18 U.S.C. § 178

As used in this chapter— (1) the term “biological agent” means any microorganism (including, but not limited to, bacteria, viruses, fungi, rickettsiae or protozoa), or infectious substance, or any naturally occurring, bioengineered or synthesized component of any such microorganism or infectious substance, capable of causing— (A) death, disease, or other biological malfunction in a human, an animal, a plant, or another living organism; (B) deterioration of food, water, equipment, supplies, or material of any kind; or (C) deleterious alteration of the environment; (2) the term “toxin” means the toxic material or product of plants, animals, microorganisms (including, but not limited to, bacteria, viruses, fungi, rickettsiae or protozoa), or infectious substances, or a recombinant or synthesized molecule, whatever their origin and method of production, and includes— (A) any poisonous substance or biological product that may be engineered as a result of biotechnology produced by a living organism; or (B) any poisonous isomer or biological product, homolog, or derivative of such a substance; (3) the term “delivery system” means— (A) any apparatus, equipment, device, or means of delivery specifically designed to deliver or disseminate a biological agent, toxin, or vector; or (B) any vector; (4) the term “vector” means a living organism, or molecule, including a recombinant or synthesized molecule, capable of carrying a biological agent or toxin to a host; and (5) the term “national of the United States” has the meaning prescribed in section 101(a)(22) of the Immigration and Nationality Act ( 8 U.S.C. 1101(a)(22) ).