Codes Industrial hygiene rode* of one form or another are not new in this wnmlry. Some of llm trades and inilualriea liavu voluntarily formulated eialea of good prnelier. I likewise, some of the slates have had rather long experience in this endeavor. A discussion of the prac tice mul experience of the Stale of N'ew Vorl; was presented by Urealuirg1 at a previuiia session of the present meeting of this Kmimiutimi. However, most of the industrial hygiene code endeavor among the slates is a comparatively recent activity. It tins paralleled the rather rapid growth and acceptance uf industrial hygiene practice as A [48 1 doirahle and necessary purt of Hie iiiuiiiteitanre of health in industry. The endeavor is u rather natural product of the Accumulation of knowledge mid experience iu llie control of occupational luunrds. ami the realization Hint the effective technique* could la* promoted ami applied more hrondly in industry, ir they were organized into sys tems or codes of good practice. Consequently. considerat ions of indus trial hygiene males are no longer those of desirability, need, nmt usefulness, but arc those of iueor|Hirating the heal knowledge into cisles that are adequate. reliable, and practical. In accomplishing this, however, it must lie realized that Hie development of these codes is necessarily based on current conceptions of need ami nei|ie, ami u|io current knowledge with its many existing ureas uf iii<lefluili'iies.s mul deficiency. (Jiiitlilira of adequacy, reliubility, mul practicability can la* only relative uml conditioned upon the current iitiilerHlaudiiigs. This emphasizes that the development of industrial hygiene codes must Ih* considered from Imlli the abort range view|miut of iiicorporuliiig the liesl present conception ami reliable kuowleilgn, ami the lung range riewiMiiiil of providing means for prompt revision to include new concepts, needs of changing conditions, ami lietler know Iedge. Kurrtier. codes must lie administered with a full understanding of their limitations. Authority fur the Development of State Coden . A comprehensive review of the Authority that exists among the stales anil other agencies in this country for promulgating and enforc ing industrial hygiene emlea. with a discussion of the general nature and trends of the existing codes, their weaknesses and deficiencies, and the need mid suggested content of a uniform rode, was presented at a former Animal Meeting of this foundation by Itlooinllrld* The general situation as presented at that time has not changed funda mentally. There lias been an increasa in tha number uf Htalea that have industrial hygiene fiii-ililies willi only tww now remaining with out them. The nluuidmiee of milhorily ami power aiming the alnles and territories to promulgate and enforce such codes, rules ami regu lations, remains. In about one-lialf of Ihc slntes llm power is broad, mul in. llm remainder it is In* s|meifie legislation. A large majority of the Aiatrs have industrial hygiene i-odes of one form or another. Subject Mailer uf Present Stale Code* The subject null ter of the slate codes varies widely. It ranges from little more Ilian general saiiitiilimi. to increasingly broader eovernga Hirmigli nt ten lion to chemical mul physical agents ami fac tors of cuvirminieiil. More or less singular attention is given in the I 4!* 1 citi|>liivnit*!!I of minors. reporting nf rases, dn|tl>yn* nml employer responsibility, nml specific hazard*. Tin* njajnrily of the finlfs* Imre lulilni of allowable concentrations of atmospheric contaminants. These tables vary widely in aeopo ami lo tome extent in llu* value* given fur the Hiuitn. The liniiln hare legal kIhIiik in almut one-lndf nf (In* slates; in the remainder they are suggested hygienic stniijlardH. Wenknesses uf Present Slate Codes There Iiiik been no very iiii|Nirtnnt remedy to I In* weaknessi-a unit dcfii-icm-ic* of the cudcs Hint were pointed out by lUiMiinfiehl.3 The vnrinliilily nml diversity of content continue to make il difficult to develop nntionnl policies for safeguarding the henllh of imluslrinl employee*. Thin in of particular importance to industrial concerns that operate in several ntalea. It in also ioipurlunt la designers of structures, equipment, nml processra, lo truile associations Hint carry on henllh activities among their memhern in many stoles, ami in fnel. to nil intcrentn. Many of the codes do not have guiding principles lo assist industry in achieving good working eomlitioos; also they are inadequate in providing specific informnliim which would show indus try Imw it rnn eamply with the rode requirement*. There are many nrens of utdcAiiilciirss and inadeipiney which hinder good admiiiis- Iralioii. 1 Tliere continue* lo lie a iimlliplicity of ngeueies within most of the slides with authority to promulgate and administer rules nml regulations pertaining to industrial hygiene. There ure few states that Intve Irsn than two such agencies nml mime have live or six. In addition, a single one of these agencies may have a dozen or more separate and sometimes cmiHieting codes. This overlapping of author ity uml purpose creates duplication, confusion, ami conflict among the ngem-ies, and creates problems for the employer and all others emireruril. The variable and diverse nature of the pr<*scnt Male codes is a rather unlttrid product of the power I hid exists within the slates to promulgate uud administer sueli regulations, and the right id each slide to promulgate n code of its own choosing. This lots resulted iu a situation which, although undesirable nml irksome, has provided n grand experiment in code preparation nml administration, the results of which have been very Hohslimtinl. There have been coolrilmlions to la-ller working conditions, to elicitation of alleutioii lo industrial hygiene pnteliees, to the desired scope, character, ami administration of such codes, nml lo the ileleriuimdiou of areas of deficiency. It appeai'K, however, that this naturally occurring experiment has prac- tieally served its purpose nml that real alleutioii should lie given to [ :tt ] improving the code situation. All hough annie pceulinriti'-s of occiipatioiml exposure to harmful iigetils may oeeor among the kIrics, the variety of processra ami agents, nml the opportunities for exposure are generally similar, and there appeura to la- only minor need of s|H*einlizitliou or tailoring of emles lo meet s|M!cilie slate requirements. Farther, if the industrial hygiene codes are to In* representative uf die Ih-sI knowledge, practices, and scieulilie data, it is a sound expec tation that they would and should lie far more uniform Ihuu they are at the present time. Their divergem-ies alone condemn them. ACG1II Model Code 11 has been mentioned tlud a pari of ItlisiiutieldV discussion per tained to a pattern for a model code I bat was desigued to remove I lie umlesirnlde features of tin* existing eodc situation; also, that n t'ommil lee of the American I'mifeeem-e uf tlovernuiriital Imluslrinl Hygi enists (At*ltl II) was engaged in tlie drafting of a eisle along the lim*s of the pattern llmt he presented. The aims ami ohjivlivea of this pattern were lirielty, a ende tlml was ndeipiatc. prneticul, and linsi*d mi seienliAv fact; aimed tu inform mnnngriiienl what its responsiliilities are, nml how sufe nml lienllli.v working emidilious may Is* achieved; ami so worded to lake into consideration various social and reoiiouiie aspects of the problems. Some of the more speeille features were to provide reasonable guides or principles whieli would enable industry to nutinluiii the health of its workers at a high level; lo reconcile this endeavor with the aim of iuduslry in achieving maxi mum production at minimum cost; to contain rules and regulations fur the prevention and control of oeeiipatimint disease; to consider the hygiene of IniIIi the working place and the individual; In provide a legal interpretation of the rides and show imlnslry how these rules can In* met liy good industrial hygiene prut-lire; and other iiiforinalioii that is pertinent and necessary to the practical application and admin istration of the i-ndr. The Cmiimiltcc of llu* AC*(1111 that has heeu working on this iiiislel code released a draft several iimuths ago that cndKidii-d the results of its deliberations ami study tu tlud dale. Copies wen* sent to representatives of a cro.--ser|inu of interest in induslriid hygiene for review, cmuiiient, and criticism. These reviewers im-lmleil indus try. labor, insurance, the pulilir, the professions and priu-tiees in volved (luedii-iuc, industrial hygiene, and safely), and the memlH-rs id the ACUlll. I'lie selis-timi of reviewers ami conveyance of the draft were tiuule in part directly by the At`til II ami iu purl by asking the American Standards Association to emiiuiuuieate with a group of interests of that Assm-iation's selection. It was originally suggested tluil the *|M'nkcr direct pari of his present discussion to smite of tlie features of this llrsl draft of (lie lonilrl emit!. However, eveiila have issrurreil wliieti iippeur to mnke any extended discussion of the first draft inappropriate, tie is informed Dial the many criticisma and eonuneiils that went received in response to the eireidation of Hie draft have been Riven serious consideration by the Code Committee of the A COM at a very ivmit meeting. and that A revised draft baa been prepared. Owing to shortness of infer* veiling lime, this tlriifl has not liccoiue availidde for general distribu-. tion. However, the Chairman* of the AClHIi Code Committee will partieipalr in a discussion of this cmle at a Mieeecdiug session of the present meeting of thin h'liiinilalioit'a Chemical Committee, where there trill be ample cp|M>rtiinily to go into detuila. There is good reason to believe that a uniform industrial hygiene code Hint is adequate, praetiea). ami fneluul, mid so worded ha to take into consideration the varioua social and economic aspects of the prob lem*, should meet with great faror by everyone, especially if adiuiuia* lered in a spirit of cooperation with management and labor.- There are, however, some practical ditlleiilliea of considerable magnitude 1o lir overcome, not ouly in the drafting of a.rode of this nature and obtaining reasonable agreement, hut also in effecting its adoption by the slutes, territories, counties, and cities, and the variety of agencies therein, that have interest and authority pertaining to industrial hygiene codes. There are ninny differences of opinion and ipiesliuus of alleged farts to he satisfied. Hricf menlion of a few of ilicae will follow. Adequacy of Knowledge A finidniiieotal i|in>slioii pertains to the ndnpiiiry of knowledge. It is the speaker's opinion, which he believes is shared by a good many others, that the creation of a uniform industrial hygiene code with the lirimd coverage that has been attempted is confronted with the dilem ma of. on one hand, the need of un adequate, practical code, hosed on good knowledge amt aeieulilie facts; and, mi the other hand, by inad equacy of knowledge, experience, and facts for preparing one. Snell iiiudeqiiseies breed variations in eoneepliqii. luck of unanimity of iipiiiinii, preferences, and prejudices and the like. This is not a criti cism--it in a slate of affairs that is lielieved to have considerable res|MiiiMihilily for the variety of codes in existence. It coiislilutrs a real basis for diltleidties in preparing a code that is adequate mid practical, and meets the desired slate of definiteness, conciseness, and eunipleteiiess. In emla making efforts, the ioudeipiiieies of knowledge are Komelinies diapimed of by omission of Hie associated requirement*. [] This may lie the lical procedure. Frequently, limvevee, in the zeal to make the rode broad in ruvrrage and effectiveness, the procedure of using general statements, iiidelinileiiess of requirements, and delega tion of authority is followed. Such procedure utay lie aeeeptaldo, to H>me reslrainetl degree, in the interest of having a code available, pro viding reasonable emiaideratinn is given to the existing deficiencies in Ibe adiniiiistratinii anil Hie demands for compliance. However, delegation of such authority In each of the many agetieiea among the stales immediately opens tlie possibility for difference* of opinion, interpretalion, noil requirements, and provides a very ittt|torluiil basis for uoii-uiiifonnily of eodrs--thereby defeating the objective of uniforinily. A mere delegation of blanket authority to a code enforce ment agency fur dealing with iuadrqunriea of knowledge, is obviously not a desirablr answer to the problem. Element of Opponcncy Another impediment to tlie preparation and adoption of emirs and regulations of the type under consideration, is tlie element of (ipjxniciirV, or even mistrust, that exists between areas of interest, particularly at the present lime tietwecu industry, lubor, ami regula tory agencies. It is no secret that, at least occasionally, industrial niaiiagemeiit believes that government is intent on bedeviling anil eneniarliiog mi industrial affairs, mid is withmil eoneeru of indus trial interests; and on Ibe other hand, that government believes Ibat industry needs more and more regulation and policing. As a result, Mima earnest differences of opinion arise. One of tbit criticisms that has frequently been directed to Ibe emirs of governmental origin, is (lie lack of iqqHirtimity given for imrlieipalioii liy nil of tlie interests, particularly industry, in the code work. Home emle-tiinking procedures provide for this participation; others do uot. It must lie agreed Ibat an indiisfriat hygiene male is of lirontl, public, interest, and Ibat ila formulation should be a joint endeavor and have the lieuefit of the knowledge, experience, and view|Miiitla of all enueemed. Such coop eration is essential to the development of good emirs, and to their acceptance and use. finde-malcing procedures should provide it. ft raiinol lie denied, however^ that the leadership in initialing industrial hygiene rode work has usually arisen in the governmental agencies, and that frequently industry and the other interests have not become concerned until a rode has iqqienrrd, mid oven then their effort lias often liren directed more to eriiieism and obstruction than to attain ment of good male objectives. There arc inane notable exceptions, blit in general, industry has uot folly met its responsibilities for leader ship and eisqieration in creating lliese code*. In the main the rela- I1 lions lictwith industry anti tin* governmental industrial hygiene fueil- ilios throughout I lie country huvc Is-eu gwal. In general there linn been iiii endeavor In la* |riu,lirnl itntl rali<m:iI in establishing and administering rules nutl regulations. iintl In iiitl and assist industry, in providing healthy working conditions. Iinluslry respects IIicm* facilities and vulucs I lie services dial are given. These relation* should Ih* very lii*l|iTill in resolving any difference* of opinmii on code* ami' regulations if im-chuitixiiix fur eisqicrativc elTurt nre provided. Iii mentioning Hit' inmlei rode dial in in course of preparnlion by tin* Al!(5lll. il wax |Miiitli*t| mil dial llir nnniucnls mitl criticism; of iinluslry. Inlsir, ami other interests mi Ili* draft liml been invited, anil liml a purl uf Hie revirtv bail been i-oinliiclcd by the American Standards Association. The. plans fur die future course uf llii.s iiiinIi*I code an* mil known to die speaker, but il ivmilil uppenr In la* .in keepini* willi propriety nml practicability In suggest pris-cssing it through die Amerieaii Standards Association. where the partieipnliuu. of all interests emilil lie furiiially .recognized. That assm-iatimt i* iialiminl in scope. Its einle procedure* pruvide fur creating balaueeil committec* emu posed uf representation willi good specialized knowledge fur dealing with a purlieiilar subject, front all interests--labor, imliislry. ami the pulilie. American Standard* Association Code* represent a eonseiisus of gissl knowledge ami gissl American praetiey. 11 is lielieved dial the issuance uf an iiidiislriul hygiene eude under Ibis. AssiN'iution's procedure, willi a emiiliinetl represeiiliitiou of all. inter ests, would greatly assist in obtaining iiatiuiial rivogiiilion and |tn proval. One way of M*lling an idea to n prospective i-usloiucr is to share die idea. That procedure not only helps to sell the idea, lull at the same lime removes its faults. Type, Scope, and Conlenl of Codes The type, scope, ami content of industrial hygiene code* are sub jects mi which (here is honest ami sound disagreement among am! Iielween both regulatory and lion-regulatory interests, from several view'|MiiiitH. A basic pieslimi pertains to whether codes should bn H|Hu*ialin*l. aueli an specific industry, trade, occupation or product codes, or whrlhrr they ahould he general, all-inclusive, all-industry cimIps. doth praelieea are in use, both have advantage* and disadvan tages, hut either one would lie satisfactory if well devchqicd amt administered. The next tptcslimt pertains ......... within a par-- lieular type of rode, it linvitig Ih-cii previously staled that the pitmmiH i-ovcrnge of emh*s range* frmu little more than general xiiiiitation. ltd miHleralely eomplele coverage of eiiviroinueut. Il is lielieved that coverage should lie eoiuplele to tin* extent tlint valid information i* [S U available for defining the reipiiretueiit*. A third qucsliuii pertain* In whether the snipe shall Ik* emifiunl to the rather general present eon- crpl uf duties of industrial hygieitislx in cITcetiug control of environ- liieitlsl factor* that are directly related to health a* cmunimdy inter preted, nr whether it shull include auhjcet* of safely ami health and medical service* that are commonly recognized lube within the purview* Mini province of industrial safety and industrial innliriite. The pro|NMrd model At'lllII code previously referred tu followa the latter pnttern to mimic extent. For a Ipug lime the speaker Ita* had a conviction that insofar a* harmful agrul* of iiuln*trinl ruvirnuiiient are con cerned. the knowledge, skill*, procedures, mid teamwork liml is rriptirnl to control the agent* and protect worker* are tm Kiiuilar. over lapping, ami interdependent to scgregnln industrial health, iudtislrinl hygiene, and industrial safety iutn three distinct service* or jurisdic tions. Attempts to do this are not only difllcull hill also rather uurenl. However, llda vicw|Miiut of brond x*ope ami emitent of code* may In* loo idealistic for wide acceptance at the present lime, owing tu exist ing practices of industrial organization nml administration uf depart ment* uf nicdiciiiK, hygiene, ami safety. M Some Agreement on Scope T|ie difference* of npiiiion relating to type and scope of industrial hygiene codex will tie diflictilt to liariunuUr, nt least in the near future, because there is more than one good answer to many of the ipiesliniis. Perhaps the way will lie open to more progress if utleutimi would Ik: given to relative. iiti|nrt alien of some of the quest ions. The sjienker has previously indicated his npinimi that cither type of rode. K|M*cifir. or all-iudiislry, would serve the pur|ose if well developed and well uihiiiuislered. Uf more importance is n practical definition of scope or at least $nnr agreement mi scope aiming both the interests and the professions that are involvrd in carrying out the provisions of a code. Adequate-representation of all iulerests should lie a part of any rudemaking body. When industrial hygiene rode* transgress to siguifi. mill extent into field* of safety and medicine they should Is-nr a title Hint is indicative uf their scope. The moat urgent present need is. that regardless of variation in scope ami coverage aiming rode*, the definition of good practices and requirement* should. In the extent lhal they an* included in rude*. In* muni uniform than now prevails among the rodes in this country. Il is rather generally agreed lhal a qiiiinlilnlive definition of hygienic environment in terms id required qualities mul hurinfiil chemical, physical, and liiologicul agent*, is n very essential purl of nn iiidiislriul hygiene code. Hitch definition i* a statement of mi objec tive which, if attained, will provide the deniretl result of hcnllhv work- I1 ' ini' vomlitiunx. Further, it provides n measure that in necessary for the creation of Mich conditions lliroitgli the tlcsiiru of structiirn, e(iiiiniK'iit, nml working surroundings, nml tin* nminlctiniicc thereof. However, the endeavor to dcliiio hygienic environment him been one of the most important sources of disagreement nml ilinU'iilty in the |iro|inrutiuii of industrial hygiene codes. Disagreement on Terminology and Definition I The |Miiiitii of disagreement ami the problems to he rc*ol\cd arise from iitiiny source* ami arena of tnuxiilnralinii. They iuelmle the existence of lenoinolniry with inialemliuir connotation, differences of rom-cpi, deficiency of kmiwleil|tc in many areas for <|muiti!niivc tlcJinilioii. misinterpretation of iuforinatioii, nml ronfereuee of un warranted or unjustified reliability to alleged fueU and ilutn. A feiv of these will be iliiriiml rut her briefly. The commonly used terminology, "maximum ullownblc concen tration," "muximum permissible concentration," "toxic limit." uml I In* like, for designating standards of hygiene arc unfortunate extrac tions from phrases originally used to laliel experimental iliila, espe cially that pertaining to a miiximiiiu dosage in rclnliou to an ncule pliysiologiciil or pathological respouse. These phrases connote a rather precise i|uaulitatioii and association of environment with toxic inaui- festal ions. In becoming rather synonymous with standards of environ ment they euuvcy to many persons an understanding that ancli stand ards are also rullicr precise eritieul values just below which a person is safe and above which lie will be injured--or a condition which a niuit ran tolerate but beyond which bo is immediately in danger. Such a concept of u hygienic standard is unsound, liven though u fair degree of precision might be established for a small group of individ uals under a specified controlled condition of contact, the precision of such homogeneous data would, in most installers, lie lost iiumcdi- nlily when applied to the heterogeneous nature of both industrial cuviriiumriil and the response of individuals of a group of workmen In the environment. The foregoing is not a condemnation of llm use of (oxiculugieii! data as an element of important consideration in deriving acceptable alaudards of environment. Such knowledge is a necessity for avoiding the area of danger. The pur|Hise of the discus- sinn is to |Miiut out the desirability of disassociating the idea of maxi mum tolerable stress from (hr euueept of hygienic standards and to adopt the riitiinmlf of including fueliirs of safety ami good practice. N'o engineer would think of using the near failure limits of materials in designing a structure. ' Aiinllirr viewpoint that is receiving increasing iillculinit in defin ing acceptable standards of environment, is that of more considernlioif [ 3 1 of comfort. In particular, this pertains In sensory effect* of transient ami. on the basis of present knowledge, harmless manifestations sueli h- slight irritation of the eyes or nose, unuseating odor*, ami mild degrees of narcotic ciTis-ta; also, to condition.* such as uncomfortable i.'Oipcraturr Hint exclusive aiimuntx of nuisance dusts. . A ipieslion that is fnspicully asked regarding the extended lists of M.A.C.'s that arc included or suggested for inclusion In codes int Arc these "limits" reliable enough to he written into industrial hy giene coilcs as mandatory riH|iiirciiieulsf In Ilia stale codes llml have been developed, the limits are iiiuiulutory in atmut half of I hem and suggested hygienic simulants in the reitiiiimlcr. It it the speaker's opinion llml there is iideiputle. knowledge for deriving a reliable stand ard for relatively few .substance*. There is also soma useful knowl edge pertaining to most of the substances encountered in industry amt appearing in current lists of stniulanls. This knowledge is in general not believed to be adetpinlc fur a determination of stniiilnrds that have the reliability and validity that mandatory requirements should possess. They should be considered to ha tentative working guides pending the availability of Ixdtcr information. For this pur pose Ihry.nre useful if consideration is given to their limitations. It i* believed that this opinion is shared by toxicologists Unit have acquaintance with the situation; also, hv sonic of the persons that are responsible for compilation of such lists. Allowable Exposure Limits In the past the endeavor has liecn, with few exceptions, to select u single "limit," "concentration" or "tolerance level" for defining the |H`nniltcd ex|Hisiirc for a working day of eight hours. There has also been a rather general understanding among nmsl persons that Mich definition was applicable to all other conditions of environment amt occupational activity, h has tarn meidioiiud previously that industrial,atmospheres am rarely lioumgcucoiiH. with llm rcsti'll that in most sit uni ions llm exposure levels during a day vary considerably for a numtar of practical reasons. This creates a very ini|orlaul difliriilly in attempting tu appraise industrial exposures in terms of a simple, single standard of hygiene. In meeting the problem, the general industrial hygiene practice varies from making a few *|orndi`e determination* (which may lie worthless or even vicious! to umre extended systematic investigations, with result* represented either hv simple averages nr hv an integration of the time nod conceitI rat ioii of exposure cycles. These pns-cdiircs, especially that of idlegratiug the lime and concentration, may ta a practical expedient, hat even tin* biller may result in erroneous appraisal of either llm harmless or harmful mi lure of I he environment. For several reasons, loximhigi- [] Ifni rcn|Hiiixc cannot bo expected to bo a linear function of lime Hint cmu-ciilralion. The Amplitude And frequency nf variation from a defined iik'aii mny be very im|Mirlaiil. Many ullirr rlicmicid, physical, nud perhaps nvu biological agent* nr favtiin uf environment--even variation iu i-ltrinicid iinturo or pliynienl form of the Rainc>idistumc-- may linvi* a very Rigidficaul iiillueuce oil Hip physiological or pnlliologicul response In n npeeitled amount of mu* u|n*iit. mid even mi i another with which it in associated. In Mime instances Hie influence I tnuy be synergistic and in olliem antagonistic. Although lime dm** mil permit mi extended dineuxKinit uf toxicology, it is pertiiienl In Hie question of industrial hygiene standards to incut inn a few examples nf these iiillueiiees. The minute-volume of air inspired mid uf liluud eireidaled Hirough the lungs increase ropidly with physieal aetivily. I*'nr slreiinuiin work the volume of air mny Ini or Hu* order uf III or more and blood cireululed n limes Hint for nedeiilnry Melivity. The ninomit of most harmful. airborne contaminant* tlmt arc ueipiired through Hie lungs from a particular environment mid its triius|>orlalinn into Hie body mny vary in Hie same general order. For these reasons n "niuximiiiu allowable concentration'* may readily hqve a large safety fuetur for one degreo of activity or a large factor or "unsafely" for another. Jlot cnviroiimciit also iiierenses respiration Niul circulation. Increased pressure of atmospheric euriroiimeiil. such rus experienced in eumpressed air work, inereiisrs the muss of a harm ful gas in unit volume of sir and emi be. generally expected to increase Hie effectiveness concentration of Hie environment ms compared to Hie same, air-eoutuiuiiiHut proportions at "uonual" pressures, exceptions being those in which an aiitsgonUlie agent is likewise clfectively coneenlraled. Kticli increase in potency may be expected owing uni only Ito Hie fact Hint Hie mass of ngenl is directly iiicrriiscd, lull owing also to iion-liiiearily of response with concentration. I<itllc is known about the variation iu response with particle size uf dispersants--their relent ion in the liuign, their solubility, mid other elements of plivsieai, chemical, mid biolugieal behavior Hint ure associated with size and surface. However, enough la known to give a basis far expecting con siderable differences. The foregoing pertains to Hie relation uf only a few specific agents and faelnra. The situation liecomes very rmnplcx when all factors are considered. It requires that more attention lie given to all iui|Nirtaiit agents mid forlorn of iiutiiKlrial environment and occupational activity in the development and use of standards; it supports Hie necessity of including an ample factor of safety in standards; it suggests the |Mnsihle usefulness of multiple standards; ami it emphasizes an existing iundeipiaey of knowledge and I he need of on expanded program uf rescureU. I;iifur|uuntely this need greatly exceeds the facilities that are available for supplying it. i [TM1 procedures fur Solving Problem* - A procedure that offers good |wssihilitirM fur rcsolviug some of the problems arising from limited knowledge Is to define iudiifclriul hygiene standards for atmospheric agents in terms nf an estuldUlied system of zones; such as (for illustralian only 1 Zone I. tl-!l ppm; Zone 2. 4-HI ppm; Zone 2. lUdlll ppm. ete. A |mrlruyal and use uf Hie present knowledge in this mnimer would not only give recognition to the limitations of kiimvh*dge lint aImi to Hie difficulty uf aeeuealidy assessing the eiiviroitiueiil In which a standard is to lie applied. It would avoid the multitude of individual iiiiudiera and tiuir-line deci sions that industrial hygienists must deal with at the present time. A eery important feature wuuld lie the possibilities for l*rutoziixiiiiz dilTcrcnccx of opinion on simulants for psrtieidar RtilistituccH uiul obtaining more uniroriuity among codr-mukiug agencies. It is appar ent Hint the development of an acceptable schedule of zones will require considerable study, and Hint sonic Inter modification may In* ucerKsury to meet individual sulwlane.es and new knowledge. Also that there will lie smite enuliiiutiiiee of differences of opinion relaliug la zone assignmeiits. However, the inherent gnml |Missihilitics for mitigating soma of flic present pnihleins, invites real attention with open-minded considerations. A procedure of this kitul was diM-ux-M-d by the American ftlmnliirds thiiiiiuittec on Allowulile ('oiu-entrations of Toxic Dusts ami Oases, Z.'IT, at its meeting on DeeeiulH*r !l, l!47, amt subsequently published by Drinker aiul (took.* ANA Cmniiiitlce SKIT is eonliuiiiiig to exphtra the |mssibililies with a view to the devel opment of a Schedule of zones. Some of tlm oilier comments that are |H*rliiieiit to ninny of Hot lists of limits may Ik* lucid ioned, briefly. The first of llicsc has been discussed, namely, thr laUding of the limits ns "maximum allowable" or "maximum permissilile," or the like. Another is tlm mixture of concepts represented by Ilia limits; iu smite il is tlinl of maximum tolerable, in others it is a sound cuuccpl of hygienic standarda A real deficiency is failure In designate whether I In* definition is reluted In toxicological olfirls or to sensory uiferls--to niaiiiti-iiuiieu of goml healtli or romfort. In many iusliiueea Ike origin of the limit is ulmrnre and validity is diflieull to assess. However, notwithstanding Hicir dellrieneies and limit lit ions. Him* limits appear to lie gaining iu prestige and authority through mere copying aiul repetition, (t should be realized Hint re|H*litiou dH*s not improve validity. Again, this is not a emiileiimalion of the use of sueli information as guides (even Ihuugli recognized as Is'ing inndequalel. if it represents Hie InkI information and is" used with eoiisiileratioii of its limilalimis. fr.tt ] A wry broad basic question relating to tt|ict:ille mandatory requirriiieiils of any nature, u that of desirability, eveu though reliable. Mmidalory requirements are usually minimum requirements, or repre sentative of the worat permissible condition*. From one viewpoint siutli requirements are a nmnsary ail to code adminislration for deallug with recalcitrants; from another view|wiut, they tend to slille progress autl frecse endeavor at the established iuiuim|m. Determination of Compliance with Environmental Standards Procedure for a reliable determinatioii of eoiiiidiauee with the requirement of a code in an essential eoiii|ioueut of the requirement. Frequently the numerical value is a product of a specific technique. An iindcriilunding of the necessary technique should always be pro vided by text or by reference. The mere choosing of u sample or scries of samples that will reliably represent the air breathed by workmen and provide a quantitative result that van bo integrated with a stand ard of hygiene is not only difficult, but at best involves much uncer tainty. A few iucliea variation in position or time in production cycle, or from day to day, scusun to kcusoii, or other facts may chuuge I lie composition many fold. Doth theoretically and practically, a sample of air can lie relied on to represent only the air that existod at the exact point of sampling at the time the sample was taken, and the. same condition may never again occur, i This situation can he the cause of large error in the coucluaions drawn from investigations made for determining compliance with code requirements, or for quantitating the agent that is responsible fur the occurrence of ill health arising out of iudiuitrial exposure. The conditions that were rcsponaihle for the episode may differ greatly from those found at some previous or auliscqiienl time. Since standards or changes in standards arc often based on such investigation*, the |mssible lack of reliability is very appurent. Although major attention is usually given to precision ami accuracy of methods of determination, the real possibilities of error are inherent in obtaining a sample or a physical observation that represents the exposure. * Some Problems Relating to Adoption of a Uniform Code There are some knotty problems to he solved in an endeavor lo obtain wide aeeeptauco of any kind of uniform rode pruclice among the slates and agencies within a stale. Much hnriuoiiituig of view points and integration with existing cmles and codo administration will he necessary. Nearly all of Hu: stales liuvc two or more separate agencies with rude prerogatives Ihut are related lo matters of health ami safety. The reiuetaiiee of siieh agencies to relinquish authority (] ha Iteen demonstrated rc|>calrdly. Tito problems (hat are presented will pmlmbly 1st more difficult lo nolvo than those of developing an acceptable form of etsle. An approach to the problems might well he for the several agencies within a stale to find endeavor lo elimiiutle existing differences in aperifle requirements of their codes and then agree u|mti a single administrator for all ileum relating to industrial hygiene. Agreement among the tiiuuy states presents a more difficult problem. Tiie existcnee of states' rights, with opportunity for iinlependent thought iitnl set imp remains indent in many areas. Summary In this dismission Hide has been mii eudeuver to deni, rullier generally and brielly. with Mime of the objectives of industrial hygiene eod'-s. their desirable features, particularly those pertaining to more tmiformily of practice. Altiqilioii bus hero given lo Nome of (lie defi ciencies of present codes uml to mmiic of the obstacles to the develop ment and use of bolter rode*. The treatment of these subjects is not only inadequate, but many oilier pertinent ones have ueecnsneily been milted from Ibis relatively abort discussion. A general appraisal of the code.sit nation ns porlrAyrd may create some doubt as to whether uov of the existing codes are very useful, or if an adequate uuifnriii code cun lie developed. That is not a proper inference nr conclusion. The broad underlying tlu-sis that an attempt has been made to con tribute, is that of encouraging endeavor to improve codes from the over-all view|Hiiuls of validity, adequacy, and practicability. Where critical, the endeavor Una Iteen either that of re-orienting thought or to pointing out areas for improvcnie.nl. Many of the problems have real elements of difficulty, but arc amenable to aolution through Iho mod faith and cooperation of all concerned, supplemented with inves tigation and research for improving knowledge mid removing areas of dcliciriu-y. It is betir-ved that most of Iho problems and diillciiltics arise out of a lack of knowledge for preparing a broad honmgcnemia definition for an indefinite heterogeneous situation. ItHFHIt K.NOKS 1. Crecnburg, i^onsril: Procedure in tho Formulation and Adoption of Codes of Industrial Hygiene. I .east Conference, 1.1th Annual Meeting of the Industrial llygieno Foundation (November 17, HUH). *. Bloomfield, J. J.: Codes for the Prevention end Control of Occupntlonal Diseases. Ilth Annual Meeting of thu Industrial Hygiene Foundation (November 7, ItHfi). 3. YstTe, 0. I).: Proposed Uniform Industrial Hygiene Code. Chemists' Conference, CUh Annual Meeting of the Imlustrinl Hygiene Foundation (Nevcmlwr IW, 10481. 4. Drivker, PltlUp, nml Cook, Warren A.: Mnsimum Allowable Concentwtluns of Atmnapherie Impurities. Jour. Ind. Ilyg. and Tos., 31, p. hi, (January 1040).