Glossary
This multilingual glossary provides easy-to-understand definitions for the main scientific terms used on this website in the risk assessment domain. Terms and their definitions are referenced in our communication products as pop-up notes to explain concepts to the public with no specialist knowledge.
Standard English spelling is used throughout. Acronyms are capitalised. Terms are presented in lower case. Entries are translated into all 24 EU official languages.
The glossary is a living document subject to regular updates. Relevant missing terms may be suggested by using the Ask A Question online form.
Disclaimer: Definitions in the glossary are intended solely to help this website's users understand scientific terminology. Definitions may differ from those given in European Union legislation and in the EFSA Journal.
U
Scientific concept used in risk assessment to describe all types of limitations in available knowledge at the time an assessment is conducted, with the agreed resources, that affect the probability of possible outcomes to the assessment.
A method of identifying the sources of uncertainty in a risk assessment calculation and estimating their size and direction so that errors can be taken into account.
A way of estimating exposure to a particular compound from analytical data by assigning the lowest value which can be detected (or quantitated) to all samples with levels below this value. For a toxic chemical this gives the most pessimistic estimate of exposure (i.e. the real level of exposure will always be below the upper bound estimate).