Safety in the Use of ChemicalsGlossary of Terms, Bibliography |
Accumulation: The phenomenon whereby the quantity of a substance in an organ, organism or a part of the environment continues to increase with time as additions of the substance take place from outside.
Acid rain: An environmental problem in which mineral acids (sulphuric and nitric) fall with the rain. These acids are formed in the atmosphere due to reactions of the oxides of sulphur and nitrogen released from the burning of fuels.
Action level: The level of harmful substances in air in the environment, determined by the authorities, at which some kind of control measures have to be adopted. It is below the exposure limit for the substance (usually somewhere between a third and half of the exposure limit).
Acute effects: The effects which occur soon after exposure and are normally short lived.
Additive effect: The effect of a mixture of chemicals, which is the sum of the individual effects of the components of the mixture.
Adverse effect: Abnormal or undesirable harmful effect of a chemical on an organism.
Aerosol: A suspension of solid or liquid particles in the air fine enough to remain suspended in air for a long time. It is a broad term which includes dusts, smoke, fog, mist, fumes, etc.
Air pollution: The presence of substances in the air resulting from human activities or natural processes. The substances should be present in sufficient amount and for sufficient duration to have effects on the comfort, health or welfare of the persons or the environment.
Allergic contact dermatitis: Allergic reaction caused by exposure of skin to certain chemical or biological materials. Once the skin is sensitised, the allergy remains with the person for his life, symptoms returning, after a brief exposure to the sensitising agent.
Allergin: A term used to describe the materials which can cause allergies.
Allergy: A broad range of disease symptoms caused by the response of the immune system to exposures to certain substances.
Asbestosis: A lung disease caused by inhalation of asbestos fibres.
Biological monitoring: The assessment of exposure to harmful substances by monitoring the health of the persons and by analysing the samples of biological origin. Most often, blood or urine are analysed, but other materials like expired air, faeces, hair, biopsy may be used for the assessment of exposure to certain materials. The term may also be applied to monitoring of the effects of exposure.
BOD (biological oxygen demand): Defined as the mass of dissolved oxygen required by a specific volume of solution of the substance to carry out biochemical oxidation under prescribed conditions. It is used as a parameter to assess the ability of the micro-organisms to metabolize an organic substance in the presence of oxygen. It is used as an index of water pollution by bio-degradable materials.
Byssinosis: A debilitating lung disease caused by prolonged exposure to cotton dust and trash.
Cancer: The name given to a number of diseases which result from uncontrolled growth of cells and often accompanied by malignant tumours.
Carcinogen: An agent, chemical, biological or physical, that can act on living tissue in such a way as to produce malignant growth.
Chronic effects: Effects of exposure which develop slowly and may sometimes appear long after the exposure has ceased. Such effects are often irreversible.
Ceiling value: The maximum airborne concentration of a harmful substance, to which a person should never be exposed.
COD (chemical oxygen demand): The mass of dissolved oxygen required by a specific volume of solution of the substance to carry out chemical oxidation under prescribed conditions. It is used as a parameter for assessing the extent of water pollution.
Concentration: The quantity of a material or substance in a unit quantity of a given medium.
Contact dermatitis: A skin disease resulting in inflammation or reddening caused by contact of skin with certain agents.
Contaminant: Used as a synonym for pollutant.
Corrosive (of tissues): A material which destroys tissues on contact.
Criteria: Validated set of data used as a basis of judgement.
Cumulative effect: The effect of repeated exposure to certain harmful substances which continue to produce enhanced effects with each increased dose.
Dermatitis: Inflammation of skin.
Dose: The amount of a chemical to which a person or organism is exposed.
Effect: The change in an organism, tissue, organ or part of the environment due to introduction of external chemical, biological or physical factors.
Elimination: The total removal of harmful materials or processes. Also applies to removal of the substance or material from the body.
Embryotoxic: A substance capable of inducing harmful effects in the first period of pregnancy, after conception but before formation of foetus.
Emission: The process of giving off environmental pollution.
Environment: A term encompassing all the external conditions and influences to which a system is subjected. The system covers all living organisms including human beings.
Environmental quality standard (EQS): A term used in environmental law defining the maximum concentration of a potentially toxic substance which can be allowed to be released in a certain type of environment (usually air or water) over a definite period of time.
Excretion: The elimination or discharge of a waste product, absorbed or internally produced from the body, through urine, faeces or other types of waste products.
Exposure: The amount of an environmental agent which has reached or has been absorbed by a person.
Exposure assessment: The process of quantification of the exposure of a person or a group.
Exposure limit: The level of exposure which should not be exceeded. Different forms of exposure limits may be adopted in the laws of various countries.
Fetotoxic: A substance or agent which can harm the foetus in an organism. In humans the embryo develops into a foetus after about three months of pregnancy.
Food chain: The sequence through which matter and energy in the form of food are transferred from organism to organism.
Fungicide: A chemical used to kill fungi.
Gas: The formless state of matter which expands to occupy the space or enclosure to which it is confined.
Gene: A part of the DNA molecule carrying instructions for building the peptide chains with specific sequences of amino acids.
Hazard: A source of danger.
Health: A state of complete physical, mental, and social well-being.
Hepatotoxic: Any material or agent which is harmful to the liver.
Herbicide: A chemical used to kill plants.
Immune system: The defence mechanism of the body, through which it fights invading foreign materials like biological and chemical agents.
Insecticide: A chemical used to kill insects.
Irritant: A substance capable of causing inflammation of the skin or mucous membranes after immediate, prolonged or repeated contact.
Latent period: The delay between the exposure and the onset of symptoms of exposure.
Lower explosive limit (LEL): The lower limit of the concentration of gas or vapour at normal ambient temperatures, at which it becomes flammable. It is expressed as percent by volume of the gas or vapour in the air.
Malignant: Cells with cancerous growth.
Mesothelioma: A form of cancer caused by exposure to asbestos fibres and occurring in the mesothelium of some protective cell layers in the lungs, heart and abdomen.
Metabolism: The sum of all the physical and chemical processes taking place in the body.
Metabolite: A substance produced by the physical and chemical processes taking place in the body.
Mist: The finely divided liquid droplets in air formed through condensation or dispersal of liquids.
Monitoring: The repetitive and continued observation, measurement and evaluation of health, environmental and technical data following some defined principles and for defined purposes.
Mutagenicity: The capability of a chemical, biological or physical agent to induce changes in the genetic material of the body.
Mutation: A change in the genetic material of the body.
Occupational environment: The environment at the workplace.
Occupational hygiene: The science dealing with the recognition, evaluation and control of chemical, biological or physical hazards arising from the workplace.
Oxidation: The chemical reaction of oxygen with another chemical.
Pesticide: The chemicals or materials used to kill pests, usually to protect the agricultural and health interests of the humans.
pH: A criterion used to express the acidity or alkalinity of a solution. A solution with pH of 7 is neutral, that with pH 7-14 is alkaline and that with a pH lower than 7 is acidic.
Pollutant: Any undesirable solid, liquid or gaseous matter in a solid, liquid or gaseous medium. The media for most types of pollutants are air and water.
Pollution: The introduction of pollutants into solid, liquid or gaseous media.
ppb: Parts per billion.
ppm: Parts per million.
Reproductive effects: The harmful effects of a chemical on the capability of an organism to reproduce.
Risk: The probability that an event (or harmful effect) will occur.
Risk assessment: The process though which hazards are identified, their risks are quantified and the likely impact upon the health and well-being of individuals and society in general is evaluated.
Sample: One or more items taken from a population with the intention of obtaining information and forming an opinion about the characteristics of the population.
Sensitization: The activation of the immune response by certain substances in such a way that disease symptoms appear once the person is exposed to the substance in future, even for brief periods of time.
Short term exposure limit (STEL): A term introduced by the American Conference of Governmental Industrial Hygienists (ACGIH). It is the time-weighted (TWA) average of the airborne concentration of a contaminant, to which workers may be exposed for a period of 15 minutes, with no more than 4 such exposures per day and at least 60 minutes between them.
Silicosis: A lung disease caused by exposure to free silica or quartz.
Smoke: The fine suspension of carbon particles and unburnt carbonaceous fuels in the air resulting from incomplete burning of such fuels.
Static electricity: The electric charge generated by contact and separation of dissimilar materials.
Synergistic effect: The combined effect of two chemicals which aggravate the effect of each other and thus the combined effect is higher than the sum of individual effects.
Teratogen: A substance which can cause non-heritable birth defects.
Threshold limit value (TLV): A guideline exposure limit defined by the American Conference of Governmental Industrial Hygienists (ACGIH). For chemicals, it is defined as the airborne concentration of a potentially toxic substance to which a healthy adult worker can be exposed safely through a 40-hour working week and a full working life. The concentration is measured as a time- weighted average for a specified duration.
Time weighted average: The concentration of a substance to which a person is exposed in the ambient air divided by the total time of observation. For exposures in the working environment, the full working shift of 8 hours is used largely as the averaging time.
Toxicity: The capacity of a substance to cause injury to an organism, when it comes in contact with it.
Tumour: A mass of tissue resulting from abnormal growth of cells.
Vapour: The gaseous form of substances that are normally in solid or liquid form at room temperature and pressure.
ILO, Major Hazard Control, A Practical Manual, International Labour Office, Geneva (1988).
ILO, Prevention of Major Industrial Accidents, International Labour Office, Geneva (1991).
ILO, Convention concerning Safety in the Use of Chemicals at Work, 1990 (No. 170).
ILO, Recommendation concerning Safety in the Use of Chemicals at Work, 1990 (No. 177).
ILO, Convention concerning the Prevention of Major Industrial Accidents, 1993 (No. 174).
ILO, Recommendation concerning the Prevention of Major Industrial Accidents, 1993 (No. 181).
IPCS, Chemical Safety Training Modules, International Programme on Chemical Safety, World Health Organization, Geneva.
Watfa, N., Safety in the Use of Chemicals at the Workplace, Chemical Safety, International Reference Manual, VCH Verlagsgesellschaft, Germany (1994). ISBN 92-2-110896-1
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