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Course 706 - Conducting a Job Hazard Analysis (JHA)

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

Describe the Hazards in Each Step

Look for possible hazards in each step.


A very important part in the JHA development process is to discover the hazards lurking within each step. A basic safety concept must be understood by all safety staff: to have an accident, a hazard and exposure to the hazard must exist.

  • A hazard is an unsafe condition that could cause injury or illness to an employee.

  • Exposure usually refers to an employee's placement relative to the hazard's "danger zone". If the employee is within the danger zone, the employee is exposed.

1. A/An _____ is an unsafe condition that could cause injury or illness to an employee.

a. accident
b. hazard
c. exposure
d. action

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How To Identify Hazards

Whoah! Where's the guard?

A job hazard analysis is an exercise in detective work. A very successful analysis method asks "who, what, where, why, when, and how" questions. Your goal is to discover the following:

  • Who is required to perform the task?
  • What can go wrong?
  • What are the consequences?
  • Where is the task performed?
  • when is the task performed?
  • How could the hazard arise?
  • What are contributing factors?
  • How likely is it that the hazard will occur?

To make your JHA useful, document the answers to these questions in a consistent manner. Describing a hazard by answering the questions above ensures you target the most important contributing factors to the hazard.

2. A successful method in conducting a Job Hazard Analysis involved asking _____ questions.

a. closed-ended true/false
b. yes-no questions
c. open-ended questions
d. who, what, where, why, how, and when

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How To Identify Hazards (Continued)

In the metal shop (environment), while clearing a snag (trigger), a worker’s hand (exposure) comes into contact with a rotating pulley. Thankfully, the worker acted fast and was able to pull his hand back before it was pulled into the machine. He reported the near-miss incident to his supervisor. The supervisor asked you to conduct a JHA on the worker's task to see if the hazard could be eliminated or effectively mitigated.

Let's look at the questions you might ask using the who-what-where-how-why method, and the findings will help you identify and correct the hazards inherent in this task:

  • What can go wrong? The worker's hand could come into contact with a rotating object that "catches" it and pulls it into the machine.

  • What are the consequences? The worker could receive a severe or fatal injury.

  • How could it happen? The accident could happen as a result of the worker trying to clear a snag during operations or as part of a maintenance activity while the conveyor is operating. Obviously, this hazard scenario could not occur if the conveyor is not rotating.

  • What are other contributing factors? The hazards and exposure related to this task can occur very quickly. It does not give the worker much opportunity to recover or prevent it once his hand comes into contact with the rotating rollers. This is an important factor, because it helps you determine the severity and likelihood of an accident when selecting appropriate hazard controls. Unfortunately, experience has shown that training is not very effective in hazard control when triggering events happen quickly because humans can react only so quickly.

  • How likely is it that the hazard will occur? This determination requires some judgment. If there have been "near-misses" or actual cases, then the likelihood of a recurrence would be considered high. If the pulley is exposed and easily accessible, that also is a consideration. In this example, the likelihood that the hazard will occur is high because there is no guard preventing contact, and the operation is performed while the machine is running. By following the steps in this example, you can organize your hazard analysis activities.

  • 3. Which is true regarding accidents?

    a. They can always be blamed on an unsafe behavior
    b. They most often occur in the morning
    c. They always occur due to a lack of common sense
    d. They are rarely the result of one single event

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Potential Hazards

Ask questions to uncover potential hazards.

To ensure all hazards are identified, analyze each step to uncover potential, as well as actual, hazards produced by both work environment and the action. During the JHA, after asking the who-what-where-when-why-how questions, ask "what-if" questions to identify potential hazards and exposures that may not be evident at first. See the underlined examples below.

Be sure to consider the following examples of what-if questions that serve as initial questions :

  • What if the worker hits a column? Is there danger of striking against, being struck by, or otherwise making harmful contact with an object?

  • What if an employee has to walk between moving machinery? Can the worker be caught in, by, or between objects?
  • What if workers have to work on wet floors? Is there potential for a slip or trip?
  • What if the worker has to climb a ladder to clean windows? Can the employee fall from one level to another or even on the same level?
  • What if an employee has to carry heavy boxes? Can pushing, pulling, lifting, lowering, bending, or twisting cause strain?
  • What if workers need to complete tasks in a cold workplace? Is the work environment hazardous to safety or health?
  • What if employees need to work in unventilated spaces? Are there concentrations of toxic gas, vapor, fumes, or dust?
  • What if an employee work in a noisy workspace? Are there potential exposures to heat, cold, noise, or ionizing radiation?
  • What if workers have to handle hazardous chemicals? Are there flammable, explosive, or electrical hazards?

4. After asking the who-what-where-when-why-how questions during the JHA, next ask _____ questions.

a. focused
b. what-if
c. open-ended
d. closed-ended

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Common Hazards and Descriptions

Physical and Chemical Properties - Mr. Causey Video

Chemical Properties

Chemical hazards are very common in all workplaces. Chemical properties are those that you can observe only if matter experiences a chemical chemical reaction. The definition of a chemical is "any element, chemical compound, or mixture of elements and/or compounds." Thus, virtually any product is a chemical.

Basic properties of hazardous chemical include:

Toxicity: Toxicity is the degree to which a chemical can poison or damage an organism. A toxic chemical exposes a person by absorption through the skin, inhalation, or through the blood stream that causes illness, disease, or death.

Reactivity: A reactive chemical is a solid, liquid, or gaseous chemical that has the power to cause irreversible damage or destroy another substance upon contact. Examples of reactive chemicals include acids, oxidizers, and bases.

What is a "BLEVE?"

Flammability: Flammability is a measure of how readily a chemical will ignite or flash. A chemical's flash point is the lowest temperature at which an ignition source causes the vapors above the liquid to ignite. Typically, the lower a chemical's flash point and boiling point, the more flammable it is. A chemical with a high flash point is considered a combustible.

Explosivity: Explosivity is a measure of the extent to which a material is explosive. An explosion is a substantially instantaneous release of gas and heat, unless the compound, mixture, or device. A "BLEVE" (boiling liquid expanding vapor explosion) is a sudden and violent release of a large amount of gas/energy due to a significant pressure difference, such as rupture in a boiler or compressed gas cylinder.

5. Typically, the lower a flammable chemical's flash point, _____ it is.

a. the less toxic
b. the more flammable
c. the less stable
d. the more reactive

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Common Hazards and Descriptions (Continued)

Electrical Hazards

Common Electrical Hazards -

Electrical (Shock/Short Circuit): Contact with exposed conductors or a device that is incorrectly or inadvertently grounded. Example: a metal ladder comes into contact with power lines. 60Hz alternating current (common household current) is very dangerous because it can stop the heart.

Electrical (Fire): Use of electrical power that results in electrical overheating or arcing to the point of combustion or ignition of flammables, or electrical component damage.

Electrical (Static/ESD): The moving or rubbing of wool, nylon, other synthetic fibers, and even flowing liquids can generate static electricity. This creates an excess or deficiency of electrons on the surface of material that discharges (spark) to the ground resulting in the ignition of flammables or damage to electronics or the body's nervous system.

Electrical (Loss of Power): Safety-critical equipment failure as a result of loss of power.

6. Which of the following is an example of a harmful electrical short circuit?

a. An electrical over-heat condition
b. A metal ladder contacting an exposed conductor
c. Rubbing wool, cotton, or nylon fabrics
d. Loss of electrical power to lights

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Common Hazards and Descriptions (Continued)

Other Hazards

Workplace Ergonomics - ASC Process Systems.

Ergonomics (Strain): Damage of tissue due to overexertion (strains and sprains) or repetitive motion.

Ergonomics (Human Error): A system design, procedure, or equipment that is error-provocative (A switch goes up to turn something off).

Excavation (Collapse): Soil collapse in a trench or excavation as a result of improper or inadequate shoring. Soil type is critical in determining the hazard likelihood.

Fall (Slip, Trip): Conditions that result in falls (impacts) from height or traditional walking surfaces (such as slippery floors, poor housekeeping, uneven walking surfaces, exposed ledges, etc.).

Fire/Heat: Temperatures that can cause burns to the skin or damage to other organs. Fires require a heat source, fuel, and oxygen.

Mechanical: Self-explanatory. Typically occurs when devices exceed designed capacity or are inadequately maintained. Skin, muscle, or body part exposed to crushing, caught-between, cutting, tearing, shearing items or equipment.

Noise: Noise levels (>85 dBA 8 hr TWA) that result in hearing damage or inability to communicate safety-critical information.

7. A switch that goes up to turn equipment off is an example of _____.

a. an ergonomic human error
b. a mechanical error
c. a physical error
d. a work practice error

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Common Hazards and Descriptions (Continued)

Vibration can be a serious hazard.

Radiation (Ionizing): Alpha, Beta, Gamma, neutral particles, and X-rays that cause injury (tissue damage) by ionization of cellular components.

Radiation (Non-Ionizing): Ultraviolet, visible light, infrared, and microwaves that cause injury to tissue by thermal or photochemical means.

Struck By (Mass Acceleration): Accelerated mass that strikes the body causing injury or death (Examples are falling objects and projectiles).

Struck Against: Injury to a body part as a result of coming into contact of a surface in which action was initiated by the person. (An example is when a screwdriver slips.)

Temperature (Heat/Cold): Temperatures that result in heat stress, extreme exhaustion, or metabolic slow down such as hypothermia.

Vibration: Segmental or whole-body vibration can cause damage to nerve endings, and organs.

Visibility: Lack of lighting or obstructed vision that results in an error or other hazard.

Weather Phenomena (Snow/Rain/Wind/Ice). Self-explanatory.

Let's see what the sample JHA looks like now that we've identified some hazards in each step.

8. Alpha, Beta, and Gamma particles are examples of _____.

a. photo-chemical radiation
b. ionizing radiation
c. visible radiation
d. non-ionizing radiation

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Sample JHA Worksheet

In the JHA form below, we have added some potential hazards and possible injuries that might occur as the worker performs each step in the form below.


1. Spotter: Spotter: Spot position of trailer as it nears loading dock. Spotter could be caught between trailer and dock.
2. Driver: When trailer is in position, turn engine off, set parking brake, and notify forklift operator. Driver could be injured if he/she jumps off the truck.
3. Driver: Set chocks. Driver could strike head on trailer.
Driver could trip, slip, fall while in the dock well.

9. What type of hazard would be listed in a JHA if an employee might receive a concussion if he did not wear a hard hat?

a. Fire/Heat
b. Fall
c. Vibration
d. Struck-by

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.

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