Most workplace accidents involve human error. But blaming the individual misses the point. HSG48 is the HSE's guidance on understanding why people make mistakes at work — and what organisations can do to prevent them.
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What is HSG48?
HSG48 — "Reducing error and influencing behaviour" — is the HSE's practical guidance on human factors in workplace health and safety. First published in 1999 and updated in 2009, it remains the foundational UK guidance on this topic.
Human factors is about understanding people at work — their capabilities, limitations, and behaviour. It's not about blaming individuals for accidents. It's about designing work, jobs, and organisations that account for how people actually function.
Why human factors matter
Research consistently shows that human error is involved in most workplace accidents. But the traditional response — telling workers to "be more careful" or adding more rules — rarely works.
HSG48 takes a different approach. It recognises that:
- Errors are normal — humans are not machines and will inevitably make mistakes
- Most errors are predictable — they follow patterns that can be anticipated
- Work systems can be designed to reduce errors — and to minimise harm when errors occur
- Blaming individuals doesn't prevent future accidents — understanding why errors happen does
Who needs to understand HSG48?
HSG48 is relevant to anyone responsible for workplace health and safety:
| Role | Why HSG48 matters |
|---|---|
| Employers and directors | Legal duty to manage health and safety includes human factors |
| Health and safety managers | Fundamental to effective risk assessment and accident investigation |
| Supervisors and line managers | Daily decisions about workload, procedures, and people |
| HR professionals | Selection, training, and fitness for work |
| Designers and engineers | Designing tasks, equipment, and workplaces |
| Anyone investigating accidents | Understanding root causes, not just immediate triggers |
The HSG48 framework: three factors
HSG48 organises human factors into three interconnected areas. To reduce human error, you need to address all three.
The job (task design and work environment)
The job itself can make errors more or less likely. Poor job design sets people up to fail.
Task factors that increase error:
- Poorly designed tasks — illogical sequences, unnecessary complexity
- Inadequate procedures — missing, unclear, or impractical
- Poor interface design — confusing controls, unclear displays
- Inadequate tools and equipment — not fit for purpose
- Time pressure — unrealistic deadlines, rushing
- High workload — too much to do, too many tasks at once
- Monotonous work — boredom leads to lapses in attention
- Environmental conditions — noise, poor lighting, temperature extremes
If workers regularly deviate from procedures, ask why. Often the procedure doesn't match how the work actually gets done. Workers develop workarounds because the official method doesn't work in practice.
The individual (capability and limitations)
People bring their own capabilities and limitations to work. Some are fixed; others change day to day.
Individual factors that affect performance:
- Competence — skills, knowledge, training
- Physical capability — strength, reach, sensory abilities
- Mental capability — attention, memory, decision-making
- Personality — attitudes, risk tolerance
- Health and fitness — fatigue, illness, medication
- Stress and emotional state — anxiety, distraction
- Age and experience — both inexperience and over-familiarity can cause problems
Competence isn't just about training. A newly trained worker may know the theory but lack practical experience. An experienced worker may have developed bad habits. Both need appropriate supervision and support.
The organisation (culture and systems)
The organisation creates the conditions in which work takes place. Organisational factors often underpin both job and individual factors.
Organisational factors that influence safety:
- Safety culture — how safety is valued and prioritised
- Leadership — visible commitment from senior management
- Communication — how safety information flows
- Resources — staffing levels, equipment, time
- Work scheduling — shift patterns, overtime, rest breaks
- Procedures and policies — how they're developed and maintained
- Management of change — how changes are controlled
- Learning — how the organisation responds to incidents
When investigating an accident, don't stop at the individual's error. Ask: what conditions allowed this error to happen? What organisational factors contributed? The answers point to systemic improvements that prevent future incidents.
Types of human error
HSG48 distinguishes between different types of human failure. Understanding these helps you design appropriate controls.
Errors (unintentional)
Errors are unintentional — the person didn't mean to do it wrong.
Slips and lapses:
- Slips — actions that don't go as planned (pressing the wrong button, misreading a dial)
- Lapses — memory failures (forgetting a step, losing place in a sequence)
Slips and lapses happen when:
- Tasks are routine and automatic
- Attention is distracted
- The person is tired, stressed, or unwell
- The environment is poorly designed (similar-looking controls, confusing displays)
Mistakes:
- Rule-based mistakes — applying the wrong rule to a situation
- Knowledge-based mistakes — making a wrong decision when facing an unfamiliar situation
Mistakes happen when:
- Procedures don't cover the situation
- Training didn't prepare the person for this scenario
- Information is incomplete or unclear
- Time pressure forces quick decisions
Violations (intentional)
Violations are deliberate departures from procedures — but they're not necessarily malicious.
Types of violation:
- Routine violations — cutting corners that have become normal practice ("everyone does it")
- Situational violations — breaking rules because of time pressure or equipment problems
- Exceptional violations — breaking rules in unusual circumstances, often believing it's justified
- Malicious violations — deliberate sabotage (rare)
Errors vs Violations
Errors
- •Unintentional
- •Person tried to do the right thing
- •Action didn't go as planned
- •Often due to poor design or conditions
- •Reduced by better task design
- •Training helps but doesn't eliminate
Violations
- •Intentional (but not usually malicious)
- •Person deliberately departed from procedure
- •Action went as planned (but procedure not followed)
- •Often due to organisational factors
- •Reduced by addressing root causes
- •Enforcement alone rarely works
Bottom line: Both errors and violations contribute to accidents. Effective prevention requires different approaches for each — better design for errors, addressing root causes for violations.
Why do people violate procedures?
Understanding why people break rules is essential to preventing violations. Simply adding more rules or punishments rarely works.
Common reasons for violations:
The procedure doesn't work:
- Takes too long
- Equipment or tools don't allow it
- Doesn't match how the job actually gets done
- Based on ideal conditions that don't exist
Production pressure:
- Unrealistic targets or deadlines
- Implicit message that output matters more than safety
- Not enough staff or time
Normalisation of deviance:
- "Everyone does it this way"
- Shortcuts have become standard practice
- Never caused a problem before
Poor supervision:
- Managers don't check compliance
- Violations overlooked or even encouraged
- No consequences for breaking rules
Belief the rule is unnecessary:
- Risk seen as low
- Worker believes they know better
- Rule seems designed for others
If violations are widespread, the problem is organisational, not individual. Punishing workers while ignoring the conditions that encourage violations won't prevent the next accident.
Practical steps to reduce human error
HSG48 provides a framework for reducing human error. Here's how to apply it practically.
1. Design out error at the job level
Task design:
- Simplify tasks where possible
- Arrange steps in a logical sequence
- Build in checks and verification points
- Avoid reliance on memory for critical steps
Procedures:
- Involve workers in developing procedures
- Write procedures for how work is actually done
- Test procedures before finalising
- Make procedures easy to follow (checklists, visual aids)
- Keep procedures up to date
Equipment and interfaces:
- Choose equipment that's suitable for the task
- Ensure controls and displays are clear
- Differentiate similar controls (shape, colour, position)
- Provide clear feedback on system status
Work environment:
- Ensure adequate lighting, temperature, noise control
- Reduce distractions during safety-critical tasks
- Provide adequate workspace
2. Address individual factors
Selection and fitness:
- Match people to jobs based on capability
- Consider physical and mental requirements
- Manage fitness for work (health, fatigue, substances)
Competence:
- Provide adequate training (initial and ongoing)
- Assess competence, don't just assume it
- Allow time for skills to develop
- Provide supervision appropriate to experience
Workload and fatigue:
- Monitor workload — both overload and underload
- Design shifts to allow adequate rest
- Limit overtime and consecutive shifts
- Recognise signs of fatigue
3. Build a positive safety culture
Leadership:
- Senior management visibly committed to safety
- Safety considered in all business decisions
- Resources provided for safety
Communication:
- Open reporting of hazards and near misses
- Workers involved in safety decisions
- Learning shared across the organisation
Just culture:
- Distinguish between errors, violations, and negligence
- Support people who report problems
- Focus on learning, not blame
A "just culture" doesn't mean no accountability. It means responding proportionately — learning from honest errors, addressing systemic causes of violations, and reserving disciplinary action for reckless or malicious behaviour.
Human factors in risk assessment
Risk assessment should consider human factors — but often doesn't.
Questions to ask:
About the task:
- What errors could occur? What are the consequences?
- Is the procedure practical? Do workers actually follow it?
- What happens under time pressure or when things go wrong?
- Could someone unfamiliar with the task understand it?
About the individual:
- What training and experience is needed?
- Could fatigue, stress, or health issues affect performance?
- What happens when the regular person is absent?
About the organisation:
- Does production pressure compromise safety?
- Are resources adequate?
- What's the attitude to shortcuts and workarounds?
Red flags in your workplace:
- Workers regularly deviate from procedures
- Near misses that "almost" caused an accident
- Heavy reliance on individual skill and experience
- "It's always been done this way" mentality
- Time pressure regularly affects safety-critical tasks
- High turnover or inexperienced workforce in critical roles
If you're investigating an incident, don't stop at "human error" as the cause. That's the starting point, not the conclusion. Ask why the error happened, and what conditions allowed it to cause harm.
Common mistakes when applying HSG48
Mistake 1: Focusing only on the individual
It's easy to blame the person who made the error. But individual-focused interventions (retraining, warnings, disciplinary action) rarely prevent the next incident if job and organisational factors aren't addressed.
Mistake 2: Adding more procedures
When something goes wrong, the instinct is often to add a new procedure. But more procedures can make things worse — workers can't remember them all, and the important rules get lost among the trivial.
Mistake 3: Assuming training is the answer
Training is important, but it doesn't prevent slips and lapses (which happen even to trained, experienced people). And training can't overcome poorly designed tasks or inadequate equipment.
Mistake 4: Ignoring violations
Violations that don't cause accidents get ignored — until one day they do. If workers routinely break rules, find out why and address the root cause.
Mistake 5: Treating all errors the same
Different types of error need different solutions. Slips need better design. Mistakes need better information and decision support. Violations need organisational change.
When to get professional help
Human factors is a specialist field. Consider getting professional help if:
- You're investigating a serious accident involving human error
- You need to redesign a complex or safety-critical process
- You have recurring incidents despite interventions
- You're introducing new technology or major changes
- You need to assess safety culture
- You want to implement a formal human factors programme
Beyond individual blame
A worker was injured when they operated a machine without following the isolation procedure. The initial reaction was to blame the worker for 'not following procedures'.
- ✗The isolation procedure was time-consuming and rarely enforced
- ✗Production targets created pressure to skip steps
- ✗Experienced workers regularly skipped isolation without incident
- ✗New workers learned from watching experienced colleagues
- ✗The machine had no interlock to prevent operation during maintenance
Investigation revealed this was a systemic issue, not individual carelessness. The company redesigned the isolation process, installed interlocks, and addressed the culture that normalised violations.
When investigating human error, look beyond the individual. Ask what conditions allowed the error to happen and what organisational factors contributed.
Source: Based on HSE investigation principles
Frequently asked questions
HSG48 itself is guidance, not law. However, the Health and Safety at Work Act and Management Regulations require employers to assess and control risks — and human factors are a significant source of risk. HSG48 provides practical guidance on meeting these legal duties. Inspectors will expect you to have considered human factors in your risk management.
Focus on the business case: most accidents involve human error, so addressing human factors prevents incidents, reduces costs, and improves productivity. Human factors improvements often deliver operational benefits beyond safety — better-designed tasks are usually more efficient. Point to specific incidents where human factors were involved and explain how a different approach could have prevented them.
Punishment for genuine errors (slips, lapses, mistakes) is rarely appropriate and often counterproductive — it discourages reporting and doesn't prevent future errors. Focus instead on understanding why the error happened and what conditions contributed. A 'just culture' reserves disciplinary action for reckless or malicious behaviour, not honest mistakes.
Safety culture is one of the organisational factors in HSG48. A positive safety culture supports human factors principles — it values reporting, learning from incidents, involving workers in safety decisions, and designing work to reduce error. Poor safety culture undermines everything else you try to do on human factors.
Human factors focuses on designing systems that account for human capabilities and limitations — it's about changing the work, not the worker. Behavioural safety focuses on observing and reinforcing safe behaviours. Both have value, but behavioural programmes alone won't address job and organisational factors. HSG48 provides the broader framework.
Include human factors in your standard risk assessments by asking: What errors could occur? What are the consequences? What makes errors more likely (time pressure, complexity, fatigue)? Who might be involved (experience level, competence)? What organisational factors affect safety (culture, resources, procedures)? HSG48's three-factor model (job, individual, organisation) provides a structure.
HSG48 is available free from the HSE website. For more detail, see the HSE's Human Factors webpages and their guidance on specific topics like fatigue, shift work, and safety culture. The Energy Institute and other sector bodies also publish human factors guidance for their industries.
Yes. Human error occurs in every workplace regardless of size. Small businesses may have simpler systems, but the same principles apply — design tasks to reduce error, ensure people are competent, and create conditions that support safe behaviour. The level of formality should be proportionate to your risks.
Summary: the HSG48 approach
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Recognise that errors are normal — people will make mistakes; design systems that prevent errors or minimise their consequences
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Look beyond the individual — when errors occur, ask what job and organisational factors contributed
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Address all three factors — the job, the individual, and the organisation are interconnected
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Understand different error types — slips, lapses, mistakes, and violations need different solutions
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Investigate violations — if people routinely break rules, find out why and address the root cause
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Build a just culture — support reporting, focus on learning, and reserve blame for reckless behaviour
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Include human factors in risk assessment — consider how people might fail and what conditions make failure more likely
Next steps
Understand your general health and safety duties:
Employer Safety Duties Explained
Learn about risk assessment:
Explore employee responsibilities:
Employee Safety Responsibilities
Need help implementing human factors principles? A health and safety consultant can assess your workplace, identify error-prone tasks, review your procedures, and help you design work systems that reduce human error.
Related articles:
- Employer Safety Duties
- Employee Safety Responsibilities
- Risk Assessment: The 5 Steps
- Accident Investigation
HSE guidance documents:
- HSG48 — Reducing error and influencing behaviour — Full HSE guidance
- INDG36 — Working together to reduce stress at work — Related guidance on workplace stress
- HSG65 — Managing for health and safety — General management guidance
Useful resources:
- HSE Human Factors webpages — Additional guidance and tools
- HSE Safety Culture guidance — Building positive safety culture
Disclaimer: This guide provides general information about HSG48 and human factors principles. It does not constitute legal advice. For complex situations or serious incidents, consult a qualified health and safety professional with expertise in human factors.