[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]
half-life (t0.5) Time
taken for the concentration of a pesticide in a compartment to
decline by one half. Usually an estimate based on observed dissipation
over several half-lives that can be described by first order kinetics
with rate constant k, t0.5 = 0.693/k. See also
dissipation time 50%.
hazard Set of inherent properties of a
pesticide which gives potential for adverse
effects to man or the environment under conditions of its production,
use or disposal, and depending on the degree of exposure.
(after Duffus, 1993)
hazard assessment Determination
of factors controlling the likely effects of a hazard
such as mechanism of toxicity, dose-effect
relationships and worst case exposure levels. This is the prelude
to risk assessment. (US-EPA,
1992)
hazardous distance for the most sensitive
effect (HDSE) Statistically determined safety margin corresponding
to a distance from treated areas at which protection of the terrestrial
environment can be adequately achieved as measured by the most sensitive
non-target species. See also buffer zone,
margin of safety.
health advisory level (HAL) Estimate
of upper concentration limit for a pesticide in drinking water that
can be consumed for a lifetime without adverse effects. HALs
generally do not have formal legal significance but have been used,
particularly in the USA, for preliminary risk
assessment.
HPLC High performance liquid chromatography.
HPTLC High performance thin layer chromatography.
HRGC High resolution gas chromatography (GLC
with narrow bore capillary columns).
hydrolysis Reaction in which a chemical
bond is cleaved and a new bond formed with the oxygen atom of a molecule of
water.
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