1. Welding Explosion— The Case of the Cracked Fuel Tank
P O W E R P O I N T ® T R A I N I N G
Target Audience: This training session is intended for workers who weld as part of their job duties. It can be used as part of a full training session on welding or it can be used as refresher training.
Learning Objective: The focus in this session is specifically on teaching affected employees to follow proper safety precautions when welding a fuel tank that has contained combustible materials. This session can be used to reinforce points made in a full welding safety training session or it can be used as refresher training.
Background for the Trainer:
The session presents a case study of an actual accident, which was inspected and documented by the Occupational Safety and Health Administration (OSHA). The case presented in this training session is:
Accident: : Employee Injured in Explosion While Welding Tank
Report ID:
Inspection:
You may choose to present this training information in a lecture format or make the training presentation interactive by engaging your class in discussions that will help them identify facts of the case, potential causes of the accident, and future accident 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 is provided on the disc. The Case Study Student Handout can be used as a worksheet during the training session or as a take-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 Word® document. The students can take the quiz at the end of the training session in order to help reinforce the information presented. Note that the same quiz is included at the end of this PowerPoint® presentation.
Consider taking pictures of welding operations in your workplace. You can add these pictures to the presentation by inserting them into existing slides or creating new slides.
To ensure trainees understand the information presented, we recommend that you periodically pause the training to ask if trainees have any questions.
Speaker’s Notes:
Welcome everyone. Today we will conduct a Case Study of an actual accident investigated by the Occupational Safety and Health 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 welding safety in our workplace in order to prevent tragic accidents. Specifically, this training session focuses on the hazards of welding a fuel tank that has contained hazardous chemicals.
Welding Explosion—
The Case of the Cracked Fuel Tank

2. Let’s Talk About Welding Hazards
Welder’s flash
Exposure to fumes and gases
Explosions or fires
Electric shock
Asphyxiation
Background for the Trainer:
Bring your company’s written welding program or welding safe work practices for employees to review or discuss.
You may want to use this slide to ask if trainees know what the hazards of welding are before giving them the information. In doing this, the class will be more interactive, and this gives peers a chance to learn from peers.
Speaker’s Notes:
Welders must understand the hazards that they face in order to protect themselves and other nearby workers. Welders are exposed to a number of hazards, including:
Welder’s flash or a burn to the eyes. Welders must make sure they use lens shading that is appropriate for the type of welding they are doing. Welders must also protect nearby workers from welder’s flash by positioning a welder’s screen between the welding job and other workers.
Exposure to fumes and gases that could generate heavy metal poisoning, metal fume fever, lung cancer, etc. Fumes contain particles from the electrode, material being welded, other finishes on the metal, and gases used in the welding process. Fumes and gases should be extracted from the welding area with local ventilation. If not available, the welder must wear an appropriate respirator.
Explosions or fires. Explosions are typically connected to welding work on drums or tanks that have contained fuels or solvents. Welders often forget that even though a tank may be empty, it still contains flammable vapors. Fires result when welders don’t take the time to clear the welding area of combustible materials or forget to maintain a fire watch after the welding job is completed.
Electric shock. This is very possible when doing electric arc welding. The welder must check the area for hazards such as water, condensation, oil, grease, paints, etc. Also, check the cables, ground clamp, electrode holder, gauges, and switches to make sure all are in proper working order.
Asphyxiation from lack of oxygen in a confined space. Welding work depletes oxygen, which, in a confined space, is very dangerous. Make sure your job is properly ventilated or you are wearing a supplied air respirator. Follow all confined space safe work practices.
Can you think of other welding hazards in your workplace?

3. Take a Look at the Facts Experienced welder
Assigned to weld crack in empty fuel tank
Diesel fuel tank had been removed that morning
Background for the Trainer:
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’s notes below to describe the accident.
Speaker’s Notes:
The injured employee is a very experienced welder who had worked for 11/2 years for this employer. Question for the trainees: Do we know whether this welder has ever worked on fuel tanks before?
He was assigned by the shop foreman to weld a 11/2-inch-long crack in an empty diesel fuel tank.
The fuel tank had been removed that morning from a diesel truck.

4. Take a Look at the Facts (cont.)
Welder did not personally inspect tank before commencing his work
At 7:30 a.m., welder struck an arc on the tank
Speaker’s Notes:
The welder did not personally inspect the tank for diesel fuel or fumes before beginning his work.
At 7:30 a.m., the welder began to weld with an arc welder unit. Question for trainees: If the welder started work at 7:30 a.m. and the tank had been removed that morning, how long do you think the tank had been out of the truck? Could it have been much more than an hour? Is that enough time for diesel fuel and fumes to dissipate?
© Business & Legal Reports, Inc. 0908

5. Take a Look at the Facts (cont.)
Tank exploded away from welder
Fractures to jaw, wrist, and hand
Hospitalized for 4 days
Speaker’s Notes:
The tank exploded at the seam line away from the welder.
The welder suffered serious fractures of his jaw, right wrist, and left hand, along with other injuries.
The welder was hospitalized for 4 days.
© Business & Legal Reports, Inc. 0908

6. What Do You Think Went Wrong?
Why do you think the tank exploded?
Is it important to inspect fuel tanks before welding?
Is it important to always clean a tank of fuel and fumes before welding it? Why?
Who should ensure the tank has been cleaned?
Do you think “assumptions” or “miscommunication” contributed?
Does the company need a written procedure?
Background for the Trainer:
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 determine the 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.

7. Let’s Review the Causes
Fuel tank not cleaned
Fuel tank removed that morning
Tank still contained diesel vapors
Background for the Trainer:
Ask trainees to put themselves in the place of the person in the case study—what would they have done differently if this had happened to them?
When investigating accidents and trying to determine potential causes, it is very important not to just blame the injured worker or stop the investigation when an obvious cause is discovered. Dig deeper and determine if there were underlying system factors that contributed to the obvious cause.
Quite often there are underlying reasons that contribute to a worker committing an unsafe act. Other issues to consider when investigating accidents might include training, written procedures, machinery not operating properly, tools or personal protective equipment not readily available, pressure from management to speed up production, etc.
Speaker’s Notes:
The primary cause of the accident was that the fuel tank was not cleaned before the welder struck an arc on the tank. Although the tank was empty, it still contained diesel vapors at a high enough concentration to cause an explosion.
This may have been a rush job, because the fuel tank was removed that morning, and by 7:30 a.m., the welder was beginning to weld on it. This did not allow enough time to properly clear the tank of diesel liquids and diesel-saturated air. Maybe the welder felt the need to get the job done right away and decided to cut a safety corner by not cleaning the tank.
Diesel Vapors

8. Let’s Review the Causes (cont.)
Shop foreman did not communicate that tank needed cleaning
Welder did not personally inspect tank
Welder not trained to clean tanks first
Speaker’s Notes:
The shop foreman that assigned the welder to the job of welding the diesel tank may not have communicated the fact that the tank needed to be cleaned first. He may have assumed that the welder would know to clean the tank first. He may have assumed that whoever removed the tank from the truck had cleaned the tank. Unclear communication and unfounded assumptions are at the root of many serious accidents.
The welder may have assumed that the tank was cleaned first. However, a quick inspection of the tank would have revealed that it was not cleaned when it still smelled like diesel fuel.
Although the accident investigation does not specify, the welder may not have known that the tank should have been cleaned first. Even though he is an experienced welder, he may have never welded a fuel tank before. He may not have been trained properly on the dangers of welding fuel tanks or trained on how to properly clean and flush out a fuel tank.
Can you think of any other causes that may have contributed to this accident?
© Business & Legal Reports, Inc. 0908

9. Safe Welding Practices
Read and follow your company’s safety policy for welding
Always wear proper personal protective equipment
Clear the area of combustible objects
Inspect your equipment
Inspect your work before starting
Clean and flush tanks or drums
Background for the Trainer:
Bring any written procedures your company has for welding—specifically welding of tanks or drums.
Show pictures of welders following safe work practices in your workplace.
Speaker’s Notes:
Be sure to read and follow your company’s written policies regarding welding.
Welders must always wear the proper protective equipment and clothing.
Clear the area of combustible objects. Look for cardboard, paper, rags, etc.
Inspect your equipment before starting the job. Make sure everything is in good working order.
Inspect your work before starting. Do not assume that everything is safe. Check for yourself—you are the one who will be injured if the work is not safe.
If absolutely necessary to weld on a tank or drum, be sure to clean out all liquids and flush out the air before starting to weld. Even if you are told that the tank has been cleaned, inspect it yourself to be sure. Inspection takes only a few minutes and can avoid a serious injury. The welder in this case study could have avoided a 4-day hospital stay if he had taken a few minutes to inspect the tank before starting work.

10. Protective Clothing Fire-retardant clothing with no cuffs or pockets
Flameproof skull cap
Eye and face protection with filter lens
Fire-resistant gauntlet gloves
Protective boots
Speaker’s Notes:
The goal of wearing fire-retardant clothing is to protect your skin from hot sparks or slag. You also do not want to give hot slag a place to land in your clothing where it can smolder and eventually burn you. Wear fire-retardant clothing with no cuffs or pockets. Button up the shirt collar all the way so that sparks can’t go down your shirt. The shirt should have long sleeves. Wear the shirt outside of your pants; otherwise, sparks could go into the top of your pants. Make sure your clothing does not have any rips or tears that will allow sparks in.
Wear a flameproof skull cap to protect your hair. A face shield should easily fit over the skull cap.
Wear eye and face protection. If you wear a face shield with a filter lens, be sure to wear safety glasses or goggles underneath the face shield. This will ensure that your eyes are still protected when you flip up the face shield and start grinding or chipping at the weld. Make sure your filter lens is appropriate for the type of welding that you do.
Wear fire-resistant gauntlet gloves, which are typically made of a thick leather material.
Wear sturdy leather work boots with toe and metatarsal protection that will prevent injury if you drop metal onto your foot.

11. Don’t Let It Happen to You
Clean fuel tanks or drums
Allow fuel tank to “breathe”
Inspect work before starting a job
Make sure you are trained on the job requirements
Never assume and always communicate
Speaker’s Notes:
Remember: You can take the necessary steps to prevent accidents like this from happening in your facility. Let’s review how:
Fuel tanks must be cleaned and flushed to remove all residual fuel liquids. Remember, flushing the tank with a solvent will only replace the fuel with a combustible solvent that also has very flammable vapors. Clean the tank with a water-based solution. Remember to manage the fuel-contaminated cleaning solution appropriately. Do not put it down the sink.
Then the tank must be opened up and allowed to “breathe” for a while in order to remove the fuel-saturated air that is contained in the tank. To expedite this process, a fan can be used to help flush the fuel-saturated air out of the tank. Be sure to wear the appropriate protective equipment, such as a respirator, if one is required.
Inspect the work and the work area before starting any job. This welder could have avoided the accident if he had done a quick inspection of the tank. He would have discovered that the tank smelled like diesel. In addition to the job, inspect the work area for any combustible or flammable objects. If necessary, complete a Hot Work Permit before starting to weld.
Make sure you are properly trained on the requirements of the job. Learn about the hazards of the job and follow all company safe work practices.
Never make any assumptions about the work you have been assigned. Communication is critical for making the workplace safe. If you have any questions, ask your supervisor.

12. Quiz
1. Fuel tanks should be cleaned with a solvent before welding True or False
2. What are welder’s gloves typically made of?
3. Describe why welder’s clothing should not have cuffs or pockets
4. What should a welder do to prevent electric shock?
Background for the Trainer:
Remind employees that the purpose of 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.

13. Quiz (cont.)
5. What should welders do if local ventilation is not adequate?
6. What can a welder do to protect nearby workers from welder’s flash?
7. Why should welders wear safety glasses under face shields with filter lenses?
8. Diesel in the liquid form is easier to ignite than diesel vapors True or False
© Business & Legal Reports, Inc. 0908

14. Quiz Answers
1. Q. Fuel tanks should be cleaned with a solvent before welding True or False
A. False; solvents also generate flammable vapors—clean with water-based solution
2. Q. What are welder’s gloves typically made of?
A. Leather

15. Quiz Answers (cont.)
3. Q. Describe why welder’s clothing should not have cuffs or pockets
A. Because hot slag might get trapped in a cuff or pocket and smolder and burn you
4. Q. What should a welder do to prevent electric shock?
A. Check the area for water, oil, grease, and inspect welding cables, electrodes for signs of damage
© Business & Legal Reports, Inc. 0908

16. Quiz Answers (cont.)
5. Q. What should welders do if local ventilation is not adequate?
A. Wear an appropriate respirator
6. Q. What can a welder do to protect nearby workers from welder’s flash?
A. Put welding screens between welding job and the workers
© Business & Legal Reports, Inc. 0908

17. Quiz Answers (cont.)
7. Q. Why should welders wear safety glasses under face shields with filter lenses?
A. Welders often flip up the filter lens face shield and grind or chip at the weld
8. Q. Diesel in the liquid form is easier to ignite than diesel vapors True or False
A. False; vapors ignite more readily than flammable liquids
© Business & Legal Reports, Inc. 0908