In occupational safety and health (especially in construction), which of the following definitions best describes a physical hazard?

Introduction / Context:
In occupational safety and health, hazards are often grouped into categories such as physical, ergonomic, chemical and biological. Each category has a specific definition and examples that help safety professionals identify and control risks at workplaces, especially on construction sites. This question asks you to select the definition that correctly matches a physical hazard.

Given Data / Assumptions:

• Physical hazards relate to environmental conditions like noise, vibration, radiation and temperature.
• Ergonomic hazards relate to how work is performed, including lifting and repetitive movements.
• Chemical hazards come from substances such as dusts, fumes and vapours.
• Biological hazards come from living organisms such as bacteria and viruses.

Concept / Approach:
A physical hazard is any environmental factor that can harm the body without necessarily touching it directly as a chemical or biological agent. Examples include loud noises that can damage hearing, vibration that can affect circulation or nerve function, extreme hot or cold conditions that can cause heat stress or hypothermia and different forms of radiation such as ionising radiation and ultraviolet light. Ergonomic hazards are different because they involve the design of work tasks and can cause musculoskeletal injuries. Chemical hazards involve harmful substances, while biological hazards involve infectious organisms. Therefore, the definition that lists radiation, temperatures, noise and vibration is clearly describing physical hazards.

Step-by-Step Solution:
Step 1: Recall the standard categories of workplace hazards: physical, ergonomic, chemical and biological.Step 2: Match radiation, extreme heat or cold, noise and vibration to the physical hazard category, as they involve environmental energy and conditions.Step 3: Recognise that heavy lifting and repetitive tasks describe ergonomic hazards that affect muscles, joints and posture.Step 4: Identify that dust, fumes, liquids, mists, vapours and gases are examples of chemical hazards.Step 5: Identify that microorganisms such as bacteria, fungus, mould and viruses are biological hazards.Step 6: Conclude that option A, which lists radiation, temperatures, noise and vibration, is the correct definition of a physical hazard.

Verification / Alternative check:
Occupational safety guidelines, such as those from national safety agencies, consistently classify noise, vibration, radiation and temperature extremes as physical hazards. Training materials for construction workers also treat lifting technique and repetitive strain injuries separately under ergonomic hazards, while material safety data sheets cover chemical hazards and infection control guidelines address biological hazards. This clear separation confirms the mapping from the options to each hazard type.

Why Other Options Are Wrong:
Option B describes ergonomic hazards because it focuses on tasks that strain the musculoskeletal system. Option C describes chemical hazards arising from substances in different physical forms such as dust or vapour. Option D describes biological hazards caused by microorganisms that can lead to infection. None of these match the standard definition of a physical hazard.

Common Pitfalls:
Students may confuse physical and ergonomic hazards because both can result in bodily harm. Others may lump all invisible hazards together without distinguishing chemical, physical and biological types. To avoid confusion, remember that physical hazards are about environmental conditions and forms of energy, ergonomic hazards are about the way work is organised and performed, chemical hazards are about substances and biological hazards are about living organisms.

Final Answer:
A physical hazard is best described as exposure to things like radiation, extreme temperatures, noise and vibration.