NEBOSH IDip key terms

A test balancing the likelihood and severity of harm against the money, time and trouble needed to control it, so that grossly disproportionate cost can justify not adopting a measure.

As low as reasonably practicable: the point where the cost of further risk reduction is grossly disproportionate to the benefit gained, used to justify continuing operation of a residual risk.

A structured process of identifying hazards, deciding who might be harmed and how, evaluating the adequacy of existing controls, and recording the actions needed to reduce risk.

Any source, situation or act with the potential to cause harm, ill health, injury or damage to property and the environment, independent of how likely that harm is to occur.

The combination of the likelihood that a hazardous event will occur and the severity of the harm or loss that would result from it, often expressed as a simple score.

The risk that remains after existing control measures have been applied, which must itself be evaluated and, where necessary, reduced further before work proceeds.

A ranked order of risk-reduction measures, from eliminating the hazard through substitution, engineering controls, administrative controls and finally personal protective equipment, with higher levels preferred.

The most effective control in the hierarchy, removing the hazard entirely from the workplace, for example by changing a process so a hazardous substance or task is no longer needed.

Replacing a hazardous substance, machine or process with a less hazardous alternative, such as swapping a toxic solvent for a water-based one, while checking the new option is genuinely safer.

Equipment worn or held by a worker that protects against one or more hazards, treated as a last resort because it relies on correct selection, fit, use and maintenance by individuals.

The systematic search for hazards using techniques such as inspections, task analysis, incident data review and worker consultation, forming the first stage of any risk assessment.

Hazard and operability study: a team-based technique applying guide words to process parameters to find deviations from design intent and their potential consequences in complex installations.

A diagram showing threats on one side and consequences on the other, linked through a top event, with preventive barriers on the left and mitigation barriers on the right.

The principle that controls closer to the hazard source, such as engineering design, are more reliable than those depending on human behaviour, and should therefore be preferred in decision-making.

A grid plotting likelihood against severity to give a risk rating, useful for prioritising actions but limited by subjective categories and inconsistent interpretation between assessors.

The shared values, attitudes, perceptions and behaviours of an organisation's members that determine how seriously health and safety is treated in everyday decisions and practice.

The measurable, short-term snapshot of workforce perceptions about safety priorities at a point in time, often surveyed to indicate the underlying safety culture.

An approach that distinguishes honest human error from reckless or deliberate rule-breaking, encouraging reporting of mistakes without blame while still holding people accountable for wilful violations.

A programme that observes and reinforces safe behaviours through feedback and coaching, effective for behaviours within individual control but weak where hazards are engineered or organisational.

An unintended action or omission by a person that deviates from what was intended or required, arising from slips, lapses or mistakes rather than deliberate disregard of rules.

A deliberate deviation from a rule, procedure or safe practice, which may be routine and tolerated, situational due to pressure or poor design, or exceptional and reckless.

A continual improvement cycle: plan objectives and processes, implement them, monitor and measure results against criteria, then act to correct and improve performance before repeating.

The set of interrelated policies, arrangements, responsibilities and processes an organisation uses to manage health and safety systematically and to drive continual improvement.

A written statement of an organisation's overall health and safety intentions, principles and commitment to legal compliance, signed by top management and setting the framework for objectives.

Specific, measurable goals an organisation sets to improve health and safety performance, derived from its policy and used to focus resources and monitor progress over a defined period.

A proactive measure of preventive activity, such as training completion, inspection rates or near-miss reporting, that predicts future performance rather than recording past failures.

A reactive measure of outcomes already experienced, such as injury rates, lost-time incidents or compensation claims, which shows where harm occurred but not how well risk is controlled.

A normalised measure of incidents per unit of exposure, such as per 100,000 hours worked or per 1,000 workers, allowing comparison between sites, periods or organisations of different size.

An unplanned event that results in injury, ill health, damage or other loss, distinguished from a near miss only by the absence or presence of actual harm.

An unplanned event that did not cause injury or damage but had the potential to do so, valuable as free information about weaknesses in controls when reported and investigated.

A structured investigation technique, such as the five whys or fault tree analysis, that traces an incident beyond immediate causes to underlying management and organisational failures.

A systematic, independent and documented process for obtaining evidence and evaluating it objectively against defined criteria to judge whether arrangements are conforming and effective.

A routine, often internal check of physical conditions and observable practices against standards, typically carried out by managers or safety representatives rather than independent auditors.

Applying the control hierarchy to a real task, documenting why each chosen measure is suitable and sufficient, and recording any residual risk that workers and managers must understand.

A written account of a practical assessment that describes hazards observed, evaluates the adequacy of controls, and recommends prioritised, costed actions with responsible persons and timescales.

Sustained, recorded learning and reflective practice that maintains and develops the knowledge, skills and ethical competence a health and safety professional needs throughout their career.

The ethical standards a professional body requires of members, covering honesty, competence, confidentiality, avoiding conflicts of interest and acting in the public interest.

Working only within one's knowledge, training and experience, seeking specialist advice where a task exceeds that boundary, and keeping technical and legal knowledge current.