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Pure Appl. Chem., Vol. 65, No. 9, pp. 2003-2122, 1993.



Glossary for chemists of terms used in toxicology
(IUPAC Recommmendations 1993)


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> Synopsis


The International Union of Pure and Applied Chemistry (IUPAC) established a COMMISSION ON TOXICOLOGY, within the framework of the Clinical Chemistry Section, in 1973. Like other IUPAC bodies, the Commission was concerned to promote world-wide "regulation, standardization, or codification" in relevant areas of chemistry. Over the years, toxicology has grown rapidly. A need has been recognized for globally acceptable definitions of terms used in toxicology and ecotoxicology and this glossary was commissioned with the objective of fulfilling that need.

The glossary is compiled primarily for chemists who now find themselves working in toxicology or requiring a knowledge of the subject. Faced with an extensive literature and terms that are not always defined in accessible dictionaries, newcomers to the subject can have great difficulty in obtaining the background knowledge essential for their work. Further, many toxicologists, whose previous experience has been limited to clinical and experimental toxicology, now have to assess possible environmental effects of chemicals and need to understand terms used in ecotoxicology. Equally, specialists in ecotoxicology often lack knowledge of the terms used in clinical and experimental toxicology. There are also regulators and managers who have to interpret toxicological information and therefore need ready access to internationally accepted definitions of relevant terms in common use.

Satisfying the requirements of the various groups now concerned with the generation or use of toxicological knowledge is a wide remit and hence the terms to be included in this glossary have come from a wide range of disciplines. Many medical terms are included because of their frequent occurrence in the toxicological literature and because chemists would not normally be expected to be familiar with them. Major epidemiological terms are included for the same reason. Specialists in these and other areas may believe that such terms can be omitted because they are well defined elsewhere. While this glossary may err on the side of including peripheral terms, it is believed that some redundancy of content is preferable to the difficulties currently presented to a newcomer to toxicology in having to consult several
dictionaries in order to make a start with the subject.

The definitions given in this glossary are believed to reflect current usage and no attempt has been made to introduce new or "preferred" definitions. Obsolete terms such as "cytochrome P448" have been included because they are to be found in scientific articles which still have relevance. For some of the entries, alternative definitions are given because significant differences in usage have been recognized between disciplines or even between different languages where similar words to the English terms are used.

More people than we can name in the Acknowledgments have contributed to this glossary and we are grateful for all the contributions that have helped to improve each version that has been produced. Inevitably there will still be flaws but we hope that the final version will be sufficiently close to achieving the original objectives to justify the very widespread support that this Working Party has enjoyed.


The active collaboration of Professor Paolo Preziosi, President of the International Union for Toxicology (IUTOX) and of Professor Norman Aldridge, together with the support of IUTOX in the compilation of this glossary, has been particularly welcome and greatly appreciated by the Working Party.

The Working Party was fortunate in having scientific support from the International Programme on Chemical Safety, the International Register of Potentially Toxic Chemicals and the United Nations Environment Programme which allowed IUPAC to use published and unpublished material. The Working Party acknowledges the support of The Royal Society of Chemistry, London, GBR, in permitting the use in the original drafts of definitions from its books, "Toxic Hazard Assessment of Chemicals", and "Risk Assessment of Chemicals in the Environment", both edited by M.L. Richardson. The Regional Office for Europe of the World Health Organization also generously permitted incorporation of definitions from Environmental Health Publication 10, "Environmental Toxicology and Ecotoxicology", edited by J.H. Duffus. We are particularly grateful to Professor J.M. Last, the International Epidemiological Association, and Oxford University Press for permission to quote definitions from "A Dictionary of Epidemiology", Second Edition. We are also grateful to the Association of Clinical Biochemists Scientific Committee who kindly reviewed a draft of the glossary and annotated it with their suggestions.

The Working Party exchanged information with the IUPAC Commission on Biotechnology and a number of terms are found in both this glossary and the "Glossary of Terms Used in Biotechnology" prepared by that Commission. In addition, helpful comments were received from the Commission on Agricultural Chemistry and from other Commissions, such as the Commission on Water Chemistry.

For the first draft, the Working Party received financial assistance from the European Community Directorate General XI, and from Ashton-Tate Ltd. in the form of a gift of software. IUPAC made funds available for the second and third drafts.

For the preparation of the second draft, grants were received from the National Rivers Authority - Thames Region, and from Albright & Wilson (European Headquarters).

For the preparation of the third draft and assistance in travelling and subsistence, the Working Party is indebted to the IUPAC Committee on Chemical Industry (COCI) for their support. Additionally, support, both financial and moral was given by the member companies CIBA-GEIGY, Lonza, Hoffman-La Roche, and Sandoz, and the permanent staff of ECETOC. General thanks for financial support are due to Betz, Procter and Gamble - Belgium, ICI Agro-chemicals, Houseman Speciality Chemicals, Monsanto, and Rohm & Haas Italia.

Finally, the preparation of the glossary would not have been feasible without the efforts of Pauline Sim, Principal of Gascoigne Secretarial Services, High Wycombe, GB, who typed the first 3 draft copies, was responsible for the original compilation in alphabetical order of terms from many sources, and typed the several hundred letters needed to get the project started.


In compiling this glossary, it became clear that toxicologists have not conformed to the rules laid down by IUPAC in their current practice. For example, one of the IUPAC rules about abbreviations is that they should not be used as symbols for physical quantities but by long tradition toxicologists have used the abbreviation LD50 and related abbreviations in just this way. The compilers of this glossary have accepted the prevailing toxicological usage but this is not to be taken as an indication that it has their approval and they recommend that some attempt should be made to improve on current usage to bring it into line with IUPAC rules. Similarly, the compilers recommend that, contrary to much current usage, toxic components (like other chemically definable components) in doses, dosages and exposures should be expressed as amounts-of-substance, substance concentration, substance content or a time integral of one of these. Thus, for example, a pesticide should be expressed as amount-of-substance, not as its mass including binding agents and other ingredients, nor its volume including solvent.

There is a need for translations of such terms as "absolute lethal concentration" into the recommended format for clinical chemistry with component, system, and kind-of-quantity with parenthetic specifications of each as necessary. Thus, "absolute lethal concentration in air" might become ambient-air-toxicant substance concentration (number fraction of organisms killed = 1).

There is also a need for a careful revision of symbolic practices to bring them into line with ISO-31 (for example c (d killed = 1) for absolute lethal concentration in stead of LC100).

Throughout the glossary the following abbreviations are used to ndicate the relationships between terms:

AN antonym, opposite
BT broader term
NT narrower term
PS partial synonym
RT related term
SN exact synonym

Working party
S. S. Brown; N. de Fernicola; P. Grandjean; R. F. Herber; C. R. Morris; J.A. Sokal

W. N. Aldridge; D. H. Bangham; R. E. Bareiss; C. Bismuth; J. C. Bollinger; A. Cavalleri; J. Molin Christensen; T. M. M. Coenen; L. E. Coles; A. Cornish-Bowden; A. T. Costello; A. D. Dayan; P. de Bievre; J. Debord; H. B. F. Dixon; H. V. Ellis III; G. Ferard; R. J. Flanagan; D. M. Gott; P. F. Headley; B. Heinzow; R. J. Hemingway; H. P. A. Illing; M. Jakubowski; J. O. Jarvisalo; Chen Jisheng; Kaew Kangsadalampai; D. Kello; W. H. Konemann; P. Kratochvil; K. Kuchitsu; G. Lachatre; A. Lamberty; M. Lauritzen; M. S. Madiwale; E. Magid; I. M. Mills; N. Montalbetti (deceased); C. R. Krishna Murti (deceased); M. Okagawa; H. Olesen; D. V. Parke; K. K. Parker; O. M. Poulsen; R. Plestina; P. Preziosi; J. Prokes; W. C. Purdy; S. RendiE; M. Repetto; J. C. Rigg; D. M. Rutherford; E. Smith; H. Smith; W. G. Temple; D. Templeton; J. S. Thompson; A. J. Thor; E. M. den Tonkelaar; D. Tonks; H. Vainio; F. Weber; M. I. Weitzner; H. Worth

Membership of the Commission during the period (1989-93) when this report was prepared was a follows:
Chairman: 1989-91 P. Grandjean (Denmark); 1991-93 Rita Cornelis (Belgium); Secretary: 1989-91 R. Cornelis (Belgium); 1991-93 B. Heinzow (Germany); Titular Members: S. S. Brown (1989-91; UK); J. H. Duffus (1991-93; UK); R. F. M. Herber (1989-93; Netherlands); M. Jakubowski (1989-93; Poland); Jytte Molin Christensen (1991-93; Denmark); E. Nieboer (1989-91; Canada); D. M. Templeton (1991-93; Canada); C. Veillon (1989-91; USA); Associate Members: A. Cavalleri (1989-93; Italy); Sheila bawling (1991-93; UK); Andree Lamberty (1989-93; Belgium); S. Rendie (1989-91; Yugolsavia); D. Rutherford (1991-93; Australia); Y. Thomassen (1991-93; Norway); Marie Vahter (1991-93; Sweden); C. Veillon (1991-93; USA); National Representatives: O. Augusto (1991-93; Brazil); I. Ddsi (1989-93; Hungary); P. K. Ray (1989-93; India); W. King (1991-93; Ireland); W. A. Temple (1989-93; New Zealand); M. Repetto Jimenez (1989-93; Spain); Zeliha Imre (1989-93; Turkey); Representative of IUPHAR Section on Toxicology: J. G. Salway (1989-91; USA); Representative of IUTOX: P. Grandjean (1989-93; Denmark).

Alphabetical entries

A | B | C | D | E | F | G | H | I | J | K | L | M

N | O | P | Q | R | S | T | U | V | W | X | Y | Z  

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