ATTA31MEUT II - PAGE 2 
Additional precautions may be desirable if synergy or potentiation occur 
as, for example those bacterial exotoxins that enhance the toxicity of 
endotoxin. 
Itoxicity Determination 
A toxin shall be considered potent at a certain level if parenteral admin- 
istraticxi of a certain amount causes death, disfigurement or profound 
neurological effects. 
a) If the human toxicity is kncwn, this information shall be paramount. 
b) If human toxicity is not known, it may be inferred pro tern from assays 
of toxicity to another primate (intravenous injection to at least four 
animals) . 
c) If neither human nor other primate toxicity is known, human toxicity 
may be inferred from 16 most sensitive of three small animals, namely 
mice, guinea pigs and rabbits, using intravenous injection into at 
least four anijrals of each species. 
Hie toxin used for the tests must be of good quality without substantial 
denaturation or chemical alteraticxi from its most effective form. Ihe 
purity must be known sufficiently to determine the content of specific 
agent. If the purity is in doubt the most conservative assunption must 
be made. An iirqpure toxin that a^spears similar in structure and action to 
a knovm toxin may be assunned pro tan to be ten times as toxic as the 
known toxin. 
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