Ear Muff: Ear protection worn externally normally comprising a retaining band with two cups which enclose the outer ear.
		Ear Plug: Ear protection in the form of a plug which is inserted into the entrance to the ear canal.
		Ear Protection: Generic term used to cover all forms of hearing protection.
		Ear Protection Zone: An area required to be demarcated with suitable signs in which a person is likely to be exposed to noise at or above the second action level or the peak action level.
		Earth: A protective device by which an electrical circuit is connected to the general mass of earth so as to ensure an immediate discharge of energy reducing danger.
		Earth Fault Loop Impedance: This is the impedance of the normal earth fault loop.
		EAWR: The Electricity at Work Regulations.
		E-coli: See Eschericia coli.
		Education: Activity aimed at developing the knowledge, skills, moral values and understanding required to function effectively in a social environment (see training).
		Effective Dose: The quantity obtained by multiplying the equivalent dose to various tissues and organs by a weighting factor appropriate to each and summing the products. Unit: sievert, symbol: Sv. Generally abbreviated to dose.
		Effective Temperature Index: Originally intended for predicting comfort rather than heat stress, taking account of the wet bulb temperature, dry bulb temperature and air velocity.
		EHO: Environmental Health Officer.
		Electric Arc: Ultraviolet radiation generated by ‘sparking’ which can cause damage similar to severe sunburn and a painful eye condition known as ‘arc-eye’. Molten metal particles from the arc itself can penetrate, burn and lodge in the flesh. These effects are additional to any radiated heat damage caused by the arc.
		Electric Burn: Caused by the heating effect of the passage of electric current through body tissues, these occur in and on the skin layers at the point of contact with the electrical conductors which gave rise to the electric shock.
		Electric Shock: Electric current may take multiple paths through the body causing muscular contractions, respiratory failure, fibrillation of the heart, cardiac arrest or injury from internal burns. Any of these can be fatal.
		Electrical Equipment: Every type of electrical equipment from for example a 400 KV overhead line to a battery-powered hand lamp, and also includes conductors used to distribute electrical energy such as cables, wires and leads and those used in the transmission at high voltage of bulk electrical energy, as in the national grid.
		Electrical Explosion: The violent and catastrophic rupture of any electrical equipment such as switchgear, motors and power cables which are liable to explode if they are subjected to excessive currents.
		Electrical System: All the constituent parts of a system, eg conductors and electrical equipment in it, this will include all of the electrical equipment connected together and the various electrical energy sources in that system.
		Electrochemical Detector: A direct reading instrument for inorganic gases in which a sensitive electrode, separated from the contaminant gas by a permeable membrane, is promoted into a chemical reaction with the electrolyte in which it is immersed. As the chemical reaction takes place a change in the electrical current in the electrochemical cell occurs which is proportional to the gas concentration.
		Electromagnetic Field: The region in which electromagnetic radiation from a source exerts an influence on another object with or without there being contact between them.
		Electromagnetic Radiation: Oscillating electric and magnetic fields travelling together through space. There are limitless possibilities to the range of frequencies which exist but the main types are listed in the form of a ranking as an electromagnetic spectrum.
		Electromagnetic Spectrum: A table of energy in which forms of electromagnetic radiation are ranked according to their wavelengths. eg Gamma rays, X-rays, ultra-violet, visible light, infrared, microwaves, and radio-waves. See Ionising Radiation and Non-Ionising Radiation.
		Electron: An elementary particle with low mass, 1/1836 that of a proton, and unit negative electric charge. Positively charged electrons, called positrons, also exist. See also Beta Particle.
		Electron Capture Detector: In sample analysis, uses a radioactive source to ionise the carrier gas inside a chamber. This induces the gas to produce a steady stream of ions which can be measured as a steady current whose strength depends on the gas component and its concentration.
		Electron Volt: Unit of energy employed in radiation physics. Equal to the energy gained by an electron in passing through a potential difference of 1 volt. Symbol: eV. 1 eV = 1.6 × 10-19 joule approximately.
		Electrostatic Precipitator: An air cleaning device which utilises the principle of static attraction to remove dust particles from air. Capable of achieving very high degrees of efficiency, irrigated versions exist.
		Element: A substance with atoms all of the same atomic number.
		EMAS: Employment Medical Advisory Service.
		Emergency Lighting: Battery (usually) powered lighting system which activates upon the failure of the mains electricity supply to illuminate escape or exit routes in occupied buildings.
		Emergent Properties: Characteristics of a system which are tangible but cannot be attributed to any one component in particular, see Synergy.
		EMF: See Electromagnetic field.
		Employment Appeal Tribunal (EAT): A tripartite body comprising high court judges nominated by the Lord Chancellor and a panel of lay members chosen from employers’ and workers’ organisations. Cases are heard by a judge and either two or four lay persons, all of whom have equal voting rights. Appeals against an employment tribunal decision can normally only be considered by the EAT if there has been an error of law.
		Employment Tribunal: A tripartite body set up by statute to deal with certain minor matters determined by statute. It comprises a legally qualified chairperson and a representative from an employer’s association and one from a worker’s association or union.
		Enclosure: A control measure involving the separation of a hazardous process from the external environment by keeping it under negative pressure for example.
		Endocrine System: Comprises glands, like the pituitary, thyroid, pancreas, and the gonads, which control many functions from growth to glucose metabolism and reproduction.
		Endotoxin: Intracellular toxin (retained within bacteria and liberated when bacteria disintegrates).
		Enforcement Authority: An authority given powers by statute to enforce health, safety and environmental legislation. See Health and Safety Executive (HSE), Environmental Health Officer (EHO) and Environment Agency.
		Environment: All or any of the following media, namely, air, water and land; and one medium of air includes air within buildings and the air within other natural or man made structures above or below the ground (Environmental Protection Act).
		Environment Agency: Regulatory body set up to administer environmental legislation in England and Wales. See SEPA.
		Environmental Health Officer: An enforcement officer employed by local authorities having jurisdiction over spheres of non-industrial employment, (offices and shops etc). Powers are the same as HSE in occupational safety and health.
		Epidemiology: The study of the distribution of disease and of the factors which determine it within a population.
		Equivalent Continuous Sound Pressure Level: See Leq.
		Equivalent Dose (Radiation): The quantity obtained by multiplying the absorbed dose by a factor to allow for the different effectiveness of the various ionising radiations in causing harm to tissue. Unit: sievert, symbol: Sv.
		Ergonomics: Process by which work systems are designed so that machines, human tasks and the environment are compatible with the capabilities of the people using the system. Encompasses physical, physiological and psychological considerations.
		Errors: A category of human failure which includes skill-based errors such as slips of action and lapses of memory, and mistakes such as rule based mistakes and knowledge based mistakes.
		Erythema: Reddening of the skin caused by dilation of blood vessels.
		Eschericia coli: Rod shaped bacterium commonly found in the large intestine of humans and other animals. Its presence in water is an indicator of faecal pollution and upon ingestion it can cause (severe) food poisoning.
		Essential Health and Safety Requirements (EHSR): A term used in some European Directives to describe certain safety features or standards to be incorporated in products placed on the European market (eg Annex I of the Machinery Directive).
		Estimated Risk: The level of risk (of a particular outcome) where a degree of certainty or precision can be claimed. See Risk Estimation.
		EU: European Union.
		EUDS: Equivalent unit density sphere. See Unit Density Sphere.
		European Agency for Safety and Health at Work: A tripartite European Union organisation which brings together representatives from three key decision-making groups in each of the EU’s Member States – governments, employers and workers’ organisations. The Agency acts as a catalyst for developing, collecting, analysing and disseminating information that improves the state of occupational safety and health in Europe.
		European Commission: Civil service body which administers the programme of legislation emanating from European Union.
		European Court of Justice: ECJ is a court of the European Union, independent of other community institutions, whose task is to interpret the European Constitution and other enactments in times of dispute. It can hear cases involving EU treaties and subordinate European legislation brought by, or against, the Council of Ministers or the European Commission. It can also provide preliminary rulings to national courts on the clarification of community law.
		European Directive: A legal instrument of the European Union used frequently to harmonise the laws of member states. It is binding in principle (as regards the objective to be achieved) but leaves the choice of form and methods used to achieve it to the domestic legal processes of member states (see also Decision).
		European Regulations: Legal acts which override the domestic legal systems of members states of the European Union. These apply directly in the form expressed and are binding in their entirety.
		European Safety Agency: See European Agency for Safety and Health at Work.
		European Union: A family of democratic European countries, committed to working together for peace and prosperity.
		Event Tree Analysis: A technique used for assessing major hazards which starts at the initiating event and constructs a tree from that event through a number of paths representing the success or failure of each relevant control device. It is based upon a binary logic that the control will operate or fail to operate and a probability is assigned to each outcome. From this each failure path can be ranked to its relative importance.
		Exceptional Violation: A violation created when something goes wrong and the operator believes that the only solution is to break the rules even though it could be seen as taking a risk. The benefits of following this course of action may appear to outweigh the risk. The accident at Chernobyl nuclear power station is a prime example of this type of behaviour, with engineers continuing to improvise after a mistake and making things worse. See Routine Violation and Situational Violation.
		Excitation: A process by which radiation imparts energy to an atom or molecule without causing ionisation. It is dissipated as heat in tissue.
		Excretion: The process of expelling toxic substances from the body through the kidneys via the urine, but also via bile (high molecular weight compounds), lungs (volatile hydrocarbons excreted unchanged), gastric juices (nicotine), breast milk (pesticides) and skin (iron).
		Exotoxin: Toxin released from the exterior of an organism.
		Expectation: A ‘built in’ model of the world outside our head which influences our behaviour in a given situation. If the world does not meet our expectation we compare reality with what we expect and modify our behaviour and future expectations accordingly. See Stereotype.
		Expert Power: The ability to influence the behaviour of people because of superior knowledge and expertise relevant to the particular situation.
		Explosion: The rapid release of energy arising from combustion processes, electrical systems or pressure storage systems. See also Secondary Explosion.
		Explosion Power: The maximum over pressure which can be reached under the prevailing conditions, measured in bar or kNm-2.
		Explosion Violence: The rate at which the pressure of an explosion increases measured in bar/sec or kNm-2s.
		Explosive: A chemical substance or mixture in which fuel and oxidising agent are combined.
		Exposure Limit: See Occupational Exposure Limit.
		Express Term: A condition of a contract of employment that is expressly stated to form part of the contract and is subsequently binding.
		Extra-high Pressure (electrical): Pressure in a system (UK) normally exceeding 3000 volts where the electrical energy is used or supplied.
		Extrinsic Allergic Alveolitis: Name given to a collection of diseases which cause allergic inflammation of the alveoli. It results from exposure to the spores of fungi found in mouldy hay and other vegetable matter. Common forms of the illness are Farmer’s Lung, Bagassosis (mouldy sugar cane), Malt Worker’s Lung and Mushroom Picker’s Lung among others.
		Eye bolt: A ring incorporating a threaded bolt which is connected to a load to create a lifting point.

Disclaimer:
Whilst every effort has been made to ensure the accuracy of the information contained in this book opinions may vary regarding some concepts. The Key Consultancy Ltd and Safety and Health Practitioner accept no responsibility for any loss arising from reliance on this content and readers should take steps to verify interpretations to their own satisfaction if there is doubt.