Skip to content

77.1710 Protective Clothing; Requirements
This Section does not require operators of service vehicles making visits to surface mines or surface work areas of underground mines to wear protective clothing.

Paragraph (c) of this Section requires that miners wear gloves whenever they troubleshoot or test energized electric power circuits or electric equipment. Work gloves in good condition are acceptable for troubleshooting or testing energized low- and medium-voltage circuits or equipment. High-voltage gloves, rated at least for the voltage of the circuit, are required for troubleshooting or testing of energized high-voltage circuits or in compartments containing exposed energized high-voltage circuits.

The purpose of paragraph (d) is to provide substantial protection for the head from falling objects and to protect miners against electrical shock or burn. Hard hats are required to be suitable for these purposes and, if they are painted, the paint base must be nonmetallic.

Hard hats or caps that meet or exceed the applicable specification of the American National Standards Institute (ANSI) provide appropriate head protection and comply with these requirements. The applicable standards are ANSI's "Safety Requirements for Industrial Head Protection," Z89.1, and "Safety Requirements for Industrial Protective Helmets for Electrical Workers, Class B," Z89.2.

Hard hats or caps that do not meet or exceed the applicable ANSI or equivalent standards should not be used. Plastic "baseball-type" caps and thin plastic hats do not have adequate suspension systems and are not constructed of sufficiently substantial material to afford the necessary protection from impact and penetration of falling objects. Hats or caps constructed of metal materials create an additional hazard of electrical shock or burn because they are conductive.

Paragraph (g) of this Section requires that safety belts and lines shall be worn at all times by all miners working in positions where there is a danger of falling, except where safety belts and lines may present a greater hazard or are impractical. In those cases, the standard requires that alternative precautions be taken to provide the miners with an equal or greater degree of protection. Substantial scaffolding with adequate guardrails or safety nets are acceptable alternatives. The objective of this policy is to insure that miners working where there is a danger of falling are always protected.

77.1711 Smoking Prohibition
This Section prohibits smoking or open flame where such practice may cause a fire or explosion. Section 77.1702 requires that areas be posted with warning signs where fire or explosion hazards exist.

77.1712 Reopening Mines; Notification; Inspection Prior to Mining
Failure of the operator to notify MSHA of the reopening of the mine before operations begin is a violation of this Section. Failure to have all the plans, programs and systems submitted during this inspection is not necessarily a violation. During a reopening inspection required by Section 77.1712, the inspector should ascertain that the operator is fully informed and aware of the applicable plans, programs, and systems required by Part 77.

77.1713 Daily Inspection of Surface Coal Mines; Certified Persons; Reports of Inspection

MSHA will continue to require that daily on-shift examinations be made in accordance with this Section at active working areas of surface mines, active surface installations at these mines, and preparation plants not associated with underground coal mines. MSHA will not require daily on-shift examinations of the surface work areas of underground coal mines.

Subpart S .... Trolley Wires and Trolley Feeder Wires

77.1800 Cutout Switches
It is the intent of this Section to require that cutout switches be installed in both trolley wires and parallel trolley feeder wires at the same point. Where it is necessary to use a cutout switch in each circuit, they shall be installed reasonably close to facilitate the opening of both circuits. The practice of using a jumper to bridge a removed section of trolley wire as a means of disconnecting power shall not be accepted.

77.1802 Insulation of Trolley Wires, Trolley Feeder Wires; and Bare Signal Wires; Guarding of Trolley Wires and Trolley Feeder Wires
It is the intent of this Section that guarding shall be done with wood, plastic or other substantial nonconductive material, and be firmly secured. The mine inspector shall require additional guarding of trolley wires at all locations where a potential shock hazard exists.

Subpart T .... Slope and Shaft Sinking

In addition to the requirements of Subpart T, all applicable requirements of Part 77 shall apply to slope and shaft sinking operations unless specifically excepted by Subpart T.

77.1900 Slopes and Shafts; Approval of Plans
When inspecting shaft and slope sinking operations, Part 77 will apply for inspection purposes until such time as mining is started in the coalbed to be mined. At that time, all of the applicable provisions of Part 75 shall be met by the responsible organization that commences the mining cycle in the coalbed that is to be mined.

Excavation of a newly commenced slope or shaft progresses from the surface, through the overlying strata, to the coalbed to be mined. When an existing slope or shaft is extended that is open to the surface, excavation progresses from the existing slope or shaft bottom on down through underlying strata to the next coalbed to be mined. Part 77 standards will apply in these instances.

When excavation of a new slope or shaft reaches the coalbed to be mined, additional excavation or construction is often required before the mining cycle can commence. Frequently, horizontal excavations in the coalbed and surrounding strata must be advanced from the shaft or slope bottom to a point that permits installation or setup of mining equipment needed for the mining cycle to begin. Similarly, a skip loading pocket, a sump area, or similar vertical excavation may need to be developed above or below the coalbed before the mining cycle can begin. In order for Part 77 standards to apply, the plans for the development and construction at the coalbed level or above or below the coalbed from the slope or shaft bottom must be submitted and addressed under the approved slope or shaft construction plan.

Sufficient excavation and construction work will be permitted under the approved slope or shaft construction plan to allow installation and set up of the mining and ventilation equipment necessary to begin the mining cycle. In some cases, this excavation and construction work may include driving a connection between slopes and/or shafts. The extent of slope or shaft excavation and development work permitted under the Part 77 slope or shaft construction plan is to be kept to a minimum consistent with this policy, detailed in the approved plan, appropriate for the conditions at the mine and approved by the District Manager. After completing the work as detailed in the approved plan, application of § 77.1900 will cease, and application of Part 75 standards will commence. Part 77 standards will continue to apply to all activities on the surface.

In cases where a new slope or shaft is constructed from the surface into an existing mine or is raised from an existing mine to the surface, Part 77 standards will apply to the slope or shaft construction and to areas at the immediate slope or shaft bottom to the extent necessary to install equipment and complete construction.

Where a new slope or shaft is constructed from an underground area of an existing mine from one coalbed to another coalbed to be mined, where the slope or shaft does not directly intersect the surface, Part 75 standards will apply because the slope or shaft does not originate from the surface and will not directly intersect the surface. Construction, repair or inspection of these slopes or shafts will be covered under Part 75 standards.

In cases where construction, repairs or inspection are necessary at existing slopes or shafts that originate from the surface, Part 77 standards will be applied to the construction, repair or inspection activity. Any construction, repair, or inspection activity performed under Part 77 standards will be confined to the slope or shaft and the immediate slope or shaft bottom. Ongoing routine maintenance of the slope or shaft or routine maintenance of equipment installed in the slope or shaft would fall under Part 75 standards. An approved slope or shaft construction plan under Part 77 will not be required if Part 75 standards are complied with.

The hoist used under an approved slope or shaft construction plan is not intended for use as a permanent man hoisting installation. If the hoist used in conjunction with the slope or shaft construction, repair, or inspection does not comply with all provisions of Part 75 standards then only those persons engaged in the slope or shaft construction, repair, or inspection will be permitted to ride the hoist during these activities. It is not the intention of this policy to permit access to the mine by using a hoist approved under a slope or shaft construction plan for any other purpose except for construction, repair, or inspection activity directly related to the slope or shaft.

A slope or shaft construction plan as required under § 77.1900 shall be approved by the District Manager prior to commencing any work activity that will be addressed under the Part 77 plan.

77.1908 Hoist Installations; Use
"Crossheads," as referred to in paragraph (d), are members that engage the guides.

"Independently powered auxiliary hoists," as referred to in paragraph (f), means any safe method that can be used to remove miners from a slope or shaft quickly in the event of an emergency.

77.1908-1 Hoist Operation; Qualified Hoistman
A qualified hoistman within the meaning of this Section is an individual who meets the requirements of Section 77.105.

77.1909-1 Use of Nonpermissible Explosives and Nonpermissible Shot-Firing Units; Approval by Health and Safety District Manager
When an inspector finds nonpermissible explosives and nonpermissible shot-firing units being used, he shall check to see if a permit, as required by this Section, has been issued, and to determine if the proper safeguards were being employed.

77.1913 Fire-Resistant Wood
This Section requires that all timbers and other wood products except track crossties permanently installed in slopes and shafts shall be fire-resistant.


Subpart A .... General

90.2 Definition of Transfer
When a Part 90 miner is assigned to a job classification, work location, and regular duties, any change in the assignment of the miner constitutes a "transfer" under Part 90. For example, it is a transfer when a Part 90 miner's established assignment as a surface mechanic at a surface shop is expanded to include occasional mechanic work underground. This addition to the miner's established regular duties at the surface shop constitutes a "transfer" for purposes of Part 90.

Generally, it is not a "transfer" when a Part 90 miner assigned to a specific occupation also performs other work assignments that do not correspond exactly to his or her occupation code as long as the work assignments have been established as part of the miner's normal work duties. For example, if a Part 90 miner works as a mechanic at the surface shop and occasionally works at a nonface underground position, it is not a "transfer" when the underground mechanic work is performed because it has already been established as part of the miner's regularly scheduled work duties. However, under Section 90.2, it is a "transfer" if, at any time, a Part 90 miner is moved to or from a mechanized mining unit (MMU). Therefore, if a Part 90 miner working as a surface shop mechanic, occasionally works underground on an MMU, movement to and from the MMU is a "transfer" by regulation. A miner's normal work duties are established prior to the commencement of compliance sampling under Section 90.207(a)(1) and (a)(3).

90.3(c) Part 90 Option and Eligibility
This section requires that any Part 90 miner who is transferred to another position by the operator remains a Part 90 miner at the new position, even if the job is at a surface mine. However, the miner can exercise the Part 90 option only while employed at an underground mine. If a Part 90 miner waives Part 90 status, the option can only be re-exercised at an underground mine.

90.3(d) Exercise of Part 90 Option
Regardless of when the option was awarded, the miner is under no time limit as to when he or she must exercise the option. However, when the option is signed and dated, the miner's option must have been received by the Chief, Division of Health, Coal Mine Safety and Health, Arlington, Virginia, before the option is recognized as being exercised.

90.3(e) Re-exercising the Option
In numerous instances, miners have given up the right to work in a low dust area. This section allows the Part 90 miner or 203(b) miner under the old program to re-exercise the option, if employed at an underground mine. Re-exercise of the option means that the miner can reuse the option any time his or her status changes from active to inactive. Also, the miner must send a written request to the Chief, Division of Health, Coal Mine Safety and Health, each time the option is re-exercised.

90.3(f) Medical Information
If an operator requires medical information from a miner, the inspector shall issue a citation to the operator for a violation of Section 90.3(f).

Subpart B .... Dust Standards, Rights of Part 90 Miners

90.100 Respirable Dust Standard
The mine operator has a 20-calendar-day grace period in which to assure that a Part 90 miner is in an environment of 1.0 milligrams per cubic meter of air. If any sampling conducted after the twentieth calendar day by either MSHA or the operator shows this standard has been exceeded, the inspector shall issue a 104(a) citation for a violation of 90.100.

This section in the amended Part 90 rule supersedes the 203(b)(2) dust standard which allowed mine operators to place miners in an environment with concentrations of respirable dust that were the lowest attainable below 2.0 mg/m3 when the 1.0 mg/m3 standard was not attainable. In other words, Part 90 miners can only work where concentrations of dust are at or below 1.0 mg/m3.

90.101 Dust Standard When Quartz is Present
The 1.0 mg/m3 standard is applicable only when the amount of quartz is equal to or less than 10 percent in the Part 90 miner's environment in the active workings. Because the Part 90 miner's environment could be at any location (MMU, DWP or DA), Section 90.101 shall be cited only if the amount of quartz in the Part 90 miner's samples exceeded 10 percent and if this miner was exposed to concentrations of respirable dust that exceeded the reduced dust standard.

The maximum standard for a Part 90 miner is l.0 mg/m3 of air. Therefore, quartz must be 11.0 percent or greater to cause a reduction in the dust standard. Conversely, when a Part 90 miner is on a reduced standard and a subsequent analysis is 10.9 percent of quartz or less, do not raise the dust standard above 1.0 mg/m3 of air.

90.102(a) Transfer, Shift Protection
At some coal mines, mine employees are rotated periodically to different shifts. Under the rule the mine operator must allow the Part 90 miner to continue to work on his or her shift rotation. Exception:

90.102(b) Notifications
The letter which notifies the coal mine operator that a Part 90 miner has exercised the option is sent by certified mail, with a copy going to the District Manager. Inspection personnel can determine if the operator has met the time requirement by comparing the date the operator received this letter (from the certified mail receipt) with the date of the operator's written notice to the District Manager concerning the Part 90 miner's occupation assignment.

90.103(a) Compensation
The Part 90 miner is entitled to not less than the regular rate of pay that was being received immediately before exercising the option. If the miner was in Job 1 at $7.00 per hour when exercising the option, the operator is required to continue to pay the Part 90 miner at least $7.00 per hour.

90.103(d) Compensation, Raises
If a Part 90 miner was employed as a belt cleaner and this position received a $.30 per hour increase, the operator must give this raise to the miner.

90.103(e) Compensation, Temporary Assignment
For example, the miner was classified as belt cleaner at $7.00 per hour, but was temporarily assigned for greater than 2 months as a roof bolting machine operator. While in the roof bolting job, the miner exercised the Part 90 option. The roof bolting machine operator's regular rate of pay was $7.50 per hour when the miner exercised the option. The operator must pay this Part 90 miner at least $7.50 per hour, even if the miner is reassigned to the belt cleaner job.

Subpart C .... Sampling Procedure

90.205(c) Examinations of Sampling Devices
See policy under Section 70.205(c).

90.207 Compliance Sampling
All samples required under Part 90 must be collected while normal work duties are being performed. Section 90.2 defines "normal work duties" as "duties which the Part 90 miner performs on a routine day-to-day basis in his or her job classification at a mine." For example, a Part 90 miner, occupation code 304, surface mechanic, may be regularly scheduled to work at the surface shop and, from time to time, at other assignments in the underground mine. Because respirable dust samples must represent the mine atmosphere to which the miner is exposed, samples shall be collected during the Part 90 miner's regularly assigned duties. Therefore, if this Part 90 miner spends a significant amount of time performing other work assignments which do not correspond exactly to his or her occupation, it is appropriate to require the operator to collect samples while the Part 90 miner is working both on the surface and underground. For additional policy in relation to sampling Part 90 miners, refer to Section 70.208(c).

90.208 Bimonthly sampling
(a) Although this provision does not set forth exactly when during the bimonthly period, the required sampling should be conducted, it is to the operator's advantage to conduct sampling as early as possible during the first month of each bimonthly period because it would provide an opportunity to collect replacement samples if any sample is voided.

This section establishes the requirement for the operator to submit the required valid respirable dust samples during the established bimonthly periods. This sampling requirement is an important aspect of the monitoring program designed to ensure the Part 90 miner is provided a working environment that meets the applicable respirable dust standard. An operator with a reasonable opportunity to have collected and submitted the required valid samples during the bimonthly period who fails to do so may be cited for noncompliance. While District Managers will consider mine-specific circumstances, as a general matter MSHA would expect that operators whose identified Part 90 miner was in available status at least 50% of the bimonthly period would have had sufficient opportunity to obtain and submit the required valid respirable dust samples.

If the respirable dust standard is changed during a bimonthly period, dust samples required by this section will be processed in accordance with the policy described under 90.101.

90.209(b) Tampering With Dust Samples
See policy under Section 70.209(b).

90.209(d) Purpose of Sampling
See policy under Section 70.209(d).

90.220 Status Change Reports
See policy under Section 70.220.

Subpart D .... Respirable Dust Control Plans

90.300(a) Respirable Dust Control Plan; Filing Requirements
If the mine operator moved the Part 90 miner to another less dusty position to abate the violation, a respirable dust control plan is not required.

90.301(a) Respirable Dust Control Plan; Approval By District Manager
Section 90.301(a)(2) prohibits the approval of any dust control measures with which the operator's compliance cannot be objectively ascertained by MSHA (example: roadways will be wetted when the need arises). Each dust control measure shall be stated specifically, so if not implemented, the inspector can take appropriate enforcement action.