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

Correcting Hazards

Once hazards have been identified, it's important that they be corrected immediately.


In the last module, we examined the inspection and JHA processes to identify hazardous conditions and unsafe behaviors in the workplace. Once hazards have been identified, it's important that they be corrected immediately or as soon as possible.

Once hazardous conditions or unsafe behaviors are identified, it's important that the supervisor makes sure they are eliminated or reduced as soon as possible. To do this, one or a combination of the control strategies within the "Hierarchy of Controls" should be used.

In this module, we will look at the Hierarchy of Controls and how they can effectively correct identified hazards. For more information on improving the safety management system, see courses 704 Hazard Identification and Control and course 716 Safety Management System Evaluation.

1. Hazard control strategies attempt to eliminate or reduce ________.

a. probability of severity and severity of near miss
b. exposure to hazards and probability of severity
c. hazards and exposure to hazards
d. unsafe behaviors and poor performance

Next Section

Controlling Hazards and Behaviors

Hierarchy of Controls
Click to enlarge

Controlling hazards and behaviors are the two basic strategies for protecting workers. Controlling hazards are more effective than controlling behaviors, and for good reason. If you can eliminate the hazard, you don't have to worry about exposure because of human behavior. Traditionally, a "Hierarchy of Controls" has been used as a template for implementing feasible and effective controls.

ANSI/ASSP Z10-2019, Occupational Health and Safety Management Systems, and ISO 450001, Occupational Health and Safety, encourage employers to use the following hierarchy of hazard controls:

Controlling Hazards

  1. Elimination: "Design out" hazards and hazardous exposures.
  2. Substitution: Substitute less-hazardous materials, processes, operations, or equipment.
  3. Engineering controls: Isolate process or equipment or contain the hazard.

Controlling Behaviors

  1. Warnings: To raise awareness of the hazards to which employees may be exposed, warnings in the form of signs, placards, cones, and barriers are used.
  2. Administrative/work practice controls: Job rotation, work scheduling, training, well-designed work methods, and organization are examples.
  3. Personal protective equipment: Includes but is not limited to safety glasses for eye protection; ear plugs for hearing protection; clothing such as safety shoes, gloves, and overalls; face shields for welders; fall harnesses; and respirators to prevent inhalation of hazardous substances.

As you can see, the preferred control strategies first try to control hazards through elimination, substitution, or engineering. If the hazards can't be eliminated, replaced, or engineered, the hierarchy next attempts to control exposure to hazards through warnings, administrative methods and personal protective equipment. It's important to understand that:

  • Elimination, substitution, and engineering controls are independent: they do not rely on behavior to be effective: that's why they are preferred.
  • Warnings, administrative, work practice, and PPE controls are dependent: they rely on compliant human behavior to be effective. Any solution that relies on human behavior is inherently unreliable in the long term.

The "big 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 of controls leads to the implementation of inherently safer workplace environments, where the risk of illness or injury has been substantially reduced.

2. The Hierarchy of Controls attempts to prevent injuries by controlling ____ and _____.

a. stress, workload
b. employees, procedures
c. attitudes, unsafe practices
d. hazards, behaviors

Next Section


RF 123 Stock Photo
How can you eliminate the hazard of using a ladder when changing a light bulb?

Totally eliminating hazards, while most effective at reducing exposure to hazards, also tends to be the most difficult to implement in an existing process. This approach involves the initial design or redesign of tools, equipment, systems, production processes, and facilities in order to eliminate hazards associated with work.

If the machinery, equipment, or process is still at the design or development stage, eliminating hazards may be inexpensive and simple to implement. However, for an existing process, major changes can be very expensive. In the long term, even expensive changes that eliminate serious hazards may be cost effective.

Examples of elimination controls include:

  • using exhaust ventilation to eliminate a hazardous atmosphere;
  • using two-hand controls, safety switches, and hand guards to prevent "caught-in" and other accidents;
  • using ergonomically-designed tools to prevent cumulative trauma and other disorders;
  • placing noisy equipment inside an enclosure to reduce excessive noise; and
  • using extension poles to replace ceiling light bulbs.

3. Which Hierarchy of Controls strategy is considered most effective?

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

Next Section


RF 123 Stock Photo
Replace toxic chemicals with non-toxic chemicals.

If you can't eliminate the hazard, then your next-best strategy is to reduce it's severity by replacing it with something that is less hazardous to an exposed employee.

Examples include:

  • Replacing inappropriate tools with those that are designed for the task;
  • Replacing a toxic chemical with a less/non toxic chemical; and
  • Replacing hazardous materials such as abrasives with non-abrasives.

Replacing hazardous chemicals, materials, tools, equipment, or machinery may be expensive, but not as expensive as the average accident costs of a serious injury (over $40,000) or a fatality (over $1 million).

4. If you can't eliminate the hazard, then your next-best strategy is to _____.

a. install warning signs to keep employees clear
b. train employees more frequently
c. replace it with something less hazardous
d. create safety rules to prevent exposure

Next Section

Engineering Controls

RF 123 Stock Photo
Good design isolates the hazard and protects employees.

Engineering controls use Prevention through Design (PtD) methods to prevent injuries and illnesses by "designing out" the hazards and risks. This approach involves the design or redesign of tools, equipment, systems, work processes, and facilities in order to reduce or eliminate the hazards associated with work.

PtD considers what is needed to protect workers throughout the life cycle process, machinery and/ or process is being designed. The life cycle starts with concept development, and includes design, construction or manufacturing, operations, maintenance, and eventual disposal of whatever is being designed, which could be a facility, a material, or a piece of equipment.

It's worth saying again, well-designed engineering controls are highly effective in protecting workers and will typically be independent of worker interactions to provide this high level of protection: no matter what workers do, they won't be exposed to hazards.

Examples of effective engineering controls include:

  • using exhaust ventilation to eliminate a hazardous atmosphere;
  • using two-hand controls, safety switches, and hand guards to prevent "caught-in" and other accidents;
  • using ergonomically-designed tools to prevent cumulative trauma and other disorders;
  • placing noisy equipment inside an enclosure to reduce excessive noise; and
  • using extension poles to replace ceiling light bulbs.

When considering engineering controls, think about the feasibility, costs, and ease of implementation of replacing or redesigning the equipment. OSHA expects your employer to consider these first three control strategies before employing administrative controls or personal protective equipment (PPE).

5. Why are well-designed engineering controls considered highly effective in protecting workers?

a. They are independent of worker interactions
b. They are less expensive than other control measures
c. They cost less money for the same degree of efficiency
d. They depend only on proper education and training

Next Section


With the release of ANSI Z10-2012, "warnings" have been promoted to their own hierarchy level. Previously, they were part of administrative controls. Warnings do not prevent exposure to a hazard, but they do provide a visual or audible indicator to warn people of potential danger.

Image of Feasibility
Signs can be used to warn people of potential hazards.

Warnings can be visual, audible, or both. They may also be tactile. Some examples of warnings are:

  • Visual. Signs, labels, tags, and flashing/strobe lights.
  • Audible. Alarms, bells, beepers, sirens, announcement system and horns.
  • Tactile. Vibration devices or air fans.

For instance, a door could have both a sign warning of a hazard as well as an alarm if opened. Warnings can be effective deterrents, but are not as effective as elimination, substitution, or engineering controls.

OSHA Signs

OSHA's 1910.145, Specifications for accident prevention signs and tags details the following types of signs:

  • Danger Signs - Signs that alert people to specific and immediate dangers (including radiation hazards).
  • Warning Signs - Signs that warn people of potential hazards that can lead to death.
  • Caution Signs - Signs used to alert people to potential hazards. This class can caution people against certain unsafe practices. This class is for hazards that can result in minor (non-life threatening) accident or injury.
  • Safety Instruction Signs - These signs offer instructions for how someone should act or perform to avoid potential hazards.

One potential problem when using warnings is the misinterpretation of the warning itself. Does the symbol or text clearly explain what the hazard is to the public? For example, if a sign only contains a written warning, someone might read the sign but not know what the warning means. Or, if an alarm sounds, what does the alarm mean? These are challenges when using warnings and why they are not as effective as higher-level controls.

6. If employees see the same signs repeatedly over a period of time they _____.

a. will learn how to take short cuts
b. may eventually ignore them
c. want to take them down
d. will not believe them

Next Section

Administrative Controls

RF 123 Stock Photo
Administrative controls use policies and procedures. These controls depend on worker compliance.

When exposure to the risk is not, or cannot, be minimized by other means, you should introduce administrative and work practice controls to reduce the risk. Administrative controls address how the work is to be performed, and direct people to work in a safe manner. They help establish effective processes and procedures in the workplace that reduce risk of injury and illness.

Click on the button to see a examples of administrative controls.

  • Limiting the amount of time someone is exposed to hazards.
  • Written operating procedures.
  • Safety and health policies, rules, and guidelines for employees.
  • Alarms, signs, and labels.
  • Use of the "Buddy system," especially in hazardous operations.
  • Training on safe work practices and procedures
  • Requiring two or more workers to lift heavy loads
  • Worker rotation to minimize the duration of exertion, repetitive motions, and awkward/uncomfortable positions.
  • Written operating procedures, work permits, and safe work practices
  • Procedures that ensure workers are using and maintaining pneumatic and power tools properly

Work practice controls. These controls also focus on the way workers do their jobs to reduce exposure to hazards. Work practice controls help to limit exposure by decreasing the following factors:

  • the frequency of exposure to the hazard,
  • the duration of the task that exposes the employee to the hazard, and
  • the number of employees exposed to the hazard.

Preventive Maintenance. The best way to prevent breakdowns or failures is to monitor and maintain your equipment regularly. Determine what hazards could occur if your equipment is not maintained properly and plan to detect failures before they occur.

Administrative and work practice controls used as the primary controls for protecting workers have also proven to be less effective than elimination, substitution, and engineering because the focus is on controlling employee behaviors rather than hazards. An important principle to remember is that "any system that relies on behavior is inherently unreliable."

7. Under the Hierarchy of Controls, safety rules, scheduling, and training are examples of _____.

a. Elimination and substitution
b. Engineering controls
c. Administrative controls
d. Personal Protective equipment

Next Section

Personal Protective Equipment (PPE)

RF 123 Stock Photo
PPE works only when workers properly use it.

Personal protective equipment is equipment worn to minimize exposure to hazards that cause serious workplace injuries and illnesses. These injuries and illnesses may result from contact with chemical, radiological, physical, electrical, mechanical, or other workplace hazards. Personal protective equipment may include items such as gloves, safety glasses and shoes, earplugs or muffs, hard hats, respirators, or coveralls, vests, and full body suits.

When engineering, work practice, and administrative controls are not feasible or do not provide sufficient protection, employers must provide personal protective equipment to their workers and ensure its proper use. PPE should be used in conjunction with, not instead of, the other hazard control strategies. A common mistake some managers and supervisors make is that they try to save a little money when purchasing PPE. Do not skimp on quality PPE: it can save a life.

Employers are also required to train each worker required to use personal protective equipment to know:

  • Why it is necessary
  • When it is necessary
  • What kind is necessary
  • How to properly put it on, adjust, wear and take it off
  • The limitations of the equipment
  • Proper care, maintenance, useful life, and disposal of the equipment

If PPE is to be used, a PPE program should be implemented. This program should address the hazards present; the selection, maintenance, and use of PPE; the training of employees; and monitoring of the program to ensure its ongoing effectiveness.

8. What is a common mistake some managers and supervisors make when they purchase PPE?

a. They neglect other hazard control strategies
b. They neglect the advice of the safety committee
c. They try to save a little money when purchasing PPE
d. They assume PPE is the only protection required by OSHA

Check your Work

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 recheck your answers.


Hierarchy of Controls

Hierarchy of hazard control is a system used in industry to minimize or eliminate exposure to hazards. It is a widely accepted system promoted by numerous safety organizations. This concept is taught to managers in industry, to be promoted as standard practice in the workplace. Credit: Pertrain Pty Limited (2:06)

Next Module

OSHAcademy Ultimate Guide Banner Ad