A material, other than a gas, which is known to be so toxic to humans as to afford a hazard to health during transportation; or which, in the absence of adequate data on human toxicity, is presumed to be toxic to humans because it falls within any one of the following categories when tested on laboratory animals: oral toxicity, dermal toxicity, or inhalation toxicity.

Note: Labels used to identify a subsidiary risk must have the class number obliterated.