Environmental, Health and Safety Services

Research Using Toxins of Biological Origin (Biotoxins)

  • Biotoxins
    • are potent, highly toxic biological substances produced by living organisms; some can be synthesized by modern methods.
    • may cause death or severe incapacitation at relatively low exposure levels.
    • are handled as chemical hazards
    • safety procedures for using toxins are determined by a toxin risk assessment process.
  • Typical research applications include:
    • use as a growth factor in cell culture media (e.g., cholera toxin).
    • to produce specific neurologic effects (e.g., tetrodotoxin).
    • to produce localized tissue destruction (e.g., diphtheria toxin).
  • When you are asked (on the IBC Main Form, by EHS, or by an auditor or inspector) if your lab stores, uses or will use biotoxins for research purposes, please identify all of the toxins you utilize or store for any purpose in your research efforts (such as an additive to media, etc.), and quantities used/stored.
  • Possession and use of biological toxins or venoms in research requires:
    • Registration with, and approval by the VT Institutional Biosafety Committee (IBC).
    • Maintenance of a toxin inventory record to account for current quantities in house, and toxin use and disposition.
    • Storage of toxins in sealed, labeled containers within a secured (locked) storage device that can only be accessed by personnel authorized to work with the toxin.
    • Use of toxins only in designated rooms with posted signage to control/limit access.

Biotoxins as Select Agents and the Due Diligence Provision

  • Some biotoxins are classified by the federal government as Select Agents due to their potential to pose a severe threat to public health and safety. Possession, use and transfer of these toxins is highly regulated.
  • In small quantities, some of these agents are exempt from Select Agent registration but must still be registered with, and approved for use by the VT IBC.
  • Because it would be possible to stockpile toxins in multiples of these amounts which are small enough to be excluded from regulation, the 'Due Diligence' policy places the following responsibilities on Principal Investigators, veterinarians or medical doctors:
ToxinsExempted Amount per PI (≤)
Abrin1000 mg
Botulinum neurotoxins1 mg
Short, paralytic alpha conotoxins100 mg
Diacetoxyscirpenol (DAS)10,000 mg
Ricin1000 mg
Saxitoxin500 mg
Staphylococcal enterotoxins
(Subtypes A, B, C, D, E)
100 mg
T-2 toxin10,000 mg
Tetrodotoxin500 mg


  1. Declare your possession and provide inventory documentation to Virginia Tech's Responsible Official (RO) and Alternate Responsible Official (ARO).
  2. Contact the RO and/or ARO to schedule a SHORT informational session regarding requirements related to possession of these toxins.
  3. If no additional toxin is received after the declaration date, but at least annually, you must verify and declare your possession to Virginia Tech's RO and ARO.
  4. Immediately notify Virginia Tech's RO and ARO if your toxin inventory amounts, per toxin, ever exceed specified permissible limits.


  1. Apply due diligence in assessing/ensuring that the recipient of these toxins has a legitimate need to handle/use such toxins.
  2. Complete documentation prior to the transfer which records your information and the recipient's intended use of the toxin. The Notification of Toxin Transfer form (template can be found in the Appendices of the University Biosafety Manual and IBC website) must be submitted to Virginia Tech's RO and ARO.
  3. Immediately report to Virginia Tech's RO and ARO, if a violation of federal law is detected, or if suspicious activity related to the toxin is discerned.


  1. Immediately notify Virginia Tech's RO and ARO of the receipt of the toxin, update your inventory, and submit inventory documentation to the RO and ARO.


TitleNamePhoneEmailMail Code
ROCharlotte Waggoner540-231-5864ren@vt.edu0423
AROAnna Kroner540-231-1122akroner@vt.edu0423

Biotoxin Risk Assessment

  • Risk assessments on biotoxins should include:
    • Biotoxin characteristics (LD50 in solution and dry form; solubility).
    • Risks inherent to experimental procedures and manipulations (e.g., opportunities for accidental needlesticks, the likelihood of dispersal from static build-up when working with powder form, etc.).
    • Total amount of toxin used relative to the estimated human lethal or cytotoxic dose.
    • Volume of material manipulated.
    • Availability of successful treatment, vaccines or antitoxins.
    • Training and experience of personnel.
  • Safety measures should be determined according to a risk assessment for each manipulation involving the toxin.
  • If toxins/ infectious agents/ animals are used in combination, then risks in all of those areas must be considered collectively in the selection of containment equipment and the development of safety procedures.
  • After risk assessment review, selected operations with toxins may require modified BSL-3 procedures; typically, routine operations (e.g., toxin preparation/ animal procedures) with dilute toxin solutions can be conducted under BSL-2 conditions using 1) a certified BSC or chemical fume hood, and 2) appropriate PPE for the hazards involved.
  • Complex operations should be rehearsed without the use of live toxin in supervised practice runs until proficiency is assured.
Primary Hazards Using BiotoxinsHazard Mitigation When Using Biotoxins
Exposure to toxin by direct contact or hand-to-face contact with mouth, eyes or other mucous membranes.
  • Wrap-around disposable gowns with gathered cuffs are the best choice, and fluid-resistant gloves rated for protection against diluent should be used.
  • Double-gloving is strongly recommended if it does not hinder the worker's dexterity to the point of being unsafe.
  • There should be no unprotected, exposed skin on your body or extremities when undertaking this work. Arms, wrists and hands must be fully covered; long pants and whole shoes are required.
  • Safety glasses are strongly recommended, and must be washed after removal and before storage.
  • Disposable PPE used for this work must be single-use only, and disposed of as hazardous lab waste.
Exposure to toxin from inhaling an aerosol.
  • Work in primary containment with directional air flow (biosafety cabinet, chemical fume hood).
  • When working with dried toxin, remove all items that are not necessary for your procedure from the biosafety cabinet or fume hood before handling the toxin to reduce the potential for contamination of item surfaces.
  • Respiratory protection may be needed if you must manipulate a dry toxin in an open vessel, even if in containment. Contact EHS at 231-3600.
  • Primary containers of the toxin should be non-breakable if possible, and vials should be maintained in a closed secondary container that will not allow escape of the product even if dropped. The risk of release is greatly decreased by using a secondary container at all times.
Exposure to toxin through needlesticks or other accidents that compromise intact skin, such as could happen when inoculating animals.
  • Use only syringes with luer-lock or integrated needles.
  • Use vial adapters whenever possible as a substitute for needles when adding diluent through septums on vials.
  • When introducing a needle through a septum, assure that the vial is secured with a device that allows the non-dominant hand to be outside of the 'strike zone' of the needle. (Example: secure vial in a rack, or use a clamp to hold vial instead of holding it directly.)
  • When inoculating animals, use effective, reliable restraint methods to avoid accidental needlesticks.

For procedures in

  • Solubilizing and Using Biotoxins,
  • Toxin Spill Response, and
  • Toxin Inactivation and Disposal,
see the University Biosafety Manual, Section 4.23.

Guidance and Further Information:

BMBL, 5th Ed., Appendix I: Guidelines for Work with Toxins of Biological Origin
Federal Select Agent and Toxins Website
EHS Biosafety Office