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Course 900 - Oil and Gas Safety Management

Safety guides and audits to make your job as a safety professional easier

Hazard Prevention and Control

heirarchy of controls
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The Hierarchy of Controls

Controlling exposures to wellsite hazards is the fundamental method of protecting workers on an oil and gas site. Controlling hazards and exposures is the fundamental method of protecting workers. ANSI/ASSP Z10-2012, Occupational Health and Safety Management Systems, encourages employers to use the following hierarchy of hazard controls:

  1. Elimination
  2. Substitution
  3. Engineering controls
  4. Warnings
  5. Administrative controls
  6. Personal protective equipment

The idea behind this hierarchy is that the control methods at the top of the list are potentially more effective and protective than those at the bottom. Following the hierarchy normally leads to the implementation of inherently safer systems. The risk of illness or injury should be substantially reduced. Let’s take a closer look at each of the control measures.

1. Which of the following hierarchy of control methods is considered most effective and protective?

a. Engineering controls
b. Administrative controls
c. Elimination
d. Personal Protective Equipment

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The best control measure to control a hazard is to eliminate it. If you don’t have the hazard, you won’t get injured. While elimination is the most effective at reducing hazards, it also tend to be the most difficult to implement in an existing process.

If the oil and gas project is still at the design or development stage, elimination and substitution of hazards may be inexpensive and simple to implement. For an existing process, major changes in equipment and procedures may be required to eliminate or substitute for a hazard.


The next best control measure is to substitute something else in its place that would be non-hazardous or less hazardous to workers. For example, a non-toxic (or less toxic) chemical could be substituted for a hazardous one.

2. When is it less expensive and more feasible to eliminate hazardous conditions at the wellsite?

a. Prior to well completion
b. During the site preparation phase
c. During the design or development phase
d. Once drilling has commenced

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Engineering Controls

engineering control
A guardrail is a good example of an engineering control.
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Engineering controls are used to remove a hazard or place a barrier between the worker and the hazard. Well-designed engineering controls can be highly effective in protecting workers and will typically be independent of worker interactions to provide this high level of protection.

The initial cost of engineering controls can be higher than the cost of administrative controls or personal protective equipment, but over the longer term, operating costs are frequently lower, and in some instances, can provide cost savings in other areas of the process. Engineering controls should be designed to make it hard for employees to defeat the controls.

Engineering controls include methods such as:

  • using noise dampening technology to reduce noise levels;
  • enclosing a chemical process in a Plexiglas "glove box";
  • using mechanical lifting devices; or
  • using local exhaust ventilation that captures and carries away the contaminants.

3. Which of the following is TRUE concerning the use of engineering controls?

a. Initial costs to implement engineering controls is usually quite low
b. Over the long term, the cost of engineering controls is high
c. Engineering controls depend on worker interaction to provide protection
d. Engineering controls should make it hard for employees to defeat

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Warnings promote employee awareness of hazards. They do not prevent exposure to a hazard, but they do provide a visual, audible, and/or tactile indicator to warn people of potential danger. Greater awareness is gained by using signs, alarms, signals, labels, placards, cones, and other methods.

For example, a warning sign might be used to keep workers from entering a confined space. However, warning signs used instead of correcting a hazard that can and should be corrected are not acceptable forms of hazard control.

Administrative Controls

If engineering controls cannot be implemented, or cannot be implemented right away, administrative controls should be considered. These methods for protecting workers have usually proven to be less effective than elimination, substitution, and engineering controls. Why? Because administrative controls may require significant effort and discipline by the affected workers.

A major weakness inherent in the use of administrative controls is that they work only so long as employees comply with the controls.

Administrative controls involve changes in workplace policies and procedures. They can include such things as:

  • labeling systems
  • reducing the time workers are exposed to a hazard
  • training

For example, workers could be rotated in and out of a hot area rather than having to spend eight hours per day in the heat. Back-up alarms are an example of effective warning systems. However, warning signs used instead of correcting a hazard that can and should be corrected are not acceptable forms of hazard control.

4. What is a major weakness in the use of administrative controls to reduce exposure to hazards?

a. They work only if hazards are replaced first
b. They are not effective in mitigating hazards
c. They work only so long as employees comply
d. They are too expensive to implement during the drilling phase

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Personal Protective Equipment

The hard hat and gloves shown here are good examples of personal protective equipment.
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PPE is the last resort and least effective means of controlling exposure to hazards because of the high potential for damage to render PPE ineffective. Again, the success of this control measure depends not only on the quality of the PPE, but also the quality of human behavior.

PPE should be used only while other more effective controls are being developed or installed, or if there are no other more effective ways to control the hazard.

This is because:

  • The hazard is not eliminated or changed.
  • If the equipment is inadequate or fails, the worker is not protected.
  • No personal protective equipment is fool-proof (for example, respirators leak).
  • Personal protective equipment is often uncomfortable and can place an additional physical burden on a worker.
  • Personal protective equipment can actually create hazards. For example, the use of respirators for long periods of time can put a strain on the heart and lungs.

While there are some jobs, such as removing asbestos, where wearing adequate personal protective equipment is absolutely essential, there are many jobs where employers hand out personal protective equipment when in fact they should be using more effective hazard control methods.

5. According to the text, what does the success of using PPE depend on?

a. Quality of the PPE and barriers
b. Quality of the PPE and employee behavior
c. Quantity of safety rules and cost of PPE
d. Quantity of PPE and mitigation efforts

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Other Methods to Prevent and Control Hazards

Let’s take a look at some of the programs and processes that will help the company prevent and control typical hazards on an oil and gas wellsite.

Wellsite Inspections

Your company should conduct daily wellsite inspections. Hazards should be documented, reviewed, and corrections should be made in a timely manner. More detailed, written inspections should be conducted by a designated person on a weekly or monthly basis.

Your company’s Safety Coordinator or other designated safety person should tour each job site and observe potential safety/health hazards, and develop a plan for safeguarding the workers, which may include the following:

  • removing the hazard
  • guarding against the hazard as required by OSHA
  • providing personal protective equipment and enforcing its use
  • training workers in safe work practices
  • coordinating protection of workers through other contractors

A record of all safety inspections and correctional steps should be kept.

6. How often should walkaround wellsite inspections be conducted?

a. Daily
b. Weekly
c. Monthly
d. Quarterly

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Analyze Accident Investigations

To most effectively prevent future accidents on the wellsite while work is being performed, be sure to investigate and analyze the results of all accidents, including near misses and property damage, occurring at the wellsite. Do not limit your investigations to only those accidents that result in injury.

Investigating non-injury incidents will help prevent similar accidents at the current or future projects. Controlling the hazard that caused a near miss now, can save a life, and a lot of money and time if it helps prevent a future injury accident.

Don't forget to analyze the data from previous investigations and those investigations conducted at other wellsites.

Control Hazardous Energy - Lockout Tagout

The control of hazardous energy through lockout/tagout procedures assures that you and other employees are protected from unexpected machine motion or release of energy which could cause injury. This includes electricity, water, steam, hydraulic, gravity, and many other sources of stored energy.

All sources of hazardous energy must be shut off, de-energized at the source, and locked-out prior to you or any other employee beginning work around or on the potential hazard.

7. What should the safety professional do to most effectively prevent future accidents on the wellsite?

a. Make sure someone is reprimanded for every accident
b. Investigate injury accidents
c. Investigate and analyze all accidents and incidents
d. Analyze results of the walkaround inspection

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Confined Space Entry

Analyze the project for the potential for confined spaces. Workers should not enter confined spaces without proper training and management authorization. A confined space is defined as a space that is:

  1. not designed for continuous occupancy;
  2. is large enough and so configured that a person can bodily enter into and perform assigned work, and
  3. has limited or restricted means for entry or exit.

Confined spaces that may have a hazardous atmosphere require special precautions. Hazardous atmospheres are those that may expose employees to the risk of death, incapacitation, and impairment of ability to self-rescue caused by:

  • flammable gas
  • airborne combustible dust
  • atmospheric oxygen concentration below 19.5 or above 23.5%
  • a toxic atmosphere or substance
  • danger of engulfment

For more information on this topic, take Course 713, Confined Space Program or Course 816, Confined Space Safety in Construction.

8. Which of the following would NOT be a hazardous condition within a confined space?

a. Oxygen concentration of 21%
b. Airborne combustible dust
c. Possible engulfment
d. Nitrogen level of 85%

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Analyze Fall Hazards

fall protection

The Bureau of Labor Statistics, about 4.2 percent of all oil and gas workers are hurt on the job each year. Falls consistently account for the a large number of oil and gas worker fatalities. Workers frequently fall from elevated rig areas from the rig floor to grade below. In some cases, openings lacked safety structures, or safeguards failed to secure workers to the rig. Fall accidents can also be the result of:

  • harness failure or improper rigging methods,
  • tripping over chemicals or tools
  • being struck by tools and equipment, or
  • unstable or slippery working surfaces

Studies have shown that using guardrails, fall arrest systems, safety nets, covers and restraint systems can prevent many deaths and injuries from falls.

Analyze the wellsite project for fall hazards to identify tasks that require fall protection and how it must be used.

Once you have identified the specific fall hazards on the worksite, use the Fall Protection Hierarchy of Controls (HOC) to eliminate or reduce those hazards. Click on the button to see the fall protection HOC.

It’s important to use a systematic "Hierarchy of Controls" for fall protection. In descending order of preference, the hierarchy of controls for fall protection is as follows:

  1. Elimination or substitution. Examples: Eliminate a hazard by lowering the work surface to ground level. Substitute a hazard by moving a process, sequence, or procedure to a different location so that workers no longer approach a fall hazard.
  2. Passive fall protection. Isolate or separate the hazard or work practice from workers through the use of guardrails or covers over exposed floor openings.
  3. Fall restraint. Secure the worker to an anchor using a lanyard short enough to prevent the worker’s center of mass from reaching the fall hazard.
  4. Fall arrest. This includes systems designed to stop a worker’s fall after a fall has begun.
  5. Administrative controls. These work practices or procedures signal or warn a worker to avoid approaching a fall hazard. For example a person may be appointed to monitor work around fall hazards.

9. What would be one of the fall protection systems used to protect workers near the edges of floors, roofs, and floor holes?

a. Guardrail systems
b. Safety nets
c. Warning signs
d. Fall restraint systems

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Analyze for Excavation Hazards

The primary hazard of trenching and excavation is employee injury from collapse. Soil analysis is important in order to determine appropriate sloping, benching, and shoring.

Additional hazards include working with heavy machinery; manual handling of materials; working in proximity to traffic; electrical hazards from overhead and underground power-lines; and underground utilities, such as natural gas.

10. Which of the following is the primary hazard of trenching and excavation on a project?

a. Flooding
b. Soil collapse
c. Electrical shock
d. Heat or cold stress

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Analyze for Hazardous Chemicals


Analyze the project for the potential for hazardous chemicals requiring a Hazard Communications Program (HCP) to ensure all workers know about the chemicals that they work with and work around. The HCP involves the following elements.

  1. written hazard communication program
  2. training on the chemicals your company uses
  3. labeling: using properly labeled containers
  4. Safety Data Sheets (SDS): SDS must be readily available onsite. Workers must know where to find SDS and be able to read and properly utilize a SDS.
  5. Posting signs to inform employees of the location of SDS and when new chemicals are brought on the job site.
  6. Informing other contractors: If using chemicals around other contractors, it is your responsibility to inform the other contractors of the hazards involved. Every effort must be made to keep other contractors safe from the chemicals in use. Typically, the general contractor onsite will need to coordinate all chemical use of all contractors to maintain a safe workplace.

Note: Your written Hazard Communication program should outline the specific details of the elements listed above.

11. Who is typically responsible to coordinate all chemical use on the wellsite?

a. The HCP competent person
b. Each subcontractor
c. The safety officer
d. The general contractor

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Analyze Electrical Hazards

Many oil and gas workers are unaware of the potential electrical hazards present in their work environment, which makes them more vulnerable to the danger of electrocution.

Experts in electrical safety have traditionally looked toward the widely used National Electrical Code (NEC) for help in the practical safeguarding of persons from these hazards.

Electrical safety in oil and gas involves two primary issues:

  • powerlines
  • temporary and permanent electrical wiring and equipment

12. What is the most common cause of fatalities involving contact with power line?

a. Use of cranes
b. Use of metal ladders
c. Violation of the arc flash approach
d. Downed power lines

Check your Work

Read the material in each section to find the correct answer to each quiz question. After answering all the questions, click on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and check your answers again.