Select Agent Toxins

A biological toxin is a toxic material or product of plants, animals, microorganisms (including, but not limited to, bacteria, viruses, fungi, or protozoa).  Select Agent Toxins (SAT) or Select Toxins (ST) are biological toxins or infectious substances, or a recombinant or synthesized molecule, whatever their origin and method of production.  SATs can be used to endanger human and/or agricultural animal or plant health. The Center for Disease Control and Prevention (CDC) and the Animal and Plant Health Inspection Service (APHIS) of the United States Department of Agriculture (USDA) are charged with regulating these toxins. 


The Biosafety Program helps MIT PIs and other personnel to avoid obtaining quantities of select agent toxins (SAT) that will cause them to inadvertently exceed the per PI exclusion limit and become subject to and violate the federal regulations.  The purchase of any SAT quantity must be done through the Biosafety Program.

For more information about Select Agent Toxins and associated regulation please visit




List of regulated Select Toxins


(*) Means the aggregate amount of the toxin under the control of a principal investigator, that does not, at any time, exceed the amounts in the above table.

For a list of excluded Select Agent Toxins visit


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MIT SOP for Principal Investigators and research laboratories


Please refer to Standard Operating Procedure titled “Select Agent Toxin Control and Containment Program:  Purchasing, Inventory, Shipping, Receiving and Other Procedures” (EHS-0025) for full details.


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Registration and Training


Principal Investigators must be registered to work with a biological toxin.  Registration is typically done through an amendment to the PI’s Biological Research Registration.  This process allows EHS Biosafety and the Committee on the Assessment of Biohazards (CAB-ESCRO) to review the proposed research and evaluate any safety and regulatory concerns.  Please see our Registration webpage for more details on this process.


Prior to working with a Select Agent toxin, each researcher must complete Use of Biological Toxins Training (EHS00215C)This training is given on a quarterly basis at the EHS office.  Researchers can register through the MIT Atlas Learning Center.  Please see the Biosafety Specific Training page for more details on training.


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Basic Purchasing Select Agent Toxins procedures


Please contact your biosafety officer for details on how to order a Select Agent Toxin.

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    Authorized and EHS trained laboratory personnel should be mentored and supervised by a more experienced researcher in the safe handling of select toxin by using a current written protocol and/or Standard Operating Procedure (SOP) detailing the technique/experiments steps/handling, containment equipment, personal protective equipment (PPE), storage, disposal, internal communication and emergency response. This protocol or SOP should be updated as needed and kept accessible to users.


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    How to Generate Toxin Stock Solutions


    If at all possible, order toxins in liquid form rather than as a powder.  Powders present the greatest risk during preparation of stock solutions due to possible aerosolization and danger of inhalation during handling.  If the toxin is only available in powder form, order the toxin in vials that provide safety features (see table below). Avoid ordering toxins in powder form in scaled glass ampoules, as scaled glass ampoules are the most difficult to handle safely.


    Some of the most commonly used vendors sell toxins in screw cap vials.  These must also be handled carefully making sure the powder remains pelleted at the bottom of the tube.  This can be accomplished by quickly centrifuging the vial.

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    Steps to generate stock solution from powders or liquids:


    1. Put on personal protective equipment (PPE):
      • Gloves:  Gloves shouldn’t be permeable to toxin or solvent; double gloving is preferable
      • Lab coat
      • Safety goggles to protect from splash and/or impact
    2. When handling concentrated toxin, work inside a containment device such as a chemical fume hood or Biosafety Cabinet (BSC):
      • Remove any unneeded chemicals, satellite accumulation areas (SAAs), or unnecessary equipment (as reasonable)
      • Line the work surface of the chemical fume hood or BSC with a plastic backed absorbent liner
    3. If the toxin comes in regular screw cap vials:
      • Quickly centrifuge the tube to pellet the powder
      • Place the vial into a rack or tube holder in the chemical fume hood or BSC
      • Open the screw cap vial carefully
    4. If the toxin comes with a rubber septum (including screw caps):
      • Do not remove the rubber septum
      • Use a blunt-tipped needle or pipet tip to inject measured amount of buffer/solvent through the rubber membrane
      • Cover rubber septum with parafilm and mix carefully to avoid aerosol generation
      • Briefly spin in a centrifuge to bring the liquid on the inside of the cap or near the lid
    5. If the toxin comes in a pre-weighed amount in a glass ampoule:
      • Nick the ampoule with a file or file at the narrow end of the neck
      • Wrap the ampoule in disinfectant-wetted cotton or paper towel
      • Hold the ampoule away from you
      • Snap the ampoule to open at the nick
    6. For other containers:
      • Inject measured amount of buffer/solvent into the vial/ampoule with a pipette tip or blunt-tipped needle
      • Dissolve the powder and mix liquid contents carefully to avoid aerosol generation
      • Mix to give a known concentration stock solution.
    7. Stock solution division
      • Use a pipette tip to remove contents
      • Divide the solution into multiple tubes to reduce repeated freeze-thaw cycles
      • These are the stock solutions, with a known amount of toxin in a known volume
    8. Enter the volume and number of tubes of the stock solution in a new inventory sheet. You can get new sheets here.
    9. Store all stock solutions in a secured lock box.
    10. Waste handling:
      • Treat the glass vial, ampoule or screw cap vial with an appropriate concentration of disinfectant (see your “Toxin Use SOP”) for the appropriate contact time
      • Dispose of glass vial(s), ampoule(s), needles, syringes in a puncture proof sharp container
      • Once full, these containers are be capped tightly/sealed and placed inside a biowaste box for disposal
    11. Wipe down chemical fume hood or BSC surface with an appropriate concentration of disinfectant.
    12. Collect all solid waste (gloves, plastic backed absorbent paper) in a plastic bag and dispose in biowaste box
    13. If contamination is significant (such as in the case of a spill of concentrated toxin), this waste should be segregated as chemical hazardous waste. Please contact BSP if this situation arises for further guidance and coordination on the proper disposal. Under no circumstance must any select toxin waste reach public sewage systems.

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    Record Keeping Requirements


    The following records should be maintained at the laboratory’s location:

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    Storage of select toxins shall comply with the following criteria:

    • Storage shall be secured (see section 8 of SOP EHS-0025 for more details).
    • Shall be tampering proof, e.g. tubes, bottles, aliquots should be clearly labeled and numbered for rapid identification of material. Information should include, volume, date of preparation, vial # and user/prepared name.
    •  Tubes should be, if possible, rubber septum with screw or crimped caps for added safety and should be wrapped with parafilm and kept in a spill proof secondary container e.g. properly labeled zipper storage bag or box.
    • Inventory shall be accurate and up-to-date.
    • Access should only be given to properly trained personnel (for more information, see section 4 of SOP EHS-0025).

         For long term storage requirements see section 10.2 of SOP EHS-0025.


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    Custody of select agent toxins is the responsibility of the PI once EHS-BSP delivers the select agent toxins to the approved and trained laboratory personnel.  All stock solutions of select agent toxins are kept under lock and key. Diluted working solutions may be stored outside of the lock box but the amounts of diluted solutions should be minimized.


    For more information consult SOP EHS-0025.


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    Investigators shall only dispose of toxins using EHS BSP approved methods. For detailed information please see Appendix C: Toxin inactivation and disposal of SOP EHS-0025 (Please click link to access the SOP).   All generated select toxin liquid waste shall be treated as hazardous chemical waste and labeled with a “red tag” as “inactivated toxin” with appropriate required information before offering it for pick up by EHS.


    Solid and sharp wastes shall be assessed to determined level of toxin residue before disposing in the proper waste stream (e.g. biowaste box, puncture proof sharp container, or as chemical hazardous waste where appropriate). If necessary, researchers are encouraged to contact EHS-BSP for assistance with this assessment.


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    Shipping and receiving


    MIT Laboratories are not certified or authorized to ship via carrier (e.g. FedEx), courier, hand-carried or public transportation without assistance from EHS certified shippers; or receive select toxins under any circumstances without EHS-BSP Office involvement.


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    Transfer of possession, distribution, sharing


    PI's shall not allow purchase of select toxins for stock piling, distribution, transfer or sharing. PIs are expected to acquire select toxins ONLY through EHS-BSP, use all of the select toxins under their custody, and have complete control of their inventory.


    EHS-BSP shall assess special circumstances on a case by case basis upon PI request. Federal agencies retain the authority to, without prior notification, inspect and copy or request the submission of documentation.


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    Suspected theft, loss or release


    Upon discovery of the theft or loss of select toxins, laboratory personnel must immediately notify the PI and EHS-BSP. EHS-BSP Deputy Director and SAT program manager shall notify appropriate agencies. Thefts or losses must be reported even if the select toxin is subsequently recovered or the responsible parties are identified.


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