Glossary of Terms
The following is a list and explanation of terms used in this project and website.
a.i.
Active ingredient
Alevin
Newly hatched fish, before the fry stage. Usually refers to salmon.
CAS Number
CAS Number is a numeric designation given to a
specific chemical compound by the Chemical Abstract Service
d
Day; for example as in 10d LC50
EC
Effective Concentration; for example, EC50 is the effective
concentration where 50% of the organisms respond
F
Flow-through bioassay; for example 96h LC50,F
Fry
Small fish, especially young, recently hatched fish
h
Hour; for example 96h LC50
Half-Life
The time required for a chemical to degrade to half its initial
concentration
IC
Inhibitory Concentration; for example, IC50 is the concentration
for 50% inhibition, usually growth by microorganisms
Koc
Contaminant organic carbon partition
coefficient, proportion sorbed to carbon in soil
Kow
Contaminant octanol-water partition coefficient;
octanol/water ratio
LC
Lethal Concentration; for example, LC50 is the concentration
causing death in 50% of the test organisms exposed
LD
Lethal Dose; for example, LD50 is the dose causing death in 50% of the
test organisms exposed
log
The logarithm of a number
m
Month; for example 3m LC50
MATC
Maximum Acceptable Toxicant Concentration
Molecular Weight
The sum of the relative atomic masses of the constituent
atoms of a molecule
Molting
Periodic shedding of the cuticle in arthropods or the outer skin
of reptiles.
NOEC
No Observed Effect Concentration; the highest tested
concentration not causing an effect
NR
Mean concentration of test substance reducing viability; for example
NR50 is the mean concentration that reduces viability to 50% of controls
Parr
(1) A young
salmon during its first two years of life, when it lives in fresh water.
(2) The young of various other fishes.
pH
p(otential of) H(ydrogen); provides a measure on a scale from 0 to 14
of the acidity or alkalinity of a solution
S
Static bioassay; for example 96h LC50,S
Solubility
The quantity of a particular substance that can dissolve in
a particular solvent
y
Year; for example 1y LC50