49 CFR 173.199, IATA Section 3.6.2
Biological Substance, Category B means an infectious substance that is not in a form generally capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposure to it occurs. This includes Category B infectious substances transported for diagnostic or investigational purposes.
Both regulations 49 CFR (173.199) and IATA (184.108.40.206.3.6) require that packages containing Biological Substance, Category B are "triple-packed." Triple packaging consists of a primary receptacle, a secondary packaging, and a rigid outer packaging.
Packages containing Biological Substance, Category B must be clearly marked "Biological Substance, Category B."
The package must also be marked with the identification number "UN3373" in a square-on-point configuration.
The name, address, and telephone number of a person knowledgeable about the shipment must also be included either on a written document or on the outer packaging.