Common Hazards in Construction Sites and How to Control Them
Construction sites are inherently hazardous environments with constantly changing conditions, heavy equipment, and diverse activities. Identifying and controlling hazards is crucial to protecting workers and complying with safety regulations. This article explains the most common hazards on construction sites and outlines practical control measures to reduce risk ā complete with exam-oriented questions and FAQs.
1. Falls from Height
1.1 Why Itās a Hazard
Falls are the leading cause of fatalities in construction. They occur from ladders, scaffolds, roofs, and unprotected edges.
1.2 Examples
- Workers on scaffolds without guardrails.
- Improperly secured ladders.
- Open floor openings without covers.
1.3 Control Measures
- Install guardrails and toe boards on scaffolds.
- Use fall arrest systems (harnesses, lifelines).
- Secure ladders at correct angles and inspect before use.
- Cover and mark floor openings.
- Provide training on working at height.
2. Struck-By Hazards
2.1 Why Itās a Hazard
Workers can be struck by moving vehicles, falling tools, swinging loads, or flying debris.
2.2 Examples
- Crane loads swinging over workers.
- Vehicles operating in pedestrian areas.
- Tools falling from scaffolds.
2.3 Control Measures
- Barricade and signpost hazardous areas.
- Use tool lanyards to prevent dropped objects.
- Establish vehicle-pedestrian separation zones.
- Provide high-visibility clothing and training.
3. Caught-In or Between Hazards
3.1 Why Itās a Hazard
Workers can get caught in or between equipment, machinery, or collapsing structures.
3.2 Examples
- Getting trapped between heavy equipment and walls.
- Collapse of trenches or excavation walls.
3.3 Control Measures
- Maintain safe clearance around machinery.
- Use trench boxes or shoring for excavations.
- Implement lockout/tagout procedures for equipment maintenance.
- Train workers on hazard awareness.
4. Electrical Hazards
4.1 Why Itās a Hazard
Construction involves temporary wiring, power tools, and overhead lines, increasing electrocution risks.
4.2 Examples
- Contact with live wires or cables.
- Damaged power cords on tools.
- Working near overhead power lines.
4.3 Control Measures
- Use ground-fault circuit interrupters (GFCIs).
- Inspect and repair electrical cords regularly.
- De-energise circuits before work.
- Maintain safe clearance from overhead lines.
- Train workers in electrical safety.
5. Manual Handling and Ergonomic Hazards
5.1 Why Itās a Hazard
Lifting, carrying, and awkward postures cause musculoskeletal injuries.
5.2 Examples
- Repeatedly lifting heavy materials.
- Working in cramped spaces.
5.3 Control Measures
- Provide mechanical lifting aids.
- Plan material storage to reduce carrying distances.
- Train workers in proper lifting techniques.
- Rotate tasks to reduce strain.
6. Hazardous Substances
6.1 Why Itās a Hazard
Workers may be exposed to chemicals such as solvents, asbestos, silica dust, or welding fumes.
6.2 Examples
- Cutting concrete without dust control.
- Inadequate ventilation during painting or welding.
6.3 Control Measures
- Use dust suppression and local exhaust ventilation.
- Provide appropriate PPE like respirators.
- Substitute less hazardous materials when possible.
- Train workers on handling hazardous substances.
7. Noise and Vibration
7.1 Why Itās a Hazard
Loud machinery and vibrating tools can cause hearing loss or hand-arm vibration syndrome.
7.2 Control Measures
- Use quieter equipment where possible.
- Install barriers or enclosures.
- Limit exposure time through job rotation.
- Provide hearing protection and anti-vibration gloves.
8. Poor Housekeeping
8.1 Why Itās a Hazard
Cluttered walkways and unorganised materials increase the risk of slips, trips, and falls.
8.2 Control Measures
- Implement daily housekeeping practices.
- Store materials properly and dispose of waste promptly.
- Mark and clear walkways.
9. Weather-Related Hazards
9.1 Why Itās a Hazard
Construction work is often outdoors, exposing workers to extreme heat, cold, or storms.
9.2 Control Measures
- Provide shelters and rest areas.
- Adjust schedules to avoid peak heat or cold.
- Train workers on recognising weather-related illnesses.
10. Implementing a Construction Site Hazard Control Program
- Conduct regular site inspections and risk assessments.
- Integrate hazard control into toolbox talks and permits-to-work.
- Involve workers in hazard reporting and control selection.
- Keep emergency response plans updated.
For detailed guidance, visit OSHAās Construction Safety page.
Exam-Oriented Questions with Detailed Answers
Short Answer Questions
Q1. Name four common hazards on construction sites.
Answer: Falls from height, struck-by hazards, electrical hazards, and hazardous substances.
Q2. What is the main control for trench collapse hazards?
Answer: Using trench boxes or shoring to support excavation walls.
Q3. List two ways to prevent dropped objects from scaffolds.
Answer: Use tool lanyards and install toe boards or netting.
Long Answer Questions
Q1. Describe the control measures for fall hazards in construction.
Answer: Install guardrails and toe boards, use fall arrest systems like harnesses and lifelines, secure ladders at proper angles, cover and mark floor openings, and train workers on working at height.
Q2. Explain how to manage hazardous substances like silica dust on construction sites.
Answer: Use dust suppression methods like wet cutting or local exhaust ventilation, substitute less hazardous materials if possible, provide respirators and other PPE, and train workers on safe handling procedures.
Q3. Discuss how housekeeping affects construction site safety.
Answer: Poor housekeeping leads to cluttered walkways, increasing slips, trips, and falls. Good housekeeping ensures clear paths, proper material storage, and prompt waste disposal, reducing injuries and improving efficiency.
Scenario-Based Questions
Q1. A worker is assigned to cut concrete without dust controls. What controls should be implemented?
Answer: Use wet cutting or dust extraction systems (engineering control), limit exposure time, provide respirators, and train the worker on silica hazards.
Q2. A crane operator is moving a heavy load over workers. Whatās wrong and how should it be addressed?
Answer: Loads should never pass over workers. Barricade and clear the area below, use taglines, and ensure communication between the operator and ground staff.
Q3. Workers are working near an overhead power line. What precautions should be taken?
Answer: Maintain safe clearance distances, de-energise the line if possible, use spotters, and train workers on electrical hazards.
Frequently Asked Questions (FAQs)
1. What are the top hazards on construction sites?
Answer: Falls from height, struck-by hazards, caught-in/between hazards, electrical hazards, hazardous substances, and poor housekeeping.
2. How can construction site hazards be identified?
Answer: Through regular inspections, risk assessments, worker feedback, and incident analysis.
3. Why is PPE the last line of defence?
Answer: Because it doesnāt eliminate the hazard ā it only protects the worker if exposure occurs.
4. How often should toolbox talks be conducted on construction sites?
Answer: At least weekly, and before high-risk tasks or when conditions change.
5. Can weather be considered a hazard in construction?
Answer: Yes. Extreme heat, cold, rain, or storms can create dangerous conditions requiring adjustments to work schedules and controls.
6. Whatās the best way to engage workers in hazard control?
Answer: Involve them in hazard identification, selection of controls, and regular safety meetings.
11. Conclusion
Construction sites present a wide range of hazards, from falls and struck-by incidents to chemical exposures and poor housekeeping. By identifying these hazards and applying controls according to the hierarchy ā starting with engineering solutions, supported by administrative measures and PPE ā safety professionals can significantly reduce risks and improve site safety.
Engineering Controls vs Administrative Controls vs PPE
Task Based Risk Assessment (TBRA): A Step-by-Step Guide
How to Conduct a Job Safety Analysis (JSA) to Identify Hazards
Quantitative vs Qualitative Risk Assessment: Which One to Use?
ļ»æPsychosocial Hazards: Stress, Fatigue, and Workplace Violence
