L1 /
13
CH3041
TOXICITY
• To compare toxicity
ratings it is necessary
to consider not only the
LD50 but also the slope of
the dose-response curve.
to consider not only the
LD50 but also the slope of
the dose-response curve.
• A more potent chemical
will have the same slope
as the chemical with which
it is being compared but a
lower value of LD50.
will have the same slope
as the chemical with which
it is being compared but a
lower value of LD50.
Sig No
no. deaths
die
1s
68%
68%
eg. LD50 mg/kg ethanol
104 malathion
103
nicotine 2 tetrodotoxin 10-2 dioxin 10-3
nicotine 2 tetrodotoxin 10-2 dioxin 10-3
Toxicity: slightly / moderately / supertoxic
(tetrodotoxin is from the puffer fish – Japanese fugu)
(tetrodotoxin is from the puffer fish – Japanese fugu)
• 68% of the response is within 1s of the
LD50 ie. LD16 – LD84
LD50 ie. LD16 – LD84
