Guidelines for Instructional Materials 

on Refuge Chamber Setup,

 Use, and Maintenance

IC 9514

INFORMATION CIRCULAR/2009

REFUGE

CHAMBER

TRAINING

Department of Health and Human Services

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health
Guidelines for Instructional Materials on Refuge 

Chamber Setup, Use, and Maintenance

Katherine A. Klein, Ph.D. and Erica E. Hall

Department of Health and Human Services

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

Pittsburgh Research Laboratory

Pittsburgh, PA

July 2009
2

This document is in the public domain and may be freely 

copied or reprinted.

Disclaimer

The purpose of this document is to provide manufacturers and mine operators with 

guidance on the development of instructional materials for refuge chamber set up, use 

and maintenance in support of the Mine Improvement and New Emergency Response 

(MINER) Act of 2006. The recommendations made are not intended to serve as a legal 

interpretation of any regulation or standard issued by the Mine Safety and Health 

Administration or to substitute for manufacturer-supplied materials . Rather, this 

document offers suggestions to aid those responsible for instructing miners in the operation 

of refuge chambers. Mention of any company or product does not constitute endorsement 

by the National Institute for Occupational Safety and Health (NIOSH). In addition, 

citations to publications and websites external to NIOSH do not constitute NIOSH 

endorsement of the sponsoring organizations or their programs or products. Furthermore, 

NIOSH is not responsible for the content of these publications or websites. All web 

addresses referenced in this document were accessible as of the publication date. 

Ordering Information

To receive documents or other information about occupational safety and health topics, 

contact NIOSH at

Telephone: 1–800–CDC–INFO (1–800–232–4636)

TTY: 1–888–232–6348

e-mail: cdcinfo@cdc.gov

or visit the NIOSH Web site at www.cdc.gov/niosh.

For a monthly update on news at NIOSH, subscribe to NIOSH eNews by visiting 

www.cdc.gov/niosh/eNews.

DHHS (NIOSH) Publication No. 2009–XXX

July 2009

SAFER • HEALTHIER • PEOPLETM
3

Guidelines for Instructional Materials on Refuge Chamber Setup, Use, and Maintenance ...1

Introduction............................................................................................................................. 5

Best Practices for Creating Effective Refuge Chamber Manuals ........................................6

Introduction............................................................................................................................. 6

Manual Checklist ........................................................................................................ 6

Manual Content Recommendations...................................................................................... 7

Quick Start Guide................................................................................................................... 7

Gas and Atmosphere Monitoring.......................................................................................... 9

Oxygen Supply ............................................................................................................ 9

Carbon Dioxide Scrubber......................................................................................... 10

Supplies/Amenities................................................................................................................ 10

Water......................................................................................................................... 10

Food .......................................................................................................................... 10

First Aid .................................................................................................................... 10

Toilet ......................................................................................................................... 11

Lighting..................................................................................................................... 11

Communications ................................................................................................................... 11

Psychological and Physiological Health.............................................................................. 11

Psychological Health................................................................................................ 11

Physiological Concerns............................................................................................ 12

CO2 Poisoning .......................................................................................................... 12

Oxygen Deficiency .................................................................................................... 12

Oxygen Toxicity ........................................................................................................ 12

Movement inside the Chamber.................................................................................. 13

Exiting the Chamber............................................................................................................. 13

Troubleshooting Guide......................................................................................................... 13

Characteristics of a Good Manual....................................................................................... 14

Format and Style Recommendations ........................................................................ 14

Graphic Recommendations....................................................................................... 15

Other Considerations................................................................................................ 15

Recommendations for Items to Include In a Refuge Chamber................................................16

Introduction........................................................................................................................... 16

Items to Include in a Refuge Chamber ............................................................................... 16

First Aid................................................................................................................................. 16

Lighting.................................................................................................................................. 17

Sanitation and Cleaning Supplies........................................................................................ 18

Items to Help Pass the Time................................................................................................. 18

Repair Materials and Tools.................................................................................................. 18
4

Additional Supplies............................................................................................................... 19

Placards.................................................................................................................................. 19

Outside the Refuge Chamber.................................................................................... 19

Inside the Refuge Chamber....................................................................................... 19

Lithium Hydroxide Curtains—Deployment Schedule............................................... 20

Soda Lime Cartridge Change-out Schedule ............................................................. 20

Oxygen Flow Chart................................................................................................... 20

Photos and Graphics................................................................................................. 20

Best Practices for Manuals for Setting Up, Inspecting, and Moving a Refuge Chamber......21

Introduction........................................................................................................................... 21

Preparing for a Refuge Chamber........................................................................................ 21

Selecting a Site.......................................................................................................... 21

The Setup................................................................................................................... 21

Maintenance and Inspections............................................................................................... 22

Inspections ................................................................................................................ 22

Tamper-Proof Seals.................................................................................................. 23

Gauges ...................................................................................................................... 23

Mine Phone Connections.......................................................................................... 23

Expiration Dates....................................................................................................... 23

Parts and Accessories............................................................................................... 24

Moving a Refuge Chamber .................................................................................................. 24

Preparation............................................................................................................... 24

Securing to Transport Vehicle .................................................................................. 24

Damage Assessments................................................................................................ 24

References.....................................................................................................................................25

Appendix: Task Analysis.............................................................................................................27
5

Introduction

Refuge chambers may potentially save the lives of miners during a mine emergency. For 

this reason, it is crucial that miners know how to operate them. Unfortunately, because 

refuge chambers provide so many services, they can be very complicated and difficult to 

operate. Therefore, NIOSH has created this document with suggestions for developing 

manuals and educational materials. 

A multidisciplinary team comprised of NIOSH engineers, sociologists, psychologists, 

health communication professionals, and geologists developed the recommendations

contained in this document. These recommendations are based on an evaluation of

manufacturers’ instruction manuals from both the U.S. and globally, interviews with over 

20 mining and safety experts, and an extensive literature review. This research, focused 

on the best practices for refuge chambers, led to the formulation of this document. It is 

intended to offer suggestions to manufacturers and mine operators on how to create 

effective and easy-to-understand training manuals for miners as well as tips to create the 

most comfortable and usable refuge chambers. It should be noted that these 

recommendations are not meant to substitute for manufacturer-supplied materials but 

rather to be used in conjunction with manufacturer’s materials. Manufacturers should 

always be consulted for up-to-date information about their chamber.

Although different states and different mines refer to underground refuges by different 

names, this guide will simply refer to underground refuges nearest to the face as refuge 

chambers, whether inflatable from a skid or constructed from steel. Other popular terms 

for refuge chambers are rescue chambers, rescue shelters, and refuge shelters. Refuges 

that are nearer to the shaft, whether a prefabricated refuge chamber or one built into a 

crosscut, will be referred to as outby refuges because of their location in the mine. Outby 

refuges can be permanent, semipermanent, or portable and are usually located at every 

other SCSR cache. Outby refuges are sometimes called hardened rooms, outby shelters, 

and in-place shelters. When discussing outby refuges and refuge chambers collectively, 

this guide will refer to them as underground refuges. Other terms for underground refuges 

include refuge alternatives, locations of safety, and safe havens. 

This document is designed to be read either cover to cover or by specific section. It is 

recommended that on first read, this guide be read cover to cover. In subsequent readings, 

manufacturers and mine operators may find it easier to use the table of contents page to 

locate specific information on parts of the refuge chamber. 
6

Best Practices for Creating Effective Refuge Chamber 

Manuals 

Introduction

This section is primarily intended for refuge chamber manufacturers; however, mine 

operators may use this section to augment the materials supplied by manufacturers.

Instruction on the operation of a refuge chamber can be complicated. Therefore, all 

content should be written in a clear and concise manner. Complicated concepts or 

procedures can often be clarified by providing an analogy or example. Also, make sure 

directions are detailed and accurate, such as “turn the red-colored oxygen knob 

counterclockwise,” instead of simply stating, “turn the oxygen knob.”

Also, all instructional material should be tested through a focus group of potential users 

who can comment on usability, readability, etc. Potential users can often make 

recommendations to improve the training. 

Manual Checklist

In addition to providing detailed instructions, there are several topics that all manuals 

should address. Based on reviews of current manuals, the following have been suggested. 

Table 1: Checklist of suggested items for manuals on the operation of refuge chambers

□ When to Use

□ Quick Start Guide

□ Gas and Atmosphere Monitoring

□ Oxygen Supply

□ Carbon Dioxide Scrubber

□ Supplies/Amenities

□ Water

□ Food

□ First Aid

□ Toilet

□ Lighting

□ Communications

□ Psychological and Physiological Health

□ Psychological Health

□ Physiological Concerns

□ CO2 Poisoning

□ Oxygen Deficiency

□ Oxygen Toxicity

□ Movement Inside of the Chamber

□ Exiting the Chamber
7

Manual Content Recommendations

In addition to the suggested elements on the operation of refuge chambers, manuals 

should include the following general recommendations for surviving inside refuge 

chambers: 

• Instruct miners to keep their Self-Contained Self-Rescuers (SCSR) on until the 

environment inside the refuge chamber has reached breathable levels.

• Include the refuge chamber’s expected duration for different quantities of people. 

For example, if the occupancy is doubled, explain how this will affect the 

breathable air supply and other factors. Also, include how the refuge chamber’s 

duration may be extended. 

• Instruct miners to conserve batteries. For example, have only one cap lamp on at a 

time and turn off gas detectors when not in use.

• For inflatable refuge chambers, miners should be cautious of sharp objects in their 

pockets as these items may puncture the walls of the refuge chamber.

• Inform miners of any items within the refuge chamber that they should not sit on, 

such as the scrubber. 

• Include a warning that water may condense on the inside walls of the chamber 

and pool in low spots on the floor. This should be expected and does not indicate 

chamber malfunctioning.

• Include a warning that the temperature and humidity inside the refuge chamber 

will rise. This should be expected and does not indicate chamber malfunctioning.

Quick Start Guide

In addition to a comprehensive, detailed manual it is beneficial to develop a quick start 

guide that isolates the steps that are critical to operating the refuge chamber. Some

instruction guides for refuge chambers are complicated and list over 20 steps. For a quick 

start guide, the number of steps should be grouped into small, manageable numbers. 

Research has found that people can only remember about seven bits of information, plus 

or minus two [Miller 1956]. Because using a refuge chamber is not something that a 

miner will do on a regular basis, it is recommended that the number of steps be reduced 

to much less than 20. Further, if miners are in an emergency situation where they must 

use the refuge chamber, having groups of seven or fewer steps would make it easier to 

operate successfully.

One way to shorten instructions on the activation and deployment of the refuge chamber 

is through the use of task analysis. Task analysis involves analyzing how a task is 

accomplished in order to determine the steps involved. Using task analysis, the steps 

necessary can be broken down into tasks, subtasks, and steps. Sample task analyses for 

refuge chambers can be found in the Appendix. The subtasks and steps can be made 

available in manuals and during training, and the tasks can be developed into quick start 

guides. These quick start guides can be made into stickers or placards and should be 

placed where miners can access them before entering the chamber, such as outside the 
8

refuge chamber or inside hard hats. Once inside the chamber, miners will have a full, 

detailed manual at their disposal. 

We have standardized our examples to the following format:

• Deploy

• Purge

• Oxygen

• Scrubber

Note: Some chambers list in their operating procedures turning on the scrubber prior to 

turning on the oxygen, while others state that oxygen should come first. Most likely these 

operations will be performed simultaneously.

Using a standardized format creates a user-friendly environment by allowing workers 

who change mines to easily adapt to operating different refuge chambers; contractors will 

especially benefit from a standardized format. Adopting a standard terminology and 

keeping the order of the basic steps as similar as possible will be helpful to both miners 

and mine trainers. 

Recommended quick start guides for many types of refuge chambers follow.

Table 2: Quick start based on Task Analysis, example 1 (see Appendix)

To Deploy Chamber:

1. Deploy unit

2. Seal airlock—purge

3. Activate oxygen flow

4. Hang scrubber curtains

Table 3: Quick start based on Task Analysis, example 2 (see Appendix)

To Deploy Chamber:

1. Deploy unit

2. Purge

3. Activate oxygen

4. Activate scrubber

Table 4 below is an example of a modified quick start guide and shows how the guide 

can be adapted to almost every chamber. For this model (see Task Analysis, example 3 in 

the Appendix) it is not possible to adhere to the preferred order (Deploy—Purge—

Oxygen—Scrubber) because the release valve for the oxygen is on the exterior wall of 

the casing that houses the inflatable bay. Therefore, the step for turning on the oxygen 

must be performed first, resulting in a modified order (Oxygen—Deploy—Purge—

Scrubber). Note that the standardized terminology and steps were used, only the order 

changed.
9

Table 4: Quick start based on Task Analysis, example 3 (see Appendix)

To Deploy Chamber:

1. Open access panels and valves 

(includes oxygen)

2. Deploy - unroll bay and inflate

3. Purge

4. Activate scrubber

Table 5: Quick start based on Task Analysis, example 4 (see Appendix)

To Deploy Chamber:

1. Deploy unit

2. Purge

3. Activate oxygen & make-up air

4. Hang scrubber curtains

Gas and Atmosphere Monitoring

Although miners may already be trained in gas detection, this information should be 

readily available during an emergency and written as simply and clearly as possible. 

Manufacturers should include in their manuals information as to which gases need to be 

monitored, a chart with acceptable levels of each of these gases, and suggestions on how 

to fix an unacceptable level of a gas with instructions on adjusting the gauges.

Make sure training discusses how both the inside and outside atmosphere is monitored. 

Instructions should include where the monitoring system is located and how to use these 

systems. Training on colorimetric gas detectors may also be included since they do not 

need batteries to operate and, therefore, serve as a good back-up supply. 

Oxygen Supply

The task of setting the air flow should be made as simple as possible. Make sure that 

gauges are easy to read and easily adjusted. For example, label the gauge in terms of the 

number of occupants instead of the oxygen liters per minute. Instructions for setting the 

air flow should be as specific as possible and include directions such as “Turn the red air 

flow knob counterclockwise.” It is also important to include settings in case the chamber 

is above capacity and address how this may affect the oxygen supply and refuge chamber 

duration. 

The Mine Safety and Health Administration (MSHA) also recognizes the importance of 

instructions for maintaining an adequate supply of oxygen. The Supplementary 

Information section of the final rule states that, "instructions should include topics such 
10

as adjusting oxygen flow rates and checking for loose connections, sounds of leaking gas, 

damage to hoses along the length or at the fittings, and broken gauges.” [73 Fed. Reg. 

80672, (2008)].

If the refuge chamber is equipped with extra supplies, instructions should be included on 

the use and operation of each. For example, if oxygen masks are included, instructions 

should be available on how to properly don and adjust the mask.

Carbon Dioxide Scrubber

Instructions should be included on how to operate the carbon dioxide scrubber. Provide a

chart with a change-out schedule for the soda lime cartridges, filters, or lithium hydroxide 

curtains. If the refuge chamber includes scrubber curtains, instruct miners to label them 

with the time they are hung so they will know how long each curtain is in use. Also, if the 

carbon dioxide scrubber operates with a motor, provide instructions on how to change out 

the motor in case of motor failure. 

Supplies/Amenities

Water

Federal regulations state that “the Emergency Response Plan (ERP) specify a minimum 

of 2,000 calories of food and 2.25 quarts of potable water per person per day to sustain 

the maximum number of persons reasonably expected to use the refuge alternative at one 

time” [73 Fed. Reg. 80699, (2008)]. Make sure to include how much water is allocated

for each miner per day and why it is important to ration water. If there is additional water 

than what is required, it is especially important to specify how much water is provided for 

each miner. Also, make sure to include where the water is stored in the refuge chamber 

and how to dispose of empty bottles. 

Food

Instructions should be included on the location of all food and the allocation for each 

miner per day. Stress the importance of rationing food. It is also important that the 

ingredients are listed on the packaging in case anyone has a food allergy. One severe 

allergy that miners might have is a legume allergy. Legume allergies usually include 

peanuts, peas, and lentils. It is suggested that no peanut based food be included in the 

stored food caches as some people may have a severe allergic reaction while even in the 

vicinity of peanut products. Miners may also choose to bring their lunch pails into the 

refuge chamber with them. 

First Aid 

Make sure to list what is included in the first aid kit and where it is located. If any 

equipment requires instructions to operate, make sure they are included. Also, miners 

should be instructed that if an Emergency Medical Technician (EMT) is in the refuge 

chamber that he or she should be in charge of first aid supplies. It would also be 

beneficial to include instructions on how to care for dead and injured miners [FosterMiller 1983]. 
11

Toilet

A manual should include instructions on how to operate the toilet and information on the 

any cleansing chemicals. Miners should also be supplied with instructions on how and 

when to dispose of the waste.

Lighting

If any lighting is included in addition to the miners’ cap lamps, provide instructions on its 

location, how to operate it, and how long the lighting will last. For example, if there is a 

flashlight that can last 12 hours this should be noted so that miners can conserve power if 

necessary. (See page 16). 

Communications

According to the federal rule, refuge chambers must include provisions for

communications. The law “requires a two-way communication facility that is a part of the 

mine communication system, which can be used from inside the refuge alternative” [73 

Fed. Reg. 80700 (2008)]. Further, MSHA recognizes that new wireless technologies are 

being developed and recommends that they be included in the refuge chamber as they 

become available. Miners should be instructed on the type of communication in the 

refuge chamber and how and when it to use it. 

Psychological and Physiological Health

Miners should also be given a realistic preview as to what it will be like to spend four 

days inside of a refuge chamber. NIOSH is developing refuge chamber expectations 

training that provides miners with information about what to expect psychologically and 

physiologically while inside a refuge chamber. Manufacturers may also want to include 

this information in instruction manuals. 

Psychological Health

It is important to remember that if miners must use a refuge chamber it is in a time of 

emergency. Studies have shown that most people do not panic during an emergency, but 

some people become stressed or anxious [Sime 1983; Hodgkinson 1990]. Including a 

psychological section in a training manual may help miners to reduce their psychological 

distress by understanding that distress is normal behavior under the conditions. Also 

including instructions on how miners can help others who are in psychological distress 

may be helpful [Foster-Miller 1983]. Further, a placard with tips for reducing stress 

inside of the refuge chamber can be included. 

Sleep is also beneficial in times of distress. However, it is important that the miners take 

turns between sleeping and being alert and awake. Advise miners to make a shift 

schedule. This will allow all occupants to get some sleep while others monitor the 
12

conditions in the chamber. Wind-up timers may be useful to remind miners to change 

shifts. 

Physiological Concerns

A refuge chamber is designed to provide 96 hours of breathable air. In order to be able to 

do this, the refuge chamber environment must be closely regulated. It is possible that a 

miner may become ill from overexposure to a gas if the environment is not carefully 

regulated. Further, overexposure to a gas may occur before entering the refuge chamber. 

For both reasons, a section should be added to the manuals about symptoms of and 

treatment for gas overexposure. 

Another physiological concern for miners in refuge chambers is the heat. A large number 

of people in a small enclosed area is going to cause the heat and humidity to rise. Miners 

should be trained about what the symptoms of heat stress are and how they might be able 

to mitigate the effects of heat stress. 

CO2 Poisoning

Include a chart detailing the symptoms, exposure limits, and recommended treatments for 

carbon dioxide (CO2) poisoning. CO2 is an odorless gas emitted by humans as they 

breathe. In an enclosed area, like a refuge chamber, CO2 can build up if it is not removed 

with a scrubber system. Inhaling too much CO2, which is known as CO2 poisoning or 

hypercapnia, can lead to the following [CDC 2005]: 

• Headache

• Dizziness

• Restlessness

• Paresthesia (tingling)

• Dyspnea (breathing difficulty)

• Sweating

• Malaise (vague feeling of 

discomfort)

• Increased heart rate

• High blood pressure

• Coma

• Asphyxia

• Convulsions 

Oxygen Deficiency

Include a chart detailing the symptoms, exposure limits, and recommended treatments for

oxygen deficiency. When the oxygen concentration is less than 18.5% the atmosphere is 

said to be oxygen deficient. Oxygen is necessary for the body to perform cellular 

metabolism and when oxygen concentrations get too low, humans may lose 

consciousness or even die. 

Oxygen Toxicity

Include a chart detailing the symptoms, exposure limits, and recommended treatments for

oxygen toxicity. When the oxygen concentration is above 23%, the environment is said to 

be oxygen rich. Not only will too much oxygen cause a highly flammable environment, 

but extreme concentrations of oxygen can also be harmful to breathe. An environment is 

said to be hyperoxic if the oxygen concentration is greater than 95%. High concentrations 

of oxygen over a prolonged period of time can damage the central nervous system and 

lungs [NLM 2006].
13

Movement inside the Chamber

Another possible physiological concern in a refuge chamber is that miners may be 

uncomfortable and unable to move about for a long duration. Studies have shown that

people who sit in one position for long periods of time have an increased risk of 

developing deep vein thrombosis (DVT). DVT occurs when a blood clot forms in a large 

vein, usually in the legs [CDC 2008]. In a refuge chamber, however, too much movement 

can also be harmful. Movement may increase carbon dioxide and reduce the amount of 

breathable air available.

Exiting the Chamber

Miners may make a decision to exit the chamber to try to escape the mine. If miners use a 

refuge chamber as a way station this would mean that they are only entering the refuge 

chamber temporarily. Some possible uses of refuge chamber as a way station are to rest, 

change SCSRs, or administer first aid. The federal law suggests that, “Refuge alternatives 

also can be used to facilitate escape by sustaining trapped miners until they receive 

communications regarding escape options or until rescuers arrive” [73 Fed. Reg. 80658, 

(2008)]. Regardless of the reason, miners may need instructions on exiting the refuge 

chamber.

Make sure to educate miners about using the refuge chamber as a way station. It is 

important to include considerations about the oxygen supply and how this will be 

affected if miners do use the refuge chamber as a way station. Because every refuge 

chamber operates differently, it is important to note what miners will need to do if they 

leave the refuge chamber and try to escape. Also include information about devices that 

should be turned off prior to leaving the refuge chamber and instructions on what to do if 

they return to the refuge chamber 

When exiting the refuge chamber, miners should use the airlock to avoid contaminating 

the chamber and to conserve purge air. It is also suggested that miners don new, undeployed SCSRs before exiting. Do not attempt to use a previously deployed SCSR even 

if it was used briefly. Once an SCSR has been used, even if only briefly, the expected life 

is greatly reduced. If the refuge chamber has capabilities to measure the gas 

concentrations outside the chamber, miners should be instructed to do so. Also, instruct 

miners that if they can hear rescue crews to remain calm and stay inside the chamber until 

the crews say it is safe to leave. 

Troubleshooting Guide

A separate troubleshooting guide will be quite helpful for miners by detailing more 

commonplace problems and how to handle them should they arise. Inflatable refuge 

chambers, for example, should include instructions on what miners should do if a leak 

develops. A list of frequently asked questions, along with their answers, has become an 

increasingly popular format for troubleshooting guides.
14

Characteristics of a Good Manual

Special attention should be paid to crafting an aesthetically pleasing and well-organized 

manual. Manuals that follow a logical organizational structure and are graphically 

pleasing are easier to understand and use. Recommendations to create a good manual 

follow.

Format and Style Recommendations

Although there is some debate in the research literature about choosing a font, most 

studies have confirmed that a serif style font is best for printed material and that a sans 

serif font is best for material that is viewed on a computer screen [Wilson 2001; Graham

2002]. “Serif fonts have tiny protrusions at the tops, bottoms, or edges of the 

letters....Sans serif fonts have no serifs” [NIOSH 2008, p. 9]. Serif style fonts include 

Times New Roman, Garamond, Goudy Old Style, Palatino, and Baskerville. Sans serif 

fonts include Arial, Tahoma, Helvetica, and Century Gothic. The following table gives 

samples and summarizes these recommendations. 

In manuals, a 12 point font should be adequate. Larger fonts can be used for emphasis or 

on placards. For the refuge chamber application, manufacturers should consider using 

larger fonts as they will be more readable by those who are farsighted, especially if 

reading glasses are not supplied or if the instructions are outside the chamber. It is 

important to remember that refuge chambers may be used in a time of emergency so it is 

essential that miners are able to read the instructions. Therefore, choosing a font is an 

important matter and not a matter of personal preference or style. 

Table 6: Choosing fonts for instruction manuals

Medium Type of Font Font Size Example Fonts

Printed materials Serif 12 Times New Roman

Garamond

Goudy Old Style

Online materials Sans Serif 12 Arial

Tahoma

Helvetica

• Include the model(s) for which the manual applies. 

Other recommendations which make manuals more readable are as follows:

• Proofread for errors.

• Include a table of contents. An index may also be helpful for larger manuals.

• Include page numbers.

• Include headings and subheadings. 
15

Graphic Recommendations

Because refuge chambers are a relatively new concept, graphics and photos play an 

important role in orienting miners to the different components of a refuge chamber. 

Instead of drawings, photographic images should be used whenever possible. Any photos, 

graphics, or signs should be laminated so that they are not affected by a humid 

atmosphere. Color photos or liquid crystal display (LCD) screens can be used in 

conjunction with text to make all instructions clear. If LCD screens are used they should 

be intrinsically safe. If a LCD screen is used it may be possible to show videos and 

presentations in conjunction with photos. Color photos which show a close-up view of all 

important labels, monitors, and gauges are essential. Labeling and color coding all gauges 

and valves will also be helpful. All photos are best printed in color, but be sure to use 

colors that are optimal for people with color blindness. If color printing is not used, it is 

important that charts and photos are still readable in grayscale printing.

Other Considerations

Studies have found that having multiple sources of information may produce faster 

response times [Selcon et al. 1995]. Therefore, another option for those who have trouble 

reading small-size fonts would be to include pictorial instructions and/or audio 

instructions that guide miners through the activation and use of the refuge chamber. Any 

sort of audio equipment that is used should be intrinsically safe. These instructions could 

be similar to those found on defibrillators. Audio instructions would also help those who 

are auditory learners as opposed to visual learners. Refuge chambers will be used in an 

emergency situation and miners may be stressed so having multiple forms of clear and 

easy-to-understand instructions will increase the chances of operating a refuge chamber 

correctly.

It would also be fruitful to develop training materials in addition to a manual. Individuals 

have different learning styles and may learn best from different media. Videos, 

PowerPoint slides, and Flash presentations may also be used to convey important training 

points about refuge chambers. Manufacturers may wish to develop and conduct training

using these types of media. Although NIOSH has not developed any materials for

providing instruction to miners on how to operate refuge chambers, NIOSH has 

developed a paper and pencil training simulation for teaching miners about the types of 

factors they should consider when deciding whether to use a refuge chamber. It is called 

“Harry’s Hard Choices: Mine Refuge Chamber Training.” This product is available at the 

following website: http://www.cdc.gov/niosh/mining/products/product160.htm. NIOSH 

hopes to release additional training materials this year. 
16

Recommendations for Items to Include In a Refuge Chamber

Introduction

This section provides recommendations for items to include in a refuge chamber. These 

recommendations can be used by both manufacturers and mine operators.

Items to Include in a Refuge Chamber

Refuge chambers are a potentially life-saving device that miners can use in an 

emergency. Due to limitations imposed by the mine environment, refuge chambers 

cannot provide an abundance of amenities. However, several things should be considered 

for inclusion inside a refuge chamber to make miners more comfortable and to make the 

refuge chamber easier to operate. 

A multidisciplinary team at NIOSH evaluated several refuge chambers, conducted 

interviews with miners, and reviewed the literature to develop a recommended list of

items to keep inside a refuge chamber. 

Table 7: Checklist of items to include in a refuge chamber

□ First Aid Kit

□ Lighting 

□ Sanitation and Cleaning Supplies

□ Items to Help Pass the Time

□ Repair Materials

□ Additional Supplies

□ Placards

□ CO2 Poisoning

□ Lithium Hydroxide Curtain Deployment Schedule

□ Soda Lime Cartridge Change-Out Schedule

□ Oxygen Flow Chart

□ Photos and Graphics

First Aid

Because miners use a refuge chamber during an emergency, they may need first aid 

supplies to help the injured. 
17

Some items that are recommended for inclusion follow:

• Adhesive bandages in a variety of sizes

• Blankets 

• Antibiotic ointment 

• Burn ointment 

• Tweezers

• Sterile gloves

• Cleansing agent and/or antibiotic towelettes 

• Eye wash solution

• Critical prescription medical items such as insulin, blood pressure medication, and 

monitoring equipment and supplies (See note below). 

• A pain reliever, aspirin and nonaspirin

• Antidiarrheal medication 

• Antacid tablets

• Sugar-free cough drops

Note: It is also recommended that miners add a four-day supply of their prescribed 

medications to this first aid kit. It should be noted that some of these medications may 

have a shelf life and may need to be restocked. Also, if miners have known serious 

allergies they might want to include an auto injector of epinephrine, or EpiPen®. Mine 

operators can collect these medications from their employees and include them in their 

refuge chambers. It is also recommended that body bags be included in case of fatalities. 

More advanced medical equipment may also be added to the refuge chamber. It is 

foreseeable that anyone with respiratory and/or cardiac problems might find themselves 

in respiratory distress after taking shelter in a refuge chamber. Medical oxygen would be 

useful to such miners. Units, such as the compact Oxy-Viva 3, can provide resuscitation, 

suction, and oxygen therapy. In addition, mine operators should consider placing an 

intrinsically safe automated external defibrillator (AED) unit either near or in the refuge 

chamber. Note: At this time, there are no AED units classified as intrinsically safe, 

manufacturers should consider this and, hopefully, one will become available shortly.

Lighting

MSHA recommends “lighting sufficient for persons to perform tasks. Lighting is 

essential to allow persons to read instructions, warnings, and gauges; operate gas 

monitoring detectors; and perform other activities related to the operation of the refuge 

alternatives” [73 Fed. Reg. 80664, 80695, (2008)]. Lighting can also provide 

psychological comfort and is useful for reading or playing games. Therefore, permissible 

lighting, such as chemical lights or flashlights, in addition to cap lamps is recommended.
18 

A window will not only allow miners to see the outside environment, but will also be 

psychologically beneficial.1

Sanitation and Cleaning Supplies

Basic sanitation and cleaning supplies should be included because miners will be eating, 

drinking, and using the toilet inside the refuge chamber. The following items are 

recommended for inclusion: 

• Personal antibacterial wipes 

• Disinfecting wipes or spray 

• Paper towels

• Antibacterial hand sanitizer

It is also recommended that the toilet area allow for privacy. Two toilets per chamber are 

also recommended, if possible [Ounanian 2007a].

Items to Help Pass the Time

In addition to the above materials, items to help pass the time will greatly improve the 

psychological well-being of the miners. If the refuge chamber manufacturer does not 

supply these materials, they should be supplied by the mine operator. The following 

items are recommended for inclusion: 

• Decks of playing cards 

• Games, such as checkers

• A large chart with easy-to-read instructions on varieties of suggested games to play 

• Reading material, such as books, magazines, nondenominational Bible 

• Pens, pencils, and paper 

• Foldable table 

Repair Materials and Tools

It is recommended that a repair kit be included in the refuge chamber. MSHA 

recommends that “the refuge alternative is stocked with sufficient quantities of materials

and tools to repair components. Materials and tools should include metal repair materials, 

fiber material, adhesives, sealants, tapes, and general hardware (i.e., screws, bolts, rivets, 

wire, zippers, and clips)” [73 Fed. Reg. 80664, 80695, (2008)]. Instructions for how to 

 

1

The government of Western Australia has made recommendations for refuge chambers in metalliferous 

mines stating that “adequate lighting, ... and a small window can help occupants to cope.” [DoIR 2005]
19 

repair common problems should also be included. If the refuge chamber contains a 

window, a replacement window may be included. For inflatable chambers, a tent patch 

kit should be included. 

Additional Supplies

The following additional supplies should be included inside a refuge chamber:

• Manual wind-up timers

• Reading glasses

• A low-toxicity extinguishing agent that does not produce a hazardous by-product 

when activated

• Provisions or storage areas for equipment (for example, place empty scrubber 

canisters under the seat) 

Placards

Although all refuge chambers will be equipped with manuals and miners will have 

undergone training on how to use the refuge chamber, several placards can be hung 

inside and/or outside the refuge chamber to remind miners of key features. 

Outside the Refuge Chamber

In order for miners to be able to deploy the refuge chamber and make it operational, there 

are usually levers that need to be pulled or valves to be opened. Make sure to have large 

arrows indicating the location of important parts of the refuge chamber necessary for 

operation. Deployment instructions should also be posted on the outside of the chamber. 

Inside the Refuge Chamber

Placards should be hung around the refuge chamber to emphasize important operational 

procedures. These placards should be in color and include photos whenever possible. 

Also, it is important that the font is large enough to be read. 

It is also important to remember that charts can be used to simplify operational 

procedures. Therefore, charts should be provided so that miners do not need to perform 

any calculations. For example, some manuals instruct miners to adjust the oxygen flow at 

a rate of 0.5 liters per minute per occupant. In a time of emergency, it would be easier for 

miners to not have to make this calculation and instead have a chart that lists those values 

that correspond with the number of occupants. 
20

There are several specific placards that should be placed in the chamber including 

• Symptoms of CO2 poisoning (see page 11)

• Symptoms of O2 deficiency and abundance (see page 11)

• Chamber contents and locations

• Tips for reducing stress

• Change-out schedule of lithium hydroxide curtains or scrubber cartridges

• Oxygen flow chart based on chamber occupancy (Make sure to include levels if 

the chamber is above occupancy.)

• Charts indicating the recommended concentration of each gas and dangerous 

levels of each gas 

• Signs indicating the location of important items such as waste disposal, oxygen 

flow gauge, carbon dioxide scrubber, equipment, and exits 

Lithium Hydroxide Curtains—Deployment Schedule

If the refuge chamber is equipped with lithium hydroxide curtains, a chart should be 

posted inside the refuge chamber showing the number of curtains that need to be hung for 

various numbers of occupants and a change-out schedule. It should also be made clear to 

miners where these curtains should be hung. One way to do this is to post signs in the

refuge chamber that say something to the effect, “Hang Curtain 1 Here.” 

Soda Lime Cartridge Change-out Schedule

If the refuge chamber is equipped with soda lime cartridges or filters, a schedule should 

be posted to detail how often the cartridges or filters need to be changed. Also make sure 

that the location of spare cartridges or filters is made clear. 

Oxygen Flow Chart

A chart detailing the oxygen flow rate for various numbers of occupants should be 

posted. This chart should also include instructions about oxygen flow if the refuge 

chamber is over or under capacity. In order to make this as easy as possible, color coding 

the charts with the cylinders may be helpful. Further, diagrams or close-up photos of the 

instrumentation they use—such as the oxygen flow meter—may also be posted for 

clarity.

Photos and Graphics

Photos and graphics should also be included to assist miners in operating the refuge 

chamber. Pictures of important gauges, levers, and equipment should all be included. 

Also a map detailing where all supplies are located would be beneficial. 
21

Best Practices for Manuals for Setting Up, Inspecting, and 

Moving a Refuge Chamber

Introduction 

This section is intended to assist both manufacturers and mine operators with receiving, 

maintaining, and moving a refuge chamber. These suggestions are based on a review of 

manufacturer materials, literature, and interviews with stakeholders. A multidisciplinary 

team at NIOSH evaluated these materials to develop these suggestions. 

Preparing for a Refuge Chamber

Before a refuge chamber is delivered to a mine, instructions on how to prepare for the 

refuge chamber should be included. Each refuge chamber may have slightly different 

instructions, but some basic guidelines are offered below.

It is recommended that employees from the manufacturing company assist with the setup

of the refuge chamber when it is delivered. This will ensure that mine operators know 

how to set up the refuge chamber and have the ability to move it as mining progresses. 

Detailed setup instructions for the arrival of the refuge chamber should also be included

so that mine employees are able to move and set up the refuge chamber on their own at a 

later time. Diagrams and pictures can be used to make these instructions more clear. 

Selecting a Site

For the most part, refuge chambers should be stationed within a crosscut and not in the 

direct path of a blast wave [Ounanian 2007b]. If avoidable, refuge stations should not be 

located in wet areas, near overcasts, near gob seals, near the belt drive or track entries 

[Ounanian 2008]. Ensure that the area in which the refuge chamber will be placed is free 

of debris.

An important consideration when installing a refuge chamber is size. Refuge chambers 

differ in length, height, and width. It is critical that the dimensions of the refuge chamber 

be carefully considered prior to ordering. However, with inflatable chambers it is 

especially important to include size requirements to ensure that enough room is allocated 

for the full refuge chamber size when it is deployed. 

The Setup

Include instructions for which direction the refuge chamber should face when it is placed 

in the mine. The door should also be clearly labeled to ensure that the refuge chamber is 

placed in such a way that the entrance is not blocked. 

Also include information about what equipment needs to be connected to the refuge 

chamber, including phone lines. 
22

Any necessary preparation to the mine roof, floor, or ribs before installing the refuge 

chamber should be specified. If the refuge chamber should be secured to the mine floor, 

recommendations on how to do so should be included. 

Maintenance and Inspections

Refuge chambers need to be routinely inspected. This is important because they are 

designed to move with advancement of the mine, and this continual movement may cause 

damage to the unit. Further, refuge chambers are not disposable and will, therefore, have 

parts that need to be replaced or fixed periodically. For these reasons, refuge chambers 

should be properly maintained and inspected to ensure that they are functioning properly. 

All inspections should be recorded and a log should be kept for when components are 

changed out of the refuge chamber. Guidelines and recommendations related to 

maintenance and inspections are listed below.

Inspections

Inspection checklists, recommendations, and requirements should be included and be 

tailored for each refuge chamber model. A chart is a helpful way to display which 

components need to be inspected and how often. An example chart is shown below. It 

should be noted that this is simply an example of what a chart can look like and does not 

provide actual data about how often inspections should be conducted. Consult the 

manufacturer for scheduling inspections. 

Table 8: Sample schedule for inspections and replacements

Inspections Replace

Daily Monthly SemiAnnuallyBiAnnually3 

years

5 

Years

Yearly 3 

Years

5 

Years

External 

Visual –

Including 

Tamper 

Proof 

Seal

x

Oxygen 

Cylinder 

x x

Electrical 

System –

Including

Battery 

Voltage

x

Scrubber 

System

x x

Gas 

Cylinders

x x

Food & 

Water

x
23

As shown in the chart above, make sure to include how often inspections for different 

parts need to be conducted. Initials may also be recorded to show who performed each 

inspection. 

Mines may also wish to use lockout/tagout labels for each piece of equipment, with a 

place to record the date inspected/replaced and the next date that the 

inspection/replacement is due. An example is the inspection sticker on our car windshield 

or the oil change sticker that some service stations use to record when the next oil change 

is due.

A similar chart can also be provided to the mine so that they may mark off when 

inspections have been conducted. 

Instructions about what to do if a part of the refuge chamber fails an inspection should be 

included. Be sure to include a person to contact in the case of a failed inspection. Also 

include who should inspect the refuge chamber and if there is a special certification 

process that mine employees need to complete in order to be qualified to inspect the 

refuge chamber. 

If mine operator-supplied equipment, such as gas detectors or strobe lights, is added to 

the refuge chamber, remind mine operators that this equipment should also be inspected 

or calibrated. This information can be added to the chart above. 

Tamper-Proof Seals

If the refuge chamber contains tamper-proof seals, make sure to include instructions on 

how to check if the seal has been tampered with and what procedure to follow if 

tampering has occurred. 

Gauges

Instructions on how to make sure that the gauges are correctly calibrated should be 

included. Also, make sure to note how often the gauges need to be calibrated. 

Mine Phone Connections

Instructions on how to ensure that mine phone connections are operational should be 

included. 

Expiration Dates

Be sure to include shelf life and expiration dates of all products in the refuge chamber. 

Also include contact information for the company where replacements can be ordered. 

Further, include instructions on how to replace products inside the refuge chamber and 

which products, if any, need to be replaced by a company representative. This 

information is important to include so mine operators can anticipate delays in replacing 

certain items. 
24

Parts and Accessories

Include a basic list of parts and accessories that are tailored for that particular model of 

the refuge chamber and information about how to order new parts. 

Moving a Refuge Chamber

Preparation

Instructions for moving a refuge chamber should be similar to those for preparing for a 

refuge chamber. Include any necessary preparation to the mine roof, floor, and ribs of the 

new location before moving the refuge chamber. Also ensure that the new location for the 

refuge chamber is free of debris. 

Include a check list or document for mine employees to fill out every time the refuge 

chamber has been moved to a new location. Only persons who are task trained on how to 

move and setup a refuge chamber should be allowed to move a refuge chamber. 

Securing to Transport Vehicle

Include specific instructions on how to move the refuge chamber. If there are special 

considerations for securing the refuge chamber to the transport vehicle, make sure they 

are noted. Also the equipment that can be used to move a refuge chamber should be noted

If the unit is only meant to be towed or pushed, this should also be mentioned. Also 

include any instructions concerning how the refuge chamber should be angled or 

positioned when moving to avoid shifting its contents. 

Damage Assessments

Refuge chambers need to be inspected for possible damage as a result of the move. There 

are certain key areas of the refuge chamber that should be checked after the move,

including oxygen cylinders, piping, tamper-proof seals, deployment levers or switches, 

and the outside surface of the refuge chamber. Also make sure that the contents have not 

shifted. A checklist of places and equipment to inspect for damage should be included.
25

References

73 Fed. Reg 80655 [2008]. Mine Safety and Health Administration: refuge alternatives 

for underground coal mines; final rule. (To be codified at 30 CFR Parts 7 and 75.)

CDC [2005]. NIOSH pocket guide to chemical hazards [www.cdc.gov/niosh/npg/

npgd0103.html]. Date accessed: May 2008.

CDC [2008]. Deep vein thrombosis (DVT) [www.cdc.gov/ncbddd/dvt/default.htm]. Date 

accessed: May 2008.

Foster-Miller [1983]. Development of guidelines for rescue chambers, Volume I. 

Waltham, MA: Foster-Miller, Inc. Department of the Interior contract no. JO387210 for 

Bureau of Mines. 

Graham L [2002]. Basics of design: layout and typography for beginners. Albany, NY: 

Delmar. 

Hodgkinson P [1990]. Ways of working with panic. Fire Prev June (23):35–38.

Miller GA [1956]. The magical number seven, plus or minus two: some limits on our 

capacity for processing information. Psych Rev (63):81–97.

NIOSH [2008]. NIOSH identity guide 

[http://inside.niosh.cdc.gov/pdfs/NIOSHIdentityGuide.pdf]. Date accessed: April 2009. 

NLM [2006]. Oxygen therapy—infants [www.nlm.nih.gov/medlineplus/ency

/article/007242.htm]. Date accessed: September 2008.

Ounanian D [2008]. Refuge alternatives in underground coal mines. Final report Volume 

III. Waltham, MA: Foster-Miller, Inc. NIOSH contract no. 200-2007-20276 for NIOSH 

Pittsburgh. 

Ounanian D [2007a]. Refuge alternatives in underground coal mines. Phase I report. 

Waltham, MA: Foster-Miller, Inc. NIOSH contract no. 200-2007-20276 for NIOSH 

Pittsburgh. 

Ounanian D [2007b]. Refuge alternatives in underground coal mines. Phase II report. 

Waltham, MA: Foster-Miller, Inc. NIOSH contract no. 200-2007-20276 for NIOSH 

Pittsburgh. 

Selcon SJ, Taylor RM, McKenna FP [1995]. Integrating multiple information sources: 

using redundancy in the design of warnings. Ergonomics 38(11):2362–2370

Sime JD [1983]. Affiliative behaviour during escape to building exits. J Environ Psychol

3(1):21–41.
26

Wilson RF [2001]. HTML email text font readability study. Web Market Today, 97 

[www.wilsonweb.com/wmt6/html-email-fonts.htm]. Date accessed: May 2008.
27

Appendix: Task Analysis

Table 9: Task Analysis, example 1

Tasks: Subtasks: Steps:

1. Deploy Unit

1. Remove safety pin.

2. Open door.

3. Pull red deployment knob.

2. Purge 1. Enter enclosure—system 

automatically purges.

3. Activate Oxygen 

Flow

1. Set tube fill valve to OFF 

position.

2. Set door purge valve to 

OFF position.

3. Set OXYGEN supply 

valve to ON position.

1. Adjust the oxygen flow valve to 

the number of people in the tent: 

Turn the black knob on the oxygen 

flow counter-clockwise until the 

black ball is set to the proper number 

of people according to the scale on 

the valve.

2. Oxygen level must be checked 

every 30 min—levels should be 

between 19.5% and 22.0%.

3. Oxygen gas monitor is in the 

supplies box—turn it on; also the 

manual gas tube monitors and 

chemical light sticks are in this box.

4. Hang Scrubber 

Curtains

1. Follow arrows to scrubber 

curtain boxes—follow 

instructions.

1. The unfolded CO2 scrubbing 

curtains boxes do not absorb water 

and may be used as a mat for people.

2. Set up a minimum of one 

box of curtains per person.

2. Evenly distribute curtains 

throughout the enclosure—note the 

"Place Scrubber Here" signs.
28

Table 10: Task Analysis, example 2

Tasks: Subtasks: Steps:

1. Deploy Unit 1. Break safety seal.

2. Open door.

2. Purge

1. Slowly open slowly valves 

on both compressed air 

bottles.

2. Open valves on main 

manifold for 10 seconds.

3. Monitor CO level. 1. If CO < 50ppm, then go to Task 3.

2. If CO > 50ppm, then repeat Subtask 

1 and 2. 

3. Activate Breathable 

Air (Oxygen—Mine 

One Air)

1. Open valves slowly on all 

medical-grade oxygen 

bottles.

2. Open main control valve to 

oxygen distribution system 

on the back wall of chamber.

Make sure operating pressure gauge is 

set to 50psi.

3. Set flow control valve at a 

rate of 0.5 LPM per 

occupant—refer to chart.

4. Monitor flow rate at 

regular intervals to ensure 

correct flow rate.

Table 10 continues on next page.
29

Table 10: Task Analysis, example 2 (continued)

Tasks: Subtasks: Steps:

4. Activate Scrubber

1. Open soda lime 

cartridges.

Remove base from bottom of 

cartridge.

2. Place soda lime cartridge 

into slots located on top of 

the "Mine One Air" CO2

scrubber.

Examine each cartridge separately 

and carefully to ensure a tight seal

3. Level the soda lime in 

each cartridge with leveling 

tool attached to scrubber.

Essential to ensure proper operation 

and maximum life

4. Monitor scrubbing 

system.

1. If CO2 is > 5,000ppm, then 

recheck cartridges for a tight seal.

2. Replace each soda lime cartridge 

one at a time at the end of each 16-

hour interval. Important to change 

out one at a time to avoid 

unnecessary build-up of CO2.
30

Table 11: Task Analysis, example 3

Tasks: Subtasks: Steps:

1. Open access panels 

and valves (includes 

Oxygen)

1. Open emergency and 

maintenance access panels.

2. Open purge air, oxygen,

and scrubber fan drive.

2. Deploy—unroll bay 

and inflate

1. Before unrolling, make 

sure floor is free of debris.

2. Unroll and extend fully.

3. Inflate by pulling 

activation cable.

3. Purge

1. Keep SCSR on.

2. Check CO level.

1. Use multi-gas detector.

2. If CO < 50ppm, then go to Task 4.

3. If CO > 50ppm, then go to Subtask 

3.

3. Open purge valve, hold 

on until CO < 50ppm, then 

go to Task 4.

Table 11 continues on next page.
31

Table 11: Task Analysis, example 3 (continued)

Tasks: Subtasks: Steps:

4. Activate Scrubber

1. Remove wood cover—

duffle bag/instructions.

2. Set oxygen flow meter 

from skid.

1. Mount oxygen flow meter to side 

of scrubber frame.

2. Turn knob counter-clockwise on 

magnetic base to "on" level.

3. Set oxygen flow meter (as per 

chart) to the number of persons in 

chamber by turning knob counterclockwise until floating ball is in the 

center of the line.

3. Open soda lime cartridges 

from skid.

1. Unwrap 12 cartridges.

2. Place cartridges on top of scrubber 

tray slots.

3. Align with outside of the scrubber 

box.

4. Change cartridges every 24 hours 

for 36 people—if less or more people

consult chart for time to change.

4. Monitor atmosphere.

1. Use multi-gas detector every 2 

hours.

2. If O2 > 22%, then lower flow rate.

3. If O2 < 19.5%, then raise flow rate.

4. If CO2 is > 5,000ppm, then check 

to see if cartridges are properly 

seated on the foam, make sure air 

motor running properly, then change 

cartridges. If fan fails, refer to 

instruction manual for change-out

procedures.
32

Table 12: Task Analysis, example 4

Tasks: Subtasks: Steps:

1. Deploy Unit 1. Break safety seal.

2. Open door.

2. Purge

1. Keep SCSR on.

2. Check CO level.

1. Open package.

2. Place fiber disc in holder.

3. Use 4-gas detector.

4. If CO disc is dark grey, black or >

200 ppm, then go to Subtask 3. If 

not, then go to Task 3.

3. Open purge air valve to 

the 1/3 valve mark. If CO 

disc dark grey or black or 

>200 ppm, then re-purge

4. Check CO level.

If CO disc is dark grey, black or >

200 ppm, then repeat Subtask 3. If

not, then go to Task 3.

3. Activate air (oxygen 

and make-up)

1. Count the number of 

people.

2. Read the O2 chart (in 

green).

3. Set the O2 meter 

according to the chart.

1. Turn the knob on the flow meter 

(in green). Watch the ball.

2. Align the ball with the desired 

mark on the scale.

4. Read the Make-up Air 

chart (in blue).

5. Set the make-up air meter.

1. Turn the knob on the flow meter 

(in blue). Watch the ball.

2. Align the ball with the desired 

mark on the scale.

Table 12 continues on next page.
33 

Table 12: Task Analysis, example 4 (continued) 

Tasks: Subtasks: Steps:

4. Hang scrubber 

curtains

 

 

 

1. Locate curtains in green 

cans under seat or in corner 

of storage compartment.

2. Count the number of 

people.

3. Read the Scrubber curtain 

chart. 

1. Determine correct number of 

scrubber boxes. 

4. Hang 2 curtains on each 

hanger. 

1. Position curtains in center of the 

chamber. 

2. Position them so there is 1 inch 

between the curtains. 

5. Set scrubber timer for 12 

hours (located in 6-in square 

box in escapeway door). 

6. Using permanent markers, 

located in scrubber box, 

label scrubber curtains as 

they are hung (0,12,36) for 

the hour in which they are 

hung.

7. If space is available, leave 

old curtains hanging.
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DHHS (NIOSH) Publication No. 2009-148

July 2009