OSHRC Docket No. 83-0488 and 83-0489


Before:  BUCKLEY, Chairman; RADER and WALL, Commissioners.

This case is before the Occupational Safety and Health Review Commission under 29 U.S.C. 661(j), section 12(j) of the Occupational Safety and Health Act of 1970, 29 U.S.C. 651-678 ("the Act").  The Commission is an adjudicatory agency, independent of the Department of Labor and the Occupational Safety and Health Administration.  It was established to resolve disputes arising out of enforcement actions brought by the Secretary of Labor under the Act and has no regulatory functions. See section 10(c) of the Act, 29 U.S.C. 659(c).


FMC's plant in South Charleston, West Virginia, produces chlorine by processing brine through diaphragm-type electrolytic cells. Nitrogen trichloride (NCl3), an explosive compound, is a by-product of the electrolytic process and is contained in the waste material, which is known as "gunk".  These cases concern the procedure by which FMC neutralizes the potentially hazardous waste material and then removes it from the system.  First, the gunk, which accumulates at the bottom of two scrubbers, is transferred through pipes to three gunk tanks, also known as reboilers. During this process, chloroform and carbon tetrachloride are added to dilute the concentration of NCl3 Once a gunk tank is filled, it is heated by either steam, hot water, or both so that any chlorine present in the tank will be vaporized.  This is called "gasification."  When this process is completed, the residue is pumped to a reactor, where it is neutralized with hydrochloric acid and then transferred to drums for disposal.  There is a diked pit in the area of the gunk tank that contains a pump.   The purpose of that pump is to prevent accumulations of the hot water that is used in gasifying the tanks.

On March 1, 1983, an employee of FMC, Gary Gessel, was killed in an explosion of NCl3.  The explosion occurred in the transfer line from one of the gunk tanks to the reactor, and secondarily in the gunk tank itself, due to an exothermic reaction of NCl3. Apparently, the explosion occurred because Gessel failed to follow his supervisor's instructions to turn off the water that was heating the gunk tank during the gasification process.  While the record does not establish conclusively what caused the explosion, there is some evidence that Gessel placed the hot water hose on the pipe, thereby causing the hot water to contact the pipe and overheat the NCl3, starting the reaction that resulted in the explosion.

As a result of his investigation of the explosion, the Secretary issued in Docket No. 83-0488[[1]] a citation alleging two violations of section 5(a)(1), 29 U.S.C. 654(a)(1) of the Act.[[2]]  The items focus on two of the steps in the procedure described above:  the gasification of the gunk tanks to drive off the chlorine; and the addition of chloroform to dilute the concentration of NCl3.  The citation alleges that deficiencies in those procedures exposed employees to the hazard of explosion.[[3]]  A penalty of $720 was proposed for each item.

Administrative Law Judge Paul Brady affirmed the citation and assessed a single $700 penalty.  Judge Brady did not differentiate between the two items, but rather treated the citation as an integrated whole.   Having apparently viewed the problem as stemming from the heating required by FMC's gasification process, the judge defined the hazard as the danger of explosion when heat is applied to gunk tanks and transfer lines containing NCl3.

The judge found that both FMC and the chlor-alkaline industry in general were aware of hazards involving concentrations of NCl3 in gunk operations.  More specifically, the judge found that the evidence established that FMC's methods of gasifying gunk tanks constituted a hazard.  The judge noted that the employees were not aware of the hazard associated with sudden heat buildup and that there was no rule forbidding the application of steam or hot water to the transfer line.  Judge Brady also noted that the transfer lines were placed in proximity to the water hose used to heat the gunk tank.  With such a setup, the Judge concluded, it was incumbent on FMC to institute a safe and effective program governing its work practices.  The judge found that FMC had failed to do so and therefore found that FMC had violated section 5(a)(1).  FMC petitioned for review of the judge's decision.

For the reasons that follow, we find that the Judge erred in affirming the citation.  With respect to each step in the process that the Secretary has challenged, we conclude that the Secretary either failed to prove that FMC's safety measures were inadequate or failed to prove the likely utility of measures intended to reduce the hazard of explosion.  Accordingly, we vacate the citation.


To prove that an employer violated section 5(a)(1), the Act's general duty clause, the Secretary must prove that the cited employer failed to free the workplace of a hazard that (1) was recognized by the cited employer or its industry, (2) that was causing or likely to cause death or serious physical harm, and (3) that could have been materially reduced or eliminated by feasible and useful means of abatement.  Pelron Corporation, 12 BNA OSHC 1833, 1986 CCH OSHD 27,605 (No. 82-388, 1986).

Judge Brady defined the hazard as the danger of explosion when heat is applied to gunk tanks and transfer lines containing NCl3. The evidence in this case clearly establishes that some danger of explosion always exists when heating NCl3-FMC's gasification process necessitates the heating of gunk containing NCl3.   The Secretary has neither alleged nor adduced any evidence to suggest that the gunk neutralization process can be accomplished without heating the tanks to drive off excess chlorine.  Therefore, if the hazard were to be defined as the danger of explosion when heat is applied to the gunk tanks, it would be impossible for FMC to rid its workplace of the hazard.  The intent of section 5(a)(1) is, however, to reduce preventable hazards.  Pelron Corporation, 12 BNA OSHC at 1835, 1986 CCH OSHD at p. 35,871.  To further that intent, hazards must be defined in a way that apprises the employer of its obligations and identifies conditions or practices over which the employer can reasonably be expected to exercise control.  Pelron, 12 BNA OSHC at 1835, 1986 CCH OSHD at p. 35,872.  Accordingly, we define the hazards in this case as those practices, procedures or conditions that increase the likelihood of an explosion.

Both FMC and the chlor-alkaline industry recognized that the likelihood of an explosion is greatly increased when there are either inadequate methods of temperature control during gasification, or unknown concentrations of NCl3 due to improper methods of adding and monitoring the addition of the diluent chloroform.  This is not in dispute.  Rather, the dispute centers on, and we must decide, whether FMC's procedures for preventing high temperatures and high concentrations of NCl3 were inadequate.  Also at issue is whether the Secretary established that there were additional measures that would have feasibly and materially reduced the risk of harm.  See Cerro Metal Products Div. Marmon Group, Inc., 12 BNA 1821, 1823, 1986 CCH OSHD 27,579, p. 35,829 (No. 78-5151,1986).


The first item of the citation alleges that FMC's method of monitoring and controlling temperatures was insufficient, thus increasing the danger of an explosion due to an exothermic reaction of NCl3 in the gunk tanks and transfer pipe.

Before 1980, FMC heated the gunk tanks during gasification by applying hot water to the top of the tanks with a hose.  Because of a water disposal problem, FMC added a steam heating system in which steam was applied with a sploger (a pipe with holes) to the bottom of the tank.  In colder weather, hot water would be applied by hose in addition to the steam to speed gasification.  When used to gasify the gunk, hot water accumulated in a pit.  The pipes carrying the gunk from the gunk tanks to the reactor ran above this pit.  To prevent the hot water from rising and contacting the pipes, FMC installed in the pit a sump pump that started automatically when the water reached a pre-set level.

To prevent the gunk from reaching a critical temperature, employees were instructed not to allow the temperatures to rise above 10- 20 C during the gasification process.  The temperatures of the gunk tanks were detected by a thermocouple on each of the tanks. Digital displays of the temperatures detected by the thermocouples were located in a control room several feet away from the tanks. A continuous digital readout of the temperatures in a gunk tank could be obtained by punching up the assigned number on the buttons in tile control room.

The Secretary first argues that FMC failed to adequately train its employees with respect to the hazards of overheating the gunk tanks.   In support of this assertion, the Secretary argues that employees were allowed to use hot water to speed gasification and were not instructed to gasify the tanks slowly.   The Secretary also notes that FMC had no written procedures for gasifying the tanks, and new control room operators were trained only by other operators.   Moreover, some employees were not informed of the hazard of explosion caused by allowing temperatures to rise too high or too rapidly.

We find that the Secretary failed to establish that FMC's training methods were inadequate.  Although FMC did not have a formal training program, a formal training program is not necessarily required by section 5(a)(1).  See Jones & Laughlin Steel Corp., 82 OSAHRC 34/A2, 10 BNA OSHC 1778, 1782, 1982 CCH OSHD 26,128, p. 32,887 (No. 76-2636, 1982); Pelron, 12 BNA OSHC at 1838, 1986 CCH OSHD at p. 35,874.  The question is one of substance, not form.  The testimony establishes that all operators were aware that temperatures were not to rise above 10-20 C.  Similarly, while several employees could not recall being advised of the danger inherent in heating the tanks too rapidly, all were aware that the tanks should be heated gradually.  Indeed there is no evidence that the tanks were heated too rapidly.  Although the record establishes that gasifying the tanks in less than half an hour was hazardous, the evidence indicates that the shortest period of time taken to gasify the tanks was 45 minutes.  We also note that the operators who testified had been in their positions for periods ranging from four to thirteen years and either were experienced or were trained by highly experienced employees.  Moreover, FMC operated its facility for some 25 years without an accident, thereby evidencing that its program of on-the-job training was successful in ensuring proper operating procedures. Although the Secretary would require a formal training program, there is no evidence that such a program would have significantly elevated the level of safety at the facility, especially given the experience of the operators who gave the on-the-job training.

The Secretary next argues that FMC's temperature control technology was inadequate.   He asserts that monitoring the temperatures on the gunk tanks was difficult because the thermocouples on the tanks displayed temperatures only after a series of buttons were punched in the control room.  According to the Secretary, FMC also should have installed a high-temperature alarm that would immediately warn employees when the gunk tank temperatures had reached dangerous levels.

At the hearing, W. Duane Colpous, a retired chemical engineer with 35 years experience in the chlorine industry, was called by the Secretary as an expert witness.  It was his opinion that the temperatures at the plant were inadequately  monitored.  He criticized FMC's failure to record temperatures on a con tinuous basis so they could be followed on a chart and opined that FMC should have used a high temperature alarm to warn employees when temperatures approached the upper limit of safe operation.  Colpous' testimony was contradicted by FMC's expert witness, Dr. Chester Grelecki,[[4]] a Ph.D in chemistry with considerable experience in the chlor-alkaline industry, and a consultant in the area of chemical process design.  Grelecki found nothing inadequate about FMC's temperature detection system and testified persuasively that FMC's system was up to industry standards.

There is no evidence to support the Secretary's claim that punching buttons to obtain a continuous readout of gunk tank temperature interferes with the operators' ability to monitor temperature changes.  Testimony of the control room operators Eleanor Garrett and Robert Jones establishes that they had no difficulty monitoring the temperature of the gunk tanks in the control room.   Similarly, despite Colpous' opinion that FMC's temperature detection system would have been improved by installing a high temperature alarm and continuously recording gunk temperatures, the evidence establishes that the employees successfully monitored temperatures with the system in use.  Accordingly, we find that although the evidence establishes that the use of high temperature alarms and the continuous recording of gunk tank temperatures might have marginally improved the ability of the employees to detect high temperatures, it does not establish that such improvement would have materially reduced the hazard of undetected high temperatures in the gunk tanks.  While a means of abatement need not be perfectly protective, it must be shown by the evidence to promise a material reduction of the hazard.  See Chevron Oil Co., 83 OSAHRC 19/B2, 11 BNA OSHC 1329, 1334, 1963-84 CCH OSHD 26,507, p. 33,724 (No. 10799, 1983).   This was not shown on this record.

The Secretary next focuses on alleged deficiencies in FMC's control of temperatures on the transfer pipe.  The Secretary observes that FMC did not have thermocouples on the transfer lines, thus making it impossible to determine the temperatures in those lines. Furthermore, the Secretary argues that the transfer lines should have been relocated out of the pit to an area where they would not have been exposed to the hot water used to heat the gunk tanks.  Finally, the Secretary argues that FMC should have adopted a system to "dump" large quantities of diluents into the pipes to reduce hot spots and to "dump" the contents of the gunk tanks into diluents when the tanks reached critical temperatures.

The evidence is undisputed that FMC was unable to determine the temperature of the gunk as it passed through the transfer pipes. The danger of hot spots developing without warning due to contact with an external heat source, such as hot water or steam, and an ensuing exothermic reaction resulting in an explosion was therefore a danger inherent in FMC's system.

We find, however, that the Secretary failed to establish either the feasibility or likely utility of an abatement method with respect to this danger.  The first method of abatement suggested by the Secretary was to place thermocouples on the transfer lines that would be able to detect hot spots.  He points to the testimony of Mr. Colpous that thermocouples on the line would improve the ability to detect hot spots.  However both Dr. Grelecki and Mr. Colpous testified that due to the unpredictability of hot spot formation, numerous thermocouples would have to be placed along the transfer pipes.  Mr. Colpous could not state how many thermocouples would be necessary or how far apart they would have to be placed to be effective but opined that even one would be helpful.  Dr. Grelecki, on the other hand, testified that to thoroughly monitor the pipes, thermocouples would have to be placed about a foot apart along the entire length of the pipes.  Lionel Updyke, a chemical engineer for FMC, testified that the thermocouples might have to be placed two to three inches apart along a hundred feet of piping in order to pick up a localized heat source.  Both Dr. Grelecki and Lionel Updyke testified that the use of thermocouples to detect hot spots on the transfer pipes was not an accepted practice within the chlor-alkaline industry to reduce the hazard of hot spot formation within the pipes.   Moreover, Dr. Grelecki testified that from the viewpoint of engineering principles and industry standards, such a method of monitoring is not practical.

Having considered the testimony of both experts, we find the Secretary failed to establish the feasibility of placing thermocouples on the pipes.  Although Mr. Colpous testified that even one thermocouple would be helpful, his own testimony establishes that to detect a hot spot the thermocouple would have to be located in the immediate vicinity of the hot spot.  A thermocouple might enable FMC to monitor temperatures in the pipe as a whole, but it would be of little if any benefit in detecting hazardous hot spots.

The Secretary next argues that the hazard of hot spot formation could have been reduced by relocating the transfer lines out of the pit where water, used to heat the gunk tanks, would accumulate.  He notes that, after the accident, the transfer lines were relocated, thus establishing the feasibility of the measure.[[5]]

Although we agree that the Secretary established the feasibility of relocating the lines, we find that the evidence fails to establish the likely utility of this abatement measure.  We do not believe the record establishes that the lines were located in an area that endangered employees, a sump pump was used in the pit to prevent the accumulation of water.  It activated automatically when the water reached one inch in depth.  Superintendent Updyke testified that, with the pump operating, it was impossible for water to accumulate to the level of the pipes, which were more than 3-1/2 inches above the bottom of the pit.  He explained that while the flow rate of the hot water hose was four gallons per minute, the pump was able to handle seven gallons per minute.  Several operators testified that the pumps had worn out and were subject to corrosion.  However, FMC checked the pump three times a week and required an inspection sheet, indicating whether the sump pump was in proper condition, to be completed after each inspection.  These reports establish that during the period January 5 through February 28, 1983, a problem occurred with the sump pump only once and that the pump was repaired by the next inspection. Both Robert Jones and James Jones, control room operators, testified that during the month prior to the accident the pump was working well.  Gunk neutralization operator Cassell stated that normally a PUMP is kept in good working condition.[[6]]

Despite the efforts by FMC to keep the sump pump in good repair, FMC operators testified that water did reach the lines.  Their testimony, however, is in conclusive regarding the time when this occurred.  Both Robert Jones and James Jones testified that they had seen the lines covered with water but they did not identify when this happened.  Gunk neutralization operator Cassell said he had observed water over the pipes during the two months before the accident but weekly inspection logs for the period of January 7 through February 25, 1983, naming Cassell as operator, all state that there was no water standing in the diked area during that period.   In addition control room operator Eleanor Garrett, who recalled occasions when water accumulated to pipe level, stated this occurred when FMC was using a different system of water disposal.  She did not testify that water had ever accumulated to pipe level since the institution of the system used at the time of the citation.

In any event, even if water did reach the lines, there is no evidence that this water created or was likely to create a hazard.  As previously noted, superintendent Updyke testified that the flow rate of the hot water hose was four gallons per minute.  He also testified that approximately 300 gallons of water would be required in the pit before it would back up to the lines.  Considering these facts together with other characteristics of FMC's operation, Dr. Grelecki opined that by the time the water would reach the pipes its temperature would be too low to heat the contents of the pipe to any significant temperature.  Based on the evidence it would take at least one hour and fifteen minutes for enough water to accumulate to reach the lines.  The water would, of course, be cooling during this time period.  At some point in time the water would actually act as a conductor of heat away from the pipes much like the cooling system in an automobile engine.  There is simply no evidence to support the view that the pipes were or could ever be "submerged in hot water" as the dissent postulates.  Dr. Grelecki also testified that FMC's facility design was both appropriate and consistent with industry practice.  Given this evidence, we are not convinced that there was a problem with the water disposal system in use at the time of the inspection.

The fact that FMC relocated the lines after the accident does not alter our conclusion.  As we recently noted in another case, "Employers may decide . . . to take other precautions against injury or illness out of an abundance of caution rather than a belief that the absence of such precautions would expose employees to a significant risk of harm."  Kastalon, Inc. & Conap, Inc., ___ OSAHRC ___, 12 BNA OSHC 1932, 1986 CCH OSHD 27,643 at p. 35,970 (Nos. 79-3561 and 79-5543, 1986).  The Secretary introduced no evidence to show the reason for FMC's relocation and we decline to speculate as to why the lines were moved.

Finally, the Secretary argues that FMC should have installed a dump system that would have utilized large quantities of diluent or coolents to neutralize the development of an exothermic reaction.  Although the Secretary presented evidence to establish that the introduction of diluents into the gunk would reduce the hazard of an explosion, we find that the record fails to establish the feasibility of such a system.

The use of a "dump system" was recommended by the Secretary's expert witness Duane Colpous.  Mr. Colpous testified that either carbon tetrachloride could be quickly added to the pipes as a coolant when a hot spot developed, or the material in the tank could be dumped into a coolant.  He stated that the latter type of dump system is used in TNT plants to reduce the danger of explosion. However, Colpous did not testify that he had ever seen such a "dump system" used in a chlorine plant, or present any details that would indicate how such a system would work in the FMC facility.  He also did not identify any similarities ties between a TNT plant and FMC's facility that would indicate that a "dump system" could be used in a chlorine plant.[[7]]

Dr. Grelecki, on the other hand, testified that a dump system would not be feasible in reducing the hazard of an explosion. According to Dr. Grelecki, because the pipes would be full, there would be no way to "dump" quantities of diluent into the lines in a manner that would effectively neutralize a hot spot.  According to Dr. Grelecki, an attempt to "dump" diluents into a full pipe would only displace the gunk already in the line and move the hot, spot to another location within the pipe.  Moreover, Dr. Grelecki testified that because of the rapidity of an exothermic reaction of NCl3, once one was detected there would not be sufficient time to "dump" the material in the tanks into a coolant.

We find Dr. Grelecki's testimony to be more persuasive than that of Mr. Colpous.  While Mr. Colpous discussed a dump system in only general terms, Dr. Grelecki specifically identified technical problems that would have rendered such a system infeasible in a chlor-alkaline plant.  The Secretary introduced no evidence to show how FMC might overcome those technical problems.  We therefore conclude that the Secretary failed to establish the feasibility of a dump system.

We find that the evidence is insufficient to establish either that FMC failed to adequately train its employees in the hazards of overheating the tanks or that FMC failed to institute adequate methods of temperature control, and vacate item 1 of the citation.

The second item of the citation alleges that FMC increased the hazard of explosion by using improper methods of adding and monitoring the addition of chloroform to its system, resulting in unknown quantities of NCl3 in the system.

The upper limit for a safe concentration of NCl3 in the gunk tank is 5%.  To maintain a safe concentration FMC adds chloroform to the scrubbers and carbon tetrachloride to the gunk tanks.  Besides being a diluent in the scrubbers, the chloroform acts as an antifreeze for the carbon tetrachloride in the gunk tanks, which freezes at -23 C.  The temperature of the chlorine in the gunk tanks is -33 C.  By itself, the carbon tetrachloride would freeze and separate, leaving a concentration of pure NCl3.  The chloroform lowers the freezing point of the carbon tetrachloride, allowing it to be an effective diluent.  A device called a rotometer controls the addition of chloroform and can be adjusted to vary the chloroform flow.

The evidence establishes that both FMC and the chlor-alkaline industry recognized that the addition of insufficient quantities of chloroform to the scrubbers would greatly increase the danger of explosion from excessively pure concentrations of NCl3.  The Secretary does not argue that FMC's formal procedures and requirements for the addition of chloroform and testing for NCl3 concentrations were inadequate.  Rather, the issue is whether FMC's failure to follow those procedures increased the hazard of explosion.  The Secretary points to three specific instances where FMC's failure to follow its written procedures allegedly increased the hazard.  First, the Secretary contends that FMC failed to sample the gunk to determine the concentration of NCl3 as often as required by its own Chlorine Operating Bulletin.  Second, the Secretary contends that, during a couple of weeks before the accident, problems with the rotometer resulted in quantities of chloroform being added to the scrubbers that were below the amounts required by FMC's own operating procedures.  Third, the Secretary argues that on the day before the accident FMC began an experiment that resulted in the flow of chloroform to the scrubbers being interrupted for three hours.

We find that the Secretary failed to establish that FMC's failure to follow the sampling requirements in its own Chlorine Operating Bulletin increased the possibility of an explosion due to undetected high concentrations of NCl3.  The Bulletin, written in 1973, requires that the gunk be sampled at least three times a week to ensure that the concentration of NCl3 does not exceed 5%.  Duane Colpous testified that, in his opinion, the gunk should be sampled daily, but he agreed that three times a week would be adequate. Terry Fontalbert, FMC's senior process engineer, testified that the gunk was not sampled for NCl3 concentrations as often as recommended by the Bulletin.  However, he further testified that it was not necessary to sample the gunk this often.  He noted that the Bulletin was prepared early in the history of the system, and speculated that the sampling requirement was included because the company was still learning the dynamics of the process.   Fontalbert's testimony was corroborated by Dr. Grelecki.  Dr. Grelecki testified that industry practice is to frequently monitor the NCl3 levels when first establishing a gunk neutralization process.  After enough control over the process is established and confidence in the process grows, monitoring can occur less frequently.   At some point, Dr. Grelecki testified, monitoring of NCl3 levels can stop altogether.

Our conclusion that FMC's failure to monitor NCl3 concentrations as required by the Bulletin was not hazardous is strengthened by evidence of other FMC work practices.  Both employee testimony and work sheets introduced at the hearing establish that employees were required to check and record chloroform levels every two hours.  Moreover, Lionel Updyke testified that FMC tested their production process five days a week to determine the amount of NCl3 being produced.   Therefore, FMC knew the amount of NCl3 entering the neutralization process. Given FMC's regular monitoring of the chloroform being added to the scrubbers and the amount of NCl3 being introduced into the neutralization process, and FMC 's long experience with the process, we conclude that FMC adequately controlled the concentration of NCl3 in the system.  Accordingly, its failure to monitor NCl3 concentrations three times a week did not exacerbate the hazard of explosion.

The Secretary next argues that a pluggage in the line feeding chloroform into the scrubber that existed for a couple of weeks before the accident, together with problems with the rotometer which regulates the flow of chloroform, resulted in inadequate amounts of chloroform being added to the scrubber.   We find that, despite the technical problems described by the Secretary, the evidence establishes that the required monitoring of the chloroform by employees ensured that adequate quantities of chloroform were being added.[[8]]

Operator Robert Jones testified that, during the problem with the chloroform line and rotometer, his regular monitoring of chloroform levels disclosed that an inadequate amount had entered the scrubber.  Accordingly, he made adjustments in the rotometer until the proper amount entered the system.   Operator James Jones also stated that when there was trouble with the chloroform flow he would adjust the flow and keep checking the level until the proper amount entered the scrubber.  He also testified that whenever the rotometer or line was plugged, management would send an instrument man to correct the problem.
Duane Colpous opined that, during the days before the accident, chloroform was added at one-third to one-half of the rates called for in FMC's Operating Bulletin or about five gallons in a 24-hour period. Lionel Updyke, however, noted that even if chloroform was flowing below normal levels, the amount in the system before the accident was adequate because the system was operating at only 65% capacity.  He also stated that the minimum- required flow of chloroform was 1/4 gallon per hour or six gallons in a 24- hour period.  Updyke's conclusion was also supported by Dr. Grelecki, who noted that the fact that the explosion took place in the lines and not in the tank indicates that the flow of chloroform was sufficient.

Analysis of the gunk made after the accident revealed a chloroform concentration of 24.6%.   In comparison, FMC'S Operating Bulletin calls for a 20% concentration, while Lionel Updyke testified that 10% was sufficient.  The accuracy of the post-accident analysis was questioned by Duane Colpous, who testified that the instability of NCl3 and its ability to react with moisture might have resulted in the samples showing a lower level of NCl3 than actually existed at the time of the accident.   Dr. Grelecki agreed that the gunk samples were unreliable, but stated that "very reliable" samples from the reactor indicated an NCl3 concentration of 3-1/2 - 4%, well-within the 5% limit for safe operation.  Thus, the NCl3 was adequately diluted.

We also find that, while FMC did have occasional problems with the rotometer and chloroform lines, it promptly repaired the defects.   Moreover, its experienced and competent operators readily recognized and compensated for the technical problems to ensure that the flow of chloroform remained at safe levels.  The post-accident analysis of the gunk, which provided the only concrete evidence of diluent levels at the time of the accident, indicated more than sufficient levels of chloroform.  Those results were supported by other tests that showed that the NCl3 was adequately diluted.  We therefore find that the problems with the rotometer and chloroform lines did not create a danger of explosion due to overly pure concentrations of NCl3, and that employees were not exposed to a hazard of explosion due to unsafe concentrations of NCl3.  We therefore conclude that FMC took adequate measures to maintain NCl3 concentrations at a safe level and vacate item 2 of the citation.

Accordingly, the judge's decision in No. 83-0488 is reversed and items 1 and 2 of the citation are vacated.  The direction for review as to No. 83-0489 is vacated.


Ray H. Darling, Jr.
Executive Secretary

DATED:  AUG 28 1986

BUCKLEY, Chairman, dissenting in part:

I respectfully dissent from my colleagues' disposition of item 1 of the citation.  In my view, the Secretary established that both FMC and the chloralkaline industry in general were aware of the hazard of locating pipes containing NCl3 in an area susceptible to external sources of heat.  By placing its transfer pipes in an area where it was in proximity to hot water, FMC failed to free its workplace of the hazard, and therefore was in violation of section 5(a)(1) of the Act.[[9]]

In my view, FMC's expert, Dr. Chester Grelecki, established that nitrogen trichloride in a pipe is highly susceptible to exothermic heating and explosion if exposed to external heat.  This is due to the confinement of the NCl3 in the pipe, which allows no space for the gases generated during heating to expand, and to the very low autoignition temperature for NCl3.  His testimony also confirms industry knowledge of such susceptibility.

The record generally substantiates that the explosion which occurred at FMC's chlorine purification facility was initiated in a pipe carrying NCl3 from a reboiler (where a chlorinated organic mixture containing NCl3 was heated to vaporize and remove chlorine) to a reactor for neutralization of the NCl3.  In the heating process, water at a temperature of 80C was applied externally to the reboiler in the vicinity of the pipe, and the pipe was in an area where hot water frequently accumulated.  As the majority opinion points out, the evidence indicates that hot water which was being applied externally to the reactor flowed directly onto the transfer pipe, overheating the NCl3, and commencing an exothermal reaction within the pipe.  The evidence, however, is not clear as to precisely how the hot water came in contact with the transfer pipe.   Either of two hypotheses can be made:  that the water level in the diked pit rose due to a faulty sump pump, reaching the transfer pipe which traversed the diked pit, or that the hot water from the hose which was being used on the reboiler was directed onto the transfer pipe.

The record establishes the substantial likelihood that hot water could accumulate in the pit to a level where it came in actual contact with the pipe.  Testimony of the operators established that the sump pumps frequently broke down.  Problems with the pumps were especially acute during the winter when they would freeze up.  Significantly, it was during such cold weather when the operators were most likely to use hot water to gasify the tanks.  While FMC did act promptly to repair the pumps, there is no evidence that gasification was stopped during sump pump malfunction.  Indeed, according to FMC's daily inspection report, on January 21, 1983, the day the sump pump was reported to be not in proper condition, two drums of nitrogen trichloride byproduct were generated.

Moreover, unlike my colleagues, I find no inconsistency in the evidence concerning whether, during the two months before the accident, hot water accumulated to the level of the transfer pipes.  The majority finds it significant that, despite operator Robert Jones' testimony that he observed the water level reach the pipes during the two months before the accident, weekly logs kept during that period show that there was no standing water in the diked area.  They fail to consider, however, the possibility that the accumulation of water observed by Jones was removed by the time of the weekly inspection.

I am also not persuaded by Dr. Grelecki's testimony that even if the water did reach the level of the pipes, it would have cooled off too much to constitute a hazard.  First, Dr. Grelecki's opinion was not shared by Duane Colpous who testified that the line could have been heated up by the hot water in the pit. Second, Dr. Grelecki's opinion is undercut by other aspects of his testimony.   When discussing the temperature dynamics in the tank, Dr. Grelecki recited a principle of physics that is particularly applicable to the accumulation of water in the pit. Dr. Grelecki stated that "a hot zone in a liquid . . . tends to rise because it is less dense than the surrounding cold fluid.  So that--if you had a big vessel and a hot spot would develop in that vessel it would tend to rise and sort of stir itself, like if you heat a pot on the bottom the hot water gets from the bottom to the top."   Applying this principle to the pit area, it is apparent that while the overall temperature would have cooled, hot water continuing to flow into the pit would rise to the top where the pipes are located.

The evidence also indicates that at the time that the instruments in the control room showed an increase from -30C to -5C in the contents of the reboiler, the operator went out to the reactor, removed the hose from the reboiler, and then went to the shut-off valve, some 40-50 feet away, to close the valve.   It is not improbable that he directed the flow of water into the diked pit, and it is possible that the hose somehow became aimed at the transfer pipe.

FMC should have anticipated and avoided the danger that external heat sources would come into proximity to the pipe.  FMC knew that hot water was applied externally to assist in heating the contents of the reboiler and that hot water was in proximity to the transfer pipe.  It also knew that heat applied to the transfer pipe could initiate an exothermic reaction of the NCl3.  Its failure to prevent such contact increased the risk inherent in the chlorine purification process which FMC was using.  The Secretary established the feasibility of relocating the pipes.  Indeed, after the accident, FMC did relocate the pipe to an area away from the hazards presented by the pit.

Accordingly, I find that the record establishes that FMC failed to free its workplace of a recognized hazard that was likely to cause death or serious injury, and that the Secretary established a feasible means of abatement.   Therefore, I would affirm item 1 of the citation.

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[[1]] Another citation issued to FMC was docketed as No. 83-0489.  Although never officially consolidated, both Nos. 83-0488 and 83-0489 were heard and decided together by the judge.  Both docket numbers were listed on the direction for review.  However, neither party has taken exception to any part of the judge's decision in No. 83-0489.  Accordingly, the direction for review as to No. 83-0489 will be vacated.

[[2]] Section 5(a)(1) states:

Each employer--

(1) shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.

[[3]] Item 1 alleged a violation of section 5(a)(1) in that:

Employees were exposed to the hazard of an explosion due to critical temperature change which could initiate a decomposition of NCl3 (nitrogen trichloride) during the chlorine vaporization and gunk neutralization process at Cell Room #1, on or about March 1, 1983.

Item 2 alleged a violation of section 5(a)(1) on the grounds that:  Employees were exposed to the hazard of an explosion due to the instability of NCl3 (Nitrogen trichloride) created by unknown amounts of chloroform being added to the scrubber; and unknown levels Of NCl3 in the chlorine vaporization and gunk neutralization process, Cell Room #1, on or about March 1, 1983.

[[4]] Dr. Grelecki's name appears misspelled throughout the record.  Our spelling of his name is derived from 3 American Men & Women of Science (15th ed. 1982).

[[5]] Under the Fed. R. of Evid. 407, evidence of post-accident measures are admissible to establish feasibility.  The Federal Rules of Evidence are generally applicable to Commission proceedings.  See Commission Rule 72, 29 C.F.R. 2200.72.

[[6]] The Secretary argues that another method of reducing the danger of hot spots would have been to keep the sump pump in good repair to keep water from accumulating in the pit.  However, the evidence indicates that FMC properly maintained the pump and that the pump was replaced promptly whenever a problem arose.

[[7]] Similarly, the Secretary introduced an exhibit establishing that a chlorine plant operated by PPG uses a mandatory dump system requiring that the reactive material be dumped into a coolant at 60 F.  As with the TNT plant, however, the Secretary failed to introduce any evidence to indicate that the techniques and processes used by PPG were sufficiently similar to those at FMC to warrant a conclusion that such a dump system would be feasible at the FMC facility.

[[8]] The Secretary also argues that an experiment conducted shortly before the explosion where the chloroform flow was cut-off establishes that FMC failed to maintain the concentration of NCl3 at a proper level.  We do not agree.  The test to which the Secretary refers was conducted under the direction of FMC's engineers.  There was no showing that FMC's engineers were not skilled to perform this test.  Nor is there any evidence that cutting-off the chloroform flow for several hours in any way increased the likelihood of an explosion or endangered the employees.

[[9]] FMC contends that the citation did not contain any suggestion that relocation of the transfer lines was a proper method of abatement, and therefore should not be considered by the Commission.  I disagree.   The citation expressly addressed itself to hazards caused by critical temperature changes during the nitrogen trichloride byproduct neutralization process.  Also, the citation stated that, "among other methods," a feasible and useful method of abatement would be to "initiate the use of instrumentation to control temperatures on the piping system."  In my view, the citation put FMC on notice that if the Secretary failed to establish the feasibility of instrumentation to detect hot spots on the pipes, he would attempt establish other feasible methods of abating the hazard.   To the extent the Secretary's failure to specifically list the "other" methods of abatement may have confused FMC, such confusion could have been remedied by moving for a more particular statement pursuant to Fed. R. Civ. P. 12(e).  Similarly, to the extent the Secretary's raising of the issue of moving the pipes at the hearing may have surprised FMC, any prejudice could have been remedied by a motion for a continuance pursuant to Fed. R. Civ. P. 15(b).  Indeed, through its own expert witness, FMC introduced testimony concerning the cause of the explosion.  Therefore, I conclude that FMC was not prejudiced by having to address the relocation of the pipes.