1
25-069
Powered Air Purifying Respirator (PAPR): An Efficient Personal
Protective Device Against Respirable Dust in Underground
Mining Operations
Luis Sanchez Gonzalez
The Pennsylvania State University,
University Park, PA
Ashish Ranjan Kumar
The Pennsylvania State University,
University Park, PA
Barbara Arnold
The Pennsylvania State University,
University Park, PA
ABSTRACT
The health and safety of miners is critical in the industry.
Prolonged exposure to dust-laden air results in irreversible
ailments like pneumoconiosis that have a severe impact
on their lives. Operations use various personal protective
devices (PPEs) to alleviate their exposure to respirable
dust. Powered Air Purifying Respirator (PAPR) is one such
device that uses high- efficiency filters and positive pressure
masks to shield miners from airborne contaminants. Used
in the medical and other industries, these respirators effi-
ciently protected healthcare workers during the COVID-
19 pandemic. Recently, the mining industry has shown a
growing interest in adopting this PPE to ensure safe work-
ing conditions for the miners. We present an introduction
to the PAPRs and discuss their dust capture efficacy in this
manuscript.
INTRODUCTION
Dust exposure is a major concern in mining operations.
These particles are generated in every unit operation. This
includes extraction, material handling, crushing, and grind-
ing [1–3]. In underground coal mining, exposure to respi-
rable dust particles can lead to serious health hazards such
as coal workers’ pneumoconiosis (CWP), also known as
‘Black Lung’. This disease in its most advanced stage leads
to fatalities. Data shows an increasing trend in the cases of
CWP during the last decade [4]. A survey conducted in
1968 showed that coal miners were exposed to high con-
centrations of dust during operations (Table 1) leading to
detrimental health impacts. Later in 1969, the Coal Mine
Health and Safety Act established a limit of 2.0 mg/m3
for respirable coal dust. In 2014, the limit was lowered to
1.5 mg/m3 [4]. In April 2024, the silica PEL was updated
by MSHA, lowering it to 50 µg/m3 time-weighted average
(TWA) [5].
Lowering the workers’ dust exposure is the key step in
the alleviation of CWP. There are multiple mechanisms to
prevent workers from breathing respirable dust. Figure 1
ranks mechanisms by effectiveness, with the most effec-
tive on the right and the least effective on the left-hand
side. The best way to prevent exposure is to eliminate the
source. If this is not possible, substitution with an alternate
method can prevent the workers’ exposure. The third mech-
anism is implementing engineering controls to lower emis-
sions. Administrative control refers to implementing good
practices and procedures that minimize exposure. Finally,
Table 1. Operators’ exposure to coal dust [6]
Occupation /Operator
Mean Exposure
(mg/m3)
Continuous miner operator 4.08
Continuous miner helper 3.47
Roof bolter operator 2.46
Cutting machine operator 3.69
Loading machine operator 3.75
Figure 1. Workers’ protection mechanisms [7]
25-069
Powered Air Purifying Respirator (PAPR): An Efficient Personal
Protective Device Against Respirable Dust in Underground
Mining Operations
Luis Sanchez Gonzalez
The Pennsylvania State University,
University Park, PA
Ashish Ranjan Kumar
The Pennsylvania State University,
University Park, PA
Barbara Arnold
The Pennsylvania State University,
University Park, PA
ABSTRACT
The health and safety of miners is critical in the industry.
Prolonged exposure to dust-laden air results in irreversible
ailments like pneumoconiosis that have a severe impact
on their lives. Operations use various personal protective
devices (PPEs) to alleviate their exposure to respirable
dust. Powered Air Purifying Respirator (PAPR) is one such
device that uses high- efficiency filters and positive pressure
masks to shield miners from airborne contaminants. Used
in the medical and other industries, these respirators effi-
ciently protected healthcare workers during the COVID-
19 pandemic. Recently, the mining industry has shown a
growing interest in adopting this PPE to ensure safe work-
ing conditions for the miners. We present an introduction
to the PAPRs and discuss their dust capture efficacy in this
manuscript.
INTRODUCTION
Dust exposure is a major concern in mining operations.
These particles are generated in every unit operation. This
includes extraction, material handling, crushing, and grind-
ing [1–3]. In underground coal mining, exposure to respi-
rable dust particles can lead to serious health hazards such
as coal workers’ pneumoconiosis (CWP), also known as
‘Black Lung’. This disease in its most advanced stage leads
to fatalities. Data shows an increasing trend in the cases of
CWP during the last decade [4]. A survey conducted in
1968 showed that coal miners were exposed to high con-
centrations of dust during operations (Table 1) leading to
detrimental health impacts. Later in 1969, the Coal Mine
Health and Safety Act established a limit of 2.0 mg/m3
for respirable coal dust. In 2014, the limit was lowered to
1.5 mg/m3 [4]. In April 2024, the silica PEL was updated
by MSHA, lowering it to 50 µg/m3 time-weighted average
(TWA) [5].
Lowering the workers’ dust exposure is the key step in
the alleviation of CWP. There are multiple mechanisms to
prevent workers from breathing respirable dust. Figure 1
ranks mechanisms by effectiveness, with the most effec-
tive on the right and the least effective on the left-hand
side. The best way to prevent exposure is to eliminate the
source. If this is not possible, substitution with an alternate
method can prevent the workers’ exposure. The third mech-
anism is implementing engineering controls to lower emis-
sions. Administrative control refers to implementing good
practices and procedures that minimize exposure. Finally,
Table 1. Operators’ exposure to coal dust [6]
Occupation /Operator
Mean Exposure
(mg/m3)
Continuous miner operator 4.08
Continuous miner helper 3.47
Roof bolter operator 2.46
Cutting machine operator 3.69
Loading machine operator 3.75
Figure 1. Workers’ protection mechanisms [7]