News
& Notices
Organizations & People
Standing
Committees
Divisions
Projects
Reports
..By
Year
..By Division
..Other Committees
..Provisionals
Publications
Symposia
AMP
Links
of Interest
Search
the Site
Home
Page
|
|
Pure Appl. Chem.,
Vol. 65, No. 9, pp. 2003-2122, 1993.
CLINICAL
CHEMISTRY DIVISION
COMMISSION ON TOXICOLOGY
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
narcotic:
1. Nonspecific usage - an agent that produces insensibility or stupor.
2. Specific usage - an opioid, any natural or synthetic drug that
has morphine-like actions.
natriuretic: Substance
increasing the rate of excretion of sodium ion in the urine.
natural occurrence: Presence of a substance
in nature, as distinct from presence resulting from inputs from
human activities. The contamination of the natural environment by
some man-made compounds may be so widespread that it is practically
impossible to get access to biota with a truly natural level; only
"normal" levels can be measured, those which are usually prevalent
in places where there is no obvious local contamination.
necrosis:
1. Mass death of areas of tissue or bone surrounded by healthy areas.
2. Morphological changes that follow cell death, characterized most
frequently by nuclear changes.
negligible risk:
1. Probability of adverse effects occurring that can reasonably
be described as trivial.
2. Probability of adverse effects occurring that is so low that
it cannot be reduced appreciably by increased regulation or
investment of resources.
RT acceptable risk, accepted
risk, risk de minimis.
nematocide: Substance intended to kill nematodes.
neonat/e n., -al
adj.: Infant during the first 4 weeks of postnatal life; for statistical
purposes some scientists have defined the period as the first 7
days.
neoplas/ia, -m:
New and abnormal formation of tissue as a tumour or growth by cell
proliferation that is faster than normal and continues after the
initial stimulus (i) that initiated the proliferation has ceased.
PS tumour.
RT hyperplasia, metaplasia.
nephritis: Inflammation of the kidney, leading
to kidney failure, usually accompanied by proteinuria, haematuria,
oedema, and hypertension.
nephrotoxic: Chemically harmful to the cells
of the kidney.
neural: Pertaining to a nerve or to the nerves.
neuron(e): Nerve cell, the morphological
and functional unit of the central and peripheral nervous systems.
neuropathy: Any disease of the central or
peripheral nervous system.
neurotoxic/ adj., -ity n.: Able to
produce chemically an adverse effect on the nervous system: such
effects may be subdivided into two types.
1. Central nervous system effects (including transient effects on
mood or performance and pre-senile dementia such as
Alzheimer's disease).
2. Peripheral nervous system effects (such as the inhibitory effects
of organophosphorus compounds on synaptic
transmission).
nitrification: Sequential oxidation of ammonium
salts to nitrite and nitrate by micro-organisms.
no
acceptable daily intake allocated: This expression is applicable
to a substance for which the available information is not sufficient
to establish its safety, or when the specifications for identity
and purity are not adequate, or when the available data show that
the substance is hazardous and should not be used: the basis for
the use of the expression should be determined before action is
taken; in the first two cases above, not being able to allocate
an ADI does not mean that the substance is unsafe.
RT acceptable daily
intake.
nodule: Small node or boss that is solid
and can be detected by touch.
non-bioenvironmental transformation: Change
in the chemical or physical nature of a substance occurring as a
result of physicochemical conditions and independent of any biological
system.
non-effective
dose: Amount of a substance that has no effect on the organism.
It is lower than the threshold of harmful effect and is estimated
while establishing the threshold of harmful effect.
SN subthreshold dose.
RT threshold.
non-occupational exposure: Environmental
exposure outside the workplace to substances that are otherwise
associated with particular work environments and/or activities and
processes that occur there.
non-target organism: Organism affected by
a pesticide although not the intended object of its use.
no-observed-adverse-effect-level
(NOAEL): Greatest concentration or amount of a substance, found
by experiment or observation, which causes no detectable adverse
alteration of morphology, functional capacity, growth, development,
or life span of the target organism under defined conditions of
exposure.
WHO, 1979
RT adverse effect.
no-observed-effect-level
(NOEL): Greatest concentration or amount of a substance, found
by experiment or observation, that causes no alterations of morphology,
functional capacity, growth, development, or life span of target
organisms distinguishable from those observed in normal (control)
organisms of the same species and strain under the same defined
conditions of exposure.
RT adverse effect.
no-response level: Maximum dose of a substance
at which no specified response is observed in a defined population
and under defined conditions of exposure.
IRPTC, 1982
nosocomial: Associated
with a hospital or infirmary, especially used of diseases that may
result from treatment in such an institution.
BT iatrogenic.
nutritional table method: Procedure for evaluating
the dietary intake of a large number of people. The accuracy of
the method depends on the accuracy with which records of the food
consumption can be established and the accuracy of the nutritional
tables specifying the concentration of various nutrients, vitamins,
essential, and non-essential substances including pesticide residues.
For each record of quantity of food consumed during a certain time
period, the daily intake of the substance in question is calculated
by multiplying the substance concentration in the food item (as
obtained from the nutritional table) by the quantity of food consumed
and dividing by the time of observation.
WHO, 1979
nystagmus: Involuntary, rapid, rhythmic movement
(horizontal, vertical, rotary, mixed) of the eyeball, usually caused
by a disorder of the labyrynth of the inner ear or a malfunction
of the central nervous system.
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.
|