SNEED, Circuit Judge:
Phelps Dodge Corporation (petitioner) petitions for review of a final order of the Federal Mine Safety and Health Review Commission (MSHRC). Our jurisdiction is under 30 U.S.C. § 816(a)(1). The sole question for decision is whether a mine safety regulation, 30 C.F.R. § 55.12-16, was properly applied to justify the issuance of a citation and levy of a fine. The regulation, in this particular factual setting, did not give fair warning that it was applicable to petitioner’s conduct. Accordingly, we reverse.
I.
FACTS
Petitioner operates an open-pit copper mine, a mill and a smelter at Morenci, Arizona. The copper production process commences with the loading of stones and rocks, which contain copper ore, into trucks for transportation to the mill. There, the ore is dumped into a chute which carries it downward into the mill. It then falls onto the “panfeeder,” an electrically powered steel conveyor belt which carries the ore forward for smelting. The panfeeder is an electrically powered mechanical device; the chute is not.
[1191]*1191The rocks and stones occasionally clog the drop chute, necessitating the use of manual labor to clear the path to the panfeeder. This might occur as often as twice a week or as infrequently as once a month. Sometimes the workers can clear up a jam with one or two thrusts of a crowbar. However, the panfeeder is sometimes used to assist in this process. The panfeeder is turned on, moved a little way and then turned off, thus moving loose stones out of the way and facilitating access to the rocks remaining lodged in the chute. The panfeeder is operated by a button in a nearby control panel which must be pushed with the finger into a sleeve. When the panfeeder is used to help clear ore jams, it is shut off at this control panel.
Occasionally, the panfeeder is inspected or requires maintenance or repair. In those instances, a special process is used, under which the panfeeder, in addition to being turned off at the control box as when jams are cleared, is locked out. This is done by locking out a switch located in a distant control room. To accomplish this, an electrician goes to the control room and manually locks out the power switch controlling the panfeeder. He also places warning tags on the switch to provide notice to anyone in the area that the equipment is intended to be locked out.
On June 6, 1979, a MSHA inspector walked into the panfeeder area at a time when ore was lodged in the drop chute. The' crusher operator and the foreman were dislodging the ore in the chute and were standing on the panfeeder at the time. The panfeeder was turned off at the control box; however, it was not locked out. The crusher operator and the foreman were the only personnel in the area. The MSHA inspector issued an Order predicated upon the failure to lock-out the panfeeder under 30 C.F.R. § 55.12-16.1
Petitioner contested the penalty assessed by MSHA. Thereafter, the Secretary of Labor (Secretary) filed a proposal for assessment of civil penalty with the Federal Mine Safety and Health Review Commission in accordance with Section 105(d) of the Mine Act, 30 U.S.C. § 815(d). A hearing was held on January 20, 1981, before an Administrative Law Judge (ALJ) who concluded that a violation of 30 C.F.R. 55.12-16 had occurred.
The ALJ found that removal of rocks from the chute was “mechanical work” within the meaning of 30 C.F.R. 55.12-16. He then addressed the issue whether such “mechanical work” was done on “electrically powered equipment.” He concluded that it was. While he recognized that the chute was not electrically powered, the fact that the panfeeder was supplied the “electrically powered equipment” requirement. The ALJ found that the movement of rock down the chute and onto the panfeeder was one integral process involving “electrically powered equipment,” viz., the panfeeder. He concluded that although the work being done pertained to the chute, the operation of the panfeeder and the chute was indivisible. In this way, work on the chute was equivalent to work on the panfeeder which required its locking out under 30 C.F.R. § 55.12-16.
On March 24, 1981, Phelps Dodge’s petition for discretionary review with the Commission pursuant to Section 113(d)(2)(A) of the Mine Act, 30 U.S.C. § 823(d)(2)(A), was denied. Phelps Dodge then filed a petition for review with this court pursuant to Section 106(a)(1) of the Mine Act, 30 U.S.C. § 816(a)(1).
II.
MEANING OF THE REGULATION
Phelps Dodge has not challenged the facial validity of the MSHA regulation, [1192]*119230 C.F.R. § 55.12-16, but, rather, whether MSHA properly applied the regulation in this specific factual setting. The Secretary 2 correctly notes that an agency’s interpretation of its own regulation is entitled to great deference. Udall v. Tallman, 380 U.S. 1, 16, 85 S.Ct. 792, 801, 13 L.Ed.2d 616 (1965); Magma Copper Co. v. Secretary of Labor, 645 F.2d 694, 696 (9th Cir.), cert. denied, 454 U.S. 940, 102 S.Ct. 475, 70 L.Ed.2d 247 (1981). However, the application of a regulation in a particular situation may be challenged on the ground that it does not give fair warning that the allegedly violative conduct was prohibited. See Daily v. Bond, 623 F.2d 624, 626-627 (9th Cir. 1980) (per curiam). In all events, we are required to make a careful inquiry to determine the reasonableness of the administrative interpretation and application of the regulation. Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 416, 91 S.Ct. 814, 823, 28 L.Ed.2d 136 (1971); Sierra Pacific Power Co. v. U. S. Environmental Protection Agency, 647 F.2d 60, 66 (9th Cir. 1981). Finally, our standard of review is whether the agency’s determination is arbitrary, capricious or an abuse of discretion. 5 U.S.C. § 706(2)(A).
Free access — add to your briefcase to read the full text and ask questions with AI
SNEED, Circuit Judge:
Phelps Dodge Corporation (petitioner) petitions for review of a final order of the Federal Mine Safety and Health Review Commission (MSHRC). Our jurisdiction is under 30 U.S.C. § 816(a)(1). The sole question for decision is whether a mine safety regulation, 30 C.F.R. § 55.12-16, was properly applied to justify the issuance of a citation and levy of a fine. The regulation, in this particular factual setting, did not give fair warning that it was applicable to petitioner’s conduct. Accordingly, we reverse.
I.
FACTS
Petitioner operates an open-pit copper mine, a mill and a smelter at Morenci, Arizona. The copper production process commences with the loading of stones and rocks, which contain copper ore, into trucks for transportation to the mill. There, the ore is dumped into a chute which carries it downward into the mill. It then falls onto the “panfeeder,” an electrically powered steel conveyor belt which carries the ore forward for smelting. The panfeeder is an electrically powered mechanical device; the chute is not.
[1191]*1191The rocks and stones occasionally clog the drop chute, necessitating the use of manual labor to clear the path to the panfeeder. This might occur as often as twice a week or as infrequently as once a month. Sometimes the workers can clear up a jam with one or two thrusts of a crowbar. However, the panfeeder is sometimes used to assist in this process. The panfeeder is turned on, moved a little way and then turned off, thus moving loose stones out of the way and facilitating access to the rocks remaining lodged in the chute. The panfeeder is operated by a button in a nearby control panel which must be pushed with the finger into a sleeve. When the panfeeder is used to help clear ore jams, it is shut off at this control panel.
Occasionally, the panfeeder is inspected or requires maintenance or repair. In those instances, a special process is used, under which the panfeeder, in addition to being turned off at the control box as when jams are cleared, is locked out. This is done by locking out a switch located in a distant control room. To accomplish this, an electrician goes to the control room and manually locks out the power switch controlling the panfeeder. He also places warning tags on the switch to provide notice to anyone in the area that the equipment is intended to be locked out.
On June 6, 1979, a MSHA inspector walked into the panfeeder area at a time when ore was lodged in the drop chute. The' crusher operator and the foreman were dislodging the ore in the chute and were standing on the panfeeder at the time. The panfeeder was turned off at the control box; however, it was not locked out. The crusher operator and the foreman were the only personnel in the area. The MSHA inspector issued an Order predicated upon the failure to lock-out the panfeeder under 30 C.F.R. § 55.12-16.1
Petitioner contested the penalty assessed by MSHA. Thereafter, the Secretary of Labor (Secretary) filed a proposal for assessment of civil penalty with the Federal Mine Safety and Health Review Commission in accordance with Section 105(d) of the Mine Act, 30 U.S.C. § 815(d). A hearing was held on January 20, 1981, before an Administrative Law Judge (ALJ) who concluded that a violation of 30 C.F.R. 55.12-16 had occurred.
The ALJ found that removal of rocks from the chute was “mechanical work” within the meaning of 30 C.F.R. 55.12-16. He then addressed the issue whether such “mechanical work” was done on “electrically powered equipment.” He concluded that it was. While he recognized that the chute was not electrically powered, the fact that the panfeeder was supplied the “electrically powered equipment” requirement. The ALJ found that the movement of rock down the chute and onto the panfeeder was one integral process involving “electrically powered equipment,” viz., the panfeeder. He concluded that although the work being done pertained to the chute, the operation of the panfeeder and the chute was indivisible. In this way, work on the chute was equivalent to work on the panfeeder which required its locking out under 30 C.F.R. § 55.12-16.
On March 24, 1981, Phelps Dodge’s petition for discretionary review with the Commission pursuant to Section 113(d)(2)(A) of the Mine Act, 30 U.S.C. § 823(d)(2)(A), was denied. Phelps Dodge then filed a petition for review with this court pursuant to Section 106(a)(1) of the Mine Act, 30 U.S.C. § 816(a)(1).
II.
MEANING OF THE REGULATION
Phelps Dodge has not challenged the facial validity of the MSHA regulation, [1192]*119230 C.F.R. § 55.12-16, but, rather, whether MSHA properly applied the regulation in this specific factual setting. The Secretary 2 correctly notes that an agency’s interpretation of its own regulation is entitled to great deference. Udall v. Tallman, 380 U.S. 1, 16, 85 S.Ct. 792, 801, 13 L.Ed.2d 616 (1965); Magma Copper Co. v. Secretary of Labor, 645 F.2d 694, 696 (9th Cir.), cert. denied, 454 U.S. 940, 102 S.Ct. 475, 70 L.Ed.2d 247 (1981). However, the application of a regulation in a particular situation may be challenged on the ground that it does not give fair warning that the allegedly violative conduct was prohibited. See Daily v. Bond, 623 F.2d 624, 626-627 (9th Cir. 1980) (per curiam). In all events, we are required to make a careful inquiry to determine the reasonableness of the administrative interpretation and application of the regulation. Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 416, 91 S.Ct. 814, 823, 28 L.Ed.2d 136 (1971); Sierra Pacific Power Co. v. U. S. Environmental Protection Agency, 647 F.2d 60, 66 (9th Cir. 1981). Finally, our standard of review is whether the agency’s determination is arbitrary, capricious or an abuse of discretion. 5 U.S.C. § 706(2)(A).
Phelps Dodge contends that the regulation has been incorrectly applied in this case because its basic purpose, fairly read, is to protect workers from the hazards of electrical shock, not such hazards as may attend removal of rocks from the chute. On the other hand, the Secretary urges that the regulation does apply. He relies heavily on the ALJ’s findings and reasoning. And he asserts that the relevant legislative and regulatory histories establish that the regulation was intended to be applied in this fact situation.
Turning to the plain language and meaning of 30 C.F.R. § 55.12-16 and related regulations, we note that section 55.12-16 has been placed under the heading “Electricity.” It is sandwiched between regulations whose purpose is manifestly to prevent the accidental electrocution of mine workers. The immediately preceding regulations, to illustrate, set out procedures to ensure that workers will not be exposed to energized wires, cables or high potential electrical conductors. 30 C.F.R. §§ 55.12-10 through 55.-12-14.3 The immediately antecedent regulation, 30 C.F.R. § 55.12-17, requires that power circuits be deener-gized before work is done on them. Other regulations in 30 C.F.R. § 55.12 also are directed to abatement of the danger of electrical shock. They simply do not address the hazards arising from the accidental movement of electrical equipment while mechanical work is being done thereon.4
Prevention of electrical shock also emerges from the language of section 55.-12-16 itself. It requires that “[electrically powered equipment shall be deenergized before mechanical work is done on such equipment.” 30 C.F.R. § 55.12-16 (emphasis added). According to Webster’s Third International Dictionary of the English Language 589 (1971) (unabridged), “deenergize” means “to check the flow of current through an electric device.” This mandate to cut off the flow of electric current, particularly when read in conjunction with the other regulations in 30 C.F.R. § 55.12, strongly suggests that protection from electric shock is the regulation’s main concern.
This conclusion is supported by a related regulation, 30 C.F.R. § 55.14-29. Under the heading “Use of Equipment,” this regulation provides that: [1193]*119330 C.F.R. § 55.14-29 (emphasis added). Thus, when the intent is to protect against the danger of machinery motion, the regulation requires that the machinery be “blocked against motion,” not “deener-gized.”
[1192]*1192Repairs or maintenance shall not be performed on machinery until the power is off and the machinery is blocked against motion, except where machinery motion is necessary to make adjustments.
[1193]*1193The relevant legislative and regulatory histories, however, provide little comfort either to the petitioner or the MSHA.5 These merely establish that the general purpose of all regulations promulgated under the enabling statute was to promote safe working conditions for miners.6
We conclude that it was an abuse of discretion to apply section 55.12-16 to the facts of this case. The regulation inadequately expresses an intention to reach the activities to which MSHA applied it. Therefore, we join in the observation: “If a violation of a regulation subjects private parties to criminal or civil sanctions, a regulation cannot be construed to mean what an agency intended but did not adequately express.” (citations omitted). Diamond Roofing Co., Inc. v. Occupational Safety and Health Review Commission, 528 F.2d 645, 649 (5th Cir. 1976).
Accordingly, the regulation cannot serve as the basis for issuance of the citation or for the levy of the fine.
REVERSED.