“face=\”Arial\”>GLASS, MOLDERS, PLASTIC,POTTERY AND ALLIED WORKERS, LOCAL 208.Authorized Employee Representative.OSHRC Docket No. 88-0348DECISIONBefore: FOULKE, Chairman: WISEMAN and MONTOYA, Commissioners.BY THE COMMISSION:Industrial Glass, a subsidiary of Tropicana Products, Inc., manufacturesglass bottles at its workplace in Bradenton, Florida. In itsmanufacturing process, Industrial Glass melts sand and other ingredientsat a temperature of approximately 2100 Fahrenheit, feeds the moltenglass into molds, and then empties the molds onto a conveyor whichcarries them through stations where the bottles are inspected andtempered. The Industrial Glass employees who operate and maintain theequipment used to manufacture glass bottles in the forming departmentmust work very near the tanks containing the molten glass and the hotbottles on the conveyors, all of which radiate a large amount of heat.The Secretary of Labor, acting through the Occupational Safety andHealth Administration (\”OSHA\”), issued a citation alleging thatIndustrial Glass had violated section 5(a)(1) of the Occupational Safetyand Health Act of 1970 (\”the Act\”), 29 U.S.C. ? 654(a)(1).[[1]] becausethese employees were required to work in excessively high temperatures,exposing them to the hazard of heat stress and to other heat-relatedconditions.Industrial Glass contested the citation, and a hearing was held beforeformer Commission Administrative Law Judge Joe D. Sparks. The judgefound that, although it was clear that temperatures near the machineswere very hot and that working there was uncomfortable, the Secretaryhad failed to prove that the working conditions constituted a hazard.The judge therefore vacated the citation. The judge’s decision wasdirected for review pursuant to section 12(j) of the Act, 29 U.S.C. ?661(j). Having fully reviewed the record in this case, we find that thejudge did not err in vacating the citation. We therefore affirm hisdecision.I. THE INDUSTRIAL GLASS OPERATIONThere are three bottle-making plants at the Industrial Glass facility inBradenton. Plants I and 2 are housed in the same structure. while Plant3 is in another building. In each of the three plants there are fourbottle-making machines or \”shops.\” Each of the machines, called\”independent section machines,\” is approximately eight feet high andtwelve feet wide. There are eight-section machines, which produce 16bottles at a time, and ten-section machines, which make 20 bottles at atime. A platform four feet deep runs across the front of the machinesfor the employees to stand on while they are working near the machinesand the conveyor belts.The ingredients that go into the glass are melted in an overhead tank ata temperature of approximately 2100 F. The molten glass is then led bygravity to each of the machines, where \”gobs\” of molten glass are fedinto the molds. The machine puts two gobs into each mold to form a\”parason\” (a gob with an air bubble in the center). At this stage, themolten glass has cooled to approximately 1200 F. Compressed air is fedinto the mold to distribute the glass evenly inside the mold to form thebottle. Then the mold opens and the formed bottle is pushed onto aconveyor, which carries it through an inspection light, where theoperator checks for defects. The bottles come out of the molds onto theconveyor at a temperature of approximately 900 F. By the time thebottles reach the inspection light, the temperature has dropped to about725 F. From the inspection light, the conveyor carries the bottles to anoven called a \”lehr,\”where the bottles are \”annealed\” (alternatelyheated and cooled slowly to temper them). When the bottles enter thelehr, their temperature is about 600 F.The plants Operate twenty-four hours a day, seven days a week. With someexceptions, the employees involved in glassmaking work one shift forseven days, rotate to the next shift for seven days, work the thirdshift for seven days, and then have a week off. They therefore worktwenty-one straight days. Seven hourly employees are assigned to eachplant: four machine operators, one for each machine; two upkeepmechanics, each of whom is responsible for two machines; and one floorattendant, whose duties are to clean up throughout the plant and toassist the operators and upkeep mechanics. There is also one supervisor,who may spend approximately a third to half of his time on the floor ofthe plant, but who is generally not involved in the physical operationand maintenance of the machines.The average tenure of the non-supervisory employees in IndustrialGlass’s forming department, which is also known as the \”hot end,\” isover ten years. When a vacancy does occur, the company sometimes hires ajourneyman machine operator who has experience working in another glassfactory; but, more often, the company promotes from within. Employeeswho have worked in the \”cold end\” or packaging department of the plantmay bid for the job based on seniority. An employee entering the formingdepartment starts as a floor attendant, the job that takes the leasttraining and has least exposure to the intense heat near the machines.The floor attendant assists the operators and learns how to operate themachines on his own. After learning this job, the floor attendant may bepromoted to apprentice operator, then to journeyman operator, andfinally to upkeep mechanic.The operators’ duties include keeping the machines running smoothly,swabbing the molds with an oil-and-graphite lubricant to keep thebottles from sticking to the molds, inspecting the bottles as they gothrough the inspection light, taking a number of the bottles off theconveyor for additional testing, and helping the upkeep mechanic when heis working on the machine. The employees’ activities vary substantiallyfrom day to day and from machine to machine. Each employee receives a15- minute break in the morning, a 20-minute lunch break, and a15-minute break in the afternoon (or at corresponding times during othershifts). If there is a jam or a major breakdown, an employee may have tospend extended amounts of time at the hot machines and may have to workthrough his break, although there is some dispute about how often thisoccurs.While the entire plant is hot, the heat varies from area to area. Thehottest area is near the machines because that is where the molten glassand newly-made bottles are radiating the heat. Employees can, however,obtain relief from the intense heat nearest the machines. For example,the operator will frequently stand back several feet observing theentire machine operating and watching for malfunctions, a practicecalled \”troubleshooting.\” An operator who begins to feel that he isbeing affected by the heat can get the floor attendant or the upkeepmechanic to relieve him. There are large fans, five or six feet inheight and width, throughout the plants, with at least one and sometimestwo fans per-machine. In addition, there are water fountains locatednearby, and there are drinks available from vending machines in the air-conditioned break room.II. THE INSPECTION AND THE CITATIONOn August 26 and September 1, 1987, an OSHA industrial hygienist (\”theIH\”) inspected plants 1 and 2. During his initial visit, the IH tookreadings at several different locations in the general area where theemployees worked to determine the Wet Bulb Globe Temperature (\”WBGT\”),which combines air temperature, humidity, and air movement (whichaffects cooling by evaporation). It is considered a better indicator ofthe effects of heat on individuals than just the ambient airtemperature, which can be measured by a household thermometer, known asa dry bulb thermometer [[2]]. The WBGT readings ranged from 83.4 to101.2 F. The IH also took dry bulb readings, which ranged from 91 to 115 F.The IH made his second visit to Industrial Glass in the late afternoonbecause he had been told during his first visit that it was the hottesttime of day. He stayed about an hour and a half, during which time hetook WBGT readings in the vicinity of three different machines. Again,his readings ranged from 83.4 to 101.2 F. During the two visits, heobserved the employees’ activities and subsequently calculated anestimate of how much energy was required to perform their duties.Heat stress is caused by a combination of environmental heat andmetabolic heat. Environmental heat includes the air temperature, thehumidity, the air flow, and the radiant heat emanating from any hotsurfaces. Metabolic heat, the heat produced within the body, isincreased by physical activity. Because the IH believed after theinspection that some of the employees were exposed to a combination ofmetabolic and environmental heat that exceeded the threshold limitvalues (\”TLVs\”) recommended by the American Conference of GovernmentalIndustrial Hygienists (\”ACGIH\”), the Secretary issued a citationalleging a violation of section 5(a)(1) of the Act. The citation alleged:(a) Employees in the \”hot end\” of the glass plant were exposed to thehazard of excessive heat stress during the performance of their dutiesoperating and maintaining the equipment used to manufacture glassbottles. Typically, during the operation of the equipment the workerrotates between his desk, the front end of the equipment and the backside of the equipment.(b) The Wet Bulb Globe Temperature Index (WBGT-IN) recorded during asurvey on September 1, 1987 from a low of 26.5 degrees Centigrade to ahigh of 38.4 degrees Centigrade. Such exposures may lead to thedevelopment of serious heat induced illnesses such as: heat stroke, heatexhaustion, cramps and behavioral disorders, as correlated to guidelinesestablished by the American Conference of Governmental IndustrialHygienists and the National Institute for Occupational Safety and Health.(c) Among other methods, one feasible and acceptable abatement method tocorrect this hazard is to provide shielding or barriers that areradiant-reflecting or heat-absorbing, between the heat source and theworker.(d) Another method would be to limit exposure time by implementing awork-rest regimen which requires mandatory, regularly scheduled breaksfor employees in the \”hot end.\”(e) A water supplementation schedule presented in such a way employeesare stimulated to drink five to seven ounces of liquid every fifteen totwenty minutes will serve to augment any control measures used.(f) Other considerations include physical fitness and acclimatization ofemployees, as well as the type of clothing worn when working in hotenvironmental conditions.(g) Training of employees in the recognition and treatment of heatrelated illness and the effects of non-occupational factors such as:drugs, alcohol, and physical fitness is also recommended.Ill. THE SECRETARY’S BURDEN OF PROOFIn order to prove it violation of section 5(a)(1), the Secretary mustestablish that: (1) there was an activity or condition in the employer’sworkplace that constituted a hazard to employees: (2) either the citedemployer or the employer’s industry recognized that the activity orcondition was hazardous; (3) the hazard was causing or likely to causedeath or serious physical harm: and (4) there was a feasible means toeliminate the hazard or materially reduce it. Coleco Indus. Inc., 14 BNAOSHC 1961, 1963, 1991 CCH OSHD ? 29,200 p. 39.070(No. 84-546. 1991).IV. EVIDENCE AS TO THE EXISTENCE OF A HAZARDMuch of the hearing was devoted to expert testimony. In addition to thetestimony of the IH, the Secretary presented Dr. Wilbur Spaul, aconsultant who holds a Ph.D. degree in public health and is a specialistin industrial hygiene, concentrating in heat stress. The companypresented two expert witnesses of its own. The three outside experts andthe IH all agreed that heat stress is a combination of environmental orambient heat conditions (the heat in the air, the humidity, and the airvelocity) and the internal or metabolic heat Produced by the activitybeing performed (\”the workload\”), less the cooling effects of evaporation.A. THE SECRETARY’S EXPERT TESTIMONYIn addition to taking temperature measurements, the IH had estimated themetabolic heat generated by the employees in performing their duties. Todo this, he observed the employees performing their jobs and estimatedtheir energy expenditure using tables in a booklet entitled ThresholdLimit Values and Biological Exposure Indices published by the ACGIH. TheIH stated that he considered the work to be light to moderate andestimated the metabolic workload to he about 396 kilocalories (\”Kcals\”)per hour, which exceeded the limits for exposure to combinedenvironmental and metabolic heat contained in the ACGIH booklet.Although the IH stated that he relied on his professional judgment andhis previous experience in making this kind of assessment, he admittedthat he had no actual training in workload assessment and that he hadperformed such an evaluation only once before, in a case that had notbeen litigated. After acknowledging that the employees had given himwidely varying estimates of the amounts of time spent performing variouschores, he admitted that the figure he arrived at was simply hisestimate of the energy being burned and that it may not be an accuratereflection of the actual workload.The consultant retained by the Secretary, Dr. Spaul, testified that hewent to Industrial Glass’ plant and performed \”a very brief fieldevaluation,\” spending approximately an hour and a half in the formingdepartment, during which time he took temperature readings of his own.His observations indicated that the operators divided their timeapproximately equally at the operator’s station, the operator’s workbench, and at the machine, where they check, adjust, and swab themachine. Using a psychrometer to determine the WBGT, he took readings atthese three locations around machine number 8, plus readings in front ofthe fan in that area. He also took readings at the same locations aroundmachine number 7, as well as readings in the break room and in the shadeoutside the building. His measurements near the machines had aparticularly high globe reading, which indicates that there is a highradiant heat load emanating from the machines and the bottles.At the hearing, the expert presented an exhibit which displayed histemperature measurements at these locations. That exhibit shows the airtemperature measured by a dry bulb, the air temperature measured by awet bulb, the temperature measured by the globe, air velocity, and theWBGT reading, which is calculated by adding seven tenths of the wet bulbreading to three tenths of the globe reading. His WBGT readings rangedbetween 73.3 F in the break room to 104.4 F at the operator’s stationnext to machine number 7. He stated, however, that there are manyindexes that can be used to determine the likelihood that heat stresswill occur, and that he does not use WBGT readings when he is retainedby a company to evaluate the feasibility of engineering controls in itsplant because there are better indicators.As part of his analysis, Dr. Spaul also estimated the energy beingexpended by the employees to do the work. Using the operations performedat the locations where he took temperature readings. he calculated atime-weighted average of the environmental heat load and a one-hourtime-weighted average of the metabolic workload. First he estimated thework-rest schedule of the operators, based on his observations of theemployees’ activities during his visit to the plant and his subsequenttelephone conversations with the Industrial Glass safety director. Heestimated that, in a typical hour, the operators would spend twentyminutes at the work bench, twenty minutes at the operator’s station, andtwenty minutes at the machine. Relying on these estimates of the timespent on each task, he created a 20-20-20 model and calculated theone-hour time-weighted average WBGT readings for the areas aroundmachine number 7 and machine number 8, using the WBGT temperatures hehad taken around both machines. Based on his estimate of the workactivity, he calculated that the time-weighted average WBGT reading was98.1 F around machine number 7 and 95.4 F around machine number 8.After he had spoken to the Industrial Glass employees, Dr. Spaul checkedwith the safety managers of other glass manufacturing plants to confirmthat the employees’ estimates of the time spent doing each task soundedreasonable. Based on these conversations, he calculated three otherone-hour time-weighted WBGT exposures for machine number 8, usingdifferent estimates of how long the operator spent at each of the threelocations measured. Two of these calculations included a provision fortime spent by the operator near the fan. In each of his four sets ofcalculations, the time estimates are in multiples of five minutes.Using the three locations he had used in his calculations of WBGTexposure, Dr. Spaul evaluated the tasks performed at each of thepositions and estimated the workload for each task, performing two setsof calculations to account for the different estimates of the time spentat each location doing the tasks performed there. He also did two setsof workload calculations that allowed for time spent near the fan. Hiscalculations produced a range of energy burned between 190.5 and 312.5Kcals per hour. When he completed these calculations, Dr, Spaul had fourone-hour time-weighted averages for metabolic and environmental heat, asshown in the table below:Operator’s \tWork Bench \tMachine \tFan \tWBGT \tKcall\/hrStation \t\t\t\t(F) \t20 min (98.4) \t20 min (92.4) \t20 min (95.5) \t\t95.4 \t210 – 29015 min (98-4) \t20 min (92.4) \t25 min (95.5) \t– \t95.2 \t212.5 – 312.515 min (98-4) \t20 min (92.4) \t20 min (95.5) \t5 min (86.3) \t94.4 \t201.5 -242.515 min (98.4) \t20 min (92.4) \t15 min (95.5) \t10 min (86.3) \t93.7 \t190.5- 250.5Dr. Spaul then compared his environmental and metabolic heat quantitieswith those in the graph in the ACGIH booklet and determined that all hiscombined environmental and metabolic heat figures that he arrived atexceeded the limits on the ACGIH graph. He therefore concluded that theconditions at Industrial Glass exposed the operators to the hazard ofheat stress. Dr. Spaul testified that Occupational Exposure to HotEnvironments, Revised Criteria for a Recommended Standard, 1986 edition,published by the National Institute of Occupational Safety and Health ofthe Department of Health and Human Services (\”NIOSH\”), and theEngineering Field Reference Manual published by the American IndustrialHygiene Association (\”AIHA\”) also indicated, based on his figures, thatthe operators were exposed to the hazard of heat stress.On cross-examination by the company. Dr. Spaul agreed that there is aconsiderable amount of variation in the temperatures throughout theforming department. Dr. Spaul testified that he did observe employeesworking at a number of locations where he did not take temperaturereadings, including the water fountain, the weighing scale, and thecatwalk behind the machine. As a result, he could not say what levels ofhear the employees were exposed to at those locations.Dr. Spaul stated that the company must have known that its employeeswere exposed to a hazard because the employees complained to managementabout the heat and because the company had provided certain controls tolimit heat exposure, such as insulation on the furnaces and meltingtanks, large fans, water fountains nearby, and electrolyte drinksavailable in the vending machine in the air-conditioned break room. Inaddition, electrolyte replacements tablets and drinks were availablefrom the nursing staff. Dr. Spaul expressed the view, however, thatthese efforts were inadequate.B. TESTIMONY BY THE COMPANY’S EXPERTSThe company presented two experts, Dr. Bertram Dinman and Dr. StephenHorvath, both of whom were consultants on the panel that reviewed theNIOSH recommended standard and were contributors to Patty’s IndustrialHygiene and Toxicology, a widely-used treatise in the field. Dr. Dinmanis a physician who also holds a doctorate in occupational medicine andhas been a professor in the fields of public health, occupationalmedicine, and industrial hygiene. He was an advisor to the military onenvironmental hygiene, including heat stress, and for several years wasmedical director, then vice president for health and safety of Alcoa,which has many employees exposed to high temperatures in its aluminumsmelting operation. Dr. Horvath holds a pH.D. degree in medical sciencefrom Harvard, where he conducted research on human reactions toenvironmental stresses, including heat. He performed the same kind ofresearch for the military during World War II, and he was subsequentlyon the faculties of a number of medical schools. He also worked forAlcoa, where he and Dr. Kinmon worked together on the problems caused byhot environments.At Dr. Kinmon’s suggestion, Industrial Glass had one of its seniorindustrial engineers conduct a time motion study of an operator’sactivities. He performed an 8-hour study, covering four hours on twoconsecutive days, observing the operator of machine number 8, the samemachine observed by the Secretary’s expert, and videotaping hisactivities. He identified fourteen specific tasks that were performedseveral times during the course of the study plus miscellaneous tasksthat were not repeated, all of which he pin into one category. Listingthese activities, he then used a stopwatch to measure how much time theoperator spent during the 8-hour period performing each task. He alsodetermined how many times each task was performed during the study.Using this information, he was then able to determine the amount of timespent, on the average, on each task per day and per hour.The time motion study contains diagrams of the area where it wasconducted, identifying where each of the tasks was performed. It alsocontains a breakdown of how many minutes were spent on each of the tasksfor each hour of the study and two composite typical hours. one with andone without a break. The engineer admitted that averaging the timeswould not give an accurate picture of the operator’s activities, becauseit eliminates the peaks and valleys of certain activities, but he statedthat he did not observe a great variance from hour to hour during theperiods studied. Throughout the study, there were the sort of minorbreakdowns and jams that occur routinely, and the machine did have abreakdown on one of the days, requiring more activity close to themachine, the source of the heat. In contrast to Dr. Spaul’s 20-20-20model, the fourteen specific tasks identified by Industrial Glass’time\/motion study required between 20 seconds and 3 minutes,10 secondsper occurrence. and required a total of between 3 minutes and 1 hour, 40minutes over the course of an 8-hour shift.Both of the experts retained by Industrial Glass visited the plant. Oneof them, Dr. Dinman, observed the operation for between four and fivehours, while the other, Dr. Horvath, observed the last three or fourhours of one shift and the first two hours of the next shift. Bothquestioned the operators about their activities and satisfied themselvesthat the conditions they were observing were typical. Each of themstudied the videotapes made during the time\/motion study to help themdetermine the precise motions involved in the activities of the operator.Using the videotapes and the time\/motion study, the experts eachperformed a workload analysis similar to the one performed by Dr. Spaul.They analyzed each task, breaking it down into its various motions,determining the workload for each element of each task, then adding themto get the workload for the entire task. The Kcals for each task weremultiplied by the minutes per hour spent performing that task, and thoseproducts were then totaled. Dr. Dinman calculated the operator’sexertions as ranging from 132 to 167 Kcals\/hour, while Dr. Horvathcalculated them at 136 to 138 Kcals\/hour. Based on these figures, thecompany’s experts both concluded that the operator’s actual metabolicworkload was substantially less than estimated by the IH and Dr. Spaul.Both of them stated that, even if they accepted the Secretary’stemperature measurements and calculations of the environmental heat loadas correct. [[3]] the employees were not exposed to a total heat loadgreat enough to cause heat stress.Explaining how he reach his conclusion, the first expert, Dr. Dinman,stated that it is important to identify all locations where an employeewould work during the course of his job and to determine thetemperatures at each of those locations. He explained that, if thetemperatures vary from location to location, it is necessary todetermine how much time the employee spends in each location. Dr. Dinmantestified that the time\/motion study was useful to determine thelocations where the employees worked, the amounts of time spent in eachlocation, and the metabolic heat generated by the employee’s activities.The other expert, Dr. Horvath, stated that a person’s heart rate is anindicator of how much he is exerting himself. While he was at theIndustrial Glass plant, Dr. Horvath took the pulse of the operator on anumber of occasions, comparing the rates after certain tasks with theresting rate. The difference was so slight that he concluded that theoperator’s duties were not strenuous. Dr. Horvath reinforced thisconclusion in the laboratory, where he and his staff copied the variousmotions involved in some of the operator’s tasks, measuring the carbondioxide produced. Even though the lab had highly sophisticatedequipment, he could not measure enough of an increase to be consideredsignificant.Dr. Horvath stated that he had been involved in numerous time\/motionstudies himself and could tell that the company’s in-house study hadbeen carefully done. Dr. Horvath noted that he considered the company’sstudy \”informative,\” but he knowledge that a longer study would likelyhave included a wider range of conditions and tasks not performedfrequently. He did, however, have the benefit of a 12-day time\/motionstudy performed by another glass company which had retained him as aconsultant. That company used the same kind of machinery as IndustrialGlass, and its employees’ activities were similar. He testified thathis preliminary analysis of that study produced a metabolic expenditurevery close to the figures he got in this case.Both of the experts presented by the company had worked for Alcoa, wherethere were high levels of heat radiated by large amounts (750 pounds) ofmolten aluminum.[[4]] The temperature of the bottles coming out of themolds is approximately the same as that of the molten aluminum withwhich the two witnesses were familiar. Both of the company’s expertshad served on the panel which had developed the NIOSH recommendationsand were familiar with the studies underlying the figures and theprocess by which figures had been decided. Both were very critical ofthe series of compromises involved in developing the recommendations,asserting that there was little or no scientific basis for some of therecommendations, particularly the conclusion, represented by the curveon the graph, that continuous work at an energy expenditure below the200-Kcal level exposes employees to heat stress.C. THE NON-EXPERT EVIDENCEThe Secretary presented as witnesses a number of Industrial Glassemployees, who testified that they had experienced various ailments thatthey attributed to the heat, including headaches, dizziness, nausea,muscle cramps, and problems with their vision. For example, the unionpresident testified that he had fainted twice. The first occasion wasapproximately ten years before the hearing, when he felt hot, went toget a drink of water, and collapsed. The second incident occurred abouta week before the hearing was held, while he was in the employees’shower room talking to some other employees. He felt weak and told theother employees that he was going into the other room to lie down. Ashe started to go into the other room, he collapsed. On both occasion’s,the company’s nursing staff was called and treated him. On the secondoccasion, the nurse called an ambulance for him, but he refused to go tothe hospital. In general, the employees testified, they did not seektreatment from the company’s nursing staff or from a physician. Inresponse to an OSHA subpoena, the nursing staff reviewed its records andfound only seven reported incidents in a 4 1\/2 year period which mightbe attributable to the heat.[[5]]Some of the employees testified that, when they or other employees hadbrought thermometers to the plant from home and had placed them aroundthe work area, some of the thermometers had hit their maximum readings,and that one that was calibrated up to 180 F reached 160 F. [[6]] Therewas also testimony that the clothing of some employees had caught firefrom the heat. A witness for the company, who had been an operatorhimself, testified, however, that clothing cannot catch fire solely fromthe heat; it can happen only if the clothes come into contact with thehot glass when the bottles come out of the mold onto the conveyor. Inhis experience this occurs only rarely. [[7]]V. ANALYSISAs noted above, to prove a violation of section 5(a)(l), the Secretarymust show that the employees were exposed to a hazard in the workplace. The Secretary presented both expert and employee testimony addressingthis element. Having reviewed the record, we find that the Secretaryhas not established by a preponderance of the evidence that there was ahazard present in the Industrial Glass forming department.The citation identified the hazard as \”excessive heat stress\” (emphasisadded), perhaps in recognition that at least some amount of heat stressis an inevitable part of this operation. In her subsequent complaint,the Secretary alleged: \”Respondent violated ? 5(a)(l) of the Act in thatit allowed its employees in the ‘hot end’ of the glass plant to beexposed to excessive heat stress while operating and maintainingequipment used to manufacture glass bottles.\” The bulk of the evidencethe Secretary presented to prove that there was a hazard was the experttestimony that the employees were exposed to a combination ofenvironmental and metabolic heat that was excessive because it exceededthe limits permitted under the NIOSH, ACGIH, and AlHA documents, whilethe company’s primary evidence that there was no hazard is the testimonyof its two experts. All three expert witnesses were highly qualified,and the opinions of the company’s experts are in direct conflict withthose presented by the Secretary’s, making it difficult to evaluate thevoluminous evidence in this controversy. Had the company not presentedsuch a strong rebuttal of the Secretary’s case, we might have found thetestimony of the Secretary’s expert that the employees were exposed tothe hazard of heat stress to be persuasive.Two factors weigh heavily in our decision in favor of the company,however: the eminence of its experts; and the fact that their testimonywas based on a time\/motion study that identified four or five times asmany tasks as were assumed in the model relied on by the Secretary’sexpert. In view of the company’s time\/motion study, we simply cannotgive much weight to the portion of the Secretary’s evidence that waspredicated on the assumption that the operators spent twenty minutes ofeach hour at one location performing one task, twenty minutes at anotherlocation performing another task, and twenty minutes in a third locationdoing a third task.It is clear from the record that the operator’s duties are much morevaried than assumed by Dr. Spaul’s -20-20-20 model and that, contrary tothe assumption by the Secretary’s expert, an operator spends far moretime in locations that are removed from the bottles and the machines,which are the source of the heat. As Dr. Dinman testified, a studywhich records the operator’s minute-by-minute activities and analyzesthem job component by job component will be more precise than the roughestimates relied on by the Secretary.[[8]] Because we have no heatmeasurements for these other locations, some of which are several feetfrom the machines, we cannot determine what the temperatures are inthose locations. Since we are not able to ascertain the levels of theemployees’ heat exposure at each work station, we cannot make anydetermination of their overall environmental heat exposure.Even if we assume arguendo that exceeding the exposure limits set out inNIOSH’s recommended standard and in the ACGIH and AIHA publicationswould prove that there was a hazard within the meaning of section5(a)(1) based on the information in this record, we are unable todetermine whether an employee’s total heat exposure would in fact exceedthose levels of heat exposure. Because the testimony of the Secretary’sexpert was based on temperature readings that did not accurately reflectthe movements of the employees around the forming department, theSecretary has not carried her burden of establishing that the levels ofenvironmental heat were excessive.We are also unable to give much weight to the calculations of metabolicheat by the Secretary’s expert, who testified that he frequently doesphysiological workload assessments of the sort performed by Dr. Horvathat the plant and in the laboratory, but conceded that he elected to usethe tables in this case because such assessments are time-consuming andtedious. Dr. Horvath testified that it was it mistake for the Secretaryto assume so few tasks. The company has argued that the Secretary’scalculations of the employees’ metabolic workload were based oninadequate information because they assumed only three or fouractivities. The judge agreed with that argument and we do as well. Thecompany’s experts, working separately, both arrived at significantlylower workload levels. Given the more detailed information on whichtheir analyses were based and the more precise methods used to assessthe energy expenditure, we are inclined to give them more weight thanthe calculations of the Secretary’s expert. We note that Dr. Spaul andthe IH both admitted that the employees gave them widely varyingestimates of they time they spent performing the different tasks onwhich they based their metabolic heat estimates. We therefore acceptthe metabolic heat estimates of the company’s experts rather than thoseof the Secretary’s expert and the IH.The Secretary has emphasized that one of the company’s experts testifiedthat the work done by an operator was about twice as strenuous asdriving a car. For a number of reasons we are not certain exactly whatthat testimony means or how much weight to give.First, the witness also testified hat the figure given for driving a carin the ASGIH booklet seemed much too high to him.[[9]] In addition,both parties presented evidence that there was a base figure for a bodyat complete rest, although the figures presented by the Parties differ. Neither party, has explained whether \”twice as strenuous\” is calculatedby subtracting this base number first. Then doubling the remainder, ofby doubling the actual figure for driving a car. The Secretary’s replybrief simply doubles the figure given in the ACGIH booklet, but it isnot at all clear to us that doubling is the proper way to make thecalculation. The calculations in the NIOSH recommendation suggest thatthe basal metabolism remains constant and that additions are made tothat figure depending on the activity and the position in which theactivity is performed. The ACGIH document is not so clear, however, Wetherefore do not know whether the calculation in the Secretary’s briefis correct. Because we cannot determine on this record exactly what\”twice as strenuous\” means, we do not know how much weight to accordthat statement.The Secretary has argued that one of the company’s supervisors testifiedthat the work in the forming department was comparable to heavyconstruction, which he had previously done. A review of that testimony,however, reveals that the witness was not referring to how strenuous thework was. What he said was that the heat was comparable to being on ametal roof in the summer. His testimony therefore does not contradictthat of the company’s experts.The Secretary has further asserted that the NIOSH, ACGIH, and AIHAdocuments establish a maximum WBGT level of 86 F for employeesperforming continuous light work at a level below 200 Kcals per hour. We find, however, that, even if we assume that exceeding thisrecommended limit would he a hazard, the Secretary has not establishedthat the cited employees were performing \”continuous work\”. Althoughthe Secretary’s expert testified that it was his impression that theemployees were under a continuous workload, the testimony of theemployees shows that, to the contrary, they do rest between activities,and they can get away from the source of the heat even while they areperforming their duties. The Secretary’s expert may have believed thatthe operators’ activities placed them in the \”continuous work\” category,but the record makes it clear that working without taking an officialbreak within the meaning of the employment contract is not the same asworking without pause or rest. The employees did not engage in constantaction but took brief breaks between tasks and even rested momentarilyduring a task. We therefore find that Industrial Glass’s employees didnot fall within the \”continuous work\” category as the Secretary claims.We must note that we would be hesitant to hold that exceeding thoselevels is, in and of itself, proof of exposure to a hazard. TheSecretary asserts that they are the dominant guidelines on heat stressand are followed by all professional industrial hygienists. Dr. Spaul,the Secretary’s own expert witness, testified, however, that all threedocuments were essentially copied from each other and that they allcontained a substantial safety margin. While it would be veryappropriate for the Secretary to include a safety margin in an OSHAstandard, the presence of a safety margin in the documents she relied onto prove a hazard here gives us reservations as to whether evidence thatthe limits in the NIOSH document were exceeded would, in fact, provethat there was a hazard.[[10]] Furthermore, Dr. Horvath testified thatsome of the work on which the NIOSH curves were based had subsequentlybeen discredited to a large extent, and both of the company’s expertstestified that there was inadequate scientific information to supportsome of the assumptions shown on the graphs in these documents. Wetherefore have considerable reservations about basing a violation ofsection 5(a)(l) or those guidelines. Because we are deciding this casebased on the insufficiency of the Secretary’s evidence, however, we neednot decide whether a violation of section 5(a)(l) would have beenestablished if the Secretary had proved that the limits in the documentshad been exceeded. [[11]]Having concluded that the Secretary failed to establish the presence ofa hazard by expert testimony, we must examine the other evidencepresented by the Secretary, namely the testimony of the employees. While the employee testimony regarding the difficulties they experiencedbecause of the hot working conditions troubles us because it clearlyshows that this is an uncomfortable working environment and thatemployees do suffer from the effects of the heat, [[12]] the citation’sidentification of the hazard as excessive heat stress suggests that theSecretary recognizes that some degree of discomfort is inherent in thejob. The testimony as to headaches, dizziness, nausea, fatigue, musclecramps, and even the two instances of fainting must be balanced againstthe fact that many of the abatement measures sought by the Secretarywere already in place to one degree or another.We note that Congress intended that an employer’s duty to free itsworkplace of hazards under section 5(a)(l) to be an achievable one. Nat’l Realty & Constr. Co. v. OSHRC, 489 F.2d 1257, 1265-66 (D.C. Cir.1973). Here, Industrial Glass had installed insulation on the meltingtanks. Near every machine, there was at least one large blower and awater cooler. The company had moved the machines farther apart, whichreduced the concentration of heat. There were electrolyte drinksavailable to the employees, both through the nursing staff and in itvending machine in the break room, which was air conditioned. Thenurses also had electrolyte tablets available for any employee whosuffered from the effects of the heat. Before a new employee was hiredfor the forming department, the nursing staff took a medical history andperformed an assessment of the individual’s medical fitness to work in ahot environment. If they did not find that the candidate was medicallysuitable, they informed the personnel department. There was also a defacto acclimatization by virtue of the one-week orientation that waspart of a new employee’s training. There wits already established a\”buddy system\” among the employees of watching out for each other andrelieving, an employee who began to be affected by the heat. Also, therewas testimony that, on at least one occasion the foreman sent anemployee home when he had difficulty with the heat rather than allow himto be exposed to excessive heat. We realize that these measures do notabsolutely guarantee that an employee will never suffer from exposure tothe heat, but the record shows that it is virtually impossible toeliminate all exposure to high temperatures in this Job.[[13]]We recognize, as the secretary apparently did, that the workingconditions in the forming department are, to some extent, an inevitablepart of this kind of work. The employees who testified appear to haveconsidered the conditions to be uncomfortable rather than hazardous. Theemployees who testified that they suffered various ailments from theheat admitted that they did not seek any medical help, and the unionofficer who fainted twice refused to go to the hospital even though anambulance had been called for him. It therefore appears that theemployees considered the heat conditions to be more of a discomfort thana health hazard.[[14]] As noted above, the jobs in the formingdepartment, which involve higher pay, are considered desirable and arehighly sought after by Industrial Glass employees who work in thepackaging department. They are filled on the basis of seniority unlessan experienced glassmaker is hired.Accordingly, based on the expect testimony and the measures present inthe forming department to reduce employee exposure to heat and toalleviate its effects, we conclude that the Secretary has failed toprove by a preponderance of the evidence that the working conditions inthe forming department presented a hazard within the meaning of section5(a)(1) of the Act.VI. CONCLUSIONWe recognize that excessive exposure to heat can be a hazard, but therecord in this case shows that the company has made an effort toalleviate the effects of the hot working conditions in the formingdepartment. We find here that the Secretary has failed to establish bya preponderance of the evidence that the working conditions in theforming department constituted a hazard that was likely to cause seriousharm to the health of the employees. For these reasons, we conclude, asthe judge did, that the Secretary has failed to prove that IndustrialGlass committed a violation of section 5(a)(1) of the Act by exposingits employees to the hazard of heat stress.We therefore hold that the Secretary has failed to carry her burden ofproving that there was a heat stress hazard in the Industrial Glassforming department. Accordingly, we affirm the judge’s decisionvacating the citation.Edwin G. Foulke. Jr.ChairmanDonald G. WisemanCommissionerVelma MontoyaCommissionerDated: April 21, 1992————————————————————————SECRETARY OF LABOR,Complainant,v.INDUSTRIAL GLASS,Respondent, andGLASS, MOLDERS, PLASTIC, POTTERY AND ALLIED WORKERS, LOCAL 208,Authorized Employee Representative.OSHRC Docket No. 88-348APPEARANCES:Stephen J. Simko, Jr., Esquire, Office of the Solicitor, U. S.Department of Labor, Atlanta, Georgia, on behalf of complainant.William B. deMeza, Esquire, Holland and Knight, Tampa, Florida, onbehalf of respondent.Mr. John Ward, President, Glass Molders, Plastic, Pottery and AlliedWorkers, Local 208, Bradenton, Florida, on behalf of the authorizedemployee representative._DECISION AND ORDER_SPARKS, Judge: Respondent, Industrial Glass, contests a citation forthe serious violation of section 5(a) (1) [[1]] of the OccupationalSafety and Health Act (\”Act\”) for allowing its employees in the FormingDepartment to be exposed to excessive heat stress while operating andmaintaining equipment used to manufacture glass bottles. The case wasably tried and briefed by counsel, and extensive testimony anddocumentary evidence were received into the record.I.Industrial Glass is a division of Tropicana Products, Inc., whichoperates several facilities located on 214 acres of land in Bradenton,Florida. Industrial Glass manufactures glass bottles in various sizes inthree glass plants in Bradenton, where approximately 400 glass unitworkers are employed (Tr. 28- 29).The Forming Department in Plant 2 contains four independent sections(\”I.S.\”) glass making machines called \”5 Shop,\” \”6 Shop,\” \”7 Shop,\” and\”8 Shop\” (Tr. 97-98, 773). Employees in the Forming Department workseven-day rotating shifts. They work one shift seven straight days andthen rotate to another shift or off duty. Industrial Glass runs threeshifts each day, seven days a week. Shifts are 8:00 a.m. to 4:00 p.m.,4:00 p.m. to 12:00 a.m., and 12:00 a.m. to 9:00 a.m. Plant 2 employsseven hourly employees per shift: four operators, two upkeep mechanics,and one floor attendant (Tr. 26-27, 783, 824-825).Plant 2 shops produce between 100 and 294 bottles per minute (Tr. 39).To produce the glass bottles, the raw sand batch and glass culletmixture is melted in the tank above the I.S. machine. The glass at thatpoint is between 2000 and 2100 degrees Fahrenheit. The molten glassdrops down and is sheared into gobs through the feeder into the molds.Two gobs drop into each mold. The gob is formed into a parason, a gobwith a bubble in it, and a finish, the part of the bottle where thebottle where the cap is attached. The bottle is now upside down. Air isblown on the outside to form and cool the glass. The glass is theninverted into the mold. The mold closes around it and compressed air isblown into the bottle to form it. The mold then opens and the bottle ispushed onto the conveyor and proceeds down the inspection light and thelehr. The lehr performs annealing, a gradual cooling of the glass. Theglass is molded at about 1200 degrees Fahrenheit. When it is placed onthe conveyor, its temperature is between 700 and 900 degrees Fahrenheit.The smaller bottles are cooler. The largest bottle made on thesemachines is a 1.75-liter liquor bottle. The temperature of this bottleis about 850 degrees Fahrenheit coming onto the conveyor. At theinspection light, the temperature of the bottle drops to 725 degreesFahrenheit; and, when entering the lehr, the bottle temperature is 600degrees Fahrenheit (Tr. 775-783, 800-801).The operators’ duties include observation of the operation of the glassmaking machine, quality control checks by testing bottles, swabbing themolds with graphite oil front and back (doping), assisting on clearingjam ups and helping the upkeep men to change molds and repair machinesif needed. Operators usually work 1.5 to 5 feet from the molds (Tr. 40-46).The upkeepmen’s duties include working on and repairing machinebreakdowns, changing molds, fixing defects in the glass, working on thetanks that melt the glass, repairing and maintaining the feeders andrelieving operators for breaks. Each upkeep person is responsible fortwo machines. Duties require these employees to be next to the machines(T. 59-61, 259-260).The floor attendants’ duties are to clean glass from underneath themachines, keep glass off of the floor, keep the barrels dumped out, andsee to the needs of the operators and upkeep people. Their work oftenrequires the floor attendants to work close to the machines (Tr. 287-288).Forming Department employees receive two 15-minute breaks and a20-minute lunch break during each eight-hour shift (Tr. 107).The breakroom is air conditioned (Tr. 104).Industrial Glass employs four registered nurses who work on the plantpremises. The nurses do not work the 12:00 a.m. to 8:00 a.m. shift orany weekend shifts (Tr. 26-27). Industrial Glass does not havephysicians on the premises but uses doctors on call in the community formedical conditions and accidents or injuries (Tr. 149).OSHA Industrial Hygienist Byron Blanke began his inspection ofIndustrial Glass’ facilities on August 26, 1987, pursuant to a complaintreceived in his office (Tr. 368). Blanke took temperature measurementsat several locations throughout the facilities. He returned to thefacilities on September 1, 1987, and took additional readings (Tr.368-371). As a result of Blank’s inspection, Industrial Glass was issueda citation for the violation of ? 5(a)(1) on January 13, 1988.II.In order to establish a section 5(a)(1) violation, the Secretary mustprove: (1) the employer failed to render its workplace free of a hazard,(2) the hazard was recognized either by the cited employer or generallywithin the employer’s industry, (3) the hazard was causing or was likelyto cause death or serious physical harm, and (4) there was a feasiblemeans by which the employer could have eliminated or materially reducedthe hazard.The Duriron Co., 83 OSAHRC 22\/A2, 11 BNA OSHC 1405, 1407, 1983 CCH OSHD? 26,527 (No. 77-2874, 1983), affirmed 750 F.2d 28 (6th Cir. 1984).The Secretary alleges that Industrial Glass failed to render Plant 2free of excessive heat in the Forming Department, where operators,upkeep mechanics, and floor attendants were exposed. Industrial Glasscontends that while conditions in the Forming Department may have beenuncomfortable, they did not rise to the level of a recognized hazardlikely to cause death or serious injury. If excessive heat exposure didexist, Industrial Glass’ employees were put at a significant risk.Exposure to excessive heat can result in heat exhaustion and heatstroke. At high temperatures, the body circulates great amounts of bloodto the skin in an effort to eliminate heat through perspiration. As aresult, less blood is circulated to the body’s vital organs, includingthe brain. Heat exhaustion can lead to dizziness, nausea, and eventualcollapse. If not treated promptly, a person suffering from neatexhaustion could suffer brain damage.Beyond heat exhaustion is heat stroke…. [D]uring heat stroke the bodystops sweating, making it impossible to eliminate heat. The bodytemperature may rise to a dangerously high level and cause death.Id. at 1406.Several Industrial Glass employees testified as to the conditions in theForming Department. They established that, although their union contractsince 1983 had called for a heat relief break in addition to themorning, lunch, and afternoon break, operators did not start receiving aheat relief break until one and a half months before the August, 1988,hearing. Upkeep mechanics and floor attendants were still not receivingheat relief breaks at the time of the hearing (Ex. C-1, C-2; Tr. 64,187, 215, 317). The employees also testified that at one time theemployees in the Forming Department started bringing in various homethermometers, including baking and pool thermometers, and hung themaround the work area. The thermometers were eventually taken down bysupervisory personnel, but not before the employees observed readings of140 to 160 F. (Tr. 118, 190-191, 219-225, 269).Several employees related instances where they experienced discomfortwhich they attributed to the excessive heat. John Ward, an upkeepmechanic and union representative, testified that just two weeks priorto the hearing, he fainted due to the heat after working six and a halfto seven hours in front of the machines (Tr. 73-74):I was talking to several of my committee members in the shower room. Ihad a bad headache, I was sweating, I was burning up, I got severe painsin the back of my head, and I told them I was going to lay down. Istarted into the other room in the shower room to lay down and Icouldn’t see. And I ended up on the floor.Ward was treated by a staff nurse. He did not consult a physicianregarding this incident so there was no confirmation that his distresswas attributable to excessive heat in the workplace (Tr. 124-125).Ronald Sykes worked as a floor attendant for Industrial Glass for sixmonths, including the summer of 1987. He described the conditions asfollows (Tr. 189):Well, especially this time of year, it’s real hot. Once in a while,you’d have a kind of dizzy spell. Like, you know, it would be so hot,you would just have to back away and just stop for a while . . . Youwere always soaked with sweat or something in there . . . . Once in awhile maybe, .you know, depending on, I guess, the humidity or whatever,just different things, dizziness, stuff like that.Sykes never went to the staff nurses or sought medical treatment withregard to any of the symptoms he mentioned (Tr. 192). The companyprovided water, fans and an air conditioned break room, but theenvironment near the machines was extremely hot.The testimony of the employees establishes that the heat in the FormingDepartment at times was oppressive but standing alone, does not provethat the heat was so excessive as to excessive injury. The thermometersthat the employees brought in were for home use and not calibrated tothe degree of accuracy necessary to establish their readings. HelenHeatherington, a staff nurse for Industrial Glass for eight years,testified that employees from the Forming Department sought treatmentfrom the nursing staff less frequently than employees from otherdepartments (Tr. 175). A medical record review prepared by the headnurse, Edna Davis, for the period from January 1984 to June 1988,disclosed that a total of five employees came to) the nurses a total ofseven times complaining of symptoms that may have been heat related (Ex.C- 12). None of these employees ever consulted a physician with regardsto their complaints, and no medical evidence exists that could supportthe employees contentions that their complaints were caused by excessiveheat. As Industrial Glass pointed out at the hearing and in itsposthearing brief, symptoms of heat stress are similar to symptoms ofother ailments, including the flu and hangovers.Turning from the employee witnesses’ testimony, then, it is necessary toevaluate the testimony of the expert witnesses, who sought to calculatethe amount of heat stress present in the Forming Department. Thestandard instrument for testing heat stress is the Wet Bulb GlobeThermometer (\”WBGT\”). The WBGT takes into account humidity and airmovement (the natural wet bulb reading (\”NWB\”)), and air velocity andair temperature (the black globe reading (\”GLOBE\”)] (Ex. C-6, pp. 3,150;Tr. 464). The calculation for WBGT for indoors is (Ex. C-22, p.5):WBGT = 0.7 NWB + 0.3 GLOBEOn September 1, 1987, Compliance Officer Blanke took eight measurementsin the Forming Department, which ranged from a low of 83.4 F. to a highof 101.2 F. for WBGT (Ex. C-15). Dr. Wilbur Spaul, the Secretary’sexpert witness, who holds a Ph.D. in Environmental Health Sciences,visited Plant 2 on June 15, 1988, and took his own WBGT measurements(Tr.469). Dr. Spaul was knowledgeable, conscientious and convincing. Histestimony was defective only in that he did not make or was not allowedto make, the detailed investigative findings as was respondent’s expertwitnesses. Spaul calculated that the average ‘WBGT for machine No. 8 was4 F. based on a one-hour time-weighted average (Tr. 507, 510)Dr. Spaul spoke with Steven Looby, the safety manager for IndustrialGlass, who informed Spaul that during an average hour, operators spent20 minutes at the operators’ work station on the platform, 20 minutes atthe test stand, and another 20 minutes in the general area of themachine (Tr. 506). Based upon Looby’s estimate and his conversationswith employees, Dr. Spaul concluded that operators were under acontinuous workload (Tr. 490). Dr. Spaul also called several glassplants and spoke with the safety managers to get their estimates oftheir operators’ work\/rest schedules (Tr. 493). Although informationfrom these sources was helpful, it is not afforded the weight given tothe time and motion studies offered by respondent and relied upon by itsexpert witnesses.Dr. Spaul used three guidelines in making his calculations afterascertaining the WBGT; (1) the American Conference of GovernmentalIndustrial Hygienists (\”ACGIH\”), Threshold Limit Values and BiologicalIndices for 1986-1987 (Ex. C-4); (2) National Association forOccupational Safety and Health (\”NIOSH\”), \”Criteria for a RecommendedStandard . . . Occupational Exposure to Hot Environments: RevisedCriteria 1986\” (Ex. C-6); and (3) American Industrial HygieneAssociation (\”AIHA\”), \”Engineering Field Reference Manual\” (Ex. R-9: Tr.473-479). Respondent’s expert witnesses questioned the reliability ofthe guidelines, contending there were inadequate studies to support theconclusions but no reasonable alternative was suggested. They areendorsed by the leading organizations in the field.Dr.Spaul testified that heat stress is calculated by adding metabolicheat to environmental heat, then subtracting the heat lost throughevaporation (Tr. 471- 473). Metabolic workload is calculated inkilocalories per hour (\”Kcal\/hr\”). AIHA, ACGIH, and NIOSH define lightwork as work up to 200 Kcal\/hr (Ex. C-4, p. 70). Dr. Spaul determinedthat the average level of energy required to perform the operators’ jobwas 200 Kcal\/hr (Tr. 518-525). His actual readings ranged from 190Kcal\/hr to over 300 Kcal\/hr (Ex. C-22, p. 13; Tr. 490, 492, 495, 510, 519).ACGIH and NIOSH have established the maximum WBGT to which employees maysafely be exposed at any metabolic workload above 200 Kcal\/hr. Themaximum WBGT for a continuous workload of 200 Kcal\/hr is 86 F. (Ex. C-4,p. 72, figure 1). Based upon his calculations of the WBGT and themetabolic workload, Dr. Spaul concluded that the operators in IndustrialGlass’ Forming Department were exposed to excessive heat (Tr. 469). Theweakness in Dr. Spaul’s conclusions results from the underlyingdetermination that employees were under a continuous light workloadrequiring energy use of 200 Kcal\/hr.Industrial Glass presented two expert witnesses, Dr. Bertram Dinman, aClinical Professor of occupational Medicine, and Dr. Stephen Horvath, aProfessor of biomedical Engineering (Tr. 673, 840).. Both men have hadand distinguished careers and are highly regarded in the field of heateffects on the human work capacity. They separately evaluatedunimpeached time and motion studies which had been made on employees inthe Forming Department (Tr. 857). They observed two shifts for four orfive hours on two different shifts (Tr. 696). They also reviewed avideotape of an employee operating an I.S. machine (Ex. R-2; Tr. 693,696-697, 765). Dinman and Horvath calculated a total hour-by-hourmetabolic workload by determining that an operator performs 15 separatetasks in his or her job, and assessing the metabolic workload for eachof the 15 tasks. The individual workload components were time-weightedand totaled (Tr. 695-702). The greater weight given to the testimony ofDrs. Dinman and Horvath is directly attributable to the greaterprobativeness of the evidence upon which they based their conclusions.Dr. Dinman found that the operators’ metabolic workload ranged from 132to 167 Kcal\/hr. Dr. Horvath calculated the workload to be 136 to 138Kcal\/hr. Both concluded that the metabolic workload was mild (Tr. 857).Dinman and Horvath concluded that employees in the Forming Departmentwere not exposed to excessive heat.Industrial Glass attacks Dr. Spaul’s calculations as invalid andinaccurate. Industrial Glass notes that Inspector Blanke and Dr. Spaulmeasured temperatures only at selected points around the I.S. machines,and that Spaul only Calculated the metabolic workload for operators,ignoring the exposures of upkeep mechanics and floor attendants.Industrial Glass also points out that Dr. Spaul calculated histime-weighted averages based on rough estimates given by Looby, safetymanagers at other glass plants, with no showing that their I.S. machinesor employee tasks are similar to those of Industrial Glass. While Dinmanand Horvath identified 15 separate tasks performed by the operators,Spaul broke down the operators’ tasks into only three categories (Ex.-22, pp. 9-11). However, it is concluded that Dr. Spaul’s testimony isnot convincing only because the facts upon which he relied were inferiorin quality and quantity than those available to respondent’s experts.There is much evidence that employees suffered severe heat discomfort,especially during the summertime. Although heat is necessary in theglass making industry, evidence is lacking that respondent dideverything possible to alleviate those conditions. But the Secretary hasnot carried her burden of proof on the essential element that a hazarddid in fact exist. Looked at together, it is evident that IndustrialGlass’ expert testimony was much more specific and comprehensive; and,therefore, more accurate and creditable, than that of the Secretary. TheSecretary did not prove that employees in Industrial Glass’ FormingDepartment were exposed to excessive heat so as to establish a hazardunder section 5(a)(l). Industrial Glass was, therefore, not in violationof section 5 (a) (l).The foregoing constitutes the findings of fact in this case._CONCLUSIONS OF LAW_1. Respondent is subject to the Act and this proceeding.2. Respondent did not violate section 5(a)(l) of the Act._ORDER_The citation and complaint are dismissed.Dated this 29th day of March, 1989.JOE D. SPARKSJudgeFOOTNOTES:[[1]] Section 5(a)(1) provides \”Each employer shall furnish to each ofhis employees employment and a place of employment which are free fromrecognized hazards that are causing or likely to cause death or seriousphysical harm to his employees.\”[[2]] In contrast to a household, or dry bulb thermometer, a wet bulbthermometer has a bulb that is covered by a saturated cloth. Thisreading is affected by the rate of evaporation, which is determined byhumidity and air velocity. Another type of device, the globalthermometer, is set in a matte black metal sphere and measures radiantheat. All the global temperatures taken by the IH and the Secretary’sexpert were higher than the other readings at the same locations,indicating that there is a great deal of radiant heat in the formingdepartment.[[3]] They did, however, question the Secretary estimates of theemployees exposure to environmental heat because the time motion studyshowed that the employees were not limited to three or four locations.[[4]] Dr. Horvath noted that one of the difficulties in making anaccurate measurement of an individual’s heat exposure in a situationlike this with a high level of radiant heat is that one side of theperson may be exposed to a low level of heat while the other side isexposed to a great deal of heat radiating from the source.[[5]] Both of the incidents involving the union president fell outsidethe period surveyed by the nursing staff.[[6]] Dr. Horvath cast doubt on these readings, however, because hestated that the thermometers should be shielded from radiant heatsources in order to get an accurate reading of the air temperature. Hetestified that, depending on where the thermometer was placed, heatradiating at it from all sides could give an artificially high reading.[[7]] The citation alleged the hazard of heat stress. It does notmention burns. While there is some evidence that in employee is morelikely to be inattentive and bring his clothing into contact with thebottles if he is suffering the effects of the heat, we cannot say thatthe citation covers the situation described.[[8]]The Secretary has argued that a time motion study based on fourhours per day over two days is hardly likely to give an accuratereflection of all the conditions under which an operator will work. Weagree. All of the experts were in agreement that a study covering a muchlonger period would have been more desirable. The company’s. time motionstudy is, however, the best evidence we have. It is certainly moreaccurate than the estimates relied on by the Secretary’s consultant whoadmitted that he would prefer to base his evaluation on observation ofthe operator’s activities for a minimum of five days rather than on hisobservation for only 1 1\/2-hours.[[ 9]] In the table of energy expenditure, a substantial range is givenfor activities such as lying at ease, sitting at ease, and casualwalking, but a single figure is given for driving a car. It seems to us,however, that the level of energy expended driving an automobile canvary greatly, depending on the type of automobile and the road. Forexample, it seems unlikely that the same amount of energy would herequired to drive a car with automatic transmission and cruise controlalong a straight, flat interstate highway as would he required to drivea standard shift car along a windy mountain road or in city trafficduring rush hour. Given these potentially large differences in theamount of energy required to operate different automobiles underdifferent conditions, we cannot say with any confidence that the partieswere talking about the same activity. We also note that, on the table ofenergy expenditures in the AIHA Engineering Field Reference Manual, onwhich the Secretary relies. The value given for sitting at ease issubstantially higher than the values given for both mechanical typingand electrical typing Because we do not understand this seemingincongruity, we do not know how much authority we can attribute to thecontents of this table.[10] In 1972, NIOSH recommended that OSHA adopt a standard governingexposure to heat, and a panel appointed by OSHA endorsed thatrecommendation in 1974. Nevertheless, OSHA has not adopted a heat stressregulation but has relied here on the NIOSH criteria and on guidelinesissued by two private organizations of industrial hygienists. Theessence of the Secretary’s allegation is that the heat exposure limitsset out in those documents were exceeded and that the employees weretherefore exposed to the hazard of heat stress. The NIOSH standard,however, does not have the force and effect of law; failure to complywith it is not in and of itself illegal.[[11]] Contrary to the Secretary’s assertion, the Commission’s decisionin The Duriron Co., 11 BNA OSHC 1405, 1407 n. 2. 1983-84 CCH OSHR26,527, p. 33,798 n. 2 (No. 77-2847.1983), aff’d, 750 F.2d 28 (6th Cir.1984) does not require a difference result. In that case the Commissionfound the existence of a hazard based upon evidence other than exceedingthe limits, in the NIOSH document and was careful to state that thedocument was considered only for the purpose of establishing that theemployers industry had recognized that heat stress was a hazard. Here,the Secretary has attempted to prove that exceeding the limits set inthe documents constituted a hazard.[[12]] The company presented evidence that the effects of heat-relatedconditions resemble symptoms caused by the flu, viruses, or otherailments. We are inclined, however, to believe that the employees’complaints are more likely than not the result of their very hot workingconditions.[[13]]One of the abatement measure proposed by the Secretary in thecitation was a required drinking program for employees in which theywould drink water every fifteen to twenty minutes. We note that thecompany’s time motion study shows that the employee studied went to thewater fountain to get a drink three times an hour in hours he did notget a break and twice an hour when he did have a break during the hour.It would therefore appear that this measure is in effect already in place.[[14]]Although this evidence is not controlling it does constituteevidence from the individuals who are most familiar with and mostaffected by the cited working conditions. See General Motors Corp. 11BNA OSHC 2062.2066 1984-x5 CCH OSHD 26.961 pp 34.611-12 (No.78-1443.1984). aff’d. 764 f.2d 32 (1st Cir. 1985). We therefore accordthese views some weight and consider them together with the otherevidence on the question of whether the Secretary proved that there wasa hazard.[[1]] Section 5(a)(1) of the Act, 29 U.S.C. 654(a)(1), provides:Each employer shall furnish to each of his employees employment and aplace of employment which are free from recognized hazards that arecausing or are likely to cause death or serious physical harm to hisemployees.”