UNITED STATES OF AMERICA
OCCUPATIONAL SAFETY AND HEALTH REVIEW COMMISSION
SECRETARY OF LABOR,
OSHRC DOCKET NO. 13864
W. J. LAZYNSKI, INC.,
December 27, 1979
Before CLEARY, Chairman; BARNAKO and COTTINE, Commissioners.
A July 15, 1976, decision of Administrative Law Judge George W. Otto is before the Commission for review pursuant to section 12(j) of the Occupational Safety and Health Act of 1970, 29 U.S.C. § 661(i). This proceeding involves two serious citations issued to Respondent (Lazynski) charging it with violations of the Secretary’s construction standards regulating tunnel and shaft safety. Judge Otto affirmed both of the citations, which alleged violations of the Act for failure to comply with the standards at 29 C.F.R. §§ 1926.800(c)(1)(i) and 1926.800(c)(2)(i) and (v). He assessed an $800 penalty for each citation. On review Lazynski challenges the propriety of the judge’s findings regarding both of these citations. For the following reasons, we affirm the judge’s disposition.
The Alleged Violation Involving the Standard at 29 C.F.R. § 1926.800(c)(1)(i).
Lazynski, a Wisconsin corporation, is a sewer tunnel contractor. On May 6, 1974, it began the construction of a tunnel beneath the Fox River in Green Bay, Wisconsin. After digging a 100 foot deep employee entrance and equipment shaft, Lazynski mined 600 feet of the horizontal tunnel. During this original phase of the construction process, its employees were working in ‘free’ or ‘open’ air.
On April 9, 1975, Lazynski reached a silt pocket, and some water and material began leaking into the tunnel. In order to keep these substances out, Lazynski produced a compressed air environment. Compressed air is under greater than atmospheric pressure. It is normally used when tunneling under conditions of high hydrostatic pressure—pressure which permits either water or soil with a high water content to seep into the tunnel. By sealing off a tunnel with an air lock, which equalizes and regulates air pressure, and using low air compressors with air lines extending into the working chamber, it is possible to produce a compressed air environment. This environment has a stabilizing effect on the soil, keeping water and gases dissolved in it from seeping into the tunnel. From April 9, 1975, until May 10, 1975, Lazynski operated under compressed air which was maintained at 12 pounds per square inch (psi).
After mining 700 feet in a compressed air environment, Lazynski decided to decompress the tunnel in order to return to free air. Lazynski decided to decompress because it had completed tunneling under water, where it felt it would encounter the worst ground conditions. Decompression took place over the weekend of May 10 to May 12, 1975. It was completed at 6:00 a.m. on May 12. Approximately one hour later, six of Lazynski’s eight first shift employees reentered the tunnel to resume its construction. An explosion took place killing four employees.
Decompression is a critical process. Because compressed air is being removed from the atmosphere, gases which are present in the sediment surrounding a tunnel wall are likely to seep in. Some of these gases may be flammable; others, toxic. In the case of the tunnel explosion killing four of Lazynski’s employees, subsequent testing revealed the presence of methane gas.
Methane gas is formed from the anaerobic decomposition of organic matter. Wood chips, shells, and other organic debris of all kinds are a potential source of methane, as well as other flammable gases. These materials are found in soil located under river or lake beds.
According to several witnesses for the Secretary, the Fox River area in which Lazynski was mining contains the potential for methane and other flammable gases. Based on a review of 300 test borings taken in the area within the last eight to ten years, these witnesses concluded that the presence of wood chips and sea shells indicate a possible source of methane. A geologist in the area, Thomas Quigley, discovered that clay encapsulated the borings which he analyzed. If these materials were to decompose in an oxygen free environment, flammable gases would be released and trapped in the subsurface soils.
Lazynski, however, failed to recognize a relationship between the soil environment at the Fox River project and the presence of methane. Before commencing construction of the sewer tunnel, Kenneth Peterson, the company’s president, and Theodore Budd, the project manager, reviewed the reports of approximately 300 test borings taken in the area. They did not find that any of these borings indicated the presence of methane gas. Indeed, Theodore Budd saw wood chips and sea shells in test borings that he studied, and he actually encountered some of these materials during construction of the tunnel. However, it did not occur to him that these organic substances might indicate the presence of methane. Similarly, although he often discovered traces of organic materials while tunneling under rivers, Peterson never suspected that they were a potential source of methane gas. Because he had never come into contact with either the gas or anyone who had encountered it in Wisconsin, he did not analyze the organic materials from this perspective. Neither Budd nor Peterson inquired of anyone whether the various reports indicated the potential for flammable or toxic gases. Instead, they were primarily concerned with the soil bearing characteristics or mineability of the tunnel.
This was also true of the independent consultants who took test borings for Lazynski. Richard Brissette, a civil engineer, took several test borings for Lazynski, and he examined the reports of several others. Although he found no indication of methane gas in his soil analysis, he did not study the borings with this objective in mind. The company also retained William Perpich, the president of Soil Testing Service, to compile a report of the generalized soil conditions in the area of its project. Of the eighty soil borings evaluated within a three-mile stretch, none indicated the presence of methane gas.
Even though Lazynski was unaware of the potential for methane gas, it tested the atmosphere for flammable gases during all phases of the tunnel construction. The instruments Lazynski used to perform these tests varied. During the original free air phase of the work Lazynski used instruments capable of quantitatively testing the atmosphere for the presence of various toxic and flammable gases. While working under compressed air, however, the only device it used to test the air was a miner’s lamp, which gives no quantitative reading. This device contains a flame that flickers or rises when exposed to flammable gases and lowers when exposed to an oxygen deficient atmosphere. The record indicates that Lazynski continued to use only the miner’s lamp during decompression. In particular, peroidic checking of the atmosphere on May 12, while decompression was being completed, was performed with a miner’s lamp; no devices capable of quantitatively testing the atmosphere were used on that date.
The witnesses disagreed as to whether quantitative testing devices could have been used during all phases of the tunnel work. According to Lazynski’s president, Kenneth Peterson, there were no instruments capable of quantitative testing while under compressed air. Although he had investigated the possibility of using alternative devices for quantitative testing under a compressed air environment, he was not able to discover a more accurate instrument for this purpose than the nonquantitative miner’s lamp. Peterson, however, did not explain whether there was any point during decompression when the compressed air atmosphere was sufficiently altered so that the quantitative instruments could have been used. The compliance officer, on the other hand, stated that quantitative instruments could be used during compression and specifically pointed to the W8, manufactured by MSA, as one such instrument.
Judge Otto concluded that ‘respondent could not reasonably have expected to encounter methane gas.’ He also agreed with the company that the record did not support a finding that any instrument other than the nonquantitative miner’s lamp could be used to test the atmosphere during compression. However, the administrative law judge still affirmed the serious section 1926.800(c)(1)(i) citation, but limited the period covered by the citation from about 7:00 p.m. on May 11, 1975 until about 7:00 a.m. on May 12, 1975. See n. 7, supra. Judge Otto emphasized the critical nature of the decompression process. He noted that when returning to free air from a compressed air environment, gases trapped in the surrounding soil, including flammable and toxic gases, could enter the tunnel opening. The judge also noted that during the final hours of decompression, ‘the air was considered bad, a lamp flickered, a lamp went out.’ He, therefore, concluded that ‘the events and observations during the 12 hour period before the explosion made necessary the conducting of quantitative testing by appropriate instruments to assure that the required quality and quantity of air was maintained.’
On review Lazynski argues that the judge erred in finding that the circumstances known to it within the final twelve hours prior to the explosion gave notice that quantitative testing of the atmosphere was necessary. Pointing to Judge Otto’s finding that the company could not have reasonably expected to encounter methane gas, Lazynski maintains that the judge erred in sustaining the violation on the basis of last minute changes in the environmental conditions which two of its employees noticed but did not report. Lazynski also asserts that since Judge Otto accepted the testimony that no quantitative instruments exist for testing during compression and that, therefore, a miner’s lamp is the best device available, it was unreasonable for him to expect the tunnel contractor to quantitatively test during decompression. Finally, Lazynski contends that the administrative law judge applied an unconstitutionally broad testing standard to it when it found that the company did not follow the requirement of section 1926.800(c)(1)(i) to test ‘as frequently as necessary.’ Relying on Cape and Vineyard Division of the New Bedford Gas and Edison Light Co. v. OSHRC, 512 F.2d 1148 (1st Cir. 1975), Lazynski asserts that in order for a generally worded standard to pass constitutional muster, it must proscribe conduct which is considered ‘unacceptable in the light of the common understanding and experience of those working in the industry.’ It argues that the only evidence in the record regarding testing procedures common to the industry during either compression or decompression was that of the company’s president Peterson, and that it was using the procedure to which Peterson referred.
We conclude that Judge Otto properly found Lazynski in violation of the standard at section 1926.800(c)(1)(i), but limit our holding to a finding that Lazynski violated the standard when it failed to quantitatively test the atmosphere immediately following the completion of decompression at 6:00 a.m. on May 12, 1975. Accordingly, before sending its employees back into the free air tunnel, Lazynski should have conducted quantitative tests to assure that the required quality and quantity of air in the tunnel was maintained.
Section 1926.800(c)(1)(i) requires an employer engaged in tunnelling operations to quantitatively test the atmosphere in its work environment ‘as frequently as necessary to assure that the required quality and quantity of air is maintained.’ The standard specifically mentions carbon monoxide, nitrogen dioxide, flammable or toxic gases, dusts, mists, and fumes as contaminants that may be present in the air in tunnels and shafts, and places employers engaged in tunnelling operations on notice that such hazards may be encountered. Thus, the standard requires employers to anticipate the presence of hazardous gases, among other things, and places a general obligation upon them to test. The degree of testing required is governed by the phrase ‘as frequently as necessary to assure that the required quality and quantity of air is maintained.’
Lazynski had tested the atmosphere quantitatively while initially in free air. During compression, it used only a qualitative testing device: the miner’s lamp. It did not retest the atmosphere quantitatively before permitting its employees to reenter the free air environment after going off compressed air. The issue thus becomes whether this state of facts satisfies Lazynski’s obligation to conduct quantitative tests ‘as frequently as necessary.’ We find that it does not.
At the outset we note that the phrase ‘as frequently as necessary’ provides little if any concrete guidance as to when testing is to be performed. However, we disagree with Lazynski that the phrase is limited to conduct which is shown to be contrary to industry practice and custom. In support of its argument Lazynski relies upon the court decision in the Cape & Vineyard case. However, the court in Cape & Vineyard stated that industry practice is not conclusive and that compliance with a broadly worded standard may require methods of employee protection beyond those customarily used in the industry. 512 F.2d at 1152. The Commission reached the same conclusion in S & H Riggers and Erectors, Inc., 79 OSAHRC 23/A2, 7 BNA OSHC 1260, 1979 CCH OSHD ¶ 23,480 (No. 15855, 1979), appeal filed, No. 79–2358 (5th Cir. June 7, 1979). That case involved the interpretation and application of 29 C.F.R. § 1926.28(a), a standard that requires the use of personal protective equipment, inter alia, ‘in all operations where there is an exposure to hazardous conditions.’ The Commission concluded that the proper test for determining whether a hazardous condition exists within the meaning of section 1926.28(a) is ‘whether a reasonable person familiar with the factual circumstances surrounding the allegedly hazardous condition, including any facts unique to a particular industry, would recognize a hazard warranting the use of personal protective equipment.’ 7 BNA OSHC at 1263, 1979 CCH OSHD at p. 28,436. The Commission stated that industry custom and practice were useful reference points in determining whether such a reasonable person would recognize a hazard, but the Commission agreed with the court in Cape & Vineyard that the standard of care commonly used in the industry was not conclusive. Because the frequency of testing requirement of section 800(c)(1)(i) is also broadly stated, it is appropriate to apply a similar ‘reasonable person’ test in determining how frequently testing is required under that standard.
Lazynski’s president testified that the company’s testing procedures were acceptable in light of the common understanding and practice of the industry. However, he did not explain the basis for this conclusion, and the record is devoid of evidence supporting it. The record shows that Lazynski performed some quantitative tests during the original free air phase of the work, and used only the non-quantitative miner’s lamp during compression and decompression. There was no testimony establishing the frequency with which Lazynski conducted quantitative tests in free air, or any evidence regarding when Lazynski intended to renew quantitative testing after the completion of decompression. Furthermore, there is no evidence concerning the testing procedures that employers in the tunneling industry normally follow during and after decompression. The unexplained assertion of Lazynski’s president that Lazynski’s testing procedures were consistent with industry custom and practice sheds no light on whether the company’s procedures corresponded to those a reasonable person familiar with the factual circumstances surrounding Lazynski’s tunnelling operation would recognize as adequate. Other evidence, however, demonstrates that a reasonable person familiar with the facts would have conducted, at a minimum, quantitative tests for harmful gases before sending its employees to work in the tunnel after decompression had been completed.
The cited standard places employers on notice that flammable or toxic gases and other harmful chemical substances may be present in tunnels under construction. Regardless of whether an employer can anticipate the presence of a particular air contaminant, a reasonable employer would understand that the standard requires a program of regular quantitative testing, with the frequency of testing depending on any circumstances that affect the likelihood of the presence of harmful substances in the tunnel atmosphere.
The record shows that decompression is a critical time in a tunnel environment because, among other problems that may arise, gases present in the sediment surrounding a tunnel wall are likely to seep in. Lazynski’s president acknowledged this. Thus, the period following the completion of decompression is uniquely one during which the tunnel may contain harmful gases. Whatever frequency of testing the standard requires at other times, a reasonable person familiar with the fact that gases present in the soil can be released into the tunnel after decompression is completed would certainly understand that the standard requires quantitative testing at that critical time. We therefore conclude that Lazynski failed to comply with section 1926.800(c)(1)(i) by not conducting quantitative tests between the end of decompression and the time the employees resumed work in the tunnel.
Our conclusion that Lazynski violated the standard does not depend upon the foreseeability of the accident as it actually occurred or the foreseeability of the presence of a dangerous concentration of methane. Moreover, our holding does not depend upon any changes in the environmental conditions evidenced by the flickering of the miner’s lamp. And finally it is not inconsistent with Judge Otto’s credibility finding, which we accept, that no quantitative testing devices could be used during compression, and thus by implication, for at least part of the period of decompression.
After considering the penalty factors set out in section 17(j) of the Act, we agree with the judge that an $800 penalty for this violation is appropriate.
The Alleged Violation Involving the Standards at 29 C.F.R. §§ 1926.800(c)(2)(i) and (v)
One or two ¾-inch high air lines provided the sole source of tunnel ventilation for Lazynski’s employees during the one-hour period of free air before the fatal accident on May 12. A high air line is commonly used in the tunneling industry to operate pneumatic equipment. The high air lines ran alongside the tunnel and were loosely connected with nails to its wall. Depending on the particular phase or space of construction, they were located between 25 and 100 feet back from the face of the tunnel, that is, back from the forward wall on which excavation work was being accomplished.
The manifold valves controlling the air flow through the high air hoses were opened from ¼ to ½ of full capacity. Powered by a 900 CFM Ingersoll Rand high air compressor with a rated capacity of 125 pounds per square inch (psi), each of these hoses produced a maximum of 184.6 cubic feet of tunnel air per minute. Thus, the total amount of air supplied to the tunnel was 369.2 cubic feet per minute. The linear velocity of the airflow in the tunnel bore was substantially less than 30 feet per minute, and the direction of airflow was not reversible.
Dr. Thomas Richard, a compliance officer for the state of Wisconsin and an expert witness for the Secretary, testified that the proper mode of ventilation in a free air tunnel utilizes aboveground fans connected to underground ductwork. In his opinion, Lazynski should have already installed this system and been using it to ventilate the tunnel before sending employees into the working chamber following decompression. In such a permanent ventilation system, the ductwork extends vertically from a ground level bore hole, travels down through an access shaft, and turns at a right angle before extending into the working face. Since the fan is reversible, it can either blow fresh air directly to the working chamber or exhaust dust, fumes, and toxic gases from the tunnel face. Therefore, the system provides quality air for underground workers while it protects them from dangerous flammable or combustible gases.
Another compliance officer, Carlos Gonzales, also stated than an underground duct system should have been installed as the tunnel construction proceeded. Because the tunnel was short (1200 to 1800 feet), the duct lengths could have been twenty-four inches in diameter, varying in length from thirty to forty feet. Both witnesses agreed that, without sophisticated purification, the air generated by a compressor is not safe for breathing purposes. They also concurred that reversible fans and ductwork are generally recognized as the proper means of tunnel ventilation. Even Lazynski’s foreman, Donald Brenton, admitted that in his fifteen years with the company, he had never been in a tunnel that relied solely on high air for ventilation. Kenneth Peterson, Lazynski’s president, conceded that while there were some filters on the compressor, there were not enough to take out all impurities. Because of this, he would not recommend relying on it for more than a few hours.
The citation, which was limited to May 12, 1975, subsequent to the removal of air pressure in the tunnel, alleged that Lazynski’s ventilation system violated the standard in three respects: the total amount of air supplied was less than 200 cubic feet per minute for each employee working in the tunnel; the linear velocity was less than 30 feet per minute; and the direction of air flow was not reversible. Judge Otto found that the facts supported all three aspects of the violation and affirmed the citation.
On review, Lazynski concedes that the ventilation system was nonreversible, but argues that since that fact had nothing to do with the accident, it should not be found in serious violation of the Act. The company also takes exception to the other two aspects of the judge’s finding of a violation.
Lazynski argues that its temporary use of high air substantially complied with section 1926.800(c)(2)(i) requiring ‘mechanically induced primary ventilation in all work areas.’ Although there are OSHA regulations governing the ventilation procedures to be used during both a compressed and a free air environment, Lazynski contends that none exists describing the techniques to be employed between decompression and the opening of a more complete or permanent ventilating system. The company assumes that because no safety or health standard explicitly prohibits the use of high air, the Occupational Safety and Health Administration tacitly approves of high air as a technique for tunnel ventilation. In order to buttress its position that use of high air is a recognized form of ventilation in the tunnel industry, Lazynski points to its recent application in pipe jack mining.
Lazynski also contends that the requirement of section 1926.800(c)(2)(v) to provide 200 cubic feet of air per minute for each employee underground ‘defies logical explanation.’ Pointing to the 30 cubic feet requirement in the compressed air standard at 29 C.F.R. § 1926.803(i)(1),it asserts that there is no rational basis for the discrepancy between the two tunnel sections. The company admits that a volume of 200 cubic feet might be necessary in large and open coal mines, but it does not believe that it is warranted in a confined tunnel area. In any event, Lazynski contends that it was in compliance with the standard’s volume requirement on the day of the accident. Following decompression, the tunnel was literally ‘full’ of air. At the same time, high air hoses were pumping in additional air. Considering the fact that only a few minutes lapsed between the entry of first shift employees and the fatal explosion, there was certainly enough air in the tunnel to satisfy the 200 cubic feet mandate.
Finally, Lazynski maintains that the linear velocity requirement of 30 feet per minute only applies ‘in those tunnels where blasting or rock drilling is conducted or where there are other conditions that are likely to produce dusts, fumes, vapors, or gases in harmful quantities.’ It argues that Judge Otto made no finding of gas producing conditions in its tunnel other than to note a relatively insignificant stone drilling which took place approximately two weeks before the explosion. The company reiterates its argument made before the judge that this use of a ¼ pound charge some two weeks before the explosion for minor drilling purposes was not the 100 pound blasting contemplated by the standard for rock tunnels.
Lazynski’s argument that there are no OSHA regulations describing the ventilation system to be used between decompression and the opening of a more complete ventilation system is without merit. The requirement of section 1926.800(c)(2)(i) that tunnels be provided with mechanically induced primary ventilation in all work areas does not create any lapse in coverage for employees during the period to which Lazynski refers. Although it is clear that the company could not employ a permanent ventilation system during the periods of compression and decompression, the record supports Dr. Richard’s opinion that such a system could and should have been ready for immediate use subsequent to Lazynski’s completion of decompression and prior to its employees’ reentry into the tunnel. Furthermore, Lazynski’s argument that the standard does not prohibit the use of high air for ventilation is inapposite. Lazynski violated the standard, not because it used high air, but because the air flow was insufficient. Moreover, the fact that it may be industry practice to use high air during pipe jack mining does not affect our conclusion that Lazynski violated the standard here. The company was not using this mining technique at the Fox River Project. Furthermore, the fact that an industry uses a particular technique does not establish that its use complies with a specific standard. Lazynski’s evidence that high air is used during pipe jack mining may mean that employers in the tunneling industry routinely violate the cited standard, not that such a procedure is adequate. We also note that Peterson stated that high air is used during pipe jack mining because it is the only feasible method of ventilation that can be used in such work. Lazynski does not contend, however, that a ventilation system in compliance with the standard could not have been used in the circumstances of this case. Indeed, the record supports the judge’s finding that a proper mode of ventilation in a free air tunnel is aboveground fans connected to underground ductwork.
The standard at section 1926.800(c)(2)(v) unconditionally requires a fresh air supply of at least 200 cubic feet per minute for each employee. On review Lazynski does not challenge Judge Otto’s finding that the maximum quantity of air entering the tunnel through each high air hose was 184.6 cubic feet. Therefore, the company’s ventilation system did not meet the quantity requirement of the standard.
Lazynski’s contention that it complied with this requirement because the tunnel was “full of air” before the employees began work lacks merit. The standard is entitled ‘Ventilation,’ and obviously contemplates that it is hazardous for employees working in tunnels to simply breathe the ambient air. Thus, in speaking of a ‘supply of fresh air,’ the standard requires that 200 cubic feet per minute per employee be provided from a source external to the tunnel itself.
Furthermore, the company’s arguments that such a supply was not necessary to assure that its employees had adequate air to breathe, and that the standard is illogical in requiring a greater supply than another standard requires under different circumstances, question the wisdom of the standard in establishing the 200 cubic feet per minute requirement. The Commission has no authority, however, to decide that the requirement of the standard is too stringent or unnecessary. Van Raalte Co., 76 OSAHRC 48/B8, 4 BNA OSHC 1151, 1975–76 CCH OSHD ¶ 20,633 (No. 5007, 1976).
In contrast to the standard’s absolute requirement that 200 cubic feet per minute per employee be supplied, the standard requires that a linear velocity of 30 feet per minute be maintained only when certain conditions are present: where blasting or rock drilling is conducted or where other conditions are likely to produce dusts, fumes, vapors, or gases in harmful quantities. Lazynski interprets Judge Otto’s decision to find that it violated this requirement because of the drilling and blasting it had done before the time of the alleged violation. It is not clear whether this was, indeed, the judge’s rationale; but in any event, we agree with Lazynski that it was not performing drilling or blasting at the time of the alleged violation. Therefore, a violation of the standard’s velocity requirement cannot be predicated on such activities. Nevertheless, for the reasons stated below, we conclude that Lazynski violated the velocity requirement of the standard.
The purpose of the 30 feet per minute velocity requirement is to provide a sufficient air flow to dissipate contaminants that would otherwise accumulate in harmful quantities. Unlike the 200 cubic feet per minute volume requirement, which seeks to assure that employees have sufficient fresh air to breathe at all times, the velocity requirement only comes into play when there is an unusual condition that increases the likelihood that dangerous quantities of air contaminants will be present, and seeks to prevent such contaminants from accumulating in quantities that would be harmful. The standard does not require the actual presence of a harmful quantity of a contaminant before the required ventilation velocity must be maintained. See Westinghouse Electric Corp., 79 OSAHRC 28/B8, 7 BNA OSHC 1318, 1323, n. 13, 1979 CCH OSHD ¶ 23,542 at p. 28,521, n. 13 (No. 13955, 1979), appeal filed, No. 79–1556 (7th Cir. May 24, 1979).
As discussed above, in relation to the violation of section 1926.800(c)(1)(i), decompression is a critical time in a tunnel environment, for gases present in the surrounding soil will be released into the tunnel atmosphere as the excess pressure in the tunnel is removed. Thus, decompression increases the likelihood of dangerous air contaminants being present in the tunnel, and is a type of unusual condition that can lead to the presence of harmful quantities of any contaminant unless a sufficient ventilation velocity is present. We therefore conclude that Lazynski violated the 30 feet per minute requirement of section 1926.800(c)(2)(v) by failing to provide this ventilation velocity while its employees worked in the tunnel cavity following decompression.
In summary, we conclude that following the completion of decompression on the morning of May 12, 1975, Lazynski failed to provide each of its six underground employees with 200 cubic feet per minute of reversible primary ventilation at a linear velocity of 30 feet per minute. Therefore, the company committed a serious violation of sections 1926.800(c)(2)(i) and (v). We agree with the judge that an $800 penalty for this violation is appropriate.
Accordingly, it is ORDERED that the judge’s decision be affirmed.
FOR THE COMMISSION:
Ray H. Darling, Jr.
DATED: DEC 27, 1979
UNITED STATES OF AMERICA
OCCUPATIONAL SAFETY AND HEALTH REVIEW COMMISSION
SECRETARY OF LABOR,
OSHRC DOCKET NO. 13864
W. J. LAZYNSKI, INC.,
July 15, 1976
DECISION AND ORDER
Richard J. Fiore, Esq., and Edward J. Moran, Esq., for Complainant
Robert P. Buellesbach, Esq., for Respondent
George W. Otto, Judge
This is a proceeding pursuant to section 10 of the Occupational Safety and Health Act of 1970 (29 U.S.C. 651 et seq. hereafter called the Act). On May 12, 1975 an explosion in respondent’s tunnel killed four employees and injured others. Following investigation complainant issued citations June 3, 1975 charging respondent with serious violation of section 5(a)(2) of the Act by failure to comply with occupational safety and health standards 29 CFR 1926.800(c)(1)(i) and 29 CFR 1926.800(c)(2)(i)(v), with a proposed penalty of $800 for each alleged violation. Respondent contests the citation allegations and disputes the proposed penalty.
The parties stipulated that respondent was a corporation with an office and place of business in Milwaukee, Wisconsin, was engaged in subsurface construction and related activities and had a workplace at and about 1496 Bylsby Avenue, Green Bay, Wisconsin, where it was engaged in the construction of a sanitary district sewer tunnel under contract with the Green Bay Metropolitan Sanitary District. The tunnel was 100 feet below the surface and traveled horizontally in excess of 1,500 feet, with much of the horizontal distance constructed directly below the Fox River. There were three shifts, varying between six to eighteen employees, with work duties including mining, concrete form setting and stripping, concrete pouring, cleanup or general housekeeping. The foremen were William Alvey, first shift—Wilfred DeGrove, first shift before May 12, 1975—Larry Anderson, second shift—Donald Brenton, third shift.
Respondent began the sewer construction activities May 6, 1974 and continued under a compressed air environment from April 9, 1975 until May 10, 1975. The compressed air environment was maintained at
pounds per square inch (psi) during this period. Respondent began decompression May 10, 1975 at
81b psi and completed decompression at 6:00 a.m.
on May 12, 1975. About 6:00 a.m. on May 12 the sole source of mechanically induced air was by means of a 900 CFM Ingersoll-Rand portable high air compressor; this source was temporary in nature and was not intended by respondent as a permanent system of ventilation. On May 12 miner’s lamp testing was the sole testing utilized by respondent to test its underground atmosphere. At 6:15 a.m.
1c on May 12 miner’s lamp testing was performed by Donald Brenton, third shift foreman, and Al Zalewski, employee. No other tests were conducted at that time. Respondent foremen were responsible for conducting miner’s lamp testing and routine maintenance of the testing instruments. At 7:00 a.m.
1d on May 12 first shift employees entered the tunnel. At approximately 7:00 a.m. on that date an explosion occurred within respondent’s tunnel workplace. Subsequent testing by both parties revealed the presence of methane gas in harmful quantities (Transcript pages 23–30: T 23–30).
STANDARDS AND CITATION DESCRIPTIONS
29 CFR 1926.800—Tunnels and Shafts
2 (c)—Air quality and ventilation
(1)—Air quality and quantity
(i) Instruments shall be provided to test the atmosphere quantitatively for carbon monoxide, nitrogen dioxide, flammable or toxic gases, dusts, mists, and fumes that occur in the tunnel or shaft. Tests shall be conducted as frequently as necessary to assure that the required quality and quantity of air is maintained. A record of all tests shall be maintained. and be kept available.
Description—Employer failed to provide that tests be conducted as frequently as necessary to assure that required quality and quantity of air is maintained, and that a record of all tests be maintained and kept available; e.g., Fox River Tunnel, Contract #23 for the Green Bay Wisconsin Metropolitan Sewerage District. Instruments for conducting such tests were available (including flammable gases, carbon monoxide, carbon dioxide, oxygen deficiency, etc), but were not utilized as required on or before May 12, 1975.
29 CFR 1926.800(c)
(i) Tunnels shall be provided with mechanically induced primary ventilation in all work areas. The direction of airflow shall be reversible.
(v) The supply of fresh air shall not be less than 200 cubic feet per minute for each employee underground. The linear velocity of the air flow in the tunnel bore shall not be less than 30 feet per minute in those tunnels where blasting or rock drilling is conducted or where there are other conditions that are likely to produce dusts, fumes, vapors, or gases in harmful quantities.
Description—Employer failed to provide a tunnel with mechanically induced primary ventilation in all work areas, the direction of which ventilation shall be reversible. The supply of fresh air shall not be less than 200 cubic feet per minute for each employee underground. The linear velocity of the air flow in the tunnel bore shall not be less than 30 feet per minute in those tunnels where blasting or rock drilling is conducted, or where there are other conditions that are likely to produce dusts, fumes, vapors, or gases in harmful quantities; e.g., Fox River Tunnel, Contract #23 for the Green Bay, Wisconsin Metropolitan Sewerage District. There was no primary ventilation provided in the tunnel on May 12, 1975, subsequent to the removal of air pressure, other than that provided by partially open high air lines, which were not reversible.
29 CFR 1926.800(c)(1)(i):
Throughout the tunnel construction until May 12 respondent used the miner’s safety lamp (lamp) continuously. In operation this lamp contains a flame that flickers or rises when exposed to flammable gas and lowers when exposed to oxygen deficiencies. If the lamp is properly maintained, when the flame goes out, there is an indication of insufficient oxygen to sustain human life. The lamp gives no percentage reading. It is not an instrument capable of quantitative testing of the atmosphere. It permits continuous monitoring and serves to alert a knowledgeable employee to any change in the working environment sufficient to suggest testing, or to impel evacuation (T 152, 185, 192, 203, 246, 331, 444, 445, 792).
The lamp was the only testing instrument used in the tunnel from April 9, 1975 until May 10, 1975, the period of operation under 12
1e psi. Kenneth Peterson, president, testified respondent researched the problem of testing while under compressed air and was told there was no accurate testing equipment, that respondent buys thousands of dollars’ worth of safety equipment, that its tunnels have been inspected frequently by State inspectors and inspectors for owners and no other equipment has been suggested (T 709, 710, 711). The record is not sufficient to support complainant’s suggestion or designation of a specified device other than the lamp for this purpose (T 710). Respondent has made reasonable attempts to determine whether quantitative instruments have been available for compressed air environment testing, and has found none.
Respondent had instruments on the work site to test the atmosphere quantitatively as required by the cited standard. These included Universal testing units for nitrogen dioxide, MSA oxygen analyzer, combustible gas meter or indicator, oxygen meter (T 133, 134, 135, 149, 150, 591).
Larry Anderson, foreman, tested with the lamp and ‘with the tubes;’ about 7:00 p.m. the night before the accident he had taken a combustible gas indicator air sample (T 573, 574). He had not logged the air sampling for the weekend prior to the accident (T 573, 574).
The stipulated period of decompression was from May 10 to 6:00 a.m.
1f on May 12, 1975. The period of decompression is critical. Returning to free air from a compressed air environment permits surrounding soil airs to enter the tunnel. Pressure is released off the entire tunnel. Whenever oxygen enters anaerobic
2soil, the oxygen may be converted immediately into carbon dioxide, which may enter the workplace. Hydrogen sulfide may enter also. Flammable gases may come in (T 450, 451). Mr. Zalewski and Foreman Brenton worked in the tunnel the night before the accident; shortly before morning the lamp flickered several times; the tunnel air was bad and got worse toward morning, in the morning as they were leaving the tunnel, one of the lamps went out because it was out of fuel; it was refueled and hung on the elevator door (T 575, 576), Zalewski told DeGrove before he went down that he thought the air was pretty bad (T 576, 577). There is no indication any quantitative testing instrument was used after foreman Anderson’s sampling at 7:00 p.m. on May 11. Yet during a period of about twelve hours prior to the explosion, it appears the air was considered bad, a lamp flickered, a lamp went out (T 192, 388, 463, 576, 577, 596, 597).
Following the explosion, tests at various tunnel locations produced zero to two percent methane, oxygen about 20.5 or 20.9 percent, with no trace of carbon monoxide, carbon dioxide or nitrogen dioxide. High air
3 was flowing in up near the face. There had been tremendous concussion, extensive damage and combustible gas (T 567, 568).
Complainant contends respondent should have been aware of a methane gas potential, based upon geologic history and preconstruction subsurface investigation findings. The geologic history and content of eastern Wisconsin, including the Fox River and Green Bay areas, is detailed in the record. (T 56, 61–71, 478, 487–492, 499, 500, 503, 516, 521, 524–531, 541, 542, C–12). Despite the extensive testimony upon this subject, the fact remains that the May 12, 1975 explosion was the first recorded in Wisconsin construction history related to methane gas. No report, map, record of hundreds of borings, or other preconstruction investigative material mentions methane gas. A report of generalized soil conditions in the project area included reference to 80 soil borings; none reported a possibility of methane. Of about 300 test borings in the last 8 or 10 years in the Green Bay area, none produced methane gas. (T 40–50, 52–64, 74–82). Respondent has constructed approximately 70 miles of tunnel in the Milwaukee, Wisconsin area, with one job in Madison, Wisconsin; most of the Milwaukee jobs followed water courses and it was not uncommon to encounter traces of organic materials (which may produce or release flammable gas); the biggest gas problem has been carbon dioxide. In 21 years with respondent, Mr. Peterson has never encountered methane gas, and has never heard of anyone else reporting this gas in Wisconsin tunnel projects (T 663, 665–671). Before bidding the job, respondent took customary steps necessary to understand the project, including consideration of reports and tests of underground content, soils and formations (T 675–681, 686–689, C–2, C–3, C–4, C–4a, C–5, C–6, C–7). Prior to May 12 there had been extensive subsurface construction by other contractors within the immediate area (T 697). In addition, respondent had completed approximately 4,000 feet of tunnel as a subcontractor for others (T 691–693), plus 1,200
1g feet of the subject tunnel (R–1). No contractor or consulting engineer had encountered methane gas or had suggested its possibility.
Respondent could not reasonably have expected to encounter methane gas, but this circumstance does not serve to suspend the application of the cited standard. Methane gas is not specifically stated in the standard but it is not excluded. There is no occupational safety and health standard specifically and solely applicable to a subsurface tunnel environment during depressurization. However, the cited standard applies continuously during tunnel construction. It does not require continuous quantitative testing, unless the circumstances of the tunnel environment deem it advisable. The events and observations during the 12 hour period before the explosion made necessary the conducting of quantitative testing by appropriate instruments to assure that the required quality and quantity of air was maintained.
This was not done and a violation resulted. The violation was serious within the meaning of the Act.4
Complainant’s requirement of immediate abatement is confirmed. Respondent has been engaged in the construction of open-cut and underground sewers for approximately 40 years. This employer has received a substantially better than average industrial rating for workmen’s compensation premium purposes from the Wisconsin Rating Bureau, effecting a saving to the Green Bay owner of almost $40,000, since the workmen’s compensation rate was a bid item. This is indicative of a generally satisfactory safety record and program. However, considering the gravity of the violation, a penalty of $800 is assessed.
20 CFR 1926.800(c)(2)(i)(v):
By May 12, 1975 the tunnel construction had progressed to
6001g feet away from the shaft (T 126). For about one hour immediately before the explosion the tunnel was not functioning under a compressed air environment and during that interval, air was supplied to the tunnel employees through two 3/4 inch high air line hoses, one of which extended to about 25 feet from the mining machine and a greater distance from the face of the tunnel (T 127, 409, 410, 597). This high air was produced by a compressor with a rated capacity of 125 psi. The manifold valve controlling the air flow through the hose was opened from one-fourth to one-half of full capacity (T 597). The maximum quantity of air entering the tunnel was 184.6 cubic feet per minute per hose
(C–18)5. Six employees were in the tunnel at the time of explosion (T 566).
The high air hoses were in the tunnel to provide power to pneumatic drills. When a rock was encountered, a 1–1/4 inch hole was drilled, generally to a depth of 12 to 21 inches, with the greater number around 15 inches. A small explosive was used. There were 70 drilling and blasting entries between February 17 and April 29, 1975; the next entry was September 3 (C–9). This activity represented blasting and/or rock drilling within the meaning of the cited standard. Respondent contends that air tools were not being used near the face and that the hoses were used primarily to get air into the front (T 217, 218). However, the hoses did not add air to the tunnel sufficient to meet the required minimum of not less than 200 cubic feet per minute for each employee underground. Whatever the linear velocity of the air flow in the tunnel bore may have been, it was substantially less than 30 feet per minute. The high air hoses did not provide mechanically induced primary ventilation in all work areas in the tunnel. The direction of air flow, if any, was not reversible.
The air coming out of the hoses had no overall ventilating effect. It caused some air movement but probably fell off after a few feet (T 396, 421, 430, 431). In the absence of suitable purifying devices on the compressor, the air coming through the high air line hoses was not fresh
air6 (T 433, 434, 435). Fresh air is not necessarily ‘pure’ air, whatever that might be. ‘Fresh air’ within the meaning of the cited standard means air sufficient in quality to sustain human life.
There was no adequate ventilating system. No fan was in use. A fresh air tunnel, as distinguished from a compressed air tunnel, normally is ventilated by use of above-ground fans connected to duct work, extending vertically down a shaft or bore hole and turning at angle to extend to the working face. The fan should be reversible to either exhaust toxic flammable gases from the face, or to blow fresh air directly to the working chambers (T 378).
Respondent failed to comply with the cited standard. The violation is serious within the meaning of the
Act4a. Immediate abatement was reasonable. Fans and a duct system could have been installed. Respondent was planning to install a ventilating system; a vent or down hole had been dropped near the face area and fans were on the site but not installed (T 117, R–1:10.01). Respondent believes the tunnel would not accommodate a 24 inch duct, considering the numerous temporary installations in the
tunnel7, including car tracks; also, such ventilating system would impede employee movement in the tunnel and make rapid egress difficult. A proper ventilation system, however, would have provided the exposed employees to reasonably safe and healthful working conditions, as contrasted to the tunnel environment prevailing on and about May 12, 1975.
Based upon the gravity of the violation, a penalty of $800 is assessed.
FINDINGS OF FACT
1. W. J. Lazynski, Inc., respondent, is a corporation with an office and place of business at 4445 North 124th Street, Milwaukee, Wisconsin, and is engaged in subsurface construction and related activities.
2. On May 12, 1975 respondent had a workplace at the Fox River Tunnel, 1496 Bylsby Avenue, Green Bay, Wisconsin, where it was engaged in the construction of a sanitary district sewer tunnel under contract for the Green Bay Metropolitan Sanitary District.
3. Respondent commenced work activities for the Fox River Tunnel on or about May 6, 1974 by excavating a shaft of 24 foot diameter and 100 foot depth and on February 17, 1975 began horizontal construction of the tunnel.
4. There were three work shifts, each having from six to eighteen employees.
5. On April 9, 1975 respondent changed the tunnel atmosphere from free air to a chamber pressurized at about 12 psi.
6. Tunnel construction continued under the pressurized air system at about 12 psi until May 10, 1975.
7. Respondent began to depressurize the tunnel on May 10, 1975 and completed depressurization at approximately 6:00 a.m. on May 12, 1975.
8. At about 7:00 a.m., six of respondent’s eight first shift employees entered the tunnel.
9. On May 12, 1975 and prior thereto respondent had instruments at the work site to test the atmosphere quantitatively for carbon monoxide, nitrogen dioxide, flammable or toxic gases, dusts, mists and fumes that might occur in the tunnel or shaft. During the period from about 7:00 p.m. on May 11, 1975 until about 7:00 a.m. on May 12, 1975, respondent failed to require the use of such instruments in the tunnel to test the atmosphere quantitatively.
10. During the period set forth in Finding of Fact 9, no tests were conducted to assure that the required quality and quantity of air was maintained.
11. Test records were destroyed on May 12, 1975.
12. On May 12, 1975 and prior thereto miner’s safety lamps were used in the tunnel to check the atmosphere. The miner’s safety lamp is not an instrument capable of testing the tunnel atmosphere quantitatively.
13. On May 12, 1975 the sole source of air provided respondent’s employees, other than the air existing in the tunnel, was by means of two 3/4 inch high air hoses, with compression provided by a 900 CFM Ingersoll-Rand portable high air compressor with a rated capacity of 125 psi.
14. The high air hoses were in the tunnel primarily for operation of power tools but were used by respondent on May 12, 1975 as a temporary means of ventilation.
15. The maximum quantity of air entering the tunnel through each high air hose, set forth in Findings of Fact 13 and 14, was 184.6 cubic feet per minute.
16. The 3/4 inch high airline system was incapable of reversing the direction of airflow.
17. On May 12, 1975 the supply of additional air to the tunnel was less than 200 cubic feet per minute for each employee underground.
18. Blasting or rock drilling operations were conducted in the tunnel until April 29, 1975 and resumed September 3, 1975.
19. The linear velocity of the airflow in the tunnel bore was less than 30 feet per minute on May 12, 1975.
20. At about 7:00 a.m. on May 12, 1975 after first-shift employees entered the tunnel, an explosion occurred within the tunnel, killing four employees and injuring others.
21. Following the explosion, methane gas was found in the tunnel in harmful quantities.
CONCLUSIONS OF LAW
1. The Review Commission has jurisdiction of the parties and of the subject matter herein.
2. On May 12, 1975 respondent failed to comply with occupational safety and health standard 29 CFR 1926.800(c)(1)(i) as required by section 654(5)(a)(2) of the Act.
3. On May 12, 1975 respondent failed to comply with occupational safety and health standard 29 CFR 1926.800(c)(2)(i)(v) as required by section 654(5)(a)(2) of the Act.
It is therefore ORDERED that the above citations be and the same are hereby affirmed. Penalty is assessed in the sum of $1,600.
George W. Otto
Dated: July 15, 1976
 29 U.S.C. §§ 651–678, hereinafter ‘the Act.’
 The standard at 29 C.F.R. § 1926.800(c)(1)(i) provides:
§ 1926.800 Funnels and shafts.
(c) Air Quality and Ventilation.
(1) Air quality and quantity.
(i) Instruments shall be provided to test the atmosphere quantitatively for carbon monoxide, nitrogen dioxide, flammable or toxic gases, dusts, mists, and fumes that occur in the tunnel or shaft. Tests shall be conducted as frequently as necessary to assure that the required quality and quantity of air is maintained. A record of all tests shall be maintained and be kept available.
 This process can be defined as the decomposition of organic material by microorganisms and biochemical processes in the absence of oxygen.
 These were the same borings that were examined by the Secretary’s witnesses.
 Peterson stated that in his twenty-one years of mining experience in Wisconsin, he had never encountered methane. In addition, there was no record of any previous explosion in Wisconsin history related to methane gas.
 Some of the quantitative testing devices present included: Universal Testing Units for nitrogen dioxide; an MSA oxygen analyzer or cyl which was used in conjunction with a miner’s safety lamp to test the oxygen in the tunnel, and a general combustible gas indicator or explosimeter.
 Lazynski presented no evidence that it conducted quantitative tests during decompression. However, one of the Secretary’s compliance officers, who had investigated the accident, testified that Lazynski’s second shift foreman, Anderson, told the compliance officer that He had conducted quantitative tests at 7:00 p.m. on May 11, 1975, the evening before the accident, but had not logged in the results of those tests, as he normally did. Based on this evidence, Judge Otto found that Lazynski had conducted quantitative tests at 7:00 p.m. on May 11, and for that reason he limited his finding of a violation to the period between 7:00 on May 11 and the explosion on May 12.
We do not accept the judge’s finding that Lazynski conducted quantitative tests at 7:00 on May 11. Although we have no reason to doubt that the compliance officer accurately reported what Anderson told him, Anderson’s statement, coming during the investigation of a tragic accident, would tend to exculpate Anderson from any fault in the accident, and must be regarded as inherently suspect for that reason. Further doubt is cast by Anderson’s failure to follow the normal practice of logging in the results of the purported tests. Moreover, Anderson was not called to testify, so there was no opportunity for either party to question him on the truth of his statement.
If Lazynski had in fact conducted quantitative tests on the evening of May 11, we would expect Lazyaski to rely on such evidence as an indication that it had in fact complied with the standard. Instead, Lazynski has not contended that it conducted quantitative tests during compression or decompression, but, to the contrary, has contended that at least during compression, quantitative tests could not be conducted. This sheds further doubt on the accuracy of Anderson’s statement.
We do not reject Anderson’s statement simply because of its hearsay nature. Hearsay is admissible in our proceedings and may be used as probative evidence. Hurlock Roofing Co., OSHRC Docket No. 14907 (October 31, 1979). In this case, however, Anderson’s statement is inconsistent with other evidence and the circumstances under which it was made cast serious doubt on its reliability. Standing alone, his statement is insufficient evidence on which to base a finding that Lazynski conducted quantitative tests on the evening of May 11.
 At 6:15 a.m. on May 12, the lamp flickered somewhat. However, the employees attributed its inconsistency to either a draft in the tunnel or the result of going off of compressed air. Compliance Officer Randall Sherman testified that Zalewski told him the air in the tunnel had been ‘bad’ or ‘dead’ all night and that ‘it got worse toward morning.’ As they were leaving the tunnel at the end of the third shift, one of the lamps went out. However, the men assumed that this was due to a lack of fuel.
 The citation specified that quantitative instruments were ‘not utilized as required on or before May 12, 1975.’
 Other standards in the same subsection expand on this requirement. Thus, § 1926.800(c)(1)(iv) prohibits the exposure of employees to airborne contaminants in excess of the limits established in the 1970 edition of ‘Threshold Limit Values of Airborne Contaminants,’ as adopted by the American Conference of Government Industrial Hygienists. Subsection 1926.800(c)(2)(vi) requires that employees be withdrawn from an underground location from which the air returning through the ventilation system contains a concentration of 1.5 percent or higher of flammable gas, and prohibits their return until the concentration of such gas is reduced to 1 percent or less.
 See also General Dynamics Corp., Quincy Shipbuilding Div. v. OSHRC, 599 F.2d 453, 464 (1st Cir. 1979).
 We need not therefore address Lazynski’s argument that the failure of Brenton and Zalewski to report their observations constituted unpreventable employee misconduct.
 See C. Kaufman, Inc., 78 OSAHRC 3/C1, 6 BNA OSHC 1295, 1977–78 CCH OSHD ¶ 22,481, (No. 14249, 1978).
 Because the record is unclear as to the exact point during decompression that quantitative devices could again be used, we cannot determine the frequency with which a reasonable person would have conducted quantitative tests during decompression, and therefore do not find a violation based on Lazynski’s failure to test during decompression.
 The standards at 29 C.F.R. §§ 800(c)(2)(i) and (v) provide:
(i) Tunnels shall be provided with mechanically induced primary ventilation in all work areas. The direction of airflow shall be reversible.
(v) The supply of fresh air shall not be less than 200 cubic feet per minute for each employee underground. The linear velocity of air flow in the tunnel bore shall not be less than 30 feet per minute in those tunnels where blasting or rock drilling is conducted or where there are other conditions that are likely to produce dusts, fumes, vapors, or gases in harmful quantities.
 29 C.F.R. § 1926.804(e) contains the following definition:
(e) ‘High air’—Air pressure used to supply power to pneumatic tools and devices.
 Pipe jack mining, a relatively new concept in tunnel mining, is accomplished by pushing concrete pipes into the shaft by hydraulic jacks.
 The standard at 29 C.F.R. § 1926.803(i)(1) provides in pertinent parts:
(i) Ventilation and air quality
(1) . . . Ventilating air shall be not less than 30 cubic feet per minute.
 Lazynski keeps a pneumatic drill in its tunnel which is powered by the two high air lines. When the company encounters a boulder that is too cumbersome for its mining machine to handle, it drills a small hole in the rock and places a ¼ pound charge in it. Between February 17 and April 29, 1975, several drilling and blasting entries took place. After the May 12 methane explosion, blasting did not resume until September 3, 1975.
 The standard speaks of a supply of ‘fresh air,’ and there is evidence in the record indicating that high air may contain impurities. There is also evidence that it is, or may be, possible to filter out these impurities. Inasmuch as Lazynski was not cited for failing to provide ‘fresh’ air, we need not decide whether filtered high air would qualify as ‘fresh air’ under the standard.
 The argument that the tunnel was ‘full of air’ following decompression is also inconsistent with the testimony of Lazynski’s president, who stated that ‘in numerous jobs, numerous times, we have run into a condition where we have had an oxygen deficiency in the tunnel.’ The witness explained that the oxygen deficiency would arise from carbon dioxide replacing the oxygen in the air. He further stated that they had to be alert for oxygen deficiency during decompression, when carbon dioxide from the soil could enter the tunnel atmosphere. This testimony indicates that an adequate supply of fresh air from an external source is particularly important following decompression.
 The stated measurement, dimension or time is approximate.
1a See fn. 1.
1b See fn. 1.
1c See fn. 1.
1d See fn. 1.
1e See fn. 1.
1f See fn. 1.
2 devoid of air.
3 29 CFR 1926.804 contains the following definitions:
(e) ‘high air’—air pressure used to supply power to pneumatic tools and devices.
(f) ‘low air’—air supplied to pressurize working chambers and locks.
1g See fn. 1.
4 29 U.S.C. § 666(j).
1g See fn. 1.
Maximum amount of air possible to pass through a 3/8 inch orifice (1/2 of 3) 284 CFM
Adjustment factor for sharp-edged orifice .65
Maximum amount, net 184.6 CFM
6 Complainant has supplied a dictionary definition of ‘fresh air’ as ‘uncontaminated outdoor air.’ It appears likely that as so defined, fresh air is nonexistent.
4a See fn. 4.
7 The tunnel was excavated to 102 inches, with a finished diameter of 72 inches.