Document ByLZV3xBzypBzErLwMzv2J91L

September, 1950 the cadmium. Both ed by the method of vitb the results shown d and at the right for 5 of lead, 0.0039; per , 0.0036. The results lalysis checked within btained spectrographne required was just ef as it is, should sufie general applicability method. Its use in the giene has not been too ts versatility and senict the interest of all ;a of activity. In in use seems to have been Jtine determination of the more familiar me1 biological fluids and pies should be capable tion. Well established s need be modified but Ives to a polarographic ication to organic ma Y require the developcedureS but the method uable in many cases ods do not allow ready closely similar com- m. Liaty, 16, 266, 1922; Phil. le Analyaen mit dem Polaroerlin, 1937. arografo, Draghi, Padua, 1933. Colthopf, I. M.: J. Am. Chem. Lingane, J. J.: Polarography, c., New York, 1946. Ilkovic, D.: CoU. Czech. Chem. 498, 1934. id Rideal, E. K.: Rec, tram Industrial Hygiene Codes JAMES H. STERNER, M.D., Associate Medical Director, Eastman Kodak Co., . Rochester, New York ith a subject as ambiguous as "In ate, of flagrant violation of safe operating Wdustrial Hygiene Codes," it is neces principles are ample justification for of sary to start with some qualifications. Ffiocrial controls. As a corollary agreement, the purposes of this discussion the term with the establishment of the basic labor "code" will be limited to its more official law, the increasing complexity of industry connotation,--that of a compilation of prin requires amplification of the general law ciples, rules, and regulations promulgated by specific regulations. These are often of by an official agency to aid in the inter value in protecting industry from capricious pretation of a law. As an example, in New and arbitrary decisions of enforcing agen York State, the Board of Standards and cies, as well as being more efficient in I, Appeals, an agency of the Department of forcing compliance through a direct and | Labor, has adopted by authority of the clearly defined mechanism. Labor Law a wide variety of rules relating "* There is a definite, continuing trend in to industrial operations, each of which is the various states and larger cities, to designated as a Code. These rules have the establish codes relating to an increasing force of law, and enable the appropriate number of industrial activities. With the Jofficial agency to investigate or to take legal crystallizing of certain industrial hygiene f action against anyone not conforming to concepts, and an expanding need for more I them in practice. complex industrial environmental controls, Because the term "code" has been used as it is natural that these ideas should be con jsynonomous with "standard," it is desir- sidered for incorporation in official regula ! able to differentiate these concepts in their tions. It is at this point, however, that i present significance in industrial hygiene. disagreement, even among those individuals gParticularly, with respect to the idea of an Who are regarded as well versed in indus lacceptable concentration of a toxic agent, trial hygiene matters, becomes evident. The Ithere has developed a definite distinction in disagreement pertains to the manner in pheir meanings. "Standard" has come to which the information should be related to lean a criterion established by recognized the regulations, and to the specific values, [technical authority with general consent, particularly those designated as "maximum guide to good practice, and free from the allowable concentration" values. Regal implication of "code." It may pre " In several of the states, specific maximum scribe certain "minimum" values, a level of allowable concentration values have been Iponditions below which it is unwise or incorporated in the appropriate codes for `even dangerous to go, or it may designate the control of hazardous substances. In set of criteria which are recognized as others, the limits serve merely as a guide ^optimum practice--an objective distinctly to the enforcing agency. It is reported that |above that which generally is being done, or in one state the legislature considered the [even likely to be done for some time by a enactment of a law containing a table of |major segment of the industry. such limits, with all of the implied rigidity With the general purposes of codes de of such a procedure, but fortunately the veloped by governmental agencies for the bill did not pass. The recent action of the ^enforcing of certain minimal criteria of State of California may serve to illustrate ^industrial practice there can be little dis jane pattern. agreement. The many examples, more com- Within the past year, as a part of the Plfl.-n-o--n--ly- inadvertent but occasionally deliber- Presented at the Joint Meeting of the Rubber, Petro- / _ leum and Chemical Section of the American Association general Industry Safety Orders, specific "maximum acceptable concentration" values for 146 dusts, fumes, and vapors were or Industrial Physicians and Surgeons and the * American Industrial Hygiene Association, Chicago, * '' sfcpril 26, 1960. adopted. These values largely correspond with those recommended by the Committee Page 16h INDUSTRIAL HYGIENE QUARTERLY September, 1950 on Threshold Limits of the American Con ference of Governmental Industrial Hygien ists. In the publication of these orders, the limiting concentrations are given as an ap pendix prefaced with a good statement of the qualifications and limitations of such figures. However, reference to earlier para graphs leaves little doubt but that these spe cific values can be used for enforcement pur poses, In the section on the "Control of Ventilation" it is stated, "Whenever harm ful dusts, fumes, mists, vapors or gases exist or are produced in the course of em ployment, in quantities giving rise to harm ful exposure of employees .... such hazards shall be controlled by the application of general ventilation, local exhaust ventila tion or other effective means such as pres sure ventilation ... ." A harmful exposure is defined as "exposure to dusts, fumes, mists, vapors, or gases of such duration and such concentration as to produce effects herein defined as harmful. Concentrations which, are considered to be the maximum, acceptable for various substances are listed in Appendix A." Thus, a number of spe cific substances are assigned legal limiting values. The situation with respect to harm ful physical agents, specifically, ionizing radiations, is similar excepting that it is stated, "The Division of Industrial Safety plans to hold hearings on revision of the (values) annually." The Code Relating to the Removal of Dust, Gases, and Fumes adopted by New York State in 1931 illustrates, when com pared with the recent California orders, the considerable change in approach which has occurred. Although this rule is still opera tive in New York, modification, including a table of specific limiting values (contain ing only 52 items) was developed but not adopted in 1942, and is currently being con sidered for revision. The principle of defin ing a specific limit for a particular hazard ous substance has since been incorporated in other Codes pertaining to special in dustries. The relatively indefinite criterion of the 1931 Code was, "All machinery creat ing dust or impurities in quantities tending to injure the health of employees shall be equipped with proper hoods and pipes con nected to an exhaust fan.... to remove such dusts or impurities." It is obvious that the designation of specific limits would considerably clarify the job of the enforce ment agency. Since the question of "maximum allow able concentration" values is such an im portant factor in considering the virtues and defects of industrial hygiene codes regulating exposures to hazardous agents, it is proper to discuss the current status of this perennially disputed subject. The concept of a concentration of a particular hazardous material which will not prove harmful (or in varying degree of accep tance, uncomfortable) even though an in dividual is exposed daily and for an inde finite period, is to most industrial hygienists a very useful one. The discrepancy in opin-. ion, however, as to the possible validity of such a value--and especially to the sig nificance of a given set of data establishing a limit for a particular substance, is con siderable. There has been a change from the rela tively ready acceptance of a proposed maxi mum allowable concentration of a few yea: ago to the present mood of cautious scru tiny. We have lived long enough with some' of our earlier conclusions to see them modi fied, and we are less certain of our othe. values. In addition, we have been justifi ably alarmed at the rigid authority which a value acquires with repetition 0 though uncritical) and the threat of eve. greater immutability by incorporation in. legal regulations. The activities of the organizations which; have been most widely recognized in thf establishing of standards have contributi to the confusion. On the one hand, the lim ited output of the American Standards As sociation Committee on Allowable Concen trations of Toxic Dusts and Gases impliei an increasing doubt as to the availabilit; of adequate data for other than a few ma terials. On the other, the Committee o: Threshold Limits of the American Confer-1 ence of Governmental Industrial Hygienists, issued annual reports containing values onj well over a hundred items, and including! certain materials of which, it was generally felt, there was sufficient information onlyfor a "guestimate." A careful examinations of the purposes of both groups in developing'? standards shows that their activities are far from irreconcilable, that it may well be ? desirable to have both of them continue' V Vol. 11, No. 3 INDI setting and publishing stand portant, however, where th< ficant difference in their re ment the studies upon whic sions are based and, in addi possible, the criteria by whic were made, It is inevitable be differences, and occasion preciable differences, but it; clear that in the majority these are a matter of inte not based upon different s data. There is now a serious ap the various state agencies v incorporate in codes the vali the American Conference o: Industrial Hygienists, in spi expressed opinion of some n Threshold Limits Comm against such a practice. On the obvious responsibility e enforcing agency for sped the other, is the frequent c hygienists employed in inc selected limit and their relu values determined under con they could have no part. It out that state codes are ad public hearings, but it is d committee formed to draw code will have the technical the best judgment on a w list of substances, or that si the best means for weigl technical material upon wl be based. It would be muc! to add authority to a gh shaving it originate from nical body, representing a f-dustrial hygiene activity. .Standards Committee on A ?trations of Toxic Dusts a time seemed to have these c the limited results, as judg< of standards adopted, ha\ doubts as to whether its j will meet the needs of the - The varying degree of dards presents one of tl problems. A promising been repeatedly made th established in classes or ci ing to the amount of avail fixing a given level. Wh r, September, 1950 the job of the enforce- in of "maximum allowvalues is such an im- sonsidering the virtues dustrial hygiene codes 3s to hazardous agents, cuss the current status disputed subject. The itration of a particular i which will not prove rying degree of acceple) even though an in daily and for an indelost industrial hygienists The discrepancy in opin io the possible validity nd especially to the sig- set of data establishing Ocular substance, is con- a change from the relaance of a proposed maxijentration of a few years mood of cautious scrud long enough with some usions to see them modiess certain of our other n, we have been justifile rigid authority which with repetition (even and the threat of even ity by incorporation in the organizations which widely recognized in the ndards have contributed )n the one hand, the limAmerican Standards As-* ee on Allowable ConcenDusts and Gases implied bt as to the availability, or other than a few ma ther, the Committee on, of the American Confertal Industrial Hygienists irts containing values on ed items, and including ,f which, it was generally fficient information only " A careful examination both groups in developing that their activities are [able, that it may well be both of them continue If Vol. 11, No. 3 * < INDUSTRIAL HYGIENE QUARTERLY Page 165 setting and publishing standards. It is im portant, however, where there is a signi ficant difference in their results, to docu ment the studies upon which their conclu sions are based and, in addition, so far as possible, the criteria by which the decisions were made. It is inevitable that there will be differences, and occasionally, really ap preciable differences, but it should be made clear that in the majority of instances these are a matter of interpretation, and not based upon different sets of factual data. There is now a serious apprehension that the various state agencies will increasingly incorporate in codes the values approved by the American Conference of Governmental Industrial Hygienists, in spite of the openly expressed opinion of some members of that hreshold Limits Committee warning gainst such a practice. On the one side, is the obvious responsibility and need of the nforcing agencv for specific criteria On iSe other, is the frequent disagreement bv ivgienists employed in industry with the. elected limit and their reluctance to accent pa determined1 under conditions in which they could have no part. It will be pointed ut that state codes are adopted only after ublic hearings, but it is doubtful that the ommittee formed to draw up or revise the ode will have the technical competence for e best judgment on a widely diversified list of substances, or that such hearings are he best means for weighing the highly technical material upon which limits must e based. It would be much more desirable p add authority to a given standard by aving it originate from a common techical body, representing all phases of inustrial hygiene activity. The American tandards Committee on Allowable Concen- ations of Toxic Dusts and Gases at one me seemed to have these qualifications, but e limited results, as judged by the number standards adopted, have raised serious oubts as to whether its past performance Hull meet the needs of the situation, r The varying degree of validity of staiLi lards presents one of the most difficult Diems. A promising suggestion has lllleen repeatedly made that standards be pstablished in classes or categories, accord- to the amount of available evidence for ^llli^fixing a given level. Where there was a consiuerable amount of pertinent data, suf ficient agreement could be expected to per mit the establishment of a reasonably fixed value. While there will be continued ob jection from some individuals to the use of such information in codes, much of the present criticism of this action would be avoided. Intermediate and lower categories would include those values with lesser valid ity, and these would be used merely as guides. While all values, as at present, would be subject to revision as additional information was developed, the intermedi ate and lower level figures would be given a limited tenure, requiring regular and systematic review. Codes can be characterized as to the man ner in which they function. In one type, the "definitive" code, the engineering spe cifications are described in great detail, requiring compliance as to gauge of metal, size of ducts, velocity or volume of air flow, etc., of the equipment or device for con trolling the hazardous condition. Enforc ing agencies emphasize that these are mat ters which can be checked by less tech nically trained inspectors. In addition, guidance as to an adequate design and con struction is essential, particularly in the smaller plants, if competent engineering skill is not available. These arguments are countered by industry which complains of the restriction imposed, of the difficulties encountered in substituting newer, and per haps more economical and more effective controls for the methods dictated in the code. A second type of code is the "perform ance" code. Here the emphasis is on the end result, which is described and defined-- and the method for achieving it is left, in great part, to industry. The difficulties from the enforcement view are the paucity of criteria for defining the acceptable en vironment, and the necessity of greater technical competence in personnel investi gating the industrial conditions. Industry, however, has greater freedom as to methods for controlling the hazard. If it is agreed that codes are necessary to secure safe and healthful conditions un der certain circumstances (and the author subscribes to the viewpoint), one or the other, or a combination of the two, of the above types of code must be employed. The arS*:i I ' Pmge 166 INDUSTRIAL HYGIENE QUARTERLY September, 1950 definitive code may appear to be the easier to enforce--and perhaps the easier to com ply with--for many standard operations and processes. It lacks, however, the direct ness and versatility of the "performance" approach in dealing with the actual prob lem, the hazardous condition. With the in creasing ability to define the desired end and to evaluate the actual circumstance of exposure, there is a trend toward the adop tion of performance codes. The California Safety Orders are of this type. In addition, the suggested model or standard code re cently prepared by a committee of the American Conference of Governmental Indnstrial Hygienists was expressly a "per formance" type. In New York, a recent re vision of the Product Finishing Code, to snpplant and extend the regulations orig inally covering product spray painting, is a good example of compromise between the two principles, although no specific con centrations are given. With this background, let us consider the probable directions of Industrial Hy giene Code making, and what can be done to assure reasonable, valid, and workable regulations. In the first place, it is likely that our increasingly pomplex society and technology will require more rules and regu lations. The present trend is toward the adoption of performance codes, although enthusiastic and perhaps premature accep tance as mandatory of too many unverified "permissible concentration" values may re act to slow the development. A major need is a constantly expanding set of criteria which will be broadly ac cepted and which will define safe, healthful, and reasonably comfortable working con ditions. Values may be developed for a number of purposes, but one set or class must describe minimal standards--levels of performance below which it is unsafe and unwise to go. These standards should be set by mutual agreement, in an organiza tion where the greatest competence and experience of all phases of industrial hy giene activity can be represented. Such values as meet a certain degree of validity can be properly designated, and might be incorporated in mandatory regulations, if in the opinion of enforcing agencies that action seemed desirable. For materials about which information was less complete and less accurate, tentative values can be assigned and these used as guides while further data is collected. It is unlikely that poorly substantiated values included as mandatory features of a code would be sustained in a legal action unless there was clearly defined objective evidence of injury. The inclusion of such less well verified limits, and attempts to enforce them, must cast doubt on the valid-: ity of even the more securely establishe values. To meet the objections raised b, enforcement agencies, that smaller uni of industry will be penalized because of th; absence of definitive data on engineeriri; controls, such information could be i corporated in the codes as suggested tech niques, permissive but not mandatory. A' present, in New York, where such enginee ing details are in the code, the mechanist for obtaining exceptions is irksome and i my opinion needlessly involved. Appeal for variation cannot be granted by the Dij vision of Industrial Hygiene, even though!] concurs, but must be carried through to t) Board of Standards and Appeals. With performance code, the designated stand; can be achieved by any one of a number methods (with a few limited exclusio: such as precluding the use of respirato where ventilation or confinement should applied). In the successful development of this pri gram the cooperation of governmental private industrial hygiene forces is esse tial. Industry cannot, and an enlighten; industry will not, contend that the conti of working conditions is solely their p; rogative. Neither can the governmeni hygienist insist that the setting and enfor ing of standards or permissive limits solely his responsibility. The job is sul ciently big for all of those concerned, ai even with their maximum effort, will lag behind in effective accomplishment, must persuade the ultraconservative ti action must be taken even when the fa; are not quite as complete as we would li them. We must suppress the uncritical enthui asm of those who believe that a magic exis' in numbers, even though tenuously arrive! at. The need for information is very rew and much can be accomplished by intelll* gent and positive cooperation. Division < N R-4''' rPHE M0ST effective and eff X is an enclosure consistii (i' two or three sides with all other side or sides open fc . tank (Figs. 1, 2 and 3). Th of tank hood is an overhe canopy. Each of the four si is generally open to air fl |immediately adjacent to ,(Fig. 4). Hoods with th |are relatively immune to ects of room cross draf vo, one, or no closed sides ; (lore subject to these effec require proportionately h Ijpontrol velocities. ` The most common Objection to enclosing aoods is that they |impede access to the |tank. This objection lometimes also applies canopy hoods. In Addition, canopy floods may require jthe worker to breathe ^contaminated air ris ing from the tank to jjhe hood and are most -extravagant in their Ventilation require- .Talk. Presented at the Eleventh fj. Annual Meeting: of the `.^American Hygiene Associy * Ation, Chicago, April 26,