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GLOSSARY
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O
offgassing
The process of a material giving off gaseous matter, through its structure, into the environment. Offgassing is often the product of fumigation, or of the curing of paints or varnishes.
organic materials
Originally this term referred to materials derived from living things, that is, from plants and animals. It refers also to synthetic materials containing carbon combined with hydrogen and often with oxygen, nitrogen and other elements. Chemically, these substances are similar to the substances derived from living things. The molecules of organic substances are often very complex and contain a large number of atoms.
oxidation, oxidise
A chemical reaction in which a substance is changed to another, forming what is called an oxide. This normally happens when oxygen is combined with the substance, or hydrogen is removed from it.
The term is also used generally to include any reaction in which an atom loses electrons.
oxidising agents, strong oxidising agents
Substances which bring about an oxidation reaction. For example, hydrogen peroxide is a strong oxidising agent. There are many oxidising agents in atmospheric gases and pollutants.
oxygen scavenger
A substance which absorbs atmospheric oxygen, leaving low-oxygen environments. In conservation work, oxygen scavengers can be used to kill insects and some pests by removing oxygen from storage environments, thus providing an effective alternative to fumigation. Oxygen scavengers are also used as a means of preventing corrosion of some metals. See also Low oxygen fumigation.
ozone
An unstable gas under normal conditions with a peculiar, pungent smell. Ozone (O3) is produced when an electric discharge is passed through air or oxygen. It is present in the upper atmosphere and screens the earth's surface from excess ultraviolet radiation.
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