• Accident: An undesired event resulting in death, injury, damage to health, damage to property or other form of loss
• Abnormal Event: An unplanned, unusual, occurrence or emergency
• Adaptation: The limited ability for people to tolerate small departures from optimal conditions (equipment design, environment, etc) without significantly affecting performance, for example – use of a chair that is a little too high or a little too low
• Aerosols: Substance dispersed into the air such that the droplets or particles remain in suspension for a significant period of time
• Air Exchange Rate: The rate at which inside air is replaced by outside air. The rate may be expressed as the number of changes of air per unit of time (e.g. Air Changes per Hour - ACH) or the volume of air exchanged per unit of time (e.g. Cubic Feet per minute (CFM)
• Allergen: Substance causing an allergic reaction in a person who is sensitive to that substance
• Ambient: Surrounding, e.g. ambient temperature usually means the outside temperature
• Anthropometric Dimensions: The dimensions of the human body. These may be static measurements (i.e. when the subject standing or seated) or functional (i.e. when the person assumes an unnatural posture)
• Apparent Loudness: Measurement in decibels of sound pressure measured against the threshold of hearing, being 0 decibels. The pain threshold is 120 decibels and an increase of 3 decibels is perceived as doubling in loudness
• Appointed Person: A person who has been nominated to take charge in the event of an accident or illness (and support designated first aiders if present) and has been trained in basic lifesaving first aid techniques (See Designated Person)
• Approved Code of Practice: A code of practice, associated with specific regulations, that has been approved by the Health & Safety Commission
• Asbestos: Hydrated magnesium silicate in fibrous form
• Audible Range: Normal hearing frequency, approximately 20 Hz to 20,000 Hz
• Background Level: The normal or typical level of a chemical in the environment, often referring to the naturally occurring level
• Boiling Point: Temperature at which a liquid changes to a gas at normal atmospheric pressure
• Carcinogen: Substance that is known or suspected of causing cancer
• Carpal Tunnel Syndrome: A chronic disorder of the hand and wrist possibly resulting from repetitive work involving repeated wrist flexion or extension
• Central Nervous System: The part of the nervous system that includes the brain and spinal cord
• Cervical Spine: The uppermost 7 vertebrae of the spine which, being very delicate, is prone to degenerative processes
• Chronic: Occurring over an extended period of time
• Code of Practice: Rules established by regulatory bodies or trade associations, which are intended as a guide to acceptable behaviour. As such they do not have the force of law behind them
• Combustible Liquid: Liquid with a flash point above 37.8 C (100° F)
• Common Law: Law resulting from court rulings rather than legislative enactments
• Competent Person: A person who is appropriately trained, qualified, experienced and skilled to undertake specific health and safety duties without risk to their own safety or that of others
• Compliance: The act or process of fulfilling requirements
• Compressed Gas: Substance that is a gas at normal pressure and room temperature but is held in a pressurised container resulting in it becoming a liquid
• Concentration: The quantity of one substance contained in another substance e.g. the amount of salt dissolve in seawater
• Contaminant: Substance - usually undesirable - in another substance, product or space where it is not normally found, e.g. environmental pollutants
• Contrast: The difference in brightness between the subject (e.g. text) and the background against which it is viewed
• Control of Substances Hazardous to Health: Regulations promoting safe working with potentially hazardous chemicals
• Corrosive: Substance that causes destruction of another substance, including human tissue
• Cryogenics: Materials that exist at extremely low temperatures, e.g. liquid nitrogen
• Cutaneous: Pertaining to or affecting the skin
• Designated Person: A person who has been designated as a first aider at work and has been trained to have the knowledge and confidence to deal with any first aid emergency (See Appointed Person)
• Dose: The amount of substance to which a person is exposed in terms of the concentration of the substance and the time period during which the exposure occurs
• Employment Medical Advisory Service: Part of the Health and Safety Executive, offering advice on work related health issues and on people with health problems returning to work.
• Ergonomics: The application of information about human characteristics to design applications, e.g. equipment, tools, work tasks, with the aim of improving safety and efficiency
• Exposure Limit: Established concentration of a substance that, if not exceeded, will not normally result in adverse effects to persons who are exposed
• Fatigue: Transient reduced ability to work as a result of previous activity, resulting in reduced efficiency
• Fires:
  • Class A - Fires in ordinary combustible materials such as wood, cloth, paper, etc.
  • Class B - Fires in flammable liquids and gases such as oils and paints
  • Class C - Fires involving energized electrical equipment where the electrical conductivity of the extinguishing medium is of importance.
  • Class D - Fires involving combustible metals such as potassium or sodium
• Fire Prevention: Precautions designed to avoid an outbreak of fire, reduce the potential for fire to spread and safeguard persons and property in the event of fire
• Flammable Gas: Gas that when mixed with air forms a flammable mixture at ambient temperature and pressure]
• Flammable Liquid: Liquid with a flashpoint below 100°F (37.8°C)
• Flammable Solid: Solid that is liable to cause fires through friction, absorption of moisture, etc. or which can be readily ignited
• Flash Point: The lowest temperature at which a flame will propagate through the vapour of a combustible material
• Freezing Point: Temperature at which a liquid becomes a solid, at normal atmospheric pressure
• Glare: When a portion of the visual field has a significantly higher luminance than its surroundings, resulting in reduced contrast
• Hazard: Potential for harmful effects
• Health And Safety Executive: Organisation responsible for proposing and enforcing safety regulations throughout the United Kingdom
• Illuminance: A measure of the amount of light falling on a particular point, measured in Lux
• Incident (or Near Miss): A generic term for those events that do not cause harm but which might have done so under different circumstances
• Ingestion: Taking a substance into the body through the mouth, for example in the form of food or drink
• Inhalation: Taking a substance, typically in the form of gases, fumes, vapours, mists, aerosols or dusts, into the body by breathing it in
• Inhibitor: A substance which, when added to another substance, prevents or slows down an unwanted change or reaction
• Irritant: A substance that produces inflammation when it makes contacts with the skin, eyes, nose, or respiratory system
• Liquid Petroleum Gas: LPG consists of commercial Butane, Propane or a mixture of the two. Major hazards are fire and explosion, though asphyxiation is also a danger in low-lying areas due to LPG being heavier than air
• Lock-Off: Mechanisms that, as part of engineering controls, are designed to prevent potentially dangerous equipment from being energised during routine maintenance and/or repair work
• Luminance: A measure of the amount of light emitted or reflected by a surface in a given direction
• Lux: Unit of measurement of illumination, equivalent to lumen per square
• Material Data Safety Sheet: Contain information on the hazards associated with a chemical, along with guidance on its safe use
• Narcotic: A substance that has the potential to affect the nervous system by, for example, inducing drowsiness, stupor or insensibility
• Near Miss: See "Incident"
• Negligence: Lack of proper care and attention whereby a person acts or fails to act in a way that is considered unreasonable from a health and safety point of view
• Persistence: Remaining for an extended period of time. Applicable to some chemicals (e.g. DDT) that do not easily break down into less hazardous substances
• Parts per Billion: Specifies the concentration by volume of a substance dispersed in another substance
• Parts Per Million: Specifies the concentration by volume of a substance dispersed in another substance
• Permit to Work: Formally delivered criteria for control/risk reduction when undertaking pre-planned work that is hazardous, either because of its location or the nature of the activity.
• Planning Supervisor: Responsible under Construction (Design and Management) Regulations for coordinating the health and safety aspects of the design, preparation of a health and safety plan at the pre-tender stage and preparation of the health and safety file.
• Policy: A statement of an organisation’s strategy for achieving a safe and healthy working environment and the responsibility, organisation and arrangements for pursuing and implementing the strategy
• Preventive Maintenance: Maintenance (including inspection, cleaning, and repair) of equipment on a regular basis that is sufficient to prevent unplanned failure
• Regulation: A requirement of compliance having the force of law
• Residual Current Device: An electrical safety device that constantly monitors the electric current flowing through a circuit. If it senses a loss of current where electricity is being diverted to earth (as might happen if a person touches a live conductor), it rapidly shuts down the power.
• Relative Humidity: The percentage ratio of vapour pressure in the atmosphere compared to the saturated vapour pressure at that temperature
• Risk: A quantifiable expression of the likelihood of injury or harm resulting from a hazard
• Risk Assessment: A formal estimation of the likelihood that persons may suffer injury or adverse health effects as a result of identified hazards
• Risk Management: The introduction of change or control measures with the intention of eliminating or bringing the level of risk associated with a hazard within acceptable limits
• Safe System of Work: A method of working designed to eliminate, if possible, or otherwise reduce risks to health and safety
• Safety Committee: A committee that promotes health and safety in the workplace, with members representing employees and management from all sections of an organisation
• Safety Culture: A general term for the degree to which the culture of an organisation promotes and cooperates with safe and healthy work practices
• Self-Assessment: Assessments performed by individuals (or organizations) to determine how safely they are working and meeting their health & safety responsibilities toward themselves and others
• Sensitization: Development, over time, of an allergic reaction to a substance
• Sensitizer: Substance that may cause a person to develop an allergic reaction after repeated exposure
• Solubility: Ability of a substance to dissolve in a liquid
• Solvent: Substance that is capable of dissolving another substance
• Stress: The physical and emotional responses arising when there is a mis-match between the demands of a job and the capabilities/resources of the worker. Such responses are often harmful, leading to health and safety related problems, for example; depression, cardiovascular disease, musculo-skeletal disorders and an increased tendency to be accident-prone. Typical work-related stress factors are cited as fear of job loss, ineffective management, excessive workloads and technological change
• Synovial Fluid: A viscous fluid that lubricates joints and tendon sheaths
• Tenosynovitis: Inflammation and swelling of the tendon sheaths, usually of the wrist or hand, potentially caused by repetitive movements such as very high-speed typing rates
• Toxic: Substances that cause irritation of are otherwise harmful to health, such as carcinogens and poisons
• Toxicity: The potential for a substance to be harmful to health
• UN Hazard Codes:
  • Class 1 - Explosive Class 2 Gases
  • Class 3.1 - Flammable liquids, flash point below -18C
  • Class 3.2 - Flammable liquids, flash point between -18C and 23C
  • Class 3.3 - Flammable liquids, flash point between 23C and 61C
  • Class 4.1 - Flammable solids
  • Class 5.1 - Oxidizing agents
  • Class 5.2 - Organic peroxides
  • Class 6.1 - Poisonous substances
  • Class 7 - Radioactive substances
  • Class 8 - Corrosive substances
  • Class 9 - Miscellaneous dangerous substances
  • NR - Non-regulated
• Vapour: The gaseous form of a substance that is normally liquid or solid at room temperature
• Ventilation: Movement of air, usually associated with the introduction of fresh air
• Volatility: Ability of a substance to evaporate
• Wrist Extension & Flexion: Bending movement of hand and wrist from the horizontal (up or down respectively). Causes tendons to curve around structures in the wrist, possibly causing friction, which can in turn result in fatigue or injury.

• Acronyms & Abbreviations
• Terms