Select Toxin Guidance

Changes and Highlights

The information in this guidance document is meant to provide additional information to regulated entities to assist them in meeting the requirements for select toxins.


This is a living document subject to ongoing improvement. Feedback or suggestions for improvement from registered Select Agent entities or the public are welcomed. Submit comments directly to the Federal Select Agent Program at:


Revision History:
  • June 23, 2016: Initial posting
  • March 21, 2017: Updates include new regulatory requirements, revised List of Select Toxins and Non-Regulated Amounts, added section on food and clinical samples, revised section on toxin as a byproduct, revised section on documenting due diligence, and revised chart in Appendix A.
  • May 17, 2017: Updates to Identification of a select toxin requirements (APHIS/CDC Form 4) section.

Download PDF pdf icon[PDF – 1 MB]


The Federal Select Agent Program (FSAP) oversees the possession, use, and transfer of select agents and toxins at registered entities throughout the United States. Select agents or toxins can be regulated as HHS only, APHIS only (Veterinary Services (VS)), Plant Protection and Quarantine (PPQ)), or Overlap Agents (regulated by both agencies). Currently select toxins are only regulated by HHS (42 CFR Part 73external icon). This guidance document is intended to assist those entities that work with select toxins in meeting the requirements of the regulations. The majority of the guidance is intended for those entities that are registered to possess, use, or transfer a select toxin, regardless of whether they actually possess any amount of a select toxin. The guidance on exclusions, exemptions, and due diligence is pertinent for unregistered entities that work with select toxins below the regulatory threshold.

Regulatory Definitions (§ 73.1)

Toxin – the toxic material or product of:

  • Plants, animals, or microorganisms (including, but not limited to: bacteria, viruses, fungi, rickettsia, or protozoa), or
  • Infectious substances, or
  • A recombinant or synthesized molecule, whatever their origin and method of production, and includes
    • any poisonous substance or biological product that may be engineered as a result of biotechnology, produced by a living organism, or
    • any poisonous isomer or biological product, homolog, or derivative of such a substance.

Principal Investigator (PI) – the individual designated by the entity to direct a project or program who is responsible to the entity for the scientific and technical direction of that project or program.

Page last reviewed: January 29, 2021