I  U  P  A  C

News & Notices

Organizations & People

Standing Committees



..By Year
..By Division
..Other Committees




Links of Interest

Search the Site

Home Page


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



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


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 

ulcer: Defect, often associated with inflammation, occurring locally or at the surface of an organ or tissue owing to sloughing of necrotic tissue.
uncertainty factor:
1. In assay methodology, confidence interval or fiducial limit used to assess the probable precision of an estimate.
2. In toxicology, value used in extrapolation from experimental animals to man (assuming that man may be more sensitive) or from selected individuals to the general population: for example, a value applied to the no-observed effect level (NOEL) or no-observed adverse effect level (NOAEL) to derive an acceptable daily intake or reference dose (RfD) (the NOEL or NOAEL is divided by the value to calculate the acceptable daily intake or RfD). The value depends on the nature of the toxic effect, the size and type of population to be protected, and the quality of the toxicological information available.
     SN safety factor.
RT modifying factor, no-observed-effect-level, no-observed-adverse-effect-level, reference dose.
unit risk (as used by the USEPA): Incremental upper-boundary lifetime risk estimated to result from lifetime exposure to an agent if it is in air at a concentration of 1 mg/m3 or in the water at a concentration of 1 mg/L.
IRIS, 1986
upper boundary: Estimate of the plausible upper limit to the true value of a quantity: this is usually not a statistical confidence limit.
IRIS, 1986
uptake: Entry of a substance into the body, into an organ, into a tissue, into a cell, or into the body fluids by passage through a membrane or by other means.
PS absorption.

urticaria: Vascular reaction of the skin marked by the transient appearance of smooth, slightly elevated patches (wheals, hives) that are redder or paler than the surrounding skin and often attended by severe itching.


> Return to main menu 

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

Page last modified 12 September 2001.
Copyright ©1997-2001 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web manager.