Must-Know Health and Safety Definitions

health and safety definitions

Safeti has collated a must-know list of simple, important health and safety definitions that you need to know. We are continually adding to this list as we learn, so please let us know if there’s anything you would like included by leaving us a comment at the bottom of the page!


An undesired, unplanned incident resulting in injury, ill- health, death or damage.


A substance that causes an allergic reaction in the body.

Acute exposure

Immediate exposure to a hazardous substance over a short time period.

Appointed Person

A designated person who has been nominated to take a supervisory role in the event of an accident, injury or illness. The appointed person will have completed basic first aid training and have the skills and knowledge to deal with a first aid situation.


The name used for a group of fibrous silicate minerals that once inhaled, have adverse effects on health and can lead to fatal lung diseases.


The damage of lung tissue caused by asbestos, resulting in a shortness of breath.


An official inspection of the health and safety management arrangements of a premises, carried out by qualified auditors. The aim of an audit is to confirm that adequate control measures have been put in place to cover the risks and to ensure that these measures are being adhered to.

Best Practice

A way of delivering risk control practices which have been recognised by an authoritative body as cooperating with and even going beyond what is expected by the law.

Chronic Exposure

Multiple exposures to a hazardous substance over a long period of time. This typically results in chronic health impacts on the individual e.g. loss of hearing, reduction in lung function etc.


Chartered Institute of Environmental Health.

Code of Practice

A set of rules fixed by regulatory bodies (Health and Safety Executive) or trade associations which, although not law themselves, are intended to provide guidance on how to comply with the law.

Common Law

Unwritten law which has been devised through prior court judgements rather than from written law. A breach of common law can however, result in a criminal offence.

Competent Person

A person who has been adequately trained and has the appropriate skills and knowledge to perform certain health and safety tasks without posing a risk to themselves or others.

Confined Space

An enclosed area that has the potential to cause serious harm from hazardous substances or conditions within the space e.g. lack of oxygen supply or increase in harmful gas levels.


A substance, usually a pollutant, which has been discovered in an area where it does not usually belong. It may have harmful effects on people, materials or the environment.

Control Measures

Actions that have been put in place to reduce the risks associated with work being carried out.


A substance that has destructive effects on another substance.


The Control of Substances Hazardous to Health – this term is was created with the introduction of the COSHH Regulations in the United Kingdom.

Display Screen Equipment

A device that has an alphanumeric or graphic display screen, such as a computer monitor.

Emergency Plan

A plan detailing the exact actions to be taken in the event of an emergency with the aim of evacuating all persons from dangerous environments or conditions.

Ergonomic Hazards

Working methods that have the potential to damage the musculoskeletal system, including forceful movements, vibration, extreme temperatures, improper lifting techniques and inappropriate workstations.

Explosive Proof Protection

Preventative techniques applied to the manufacturing process of equipment for use in high-risk, explosive work environments.


There are 5 main classifications of fire;

Class A: fires with flammable solids such as wood, plastic and paper.

Class B: fires involving flammable liquids and electrical fires.

Class C: fires involving gases.

Class D: fires involving metals such as magnesium, potassium and titanium.

Class F: fires with cooking oils and fats.


The ease in which a substance will catch fire.

Flammable Gas

A gas with a low flammability limit that can be readily ignited when mixed with air.

Flammable Liquid

A liquid which can readily catch fire.

Flammable Solid

Solids that are liable to cause fires through friction or absorption of moisture.

Flash Point

The minimum temperature in which the vapour of a substance, when mixed with oxygen, will ignite when a flame is applied.

Fume cupboard

A method of ventilation, typically in the form of a cabinet with a moveable safety-glass front window. The air is drawn away from the worker or workspace to prevent contact with harmful vapours or gases given off by hazardous substances.


Bright lights that reflect off a display screen and impede a person’s sight, often causing excessive eyestrain and headaches.


A device that prohibits access to a hazardous part of a machine or equipment.


A situation or behaviour that has the potential to cause harm, injury, ill-health or damage to property and the environment.

Health and Safety Executive

An authoritative organisation that enforces health and safety legislation in the UK, including statute, approved codes of practice, regulations and guidance on work-related health issues.

Health and Safety Policy

A health and safety policy sets out your general approach to health and safety. It should explain how you will manage health and safety in your business. The law in the UK says that every business must have a policy for managing health and safety.

Health and Safety Representatives

A person that has been appointed by trade unions to represent their colleagues in regards to various issues of health and safety in the workplace.

Health Surveillance

A process of observation that involves monitoring any early symptoms of work related ill-health in employees who may be exposed to certain health risks. These may include hazardous liquids or gases.

Heat Exhaustion

A condition caused by excessive exposure to hot temperatures, usually caused by profuse sweating in warm, poorly ventilated working environments.

Hierarchy of Control

The Hierarchy of Control or risk hierarchy is a system used in industry to minimize or eliminate exposure to hazards. It is a widely accepted system promoted by numerous safety organizations.


An extreme physical response to particular substances or environments.

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The International Institute of Risk and Safety Management.

Improvement Notice

A formal notice that is given by an authoritative health and safety body following a breach of law. The notice will state the committed offence, what action needs to be taken for improvement and the specified date by which it must be taken.

Incident Investigation

The process of gathering information regarding the causes of an incident, with the purpose of formulating control measures to prevent the incident from reoccurring.

Incident/Near Miss

A term for those events that have not resulted in significant harm but have the potential to cause an accident, injury or damage under different circumstances.


The Institution of Occupational Safety and Health is the world’s largest health and safety membership body. The IOSH mission is ensuring that global work practices are safe, healthy and sustainable.


A non-corrosive substance which can cause inflammation on the body through contact.

LOLER Regulations

Lifting Operations and Lifting Equipment Regulations in the UK. Introduced to help prevent the failure of lifting equipment and related injuries. They cover a wide range of equipment including, cranes, forklift trucks, lifts, hoists, mobile elevating work platforms, and vehicle inspection platform hoists

Manual Handling Operations

Tasks that require a person to exert bodily force to transport a load by lifting, lowering, pushing, pulling or carrying an object.

Material Data Safety Sheet (MSDS)

A document that details information on potentially hazardous substances, along with guidance on how to handle them safely.

Method Statement

A document that details how a particular working process will be conducted in a safe manner, typically used for construction or installation procedures.


The National Examination Board in Occupational Safety and Health.


National Compliance and Risk Qualifications

Noise Induced Hearing Loss

An incurable condition caused by both acute and chronic exposure to a loud noise.


National Vocational Qualification.

Occupation Health

The relationship between a person’s health and the working activities that they undertake.

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Occupational Illness

An illness that occurs in employees who have been exposed to hazards whilst at work.

Permit to Work

Formal, written specifications for controlling risks when carrying out hazardous work, usually for non-routine activities that require special precautions to control the hazards.


A legally required statement of a company strategy, consisting of their objectives to attain a safe working environment, their responsibilities, and the arrangements for implementing the strategy and achieving their aims.

Preventive Maintenance

The regular maintenance of work equipment to reduce the risk of failure.

Prohibition Notice

A formal notice that is issued by an authorising health and safety body on discovery of a breach of statute that has the potential to cause an accident or injury. A Prohibition Notice commonly follows a serious accident, with the aim of preventing the hazard from developing or to put a stop to it if it is already in motion.

Reasonably Practicable

When the level of risk is weighed up against the cost (time, money, effort). If the cost outweighs the risk, then it may be deemed unreasonable for an employer to implement the measures.

Risk Assessment

An examination of the potential risks in the workplace, with the aim of assessing whether enough precautions have been put in place to prevent harm. A risk assessment focuses on the relationship between the worker, the work being carried out, the equipment being used and the conditions of the working environment.

Risk Management

The process of putting control measures into practice and monitoring the results, with the intention of reducing, or eliminating, the potential risks to health and safety.

Routes of Entry

Ways in which hazardous substances can enter the body, including inhalation, injection, ingestion and absorption.


An assessment carried out by the individual to determine how safely they are working and fulfilling their health and safety duties.


Site Management Safety Training Scheme.


Site Supervisors Safety Training Scheme.

Statute law

The formal, written law of a country or state. An example would be the Health and Safety at Work Act 1974.


Substances, usually poisonous, that cause irritation and have detrimental effects on health.


The conglomeration of equipment that an employee requires to fulfil their working practices. In regards to Display Screen Equipment, the workstation is likely to include a desk, a chair, a computer monitor and a keyboard.

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