16/02/2014
DEFINITION OF THE TERMS
Accident consequence analysis: An analysis of the expected effects of an accident, independent of frequency and probability.
Acute effect: The effect caused by a single short-term exposure (usually not more than one work shift) to a high amount of concentration of a substance.
Airborne dust: Refers to the suspension of solid particles in the air. These dust particles are generated by handling, grinding, drilling and crushing operations where solid materials are broken down. The size of these particles ranges from being visible to the naked eye (i.e. greater than one-twentieth of a millimeter in diameter) to being invisible. Invisible dust will remain airborne for a long period of time and is dangerous because of its ability to pe*****te deeply into the lungs.
Check-list analysis: A method for identifying hazards by comparison with experience in the form of a list of failure modes and hazardous situations.
Chronic effect: The effect caused by repeated exposure to a chemical over a long period of time. The effect may be felt only after many years of exposure. Both acute and chronic effects can be reversible after the termination of the exposure and appropriate treatment, or they may result in long-lasting, irreversible conditions.
Competent authority: A Minister, government department or other public authority with the power to issue regulations, orders or other instructions having the force of law.
Emergency plan: A formal written plan which, on the basis of identified potential accidents at the installation together with their consequences, describes how such accidents and their consequences should be handled either on size or off site.
Emergency services: External bodies which are available to handle major accidents and their consequences both on site and offside, e.g. fire authorities, public health services.
Failure mode and effect analysis: A process of hazard identification where all known failure modes of components or features of a system are considered in turn and undesired outcomes are noted.
Hazard: A physical situation with a potential for human injury, damage to property, damage to the environment or some combination of these.
Hazard analysis: The identification of undesired events that lead to the materialization of the hazard, the analysis of the mechanisms in which those undesired events could occur and usually the estimation of the extent, magnitude and relative likelihood of any harmful effects.
Major hazard installations: An industrial installation which stores, processes or produce hazardous substances in such a form and such a quantity that they posses the potential to cause a major accident.
Preliminary hazard analysis (PHA): A procedure for identifying hazards early in the design phase of a project before the final design has been established. Its purpose is to identify opportunities for design modifications which would reduce or eliminate hazards, mitigate the consequences of accidents, or both.
Operational safety concept: Strategy for process control, incorporating a hierarchy of monitoring and controlling process parameters and of protective action to be taken.
Poisoning: Normally the human body is able to cope with a variety of substances, within certain limits. Poisoning occurs when these limits are exceeded and the body is unable to deal with a substance (by digestion, absorption or excretion).
Threshold quantity: That quantity of a listed hazardous substance present or liable to be present in an installation which, if exceeded, results in the classification of the installation as a major hazard installation.
Toxicity: The inherent potential of a chemical substance to cause poisoning. The toxicity of chemicals varies widely. For example, a few drops of a given chemical will cause death while other chemicals will produce the same effect only after a large quantity has been consumed.
Workers: All employed persons.
Works management: Employers and persons, at works level having the responsibility and the authority delegated by the employer for taking decisions relevant to the safety of major hazard installations. When appropriate, the definition also includes persons at corporate having such authority.
