LO2: Risks to Health and Safety

AC2.1 — Hazards on a Construction Site

A hazard is anything that has the potential to cause harm. Construction sites are full of hazards because of the nature of the work — heavy materials, powerful machinery, working at height, and many different trades working in the same space.

Hazards can be grouped into categories:

Physical Hazards

Physical hazards are the most common type on a construction site.

Hazard	Example
Working at height	Scaffolding, roofwork, ladders, open floor edges
Moving plant and vehicles	Excavators, dumper trucks, forklift trucks
Manual handling	Lifting bricks, blocks, timber, pipes
Hand-arm vibration (HAV)	Using drills, disc cutters, compactors
Whole-body vibration	Operating plant on rough ground
Noise	Power tools, compressors, pile driving
Falling objects	Materials or tools dropped from height
Excavations and trenches	Risk of collapse or falling in
Electricity	Overhead power lines, buried cables, site wiring
Structural instability	Partially demolished or newly erected structures
Slips, trips and falls	Uneven ground, mud, wet surfaces, trailing cables
Confined spaces	Manholes, drainage trenches, tanks

Chemical Hazards

Hazard	Example
Silica dust	Cutting, grinding or drilling concrete, stone or brick
Cement and lime	Skin and eye contact — can cause burns and dermatitis
Asbestos	Found in older buildings being refurbished or demolished
Solvents	Adhesives, paints, varnishes — inhalation or skin contact
Carbon monoxide	Petrol/diesel engines running in enclosed spaces
Lead	Old paintwork in refurbishment projects

Biological Hazards

Hazard	Example
Leptospirosis (Weil’s disease)	Contact with water or soil contaminated by rat urine
Tetanus	Cuts and wounds exposed to contaminated soil
Legionella	Water systems in buildings being refurbished

Ergonomic Hazards

These relate to the way work is carried out and how it affects the body over time.

• Repetitive movements (e.g. using a trowel)
• Awkward postures (e.g. working in confined spaces or overhead)
• Poorly designed tools or workstations

Psychosocial Hazards

• Work-related stress from tight deadlines, long hours, or poor management
• Bullying and harassment on site

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AC2.2 — Risks Associated with Hazards

A risk is the likelihood that a hazard will actually cause harm, combined with the severity of that harm. The same hazard can present different levels of risk depending on the situation.

Hazard = the source of danger Risk = the chance that harm will result

Risks from Working at Height

Working at height is the single biggest cause of fatal and major injuries in construction. Risks include:

• Falls from scaffolding — can cause fatal head injuries, spinal injuries, multiple fractures
• Falls through fragile roofs — skylights and roof lights are a common cause of falls
• Falls from ladders — often due to overreaching or using a ladder in poor condition
• Falling objects — tools or materials dropped from height can kill workers below

Risks from Moving Plant and Vehicles

Construction vehicles are involved in a significant number of fatalities each year:

• Workers being struck by reversing vehicles — particularly dumper trucks and excavators
• Workers being run over — poor visibility from cab, no banksman present
• Overturning of plant on unstable ground
• Collisions between plant and other site traffic

Risks from Manual Handling

Manual handling injuries account for over a third of all workplace injuries:

• Back injuries — sprains and strains, prolapsed discs
• Upper limb disorders — shoulder, arm and wrist injuries
• Crush injuries — materials slipping or falling while being carried

Risks from Hand-Arm Vibration

Prolonged use of vibrating tools can cause Hand-Arm Vibration Syndrome (HAVS):

• Vibration White Finger (VWF) — reduced blood flow causes fingers to turn white and numb in cold conditions
• Permanent damage to nerves and blood vessels — the condition is irreversible once it develops

Risks from Noise

Exposure to high levels of noise causes noise-induced hearing loss (NIHL):

• Gradual and permanent — workers often don’t notice until significant damage is done
• Tinnitus (ringing in the ears)
• The Control of Noise at Work Regulations 2005 sets action levels:
  • 80 dB(A) — employer must provide information and make hearing protection available
  • 85 dB(A) — employer must provide hearing protection and ensure it is worn

Risks from Hazardous Substances

Substance	Associated Disease / Condition
Silica dust	Silicosis (irreversible lung scarring), lung cancer
Asbestos	Mesothelioma, asbestosis, lung cancer — often fatal
Cement	Contact dermatitis, chemical burns
Solvents	Dermatitis, headaches, damage to liver/kidneys with long-term exposure

Risks from Excavations

• Collapse of trench sides — can bury workers, causing fatal crush injuries or asphyxiation
• Flooding — from surface water or underground water
• Striking buried services — gas, water, electricity and telecommunications cables

Risks from Electricity

• Electrocution — striking buried cables during excavation or drilling; contact with overhead lines
• Arc flash — intense heat and light from electrical arc
• Fire — faulty wiring or overloaded circuits

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AC2.3 — Risk Assessments

A risk assessment is a systematic examination of work activities to identify hazards, evaluate the likelihood and severity of harm, and decide on appropriate control measures.

Under the Management of Health and Safety at Work Regulations 1999, employers with five or more employees must carry out and record risk assessments.

The Five Steps of Risk Assessment

Step 1 — Identify the hazards

• Walk around the site and look at what could cause harm
• Consult workers — they often know about hazards the manager hasn’t noticed
• Check accident books and near miss reports
• Consult manufacturers’ data sheets for hazardous substances

Step 2 — Decide who might be harmed and how

• Consider all groups: site workers, subcontractors, visitors, members of the public
• Think about people with particular vulnerabilities — new workers, young workers, those with disabilities, pregnant workers

Step 3 — Evaluate the risks and decide on precautions

• Consider how likely it is that harm will occur and how serious that harm would be
• Use the hierarchy of control (see below) to decide what controls are needed
• Consider what is already in place and whether more needs to be done

Step 4 — Record your findings and implement them

• Write down the significant hazards, the people affected, and the controls in place
• A risk assessment must be suitable and sufficient — it does not need to be perfect, but it must be genuine
• Put the controls into practice

Step 5 — Review and update

• Risk assessments should be reviewed regularly and whenever:
  • There is a significant change in the work
  • An accident or near miss occurs
  • A new hazard is identified

The Hierarchy of Control

The hierarchy sets out the preferred order of control measures, from most to least effective:

Level	Control Measure	Example
1. Elimination	Remove the hazard entirely	Design out working at height — use pre-fabricated components
2. Substitution	Replace with something less hazardous	Use water-based paint instead of solvent-based
3. Engineering controls	Physical measures to reduce exposure	Guarding on machinery, local exhaust ventilation, edge protection
4. Administrative controls	Systems of work to reduce exposure	Permits to work, job rotation, toolbox talks, safe systems of work
5. PPE	Personal protective equipment	Hard hats, gloves, high-visibility vests, respirators

PPE is always the last resort — it protects only the wearer and relies on it being worn correctly at all times. Controls higher up the hierarchy are always preferable.

Risk Rating

Risk is often evaluated using a risk matrix that considers:

• Likelihood — how probable is it that harm will occur? (e.g. 1 = unlikely, 5 = almost certain)
• Severity — how serious would the harm be? (e.g. 1 = minor first aid, 5 = fatality)

Risk rating = Likelihood × Severity

A high risk rating means action is needed urgently. Controls are applied to reduce the likelihood and/or severity of harm, bringing the risk rating down to an acceptable level.

Method Statements

A method statement (also called a safe system of work) is often used alongside a risk assessment. It describes, step by step, how a task will be carried out safely. Together, a risk assessment and method statement are known as RAMS.

Method statements are commonly required for:

• Working at height
• Working near buried services
• Demolition
• Working in confined spaces
• Hot works (welding, cutting)