Step 3: Controlling Hazards and Exposure
Traditionally, a prioritized Hierarchy of Controls (HOC) has been used to implement hazard and exposure controls to protect workers.
We recommend using the HOC as described in ANSI/ASSP Z10, Occupational Health and Safety Management Systems, to control hazards. The six hazard-exposure strategies are discussed below.
Hazard Controls: The first three control methods focus on controlling the hazard.
- Elimination: The best solution is to totally eliminate the hazard. For instance, a simple way to eliminate the need to work at elevation is to eliminate the need to use a ladder to change ceiling light bulbs by using a extension pole.
- Substitution: Substitution is the next-best solution. For instance, the employer might replace large heavy containers with smaller containers.
- Engineering: Hazards are controlled through the design or redesign of equipment and machinery. In this case, printing equipment might be designed to prevent the possibility of a worker getting caught by a rotating shaft. Machines and equipment may be designed with machine safety guards and other types of physical barriers to isolate the hazards from exposure.
Exposure Controls: The final three control methods focus on controlling behaviors to reduce exposure to the hazard. They are prioritized lower because they work only so long as employees comply with the controls' requirements. Unfortunately, safety management systems that rely solely on compliance behaviors are inherently less reliable.
- Warnings: Warnings are awareness-level controls that can help to isolate employees from hazards by alerting employees. Warnings may be visual, audible, or both. They may also be tactile. Visual warnings include signs, labels, tags, and lights. Audible warnings include alarms, bells, beepers, sirens, horns, and announcement systems. Tactile warnings may include vibration devices or air fans. For example, a sign would be posted at the entrance a confined space forbidding entry.
- Work Practices: These controls are less effective and pose a challenge because supervisors must regularly monitor their employees as they perform tasks. Examples include written safety policies, procedures, rules, supervision, and training. Bottom line, these controls work only so long as employees follow them.
- Personal Protective Equipment (PPE): The use of PPE is probably the most common control method used for controlling hazards. PPE forms a barrier between workers and hazards effectively isolating the hazard from the worker. For instance, knee pads might be used to protect the knees when laying carpet.
Interim Measures
Using a lower priority hazard control method over another higher priority control strategy may be appropriate for providing interim (temporary) protection until the hazard is abated permanently. If you can't eliminate the hazard entirely, the interim control measures will likely be a combination of control methods used together. OSHA believes that feasible interim measures are always available if higher-level control methods are not possible.
In December 2025, an Oregon OSHA inspection at a manufacturing facility identified hazards that exposed workers to struck-by/crushing risks from improperly installed or damaged storage racks (including unanchored baseplates) and to hand/finger injury risk from an unguarded belt sander. Using the Hierarchy of Controls, the safest response is to prioritize controls that remove or engineer out the hazard rather than relying mainly on employee behavior.
Hazard Controls (highest priority — control the hazard)
- Elimination: Remove the need for workers to access heavy materials stored at height by redesigning material flow so heavy stock is staged or stored at ground level, or delivered directly to point-of-use.
- Substitution: Reduce the hazard by changing how materials are handled—store the same material in smaller, lighter containers so less mass is elevated and handled at one time.
- Engineering: Fix the physical system—install and maintain racks to manufacturer specifications (anchoring, repair/replacement of damaged parts, correct installation) and guard moving parts on the belt sander so hands cannot contact hazardous components.
Exposure Controls (lower priority — reduce exposure through compliance)
- Warnings: Use clear signage and visual cues (load ratings, exclusion zones, and machine hazard labels) to alert workers to hazards.
- Work Practices: Implement procedures and supervision—routine rack inspections, documented storage limits, forklift operating rules, and safe-use procedures for equipment.
- PPE: Use PPE as a last line of defense (e.g., hard hats and safety footwear). PPE does not remove the hazard; it only reduces injury severity if other controls fail.
Interim Measures (temporary protection)
Until racks are repaired/anchored and the sander is properly guarded, use interim controls such as reducing stack height, isolating affected rack aisles, restricting access, and stopping or limiting machine use—then replace interim steps with higher-level controls as soon as feasible.
Knowledge Check Choose the best answer for the question.
5-9. Which Hierarchy of Control method controls hazards through design or redesign?
You forgot to answer the question!