“Docket No. 83-1293 SECRETARY OF LABOR, Complainant, v. GENERAL DYNAMICS LAND SYSTEMS DIVISION, INC., Respondent.INTERNATIONAL UNION, UNITED AUTOMOBILE, AEROSPACE AND AGRICULTURAL IMPLEMENT WORKERS OF AMERICA, and its LOCALUNION NO. 1230, Authorized Employee Representatives.OSHRC Docket No. 83-1293\u00a0ORDER OF REMANDBefore: BUCKLEY, Chairman; AREY, Commissioner. BY THE COMMISSION:The Secretary’s Motion for Expedited Remand, which General Dynamics has supported, isGRANTED, and the case is remanded to Administrative Law Judge Paul L. Brady.This case is before the Commission on remand from theUnited States Court of Appeals for the District of Columbia Circuit. UAW v. GeneralDynamics Land Systems Division, 815 F.2d 1570 (D.C. Cir. 1987), cert., denied,108 S.Ct. 485 (1987). In its decision, the D.C. Circuit reversed a Commission order thathad vacated a citation alleging a violation of the general duty clause, Section 5(a)(1),of the Occupational Safety and Health Act of 1970, 29 U.S.C. ?? 651-678. The citationalleged that employees were exposed to the hazards of poisoning and asphyxiation byentering confined spaces containing trichlorotrifluoroethane (\”freon\”). JudgeBrady vacated the citation on the basis of his holding that the standard promulgated at 29C.F.R. ? 1910.1000(a)-(d), which regulates the time-weighted average exposure ofemployees to the chemical trichlorotrifluoroethane over an eight hour period, preemptedthe application of the general duty clause to the cited conditions. The judge’s decisionbecame the final order of the Commission when it was not directed for review by aCommission member. 29 U.S.C. ? 661(j).The D.C. Circuit held that a standard does notpreempt the applicability of the general duty clause \”if an employer knows that [the]specific standard will not protect his workers against a particular hazard…\” 815F.2d at 1577.[[1\/]] The court found the hazard described by the citation to be distinctfrom that addressed by the standard. While the standard places a limit on the permissiblelevel of time-weighted exposure to freon vapors over an eight-hour shift, the citationreferred to the danger, in confined spaces requiring special entry procedures, ofshort-term exposure to toxic vapors in concentrations that may displace oxygen. Inremanding the case to the Commission the court concluded that, given the facts alleged,the judge should have determined whether the hazard described in the citation was presentat General Dynamic’s workplace (\”Is the hazard . . . accurately described?\”)and, if so, whether General Dynamics had knowledge of the hazard and took\”appropriate measures\” to \”mitigate\” it. 815 F.2d at 1577.The Secretary, supported by General Dynamics, hasmoved the Commission to further remand the matter to Judge Brady to enable the judge tomake the necessary credibility and factual findings that, due to the nature of hisdisposition, were not made when the case was originally before him.Accordingly, the case is remanded to Judge Brady withinstructions to determine, in accord with the remand order of the D.C. Circuit, whetherthe record establishes a violation of Section 5(a)(1) and, if so, whether the violationwas willful.FOR THE C0MMISSIONRAY H. DARLING, JR.EXECUTIVE SECRETARYDATED: March 24, 1989SECRETARY OF LABOR, Complainant, v. GENERAL DYNAMICS LAND SYSTEMS DIVISION, INC., Respondent, and INTERNATIONAL UNION, UNITED AUTOMOBILE, AEROSPACE AND AGRICULTURAL IMPLEMENT WORKERS OF AMERICA, and its LOCAL UNION NO. 1200, Authorized Employee Representative.OSHRC Docket No. 83-1293\u00a0APPEARANCES: Richard J. Fiore, Esquire, and Mark A. Holbert, Esquire, Office of the Solicitor, U. S. Department of Labor, Chicago, Illinois, on behalf of complainant.John P. Hancock, Esquire, and Lisabeth Coakley,Esquire, Butzel, Long, Gist, Klein and Van Zile, Detroit, Michigan, on behalf of respondent.Beverly Tucker, Esquire, and Diane Thomas, Law Clerk,United Automobile, Aerospace and Agricultural Implement Workers of America, International Union, Detroit, Michigan, on behalf of the authorized employee representative.Charles Farrugia, Health and Safety Representative,United Automobile, Aerospace and Agricultural Implement Workers of America, Local Union No. 1200, on behalf of the authorized employee representative.DECISION AND ORDERBRADY, Judge: This proceeding is brought pursuant tosection 10 of the Occupational Safety and Health Act of 1970 (\”Act\”) to contesta citation alleging two willful violations of the Act, and a proposed penalty in theamount of $18,000. General Dynamics Land Systems Division, Inc., (\”GeneralDynamics\”), is charged with violating the general duty requirements of section5(a)(1) of the Act and specific standards under section 5(a)(2) at 29 C.F.R. ?1910.1000(a) and (e). The violations are alleged to have occurred while respondent wasengaged in the production of M1 Abrams Main Battle Tanks at the Detroit Arsenal Tank Plant(DATP) which it had taken over from the Chrysler Corporation in March 1982.The violations are described in the citation inpertinent part as follows:5(a)(1) …employees working in the Heavy Repair, Test and Adjust, Marriage and M1 Hull Linewere required to spray or pour varying quantities of 1, 1, 2 trichloro 1, 2, 2trifluoroethane into the turret and driver’s compartments of M1 tanks and immediatelyenter these compartments to perform clean-up and other routine tasks thereby exposingthemselves to the hazard of asphyxiation and\/or chemical poisoning. A confined space entryprocedure, specific for these operations, had not been implemented when toxic compoundswere introduced into the vehicle.29 C.F.R. 1910.1000(a)(2) -…employees were exposed to 1, 1, 2 trichloro 1, 2, 2 trifluoroethane in excess of 1,000ppm for an 8-hour TWA in that an employee was found unconscious in M1 Tank, Hull Number163 located at Bay L-23…. Calculated range of exposure was approximately 1,200 to 5,000ppm TWA.29 C.F.R. 1910.1000(e) -…and feasible administrative and\/or engineering controls had not been implemented.There is no dispute that 1, 1, 2 trichloro 1, 2, 2 trifluoroethane (\”freon\” or\”the solvent\”) was used as a cleaning agent during production and repair of thetanks. The solvent is a colorless liquid described as having a \”light ethereal\”(sweet) odor. It has a high vaporization rate and is of high density, being six andone-half times heavier than air. While less toxic than most commercial solvents,inhalation of high concentrations can cause depression of the central nervous system,cardiac arrhythmia (irregular heart beat), and even cardiac arrest.The M1 tank is produced in three assembly stages atthe DATP. The hull assembly, turret assembly, and when connected, become fully assembledor the married vehicle. The hull enters the assembly department as an open structure withvarious electrical components, hydraulic lines, rolled wheels and tracks. Assembly fittersinstall components to the vehicle including the engine, and it becomes drivable. The hulland turret are connected in the Marriage Department and any needed repairs are performed.The vehicle is then inspected and tested in the Heavy Repair or Test and AdjustDepartment. These production tasks are performed by tank repairmen, assembly fitters. andinspectors, all skilled tradesmen. The solvent is used during each stage of assembly,usually in cleaning up hydraulic fluid or fuel which has been spilled.The M1 Abrams tank, unlike it predecessor the M60tank, has increased hydraulic systems which contributes to larger amounts of oil spillageand leaks.THE ALLEGED VIOLATION C: SECTION 5(a)(1)The inspection which gave rise to issuance of thecitation was conducted by Mr. David Morgan, an Industrial Hygiene Supervisor for theOccupational Safety and Health Administration (OSHA). He commenced his investigationbecause an employee, Charles Paling, was seriously injured from exposure to freon vaporwhile working in the driver’s compartment of a fully assembled tank.Respondent is charged with failure to develop andimplement a safe employee entry procedure into the tank compartments when the atmospherewas known to have been altered and contaminated by the solvent vapors. The willful chargeis based on allegations that respondent knew the configuration of the compartmentspresented recognized hazards associated with confined spaces yet required its employees toenter and work in the spaces without providing the necessary precautions. It is alsoalleged that respondent has a history of non-response to frequent employee complaints andunion requests that affected employees be protected.Mr. Charles Paling, a tank repairman, testified tothe events which led to his being overcome by the solvent on September 21, 1983. He statedthat,as a repairman in the Test and Adjust Department, he was assigned to correctdeficiencies on Tank No. 163 (Tr. 800). One such deficiency was a leak in a one-inchhydraulic line on the turret distribution manifold. In order to make the repair, Mr.Paling gained access to the line by entering the driver’s compartment head first andpositioning himself facing the rear of the vehicle. As a result of replacing the line, oilspilled onto the turret distribution manifold and turret floor (Tr. 802-804). At Paling’srequest his co-worker, Steven Valentine, brought him a pail containing three to fourgallons of freon which he poured on the manifold and turret platform to clean up the spill(Tr. 808). At. this point, the testimony differs as to what actually occurred. Accordingto Mr. Valentine, Paling immediately re-entered the driver’s compartment to check hisrepair. Valentine then left the area as he was instructed to perform work on another tank.When he returned approximately 20 minutes later, he found Paling unconscious in the tank(Tr. 919-920). Paling, however, testified that, after pouring the freon, he immediatelygot out of the vehicle, set up his air mover to \”blow out the fumes\” andproceeded to work on the outside of the vehicle (Tr. 809). He indicated the tank wasventilated for about 45 minutes to an hour with the three hatches and the drain open (Tr.854, 868). Paling also related that when he re- entered the tank to check the line, henoted another leak; and, while preparing to break the line, he passed out (Tr. 812, 813).After six days of hospitalization, he was discharged with the following diagnosis (Ex.C-33(c), \”Discharge Summary\”):Trichlorotrifluroethane Exposure, Industrial, Severe.Atrial Fibrillation.Atrial and Ventricular Extrasystoles.In order to establish a violation of section 5(a)(1)of the Act, the Act’s general duty clause, the Secretary must prove: (1) that the employeefailed to render its workplace free of a hazard which was (2) \”recognized\” and(3) causing or likely to cause death or serious physical harm, and (4) that feasible meansexisted to free the workplace of the hazard. Empire-Detroit Steel Division v. OSHRC,579 F.2d 378, 383 (6th Cir. 1978); National Realty & Construction Co. v. OSHRC,489 F.2d 1257, 1265 (D.C. Cir. 1973).The proof required to establish the first twoelements of the alleged violation provides the basis for this dispute. A considerableamount of evidence was presented to establish that the driver’s. crew and hullcompartments of the tank constituted \”confined space,\” necessitating safeemployee entry procedures. Generally, the characteristics of a \”confined space\”are that the space is: (1) an enclosure, (2) having limited means of access or egress, and(3) not subject to good natural ventilation (Ex. C-35(a), (b), (c), (d)). In addition, theSecretary attempts to show respondent had full knowledge of the hazards associated withemployees working in confined spaces because in August 1982 an employee was renderedunconscious from his exposure to freon.The record discloses that the employeerepresentative’s complaint to OSHA on August 25, 1982, indicated that freon vapor hadaccumulated in a pit under a conveyor line where the employee was injured. This wasfollowed by an investigation of the incident by OSHA, and issuance of a citation forviolation of section 5(a)(1). Implementation of a confined space entry procedurethroughout the plant was recommended to abate the hazards. The matter was subsequentlyresolved by a settlement agreement in Secretary v. General Dynamics Land Systems, Inc.,OSHRC Docket No. 82-1001 (Ex. C-7, C-8). The agreement, in part, states as follows:(a) Respondent represents that the violative conditions alleged have been abated inaccordance with the abatement procedures set forth in the Citation by the implementationof amended Confined Space and Lockout Procedures developed with the full input andcooperation of authorized employee representatives.(b) To the best of Respondent’s knowledge and belief,Respondent is currently complying, and in the future will in good faith continue tocomply, with the provisions of the Act, and applicable standards promulgated pursuantthereto.The evidence shows that a confined space entryprocedure was implemented at the plant, which was acceptable to complainant (Tr. 504).Respondent now argues that the confined space entryprocedures developed at the plant were not intended to include the M1 tanks. Also, at notime was it advised or made aware that confined space hazards were associated with its useof the solvent in the tanks until issuance of the instant citation.In support of this argument, respondent relied uponthe background testimony of its Safety and Health Director, Edmund Matthews. Mr. Matthewswas aware that freon had been used at the plant even prior to 1974. It was preferred as asolvent because of its relatively low toxicity, high rate of evaporation without residue,and lack of combustibility. He had first investigated its toxic effects in 1976 (Tr.2299-2300).Following the OSHA inspection in 1982, Matthewsstated he conducted a survey of the plant and compiled a list of confined spaces withinthe meaning of the Michigan Occupational Safety and Health Act (MIOSHA). He also developedsafe entry procedures for those spaces, took air samples, provided portable ventilationsystems, lifelines and safety harnesses. In addition, confined space entry classes wereconducted for employees having occasion to work in the designated spaces (Tr. 2289-2295).Respondent also argues that the Health and SafetyRepresentative for the employee’s union did not recognize the tank as being a confinedspace. The list of confined spaces submitted by the union in accordance with thesettlement agreement did not include the M1 tank in either its married or unmarriedconfiguration (Tr. 1343, 1344).Although the compliance officer who conducted theinitial inspection was not called to testify in this proceeding, it can be reasonablyassumed he thoroughly investigated the use of freon at the DATP, including its use in theM1 tanks. This becomes quite evident since another complaint was filed with OSHA by theunion concerning use of the solvent in the tanks. The complaint stated in part, that\”employees made to wash out tanks with 14 gallons of freon\” and \”employeesmade to drive under the influence of these gases\” (Ex. C-9). This complaint wasinvestigated by the same compliance officer whose earlier inspection resulted in thecitation. Upon completion of this inspection, neither he nor OSHA advised respondent theM1 tank was considered a confined space, or that use of freon inside the tank presented apotential hazard (Tr. 442, 446, 2298).The inspecting officer was clearly aware of thesolvent’s use in the tanks as Mr. Charles Farrugia, the Health and Safety Representativefor the local union, testified that, he personally explained how it was being used byemployees inside the tanks (Tr. 1353). It is also obvious that the OSHA investigationincluded an evaluation of the control measures implemented by respondent (Tr. 436,2315-2317).Although the record indicates a number of employeeshave complained of ill effects from working with the solvent, General Dynamics presentedevidence to show it had responded adequately to the complaints and that it has maintainedsafe controls and procedures. It is noted that a grievance filed by the union through aformal labor- management procedure regarding use of freon was withdrawn (Ex. C-2). Also,in August 1983, the International Union’s Safety Representative conducted an inspection atDATP with Mr. Farrugia. The inspection was followed by a meeting with company officialsregarding health and safety problems, but employee use of the solvent was not included inthe topics discussed (Tr. 1430-1431). Thus, it would appear respondent employed acceptablework procedures.The Secretary strongly contends that the respondenthad actual knowledge of the hazards associated with employee entry into confined spacesand knowingly exposed its employees to such hazards in the M1 tanks. The record indicates,however, that the basic criteria for identifying a confined space requiring safe entryprocedures is the extent of enclosure and inadequacy of natural ventilation to purge theatmosphere. In the instant case, Mr. Paling testified the hatches and drains were openwhen he ventilated the space for up to an hour as part of his normal procedure. Theconditions under which he worked suggest safe operating procedures were being employedwhich included purging of the atmosphere by mechanical ventilation.Generally, there appears some question regarding thesufficiency of the evidence to establish the violation. However, a ruling uponconsideration of all the evidence will not be made as the allegations of the violation areinappropriate and must be vacated because the alleged hazard is addressed by a specificstandard.The declared purpose of the Act is to assure so faras possible every working man and woman in the Nation safe and healthful workingconditions and to preserve our human resources . . . 29 U.S.C. ? 651(b). While the Actcontemplates specific safety standards, its purposes are also effectuated by the generalduty clause because it is obvious the Secretary can not promulgate specific standards toprotect employees from every conceivable hazardous condition. The legislative history ofthe Act reflects this view through the comments of the Senate Committee on Labor andPublic Welfare which in part state:The general duty clause in this bill would not be a general substitute for relianceon standards, but would simply enable the Secretary to insure the protection of employeeswho are working under special circumstances for which no standard has yet been adopted. S.Rept. No. 91-1282, 91st Cong., 2d Sess. (1970) at 9, 10.The general rule of statutory construction requiresthat the specific takes precedence over the general. See, e.g., CliffordF. MacEvoy Co. v. United States, 322 U. S. 10,107 (1941). This principle is recognizedby the Secretary in the regulation at 29 C.F.R. 1910.5(c)(1) which provides:If a particular standard is specifically applicable to a condition, practice, means,method, operation, or process, it shall prevail over any different general standard whichmight otherwise be applicable to the same condition, practice, means, method, operation,or process . . . .The Commission has also adopted this principle andestablished it as precedent by stating:It is the opinion of the Commission that a citation for a violation of section 5(a)(1) isinvalid and will not lie, where a duly promulgated occupational safety and health standardis applicable to the condition or practice that is alleged to constitute a violation ofthe Act. [Brisk Waterproofing Co., 73 OSAHRC 30\/E1, 1 BNA OSHC 1263, 1973-74 CCHOSHD ? 15,392 (No. 1046, 1973)]Thus, under the Act, a citation alleging violation ofsection 5(a)(1) is inappropriate if the hazard is addressed by a standard. DanielInternational, Inc., 82 OSAHRC 23\/D3, 10 BNA OSHC 1556, 1982 CCH OSHD ? 26,033 (No.78-4279, 1982). However, when no specific standard entirely protects against the hazardalleged, citation under 5(a)(1) is proper. Ted Wilkerson, Inc., 81 OSAHRC 70\/D8, 9BNA OSHC 2012, 1981 CCH OSHD ? 25,551 (No. 13390, 1981); Peter Cooper Corp., 81OSAHRC 101\/A2, 10 BNA OSHC 1203, 1211, 1981 CCH OSHD ? 25,795, p. 32,238 (No. 76-596,1981).In support of its position that 5(a)(1) is proper inthis case, complainant cites the Commission decision in ConAgra, Inc., 83 OSAHRC5\/C7, 11 BNA OSHC 1141, 1145, 1983-1984 CCH OSHD ? 26,764 (No. 79-1146, 1983) where it isstated:The failure to test in a confined atmosphere before possible exposure of employees totoxic substances is a violation distinct from a continued exposure to known quantities ofsubstances listed in section 1910.1000.The foregoing exception is not applicable to thefacts in this case because of the procedure followed by Paling in ventilating theatmosphere, and that the air contaminants standard deals fully and completely with thehazard at issue, which is employee use of trichlorotrifluoroethane in production of the M1tank. Also, in ConAgra, supra, the Commission did not deviate from itsprecedent by again stating:We note that the purpose of the general duty clause is to provide protection againstrecognized hazards where no duty under a specific standard exists, and that specific,promulgated standards will preempt the general duty clause, but only with respect tohazards, conditions or practices expressly covered by the specific standards . . . .Clearly, the circumstances of this case are governedsolely by the regulations at 29 C.F.R. ? 1910.1000(a)–(d) which set forth the limits ofemployee exposure to trichloro trifluoroethane. Protection is provided against anypotential hazards associated with employee use of the solvent by specifically prescribedlevels within which the employees may safely work. In addition, the employer isspecifically notified of the manner in which abatement is to be accomplished by1910.1000(e) which requires the following:\”[A]dministrative controls, engineering controls, personal protective equipmentor ‘any other protective measures’ . . . . The employer must use one or more of thespecified measures to assure full protection for the employees, whatever the circumstancesor the nature of the employer’s operations.\” Todd Shipyards Corp. 81 OSAHRC69\/A2, 9 BNA OSHC 2031, 2034, 1981 CCH OSHD ? 25,516 at p. 31,812 (No. 77-2545, 1981).The decision in this case recognizes that specificstandards \”are intended to be the primary method of achieving the policies of theAct.\” Brennan v. OSHRC and Underhill Construction Corp., 513 F.2d 1032, 1038(2d Cir. 1975). And further, \”the standards presumably give the employer superiornotice of the alleged violation and should be used instead of the general duty clausewhenever possible.\” Usery v. Marquette Cement Manufacturing Co., 569 F.2d 902,905 (2d Cir. 1975). Necessarily, the employer has a legal obligation to comply with thesafety regulations specifically promulgated to accomplish the stated purpose of the Act.That part of the citation alleging violation ofsection 5(a)(1) is vacated.THE ALLEGED VIOLATIONS OF THE SPECIFIC STANDARDSAT 29 C.F.R. ? 1910.1000(a)(2) AND 29 C.F.R. ? 1910.1000(e)The standards under section 1910.1000 pertain to aircontaminants and state in pertinent part as follows:An employee’s exposure to any material listed intable Z-1, Z-2, or Z-3 of this section shall be limited in accordance with therequirements of the following paragraphs of this section.(a) Table Z-1:*\u00a0\u00a0\u00a0 *\u00a0\u00a0\u00a0 *(2) An employee’s exposure to any material in table Z-1, the name of which is not precededby \”C\”, in any 8-hour work shift of a 40-hour work week, shall not exceed the8-hour time weighted average given for that material in the table.*\u00a0\u00a0\u00a0 *\u00a0\u00a0\u00a0 *(e) To achieve compliance with paragraph (a) through (d) of this section, administrativeor engineering controls must first be determined and implemented whenever feasible. Whensuch controls are not feasible to achieve full compliance, protective equipment or anyother protective measures shall be used to keep the exposure of employees to aircontaminants within the limits prescribed in this section . . . .The alleged violations are described in the citationas follows:29 CFR 1910.1000(a)(2)Employees were exposed to 1, 1, 2 trichloro 1, 2, 2 trifluoroethane in excess of1,000 ppm for an 8-hour TWA in that an employee was found unconscious in M-1 Tank, HullNumber 163 located at Bay L-23 on 9\/21\/83 at approximately 4:50 p.m. due to this exposure.Calculated range of exposure was approximately 1,200 to 5,000 ppm TWA….29 CFR 1910.1000(e)In Bay L-23 an employee cleaning inside M-1 Tank #163 was overexposed to 1, 1, 2trichloro 1, 2, 2 trifluoroethane and feasible administrative and\/or engineering controlshad not been implemented….The Commission has held that in order to establish aviolation under section 5(a)(2), it is necessary for the Secretary to show by apreponderance of the evidence that (1) the cited standard applies; (2) there was a failureto comply with the standard; (3) employees had access to the violative condition; and (4)the cited employer either knew or could have known of the condition with the exercise ofreasonable diligence. Astra Pharmaceutical Products, Inc., 82 OSAHRC 55\/E9, 9 BNAOSHC 2126, 1982 CCH OSHD ? 26,251 (No. 78-6247, 1982); Daniel International Corp.,81 OSAHRC 71\/D6, 9 BNA OSHC 2027, 1977-78 CCH OSHD ? 21,679 (No. 76-181, 1977).The Secretary also contends that these violationsoccurred when tank repairman Charles Paling was exposed to the solvent on September 21,1983. There is no question the cited standards are applicable. The solvent used by Paling,1, 1, 2 trichloro 1, 2, 2 trifluoroethane, is listed in Table Z-1 of 29 C.F.R part 1910which requires an eight-hour time weighted average exposure limitation of 1,000 parts ofvapor per million parts of air (PPM). Subsection (e) sets forth the required controls toreduce exposure to the material in order to achieve compliance with subsection (a). Theprimary issue relates to the proof required to establish the employer’s failure to complywith subsection (a).The record reveals that under the circumstances,representatives of OSHA were unable to take actual samples of the atmosphere in which Mr.Paling was working at the time he sustained his injury. Following an investigation of thefacts and circumstances, a technique known as is mathematical calculation\” wasutilized to determine Paling’s range of exposure to the solvent (Ex. C-14, p. 4; Tr.106-108, 143, 144). The formula used to determine the vapor concentration is as follows(Tr. 150-151):The concentration of the material’s vapor expressedin parts per million (C) is equal to the volume of the material in the liquid formexpressed in milliliters (v), times the density of the substance expressed in grams permilliliter (p), times the volume that one mole of the material would occupy at normaltemperature and atmospheric pressure expressed in liters (24.4), divided by the molecularweight of the material expressed in grams (MW), all divided by the atmospheric volume ofthe space or enclosure expressed in liters (vt), all multiplied by one million,(or)C(ppm) = v(ml)p(gm\/ml)24.4(liters)MW(gm) x 10^6\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Vt(liters)After determining the vapor concentration, aneight-hour time weighted average (TWA) exposure is found by inserting the concentrationinto the formula set forth in the regulation. Thus, the equivalent exposure for aneight-hour work shift expressed in parts per million (E) is equal to the vaporconcentration expressed in parts per million (C), times the duration of that exposureexpressed in hours or minutes (T), all divided by 8 hours or 480 minutes, (or)E (ppm) = C(ppm) T(hours) \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 8hoursBased upon the foregoing formula and the stipulatedatmospheric volume of a fully assembled M1 tank to be 268.5 cubic feet (Ex. C-29),complainant determined an eight-hour TWA exposure to one gallon of solvent for fiveminutes to be 1,048.6 PPM. The exposure to two gallons for ten minutes amounts to 4,194.3PPM (Tr. 157).The record shows that the vapor concentrationscalculated from the formula are based on certain factual assumptions. These assumptions,respondent maintains, are so inaccurate and unreliable that they fail to provide a basisto prove overexposure. Complainant asserts, however, that the assumptions either had nosignificant effect on the ultimate exposure determination or actually resulted in a lowerexposure determination. The questionable assumptions are: (1) that Paling introduced oneto two gallons of solvent into the M1 tank (Tr. 117); (2) that none of the solventintroduced had drained out of the tank (Tr. 393); (3) that the M1 tank was a closed spacewith no opening when the solvent was introduced (Tr. 151-152); (4) that there was noventilation in the compartments of the tank where Paling was working (Tr. 152); (5) thatthere was total evaporation of the solvent Introduced (Tr. 152); (6) that the duration ofPaling’s exposure was five minutes (Tr. 132).The evidence does show that the assumptions are inerror. Mr. Paling estimated that he used between three and four gallons of the solventprior to his injury (Tr. 808). This amount is consistent with the testimony of StevenValentine, his co-worker who brought the solvent to Paling in a five-gallon bucket, whichValentine stated was one-half to three-quarters full (Tr. 918). While the amount ofsolvent assumed to have been used is in error, it is less than the amount actually used,and therefore the error is favorable to respondent’s position.Mr. Paling also testified that the solvent was pourednear the drain which was open and some of the liquid solvent necessarily drained out ofthe tank This of course means that not all of the solvent evaporated. In addition,Paling’s testimony revealed that the three hatches on the tank were open (Tr. 862-868).The period of Paling’s exposure varied from hisaccount of 5 to 10 minutes, to Valentine’s account of about 20 minutes (Tr. 133, 920). Butregardless of the foregoing, the period of exposure used in the formula assumes the periodcommenced a few minutes after Paling introduced the solvent (Tr. 401). This assumption iserroneous because Paling actually introduced the solvent then ventilated the compartmentfor 45 minutes to an hour before he re-entered it (Tr. 867).The question of ventilation as it relates to exposureis a highly significant factor in this case. While the Secretary concedes a ventilatingdevice (air move)[[*\/]] was employed by Paling during the assumed period of exposure, itis asserted the location rendered It essentially ineffective. This apparently is based onPaling’s testimony that he thought the device was entirely inside the tank and located onthe turret seal pump above his right shoulder (Tr. 810). This testimony is consistent withthat of Mark Burns, a process inspector at the facility, who testified to the position ofthe turret seal pump in relation to the hatch (Ex. C- 36(a)(b); Tr. 1126-1133).The location of the air mover takes on added meaningin light of the testimony of the Secretary’s expert witness, Dr. Sheldon Rabinowitz. Dr.Rabinowitz, who had conducted laboratory experiments to simulate conditions at the time ofPaling’s injury, found that the only uncontaminated air being introduced came through thecompressed air line which operates the device. Therefore, all other air drawn through andblown out of the air mover was recirculated contaminated air from within the vehicle andthe vapor concentration of the solvent increased with the high rate of evaporation (Tr.1623, 1627-1628, 1739). He found that 1.6 gallons of the solvent would have evaporatedwithin 25 minutes (Tr. 1638-39). The precise location of the air mover can not be clearlydetermined from the record. On cross-examination, Mr. Paling stated that the believed thedevice was outside the tank or close to being inside or outside (Tr. 870, 871). It Isclear, however, that he waited 45 to 60 minutes to ventilate the tank before re-enteringit (Tr. 401, 402). Also, during this period, the drain and hatches were open, factors notpart of the calculations by the Secretary or the experiment of Dr. Rabinowitz.Respondent points out that both Mr. Morgan and Dr.Rabinowitz agreed if the actual facts had been used in the calculations rather than thefacts assumed by complainant, the exposure level would have been significantly reduced(Tr. 391-406). Mr. Morgan agreed that the critical factors associated with use of theformula \”are what you put into the equation\” (Tr. 428). Dr. Rabinowitz alsoagreed that, if the tank was ventilated for 45 minutes even with the air mover inside, the1.6 gallons of solvent would result in less that one thousand parts per million (Tr.1672-1673). He indicated that he air flow rate through the device would be between 500 and1,000 cubic feet per minute (Tr. 1622).Respondent also presented the finding of its expert.Dr. Richard Carchman, who calculated the actual facts into the same formula used bycomplainant. That at the time of the Paling incident, all the hatches of that tank wereopen, the drains were open, an air blower was used and Paling ventilated the tank for 45to 60 minutes before entering. He concluded that Paling’s exposure was far below the timeweighted average alleged (Tr. 320-322).Dr.Carchman had also testified that he had prepared adocument on the health effects of trochloro trifluoroethine for the EnvironmentalProtection Agency entitled, Health Assessment Document for 1, 1, 2 trichloro 1, 2, 2trifluoroethene (Ex. R-10; Tr. 3194, 3195). His research indicated that theinteraction between the solvent and a stimulant such as epinephrine or adrenaline caused asensitization to lower concentrations of the solvent which could effect the heart (Tr.3203, 3204). Although no attempt will be made to determine if Paling had developed asensitivity to freon, the record discloses such a possibility existed. The evidence showshe had been taking prescription diet pills which could have contained the stimulant whichin turn could cause heart toxicity (Ex. C-33; Tr. 3207, 3208).The proof of the violation under the standard restsessentially on the employee’s exposure to the intensity of the trichloro trifluoroethanevapor for a prescribed period of time. In this case, there was no direct proof of theactual concentrations of freon–such as air sampling of the atmosphere it the time ofemployee Paling’s exposure. Thus, the Secretary’s proof is based on \”mathematicalcalculation,\” and the medical findings following Paling’s accident. The calculationutilizes a basic gas law formula to determine the concentration of a material in theatmosphere of a known volume. Regardless of the method of proof, however, the Secretarymust establish by a preponderance of the evidence, a failure to comply with the standard. OlinConstruction v. OSHRC, 525 F.2d 464 (2d Cir. 1975). Preponderance of evidence has beendefined as \”that quantum of evidence which is sufficient to convince the trier offact that the facts asserted by the proponent are more probably true than false.\” UltimateDistribution Systems, Inc., 82 OSAHRC 22\/B12, 11 BNA OSHC 1568, 1570 1982 CCH OSHD ?26,011 (No. 79-1269, 1982).Upon full consideration of the evidence in therecord, it is hold that the Secretary failed to meet his burden in proving the violation.The mathematical calculation method through employment of the formula, necessarilyinvolves use of certain assumptions which directly effect the exposure determination.Accurate levels of exposure can, therefore only be determined with the use of assumedfacts which accurately reflect the conditions which prevailed at the time of Paling’sinjury. It is thus concluded that the erroneous assumptions used in the formula resultedin unreliable and inaccurate levels of exposure, which is deemed highly speculative.The period and manner in which the tank wasventilated are crucial factors in determining exposure utilizing the formula inmathematical calculation. Both complainant’s expert witnesses, who testified regarding thecalculations, admitted that, if the actual facts had been used in the Calculations, theexposure levels would have been significantly reduced. Respondent’s expert witness, whosecalculations under the same formula included the actual facts, concluded exposure farbelow the level alleged.Although the evidence indicates Paling suffered fromexposure to trichloro trifluoroethane, such evidence is not convincing that his exposurewas in excess of the permissible level according to the standard.The citation is, therefore, vacated.\u00a0FINDINGS OF FACT1. General Dynamics, at all times hereinaftermentioned, maintained a place of business at 28251 Van Dyke Road, Warren, Michigan. It hadbeen engaged in the business of manufacturing M1 Abrams battle tanks since March 1982 whenit took over the operation of the facility from the Chrysler Corporation.2. Commencing September 29, 1983, authorizedrepresentatives of the Secretary conducted an inspection of the aforesaid work site. As aresult, respondent was issued the citation alleging willful violations of the Act withnotice of proposed penalties for its use of trichloro trifluoroethane at the workplace.3. Trichloru trifluoroethane was used by employees invarying amounts as a cleaning solvent inside the compartments of both the fully assembledand partially assembled tanks.4. The solvent has a high evaporation rate and avapor density six and a half times heavier than air. Although less toxic than mostcommercial solvents, inhalation of high concentrations is dangerous and can prove fatal.5. On September 10, 1982, respondent was issued acitation for violation of section 5(a)(1) of the Act. The citation, which was affirmed,alleged that employees were exposed to the hazard of asphyxiation when they entered pitswhere vapors and gases had accumulated. The violation was abated in accordance with asettlement agreement which provided for implementation of a confined space entry procedurethroughout the plant.6. The designated spaces at the plant which wereapproved by the parties for safe confined entry procedures did not include the M1 tanks. 7. The compliance officer, who had conducted threeinspections of the workplace prior to issuance of the instant citation, was aware of howemployees used the solvent and the procedures respondent had developed for its use in thetanks. He, at no time, advised respondent that employee use of the solvent in the tankspresented a potential hazard.8. A formal grievance filed with the employer by theauthorized employee representative regarding use of the solvent by employees was withdrawnon August 16, 1983. Also, in August 1983, safety representatives of the international andlocal unions conducted a walkaround inspection at DATP. At a meeting with companyofficials following the inspection, employee use of the solvent was not a matter raisedfor discussion.9. The specific air contaminants standard at 29C.F.R. ? 1910.1000 governs employee use of trichloro trifluoroethane at the workplace andany potential hazards associated with use thereof in the M1 tanks.10. Neither OSHA nor the authorized employeerepresentative conducted atmospheric testing such as the taking of air samples in thetanks. This included the date of September 21, 1983, when tank repairman Charles Palingwas injured.11. OSHA determined the range of Paling’s exposure tothe solvent on September 21, 1983, by mathematical calculation using a vapor concentrationformula.12. The assumptions made by the Secretary regardingcritical factors in utilizing the formula were erroneous. This resulted in a significantlyinaccurate and unreliable exposure determination.13. After Paling poured the solvent into the tank, itwas ventilated for 45 minutes to an hour with the three compartment hatches and the drainsystem open before he re-entered it.14. The ventilating procedures employed by Paling arein accordance with the hazard abatement procedures outlined in the citation issuedSeptember 10, 1982.15. The atmospheric volume of a fully assembled M1tank is 268.5 cubic feet and the ventilating device used by Paling moved between 500 and1,000 cubic feet of air per minute.\u00a0CONCLUSIONS OF LAW1. General Dynamics, at all times pertinent hereto,was an employer engaged in a business affecting commerce within the meaning of section3(5) of the Act, and the Commission has Jurisdiction of the parties and subject matterherein pursuant to section 10(c) thereof.2. Respondent is, and at all times pertinent hereto,required to comply with the Act and the safety and health regulations promulgatedthereunder.3. Respondent was not in violation of section 5(a)(1)or the standards at 29 C.F.R. ? 1910.1000(a) and 29 C.F.R. ? 1910.1000(e) as alleged inthe citation.\u00a0ORDEROn the basis of the forgoing findings of fact,conclusions of law and the entire record, it is hereby ORDERED:The citation is hereby VACATED. Dated this 19th dayof August, 1985.Paul L. BradyJudgeFOOTNOTES: [[1\/]] We make no effort to present a complete statement of the court’s reasoning sincethat can and should be determined by reading the court’s decision. Nor are we called uponto express any views regarding the court’s reasoning. We merely seek to highlight thoseportions of the court’s decision that, in our opinion, provide guidance to the judge inhis handling of the case on remand.[[*\/]] An \”air mover\” is a ventilationdevice which is essentially shaped like a tube, approximately 5? inches long and 3?inches in diameter and operates by connecting it to a compressed air hose (Tr. 1131,1617-1618, 1622). The principle behind this device’s operation is that compressed airmoved along circular channels within the device, creates a vacuum where outside air willbe sucked through and out of the device at an increased velocity (Tr. 1617-1618).\u00a0″