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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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Controlling Exposure - 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.


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.

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 difficult 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 before they can get in the breathing zone of workers.


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.

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 also proven to be less effective than other measures, requiring significant effort by the affected workers. Administrative controls work only so long as employee behavior conforms to standards.

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

  • warning alarms
  • 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.

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.

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.

Analyze Past Accident Investigations

All accidents in your workplace resulting in injury or property damage should be investigated.

By using the information gained through analysis of accident investigations occurring on previous projects, a similar, or perhaps more disastrous, accident may be prevented.

Control of Hazardous Energy

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.

Confined Space Entry

Analyze the project for the potential for confined spaces. Workers should not enter confined spaces without proper training and management authorization.

  1. A space that is NOT DESIGNED FOR CONTINUOUS employee OCCUPANCY, and
  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

Analyze Fall Hazards

fall protection

Each year, falls consistently account for the greatest number of fatalities in the oil and gas industry. A number of factors are often involved in falls, including unstable working surfaces, misuse or failure to use fall protection equipment and human error.

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 project to determine if you will be using:

  • aerial lifts or elevated platforms to provide safer elevated working surfaces
  • guardrail systems with toeboards and warning lines or install control line systems to protect workers near the edges of floors, roofs, and floor holes; and/or
  • safety net systems or personal fall arrest systems (body harnesses)

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.

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.


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



Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. Which of the following is the fundamental method of protecting workers on a oil and gas site?

2. Which of the following "Hierarchy of Controls" strategies is effective only after attempting all other controls?

3. Replacing a highly toxic cleaning chemical with a less-toxic cleaning chemical is an example of which hazard control strategy?

4. The employer on a rig should investigate _____ accidents in your workplace resulting in injury or property damage should be investigated.

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

Have a great day!

Important! You will receive an "error" message unless all questions are answered.