Cylinder Explosion - The Case of the Greasy Oxygen Cylinder

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© Business & Legal Reports, Inc. 0908

Cylinder Explosion—The Case of the Greasy Oxygen Cylinder

P O W E R P O I N T ® T R A I N I N G

Target Audience: This case is most appropriate for workers who work with or around compressed gas cylinders.This session is probably not appropriate for workers who do not have compressed gas cylinders in their work area.

Learning Objectives: This case and its training message primarily have to do with how to store and handle compressed gascylinders – specifically oxygen cylinders. It can be used in conjunction with a complete Compressed Gas Safety TrainingSession, or it can be used as refresher training.

Background for the Trainer:

This training session presents a case study of an actual accident inspected and documented by the Occupational Safetyand Health Administration (OSHA). The case presented in this training session is:

– Accident: 014506299

– Report ID: 0830500

– Inspection: 101591337

You may choose to present this training information in a lecture format, or make the training presentation interactive byengaging your class in discussions that will help them identify facts of the case, potential causes of the accident, and futureaccident prevention measures. In either case, students will benefit by learning from a real-life scenario.

Before beginning your training session, print and make copies of the one-page Case Study Student Handout, which isprovided on the disc. The Case Study Student Handout can be used as a worksheet during the training session, or as atake-away reminder once the training session is complete.

Also, print and make copies of the Case Study Quiz, which is provided on the disc as a fully customizable Worddocument. The students can take the quiz at the end of the training session in order to help reinforce the informationpresented. Note that the same quiz is included at the end of this PowerPoint presentation as actual slides to review in class.

Consider taking pictures of compressed gas cylinders stored and used in your workplace. You can add these pictures to thepresentation by inserting them into existing slides or creating new slides.

Make sure the trainees understand the message as you go along. Periodically ask questions to test their understanding.

Speaker’s Notes:

Welcome everyone. Today we will conduct a case study of an actual accident investigated by the Occupational Safety andHealth Administration (OSHA). This is an actual tragic workplace accident that had real-life implications for the worker,the worker’s family, co-workers, and the employer. The Case Study may be disturbing and may even involve a fatality.

The purpose of this training session is to teach and reinforce the importance of properly handling and storing compressed gascylinders in our workplace in order to prevent tragic accidents. In particular, it deals with how to work with oxygen cylinders.The intention is to learn from the accident and take steps to prevent a similar accident from changing our lives.

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Compressed Gases

Highly pressurized

Cryogenic

Corrosive

Toxic

Highly reactive to oxidizers

Flammable

Dangerous even when inert


Bring your company’s written safe work practices for storing, handling, and using compressed gas

cylinders for employees to review and discuss.

Speaker’s Notes:

Compressed gases in cylinders are highly pressurized. If the valve or regulator of a compressed gas

cylinder breaks off, the cylinder becomes a very powerful unguided missile and can even break through

brick walls.

Some compressed gases are cryogenic, which means they are very cold and cause rapid freezing. Liquidnitrogen is an example.

Some gases are corrosive and can eat through certain metals. It is essential to use appropriate tank and

pipe materials for these gases. Corrosive gases include: hydrogen chloride, hydrogen bromide, and

ammonia.

Other gases can be very toxic. Some of these gases can be detected by smell and others are odorless,

which makes them especially lethal. Toxic gases include: carbon monoxide, hydrogen sulfide, phosgene,

and hydrogen cyanide.

Oxidizers such as oxygen and fluorine cause flammables and combustibles to burn more readily. Mixing

regulators that once contained oxidizers or putting oil on a regulator that has been in contact with an

oxidizer can result in an explosion.

Flammable gases are used at home and in the workplace. Hydrogen and acetylene are used for welding.

Propane is used for barbecues. Butane is used in gas lighters. Natural gas is used in many homes for

furnaces or gas-powered fireplaces. Many of these gases have little or no odor, which means a leak could

go undetected.

Even gases that are inert and do not have any particular hazardous properties themselves can be

dangerous. Nitrogen gas is nontoxic, nonflammable, and noncorrosive. However, a release of nitrogen is

still dangerous because it will displace the air in an area and cause suffocation.

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Take a Look at the Facts

Employee transferring

oxygen between cylinders

Using a brass tube pigtail

Oxygen and acetylene

cylinders stored together

Exposed oil and grease


Training Option: Pass out the Case Study Student Handout. You may have the students read the accident

description to themselves before discussing it in the class, or you may use the bullet points on the slide

and the speaker notes below to describe the accident.

Speaker’s Notes:

In this case, an employee was transferring oxygen from a large compressed gas cylinder into a small

cylinder.

The employee was using a brass tube pigtail to transfer the oxygen.

This transfer of oxygen was taking place adjacent to a storage area where both oxygen and acetylene

cylinders were kept.

This area also contained exposed oil and grease.

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Take a Look at the Facts (cont.)

Two other workers in immediate area

Explosion and fire

Three employees killed, five others injured


Speaker’s Notes:

Two other employees were also working in the immediate area where the oxygen transfer was

taking place.

An explosion and fire occurred.

All three employees in the immediate area of the oxygen transfer were killed.

Two additional employees and three members of the public that were on the property were also seriously

injured.

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What Do You Think Went Wrong?

What could have ignited the explosion and fire?

Do you think it is safe to store oxygen and

acetylene cylinders together?

What is significant about the exposed grease

and oil in the area?

How do you think the brass tube pigtail

contributed to the accident?


Use the questions on this slide to elicit discussion.

Training options: After reviewing this slide and the accident description, give the class 5-10 minutes to discuss

the accident description in small groups; or ask the students to try to determine some of the facts, potential

causes, and possible prevention measures. In either case, use the Case Study Student Handout as a way to

encourage discussion as you go through this presentation.

Speaker’s Notes:

Let’s take a few minutes and, using the Case Study Student Handout, work in groups to try to determinethe facts of the accident, potential causes of the accident, and possible prevention measures. Then we will

review the Case Study together in class.

Consider some of the questions on this slide when discussing the Case Study in your groups.

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Let’s Review the Causes

Pigtail leaked oxygen during transfer

Pigtail not compatible with oxygen

Grease and oil may have been

on pigtail or cylinder valves

Acetylene is very flammable

Smoking, welding, or a spark

may have ignited the explosion


Try to get the trainees to put themselves in the place of the person in the case study. What would they have done

in this case? Point out how a near miss can turn into a catastrophe in the presence of emergencies. In this case, the

workers may have become complacent about proper cylinder storage practices because nothing had ever happened

to them.

Speaker’s Notes:

Since the accident report does not specifically say what caused the explosion, we will discuss some of the possible

causes.

It is likely that the brass tube pigtail leaked oxygen during the transfer from the large cylinder to the small cylinder.

This could have occurred because the pigtail was not rated for the high pressure that was contained in the largecylinder, and it leaked. Or, the pigtail may not have been adequately tightened, and it leaked through a seal. Oxygen

will not burn or explode by itself. Oxygen is not a fuel, it merely supports the combustion process. Something would

have to ignite a nearby fuel source for the leaking oxygen to help create an explosion.

Another possibility is that the pigtail was intended to transfer acetylene only and it was not supposed to be used to

transfer oxygen. If this was the case, the pigtail could have contained remnants of acetylene gas – oxygen can beexplosive when combined with acetylene gas. Or, the thread sealant may not have been compatible with oxygen and

actually reacted with the oxygen. It is very important not to exchange a gauge or pigtail from one gas to another. The

results could be disastrous.

With the exposed grease and oil nearby, it is also likely that the pigtail, cylinder valves, or even the cylinders

themselves were contaminated with grease or oil from the worker’s hands. This grease or oil could have provided the

necessary fuel that the leaking oxygen needed.

Acetylene is a very flammable gas that is often used for welding or torch cutting operations. Most acetylene cylinders

are equipped with pressure relief valves to prevent the cylinder from exploding when exposed to high temperatures.

Instead, the pressure relief valve will release acetylene when heated up, which adds fuel to the fire.

The scene is set for a fire – we have leaking oxygen and plenty of fuel sources. Now all that is needed is an ignitionsource. Since we do not know what the other two workers in the immediate area were doing, we can speculate that their

activities may have contributed to igniting the explosion. They could have been welding, or smoking, or using a

hammer to bend a piece of metal – thus causing a spark. Even static electricity could have ignited this fire.

Can you think of any other causes that may have contributed to this accident?

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Let’s Talk About Cylinder Storage

Dry and well ventilated

Away from combustibles, heat sources,and electrical systems

No sparks, smoking, or open flames

Oxygen 20 feet away from fuels

Cylinders upright, secure, valves capped

“Danger” & “Warning” signs prominently posted


Bring any written procedures your company has for cylinder storage – specifically the storage of

oxygen cylinders.

Show pictures of your company’s cylinder storage area.

Speaker’s Notes:

Cylinder storage areas must be dry and protected from the weather, including rain, snow, and direct

sunlight. The storage area must also be well ventilated to prevent the accumulation of gases if there is

a leak.

Storage areas must be away from combustibles such as wood pallets, cardboard boxes, or rags. Keep heat

sources away from cylinder storage areas. Keep cylinders away from electrical systems so they do not

accidentally become part of an electrical current.

Sparks, open flames, and smoking should not be allowed within 25 feet of cylinder storage areas.

Oxygen cylinders must be stored at least 20 feet away from cylinders containing fuels such as acetylene

or other fuels such as grease and oil. In fact, combustibles such as grease and oil must not be allowed in

cylinder storage areas. It may be necessary to erect a fire wall between the oxygen cylinders and the

cylinders containing fuels.

Store cylinders standing upright. Make sure the cylinders are secured so they cannot be accidentally

knocked over. Make sure all valves are capped to prevent the valve from being damaged if a cylinder does

get knocked over.

Cylinder storage areas also have sign requirements that depend on the type of compressed gas being

stored. Most cylinder storage areas will have signs such as “No smoking, open flames, or sparks” or

“Danger– Compressed Gases.”

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Using Compressed Gas

Keep cylinders upright and secure

Keep away fromflames, sparks, electricity

Keep oil, grease,solvents off cylinders

Open valves slowly by hand

Don’t tamper with safety devices


Bring any written procedures your company has for using compressed gas cylinders —specifically

oxygen cylinders.

Show pictures of cylinders being used at your company.

Speaker’s Notes:

Always use cylinders in the upright position. If you need to transport cylinders, do so by securing them

in carts or hand trucks specifically designed for this purpose. It is important to make sure they do not

fall over and damage their valve.

When in use, keep cylinders away from open flames, sparks, smoking, electricity, and other sources

of ignition.

Do not work with cylinders when your hands or gloves are contaminated with grease, oil, solvents,

or other fuel sources. It is important to keep cylinders free of oil, grease, and solvents – especiallyoxygen cylinders.

Open cylinder valves slowly by hand. If a tool is needed to open a valve, do not use the cylinder because

the use of a tool may put too much stress on the valve and break it off. Open the valve slowly to prevent

putting a surge of pressure on the regulator and other systems.

Never tamper with any cylinder safety devices. You are only putting yourself and others in danger.

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Don’t Let It Happen to You

Store gas cylinders properly

Use proper regulators and pigtails

Make sure all fittings are sealed

Keep fuel sources away

Keep ignition sources

away from cylinders

Speaker’s Notes:

Let’s take a look at what we can do to prevent a similar incident from happening at our facility.

Store compressed gas cylinders properly. Be sure to separate oxygen cylinders from cylinders

containing flammable or combustible gases.

Use the proper regulators and pigtails. Do not share them between different gases.

Make sure all fittings on regulators, pigtails, etc., are tight and adequately sealed to prevent leaks.

Also, make sure the thread sealant material is compatible with the compressed gas.

Keep fuel sources away from where gas cylinders are used and stored.

Keep ignition sources away from cylinders.

Are there any questions?

Thanks for your attention.

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Quiz

1. Oxygen cylinders must be stored how far away

from cylinders containing fuels?

2. Oxygen is dangerous because it will explode

or burn by itself. True or False

3. Describe one way to secure a cylinder to keep

it from falling.

4. Name at least two ignition sources to keep away

from cylinders.


Remind employees that the quiz is to encourage further discussion and to help you, the trainer, be

sure that everyone understands what was discussed.

Print copies of the quiz for participants to take on their own, or go over the questions as part of the

training session.

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Quiz (cont.)

5. Where should cylinders be stored?

6. Before handling an oxygen cylinder, make sure

your hands are free of what?

7. When is it safe to share pigtails or regulators

between different types of gases?

8. What is hazardous about acetylene gas?


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Quiz Answers

1. Q. Oxygen cylinders must be stored how far

away from cylinders containing fuels?

A. 20 feet.

2. Q. Oxygen is dangerous because it will explode

or burn by itself. True or False

A. False, oxygen only supports combustion.

It needs a fuel source and ignition source.

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Quiz Answers (cont.)

3. Q. Describe one way to secure a cylinder to

keep it from falling.

A. Chain or tie it to a wall.

4. Q. Name at least two ignition sources to keep

away from cylinders.

A. Open flames, smoking, sparks, static electricity.

5. Q. Where should cylinders be stored?

A. In a dry and well-ventilated location.


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Quiz Answers (cont.)

6. Q. Before handling an oxygen cylinder, make

sure your hands are free of what?

A. Oil, grease, or solvents.

7. Q. When is it safe to share pigtails or regulators

between different types of gases?

A. Never.

8. Q. What is hazardous about acetylene gas?

A. Acetylene is very flammable.


Cylinder Explosion - The Case of the Greasy Oxygen Cylinder

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