ISSUE DATE: 4/01/2011

PROGRAM INFORMATION BULLETIN NO. P11-22

FROM: KEVIN G. STRICKLIN

 Administrator for

 Coal Mine Safety and Health

 LINDA F. ZEILER

 Acting Director of Technical Support

SUBJECT: Reissue of P08-15 - Fire Suppression Systems Used to Protect

 Battery Charging Stations and Other Unattended Electrically

 Powered Equipment in Underground Coal Mines

Who needs this information?

This Program Information Bulletin (PIB) applies to underground coal mine operators, 

fire suppression manufacturers, miners' representatives, independent contractors, and 

Coal Mine Safety and Health (CMS&H) enforcement personnel.

What is the purpose of this PIB?

This PIB informs the mining industry and CMS&H enforcement personnel of some of 

the regulations governing the use of fire suppression systems used for protection of

unattended battery charging stations and other unattended electrically powered 

equipment used underground.

What is the background for this PIB?

As a result of the fatalities at Aracoma Alma Mine #1, the Mine Safety and Health 

Administration (MSHA) is reviewing the fire protection regulations and is evaluating 

the fire suppression systems used in underground coal mines to determine their 

compliance with existing regulations. As a result of such evaluation, MSHA has 

become aware of inconsistency among the various coal districts in the enforcement of 

existing regulations governing the use of fire suppression devices used to protect 

unattended electrically powered equipment in underground coal mines. In conducting 

this review, the agency has also become aware that some systems, such as the ECKO 

341/ADX1141, are not in compliance with the regulations, as explained below.
2

The ECKO 341 and ADX 1141 are dry chemical systems equipped with individual

pressurized dry chemical containers or canisters filled with a dry chemical agent. Each 

canister is equipped with a dual purpose pressure switch and a heat sensitive fusible 

link spray nozzle located at the base of each unit. Each canister usually contains 16 

pounds of monoammonium phosphate based dry chemical. Upon detection of a 

predetermined rise in heat, the fusible link would melt (open) and allow the chemical in 

the container to be discharged into the intended protected area. Simultaneously, the 

pressure switch should detect the decrease in container pressure and cause the power to 

the equipment to be de-energized. The switch is also designed to activate an audible 

and visual alarm. The system actuates automatically and does not have manual 

actuation capability.

Other fire suppression systems used to protect unattended electrically powered 

equipment in underground coal mines may also not be in compliance with existing 

regulations. These systems must also be checked to determine if they meet the 

regulatory requirements such as those discussed in this PIB.

Information

The 30 C.F.R. § 75.340 requires that unattended underground transformer stations, 

battery charging stations, substations, rectifiers, and water pumps not housed in 

noncombustible structures or areas be equipped with a fire suppression system that 

meets the requirements of §§ 75.1107-3 through 75.1107-16. In addition, § 75.1107-

1(a)(2) requires that within 24 production shift hours after being installed, unattended 

electrically powered equipment used underground is to be equipped with a fire 

suppression device that meets the applicable requirements of §§ 75.1107-3 through 

75.1107-16 (certain exceptions apply) . 

“Noncombustible structure or area” is defined in § 75.301, which describes the 

applicable fire test. Most battery charging stations are not housed in such structures or 

areas, although MSHA does classify them as “noncombustible” if they are enclosed in 

substantial metal housings, are used to charge batteries that are also enclosed in 

substantial metal housings, and remain on the machine during charging. MSHA 

Program Policy Manual (PPM), Vol. V § 75.340. Therefore, most of these stations must 

be protected by a fire suppression system that meets the requirements of §§ 75.1107-3 

through 75.1107-16. 

For the purposes of the provisions of §§ 75.1107 through 75.1107-16, § 75.1107-1(c) 

defines “attended” underground equipment as follows:

• Any machine or device regularly operated by a miner assigned to operate such 

machine or device; or

• Any machine or device which is mounted in the direct line of sight of a jobsite 

which is located within 500 feet of such machine or device and which jobsite is
3

regularly occupied by a miner assigned to perform job duties at such jobsite 

during each production shift. “Unattended” equipment is therefore, equipment 

which does not meet one of these two situations. In addition, § 75.1107-1(d) 

requires that machines and devices described under § 75.1107-1(c) (“attended”)

be inspected for fire and the input power de-energized when workmen leave the 

area for more than 30 minutes.

Below are a few of the requirements for fire suppression systems protecting such 

unattended underground electric equipment:

Section 75.1107-3(a) requires components of fire suppression devices required to be 

installed in accordance with the provisions of § 75.1107-1 to be approved by the 

Secretary or, where appropriate, be listed as approved by a nationally recognized 

agency approved by the Secretary (Underwriters’ Laboratories, Inc., or Factory Mutual 

Research Corporation); see PPM Vol. V § 75.1107-3. It should be noted that MSHA has 

not approved any fire suppression devices (see Technical Compliance Evaluation of 

ECKO 341 Dry Chemical Fire Suppression Devices report issued May, 2008).

Section 75.1107-4(a) requires that fire suppression devices installed on unattended 

underground equipment must comply with the following:

• One or more point-type sensors or equivalent shall be installed for each 50 

square feet of top surface area, or fraction thereof, of the protected equipment;

• Each sensor shall be designed to activate the fire suppression system and 

disconnect the electrical power source to the equipment protected; and 

• At least one manual actuator shall operate the system, except where sprinklers 

are used. Where sprinklers are used, provision is to be made for the manual 

application of water to the protected equipment in lieu of manual actuator.

Section 75.1107-4(b) requires that sensors, where practicable, be installed in accordance 

with the recommendations of National Fire Code No. 72A (NFPA No. 72A-1967). The 

MSHA PPM under § 75.1107-4 specifies that “[s]ensors, as addressed in paragraph

(b) shall, where practicable, be installed above the area of the equipment that is likely to 

produce the most heat in the event of a fire.” For example; if the UL listing requires that 

the outlet of the nozzle (and sensor) must be within a distance between 4.5 and 7.5 feet 

above the hazard, the fire suppression system must be installed accordingly.

Section 1107-4(c) requires that on unattended equipment the fire suppression device is 

to operate independently of the power to the main motor (or equivalent) so it will 

remain operative if the circuit breaker (or other protective device) actuates. The PPM 

under § 75.1107-4(c) requires that “where the fire-suppression system is dependent on 

the mine power supply, the power supply to the fire suppression system must originate 

on the line side of the overload protection of the equipment being protected.” PPM

Vol. V § 75.1107-4. This can be accomplished by a backup battery power source.
4

Section 1107-4(e) requires the sensor system to have a means to determine its operative 

condition. This includes indicators for (a) normal operating status, (b) “fire detected” 

condition, and (c) conditions that can render a fire suppression sensor system 

inoperative. Inoperative conditions are also referred to as malfunction conditions. 

Examples of inoperative conditions include loss of main or backup power to the system

control unit, discontinuity (wiring break) in any sensor circuit or actuation circuit, and 

short circuit in any sensor circuit or actuation circuit. For example, on battery charging 

stations, when the sensor actuates as a result of a fire or a short circuit, the control 

circuit activates an audible and visual alarm. This indicates a fire or a malfunction of 

the sensor circuit. 

Section 1107-6(a)(1) requires fire suppression devices to be adequate in size and 

capacity to extinguish potential fires in or on the equipment protected. Fire hazards in 

underground coal mines are typically Class A combustibles. Therefore, fire suppression 

devices must be adequate in size and capacity to extinguish Class A fires and those

systems approved for Class B fires only do not meet this provision.

Section 1107-9(a) requires dry chemical fire extinguishing systems used on 

underground equipment to be of the multipurpose powder-type. According to the 

NFPA Handbook (19th edition), “[m]ultipurpose dry chemical refers to powders that are 

listed for use on Class A, B, or C fires.” However, utilizing an ABC powder does not 

mean the fire suppression system utilizing such powder is rated for Class A, B and C

fires.

Section 75.1107-13 provides that, notwithstanding the provisions of §§ 75.1107-1 

through 75.1107-12, the District Manager may approve any other fire suppression 

system which provides substantially equivalent protection as would be achieved 

through compliance with those sections provided that no such system shall be 

approved which does not meet the criteria stated in §§ 75.1107-13(a) through (m). For 

example, § 75.1107-13(f) requires that an automatic and a manual actuator be provided 

for fire suppression devices on unattended equipment. Therefore, any fire suppression 

system protecting unattended equipment that is not equipped with a manual actuator 

does not meet the applicable requirements and also could not be approved by a District 

Manager under § 75.1107-13. Because the ECKO 341/ADX1141 fire suppression system 

does not have a manual actuator, it does not meet the applicable requirements and also 

could not be approved by a District Manager.

Section 75.1107-16(b) requires fire suppression systems to be maintained and tested in 

accordance with the requirements specified in the appropriate National Fire Code listed 

therein. Item 1412 of NFPA 17 (NFPA No. 17-1969) requires that automatic dry 

chemical extinguishing systems “have a readily accessible means for manual actuation.”
5

What is MSHA's authority for this PIB?

The Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. § 801 et seq., 

and 30 C.F.R. §§ 75.340, 75.1100, and 75.1107.

Where is this PIB on the Internet?

This information may be viewed on the World Wide Web by accessing MSHA's home 

page (www.msha.gov), then choosing "Compliance Info" and "Program Information 

Bulletins." 

Who are the MSHA contact persons for this PIB?

Coal Mine Safety and Health, Safety Division

Charles Carpenter, (202) 693-9532

E-mail: carpenter.charles@dol.gov

Office of Technical Support

Michael Hockenberry, (304) 547-2075

E-mail: hockenberry.michael@dol.gov

Derrick Tjernlund, (304) 547-2301

E-mail: tjernlund.derrick@dol.gov

Who will receive this PIB?

MSHA PPM Holders

Underground Bituminous Coal Operators

Miners' Representatives

Independent Contractors