This key phase holds the most important lesson in keeping any workplace safe: before you can fix a problem, you have to know it exists.

In the world of machinery and workplaces, figuring out what dangers exist and how bad they are is called a Risk Assessment (RA). This process is usually mandatory, not optional, at multiple points in the lifecycle of a machine or process. The main goal is to eliminate or control dangers before any new machine, system, or protective feature is even switched on or used in a factory. Simply put, safety starts with good design driven by risk assessment. 

 

1. Step One: Find All the Dangers (Task / Hazard Identification)

A hazard is anything that has the potential to cause physical injury or damage to health.

Effective risk assessment begins with finding all the dangers, not just the obvious ones. This means looking for all reasonably foreseeable hazards. Identifying hazards requires looking at every stage of the equipment's life, not just when it is running smoothly:

  • Intended Use and Misuse: This includes figuring out how the machine is supposed to be used, as well as anticipating ways people might accidentally use it incorrectly ("foreseeable misuse").
  • Worker Tasks: You must look closely at what different people do, such as operators loading parts, or maintenance workers fixing components. This is how you identify when a person might meet a danger, which is called a "hazardous situation".
  • Complex Systems: In systems where robots and people work closely together (like collaborative robots), the risk assessment must consider the nearby presence of the human to figure out the right protective steps.

Specifically, if a company takes two or more separate machines and integrates them to create a single process, that company essentially becomes the manufacturer of the new combined machine and is responsible for assessing its risks.

If you miss a hazard in this step, if you don't write it down, you can't possibly protect against it.

 

2.Assessing the Danger: Severity, Frequency, and Avoidance

Once a danger (hazard) is found, you must assess the risk. Risk is the combination of how bad the resulting harm would be (severity) and the likelihood of that harm occurring.

To determine the likelihood of harm accurately, safety experts break it down into three factors:

  1. Severity of Injury (S): How bad will the injury be if the accident happens?
  2. Frequency of Access (F/E): How often and how long are people near the danger?
  3. Possibility of Avoidance (P/A): Could the person escape or limit the injury if something went wrong?

 

A. Severity of Potential Harm (S)

This factor assumes an injury is certain and asks for the magnitude of the resulting harm. Even if a severe injury is unlikely, the highest foreseeable severity must be considered.

  • S2 (Serious Injury): This is chosen if the harm could be irreversible, resulting in consequences like fatality (death), loss of consciousness, limb amputation, or other irreversible injuries (like permanent disability or broken bones).
  • S1 (Slight Injury): This is chosen if the harm is usually reversible, like a slight injury that only requires first-aid treatment or results in bruising or minor cuts.

B.Frequency of Exposure (F)

This factor quantifies how often a person needs to interact with or be near the identified hazard. It helps determine the chance of exposure.

  • F2 (Frequent/High Exposure): This rating applies if a person is frequently or continuously exposed to the hazard. For example, this applies if access is required multiple times per shift or more than once per hour. If tasks require frequent access to the machine during its cycle (ex: to feed workpieces), F2 should be selected.
  • F1 (Infrequent/Low Exposure): This applies if exposure is occasional or infrequent, such as tasks performed less than daily or less than once per 15 minutes. Infrequent tasks might include scheduled maintenance or tasks requiring lockout procedures.

C.Possibility of Avoidance (P)

This factor assesses the likelihood that a person can recognize the hazard and escape the harm before an injury occurs. This judgment relies heavily on the design speed, clearances, and human reaction time.

  • P2 (Not Likely or Not Possible): This is chosen if the injury is difficult or nearly impossible to avoid. This applies if:
    • The hazard is moving at a high speed (ex: faster than 250mm/s)
    • There is insufficient clearance to move out of the way.
    • There is inadequate warning or reaction time.
  • P1 (Likely or Possible): This is chosen if the person has a realistic chance of avoiding the accident or limiting its effect. This applies if:
    • There is sufficient clearance to move out of the way of the danger.
    • The hazard is moving slowly (at or less than 250 mm/s).
    • There is adequate warning and reaction time.

By assessing these factors for each task-hazard combination, the designer or user arrives at a quantifiable risk level. This level then dictates the level of integrity required for the safety function that controls that specific hazard. For example, the risk reduction reference chart uses the combination of Severity (S), Frequency (F), and Possibility of Avoidance (P) to prescribe a required performance level (PLr) or corresponding safety category (ex: Category 3 or 4).

 

3. Step Three: Fixing the Danger (Risk Reduction Hierarchy)

If the estimated risk is too high, you must reduce it to an acceptable level. This process is often repeated until the risk is managed effectively. Safety experts follow a strict, ordered set of steps called the Hierarchy of Risk Reduction Measures:

  1. Inherently Safe Design (Most Effective): This is the best step, where you either eliminate the hazard or make a design change that reduces the risk. For example, instead of needing a worker to manually handle material, you automate the task. Another example is reducing energy (ex: speed or force) or increasing clearance to eliminate pinch points.
  2. Engineering Controls (Safeguarding): If you can't remove the hazard by design, you must put protective systems in place. These are the guards and safety devices that prevent access or stop motion, such as interlocked gates or light curtains. They also need to have a circuit performance level as prescribed by the risk assessment.
  3. Administrative Controls and PPE (Last Resort): These are measures used to address any residual risk, the remaining risk that couldn't be eliminated by design or guards. These methods include:
    •  Awareness Means: Signs, warning lights (beacons, strobes) and alarms.
    • Procedures and Training: Written rules, job safety analyses (JSA, and required training.
    • Personal Protective Equipment (PPE): Items like safety glasses, hard hats, or gloves.

 

When to Ask for Help

Since achieving a workplace where risk is low enough to be acceptable requires specialized knowledge, many companies seek professional assistance.

If you are facing situations like:

  • Installing or modifying equipment that exposes workers to mechanical hazards, lasers, or substances.
  • Combining new equipment or processes into an existing factory.
  • Dealing with complex machinery or or integrated systems

You may require a Pre-Start Health and Safety Review (PHSR / PSR). A PSR is an in-depth, documented examination. The goal of this review is to conduct a high-level professional evaluation to identify and address hazards before the machinery is used, saving costs and, most importantly, making the workplace safer.

 

Example: Classifying a Laser Hazard Zone

Consider working with a high-power industrial laser, such as a CO2 with beam tubes requiring alignment. You might have a service contractor do this, but employers are often held accountable for contractors on their site.

  1. Identification (The Hazard): The hazard is the intense laser beam, which can cause severe, irreversible eye damage (S2/Catastrophic).The most dangerous scenario is exposure to the direct beam or a specular (mirror-like) reflection.
  2. Risk Estimation (S, F, A): If the task requires frequent access near the beam, such as with beam alignment (F2/Frequent), and the beam is invisible (P2/Not Likely to Avoid), the risk is extremely high.
  3. Control (Protection): The only way to control this is through Engineering Controls (like interlocks for the beam tubes, the preferred method) and Administrative Controls (such as specialized laser protective eyewear and laser curtains for passerby, ex: PPE, used as a last line of defence).

If you fail to identify the possibility of an errant reflection from a misplaced tool as a unique hazard, you might rely solely on procedures for the direct beam. You have controlled the obvious risk, but the unidentified hazard (the reflection) remains uncontrolled, demonstrating that you will never control a hazard you don't identify. Proper hazard identification determines the level of control required to achieve a safe workplace.