Environmental Terms

Absorption - Taking a substance into the body by penetration through intact skin - one of the Routes of Entry

Aerosols - Substance dispersed into the air such that the droplets or particles remain in suspension for a significant period of time

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

Background Level - The normal or typical level of a chemical in the environment, often referring to the naturally occurring level

Carcinogen - Substance that is known or suspected of causing cancer

Combustible Liquid - Liquid with a flash point above 37.8 C (100° F)

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 sea water

Contaminant - Substance - usually undesirable - in another substance, product or space where it is not normally found, e.g. environmental pollutants

Corrosive - Substance that causes destruction of another substance, including human tissue

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

Ingestion - Taking a substance into the body through the mouth, for example in the form of food or drink - one of the Routes of Entry

Inhalation - Taking a substance, typically in the form of gases, fumes, vapours, mists, aerosols or dusts, into the body by breathing it in - one of the Routes of Entry

Injection - Taking a substance directly into the body by puncturing the skin, for example with a needle - one of the Routes of Entry

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

Mutagen - Something that is able to cause a mutation (or genetic change) in a living cell

Narcotic - A substance that has the potential to affect the nervous system by, for example, inducing drowsiness, stupor or insensibility

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

Regulation - A statutory device made under a general provision that is contained in an act of parliament. Regulations themselves are approved by parliament and are generally absolute legal standards.

Routes of Entry - The various ways in which toxic substances may enter the body, including; Absorption, Ingestion, Inhalation, Injection and Eye-splashes

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

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

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