Safe vs. Unsafe Behaviour: Understanding the 90% Factor in Workplace Accidents

Every day in workplaces across the UK, thousands of decisions are made that impact safety. Some lead to safe outcomes, whilst others put workers at risk. But what percentage of workplace accidents are actually caused by unsafe behaviour? The answer might surprise you and understanding it could transform how your organisation approaches safety.

What Percentage of Accidents Are Caused by Unsafe Behaviour?

Research dating back to the pioneering work of H.W. Heinrich in the 1930s found that up to 90% of all workplace incidents were caused by unsafe behaviours rather than just technical failures or environmental factors. This finding, which has been validated by subsequent research, fundamentally changed how we think about workplace safety.

To illustrate this relationship, Heinrich developed the Heinrich Triangle, demonstrating that:

• For every 300,000 unsafe acts

• There may be 30,000 near misses

• 300 lost time accidents

• 30 serious injuries

• And potentially 1 fatality

The takeaway? Preventing small, daily unsafe acts can drastically reduce the likelihood of injuries or fatalities. This is the foundation of behavioural safety: influencing how people act before harm occurs.

However, it's crucial to understand that whilst unsafe behaviour plays a significant role, modern safety thinking recognises that behaviour doesn't occur in a vacuum. As the Tim Marsh (2017) notes, organisational and environmental factors often create the conditions that lead to unsafe behaviour.

Understanding Safe vs. Unsafe Behaviour at Work

What is Safe Behaviour?

Safe behaviour refers to actions taken by workers that comply with safety procedures, reduce risk and protect themselves and others from harm. Examples include:

• Wearing appropriate personal protective equipment (PPE).

• Following established procedures and protocols.

• Reporting hazards and near misses.

• Using tools and equipment correctly.

• Maintaining good housekeeping standards.

• Speaking up when something doesn't feel right.

What is Unsafe Behaviour?

Unsafe behaviour encompasses any action that increases the risk of injury or harm. These can be categorised as:

• Unintentional errors (slips, lapses, mistakes).

• At-risk behaviour (shortcuts taken without recognising the danger).

• Reckless violations (knowingly ignoring safety rules).

Common examples of unsafe behaviour include:

• Not wearing required PPE.

• Bypassing safety guards or interlocks.

• Taking shortcuts to save time.

• Working whilst fatigued or distracted.

• Failing to report hazards or near misses.

• Using equipment improperly or for unintended purposes.

• Ignoring established procedures.

Why Do People Engage in Unsafe Behaviour?

Understanding why people behave unsafely is essential to preventing accidents. The answer is rarely simple. As explored in our article on behavioural-based safety, behaviour is shaped by a complex interaction of individual and organisational factors.

Individual Factors

Risk Perception: People assess risks differently. What one person sees as extremely hazardous, another might view as routine because "we've always done it this way."

Attitudes and Habits: Personal beliefs and ingrained routines strongly influence behaviour. Repeated behaviours become automatic, whether safe or unsafe.

Stress and Fatigue: Well-rested workers make better decisions. Tiredness affects judgement, memory, and coordination, especially during long shifts.

Past Experience: If someone has repeatedly taken shortcuts without incident, they may develop a false sense of security – until something goes wrong.

Organisational Factors

Leadership and Culture: Management commitment and shared safety norms set the tone. If supervisors turn a blind eye to rule-breaking to meet deadlines, unsafe practices quickly become normalised.

Time Pressure: Rushing increases the chance of mistakes. Unrealistic deadlines often force workers to choose between safety and productivity.

Lack of Resources: Inadequate staffing or unavailable equipment (such as a ladder being in use elsewhere) creates pressure to improvise unsafely.

Poor Communication: Ambiguous instructions or infrequent briefings lead to inconsistent or unsafe behaviour.

Work Environment: Physical hazards like poor lighting, excessive noise or extreme temperatures make it harder to work safely.

About 90% of unsafe acts are influenced by organisational and environmental factors. This means effective safety strategies must go beyond individual interventions to shape the systems and culture around workers.

The True Cost of Unsafe Behaviour

Unsafe behaviour doesn't just lead to accidents – it creates a ripple effect throughout organisations:

Human Cost: Injuries, fatalities and long-term health impacts on workers and their families.

Financial Cost: According to HSE statistics, workplace injuries and ill health cost Britain around £20.6 billion in 2022/23.

Operational Cost: Lost productivity, equipment damage, investigation time and potential regulatory action.

Reputational Cost: Damage to company reputation, difficulty attracting talent and potential loss of business.

What is Behaviour-Based Safety?

Behaviour-based safety (BBS) represents the scientific application of behavioural research to workplace safety problems. Rather than relying solely on rules and punishment, BBS seeks to understand what people do, analyse why they do it and apply research-based strategies to improve behaviour. The approach recognises that people generally want to work safely but are influenced by various factors that can lead to unsafe choices.

Unlike traditional safety approaches that focus primarily on compliance and enforcement, behavioural safety emphasises positive reinforcement for safe actions and understanding the environmental factors that influence behaviour. This doesn't mean abandoning rules or procedures, those remain critical. Rather, it means complementing them with strategies that address the psychological and social dimensions of safety. IOSH (Institution of Occupational Safety and Health) advocates for behaviour-based approaches as part of a comprehensive safety management system.

The theoretical foundations of BBS draw on decades of psychological research, from B.F. Skinner's work on operant conditioning to modern models like the COM-B framework (Capability, Opportunity, Motivation leading to Behaviour). These models help us understand that changing behaviour requires more than willpower or knowledge. People need the capability to work safely (skills and knowledge), the opportunity to do so (the right environment, tools, and support) and the motivation to make safe choices (both reflective and automatic).

We have created a free overview of the background on behavioural safety:

For more on building an effective safety culture that supports behavioural change, see our articles on safety culture and behaviour.

How to Promote Safe Behaviour in the Workplace

1. Lead by Example

Leadership drives culture. When managers consistently model safe behaviour, teams follow. This means:

• Being visible on site and engaging with safety issues.

• Following all safety procedures themselves.

• Responding promptly to safety concerns.

• Making safety a consistent priority in decisions.

2. Create a Just Culture

A Just Culture approach, championed by organisations like EUROCONTROL, distinguishes between:

• Human error (console and support).

• At-risk behaviour (coach and provide guidance).

• Reckless behaviour (apply appropriate consequences).

This approach encourages reporting and learning rather than blame.

3. Implement Effective Training

Training should be practical, relevant and ongoing. Workers need to understand:

• Why procedures exist.

• How to perform tasks safely.

• What to do when conditions change.

• How to speak up about concerns.

4. Use Behavioural Observations

Structured safety observations help identify both safe and unsafe behaviours in real-time. Effective observations:

• Focus on specific, observable actions.

• Consider contextual factors.

• Lead to constructive feedback.

• Result in system improvements.

5. Provide Timely Feedback

Feedback shapes behaviour. The most effective feedback is:

• Specific: "I noticed you checked the harness anchor point before climbing".

• Timely: Given immediately or within the same shift.

• Balanced: Recognising safe behaviour as often as correcting unsafe behaviour.

• Followed up: Checking whether improvements occurred.

6. Remove Barriers to Safe Behaviour

Make the safe choice the easy choice by:

• Ensuring adequate resources and equipment.

• Setting realistic timeframes.

• Simplifying procedures where possible.

• Addressing environmental hazards.

7. Encourage Open Communication

Psychological safety, where workers feel comfortable raising concerns without fear of punishment, is fundamental. Create channels for:

• Reporting hazards and near misses.

• Suggesting improvements.

• Asking questions.

• Challenging unsafe instructions.

Common Questions About Safe and Unsafe Behaviour

Q: Can behaviour-based safety replace other safety systems?

A: No. Behaviour-based safety should complement, not replace, traditional safety management systems. You need both strong organisational controls and a focus on human factors.

Q: Isn't focusing on behaviour just "blaming the worker"?

A: Not when done properly. Modern behavioural safety recognises that behaviour is shaped by organisational systems, leadership and environmental factors. The goal is understanding and improvement, not blame.

Q: How long does it take to change safety behaviour?

A: It varies. Simple behaviours with clear benefits can change quickly with the right support. Deeper cultural change typically takes 12-18 months of consistent effort.

Q: What's the difference between unsafe behaviour and a safety violation?

A: Unsafe behaviour is a broad term covering any action that increases risk. A violation specifically refers to knowingly breaking an established safety rule. Not all unsafe behaviours are violations, some are honest mistakes or lapses.

Q: How can I get workers to report unsafe behaviour without creating a "tell-tale" culture?

A: Focus on systems and learning, not individuals. Encourage reporting hazardous conditions and near misses. Use observations as coaching opportunities. Celebrate teams that identify and fix problems together.

Q: What should I do if I witness unsafe behaviour?

A: Address it immediately (if safe) but constructively. Stop the work if there's immediate danger. Have a respectful conversation about what you observed, why it's concerning and what the safer alternative is. Follow up to ensure the behaviour changes.

Moving Forward: From Awareness to Action

Understanding that around 90% of accidents stem from unsafe behaviour is just the starting point. The real challenge and opportunity lies in creating workplaces where safe behaviour is natural, supported and sustainable.

This requires:

• Leadership commitment that's visible and consistent.

• Systems and procedures that make sense and work in practice.

• Training and communication that engages and empowers workers.

• A culture of learning where mistakes become opportunities for improvement.

• Resources and support that enable safe work.

Remember, as safety expert Sidney Dekker noted:

How We at DuoDynamic Safety Solutions Can Help

At DuoDynamic Safety Solutions, we specialise in helping organisations understand and improve safety behaviour. Our services include:

• Behavioural safety audits to identify risk factors and improvement opportunities.

• Bespoke training programmes on behaviour-based safety, safety leadership and creating a positive safety culture.

• Safety culture assessments to understand where your organisation sits on the maturity curve.

• Coaching and mentoring for safety leaders at all levels.

• Policy and procedure development that balances compliance with practical application.

Whether you're just beginning your behavioural safety journey or looking to enhance an existing programme, we're here to help. Contact us to discuss how we can support your organisation in creating a workplace where safe behaviour is the norm, not the exception.