Registration of Biologically-Derived Toxins
The use of biologically-derived toxins, in any quantity, in research and instructional activities must be reviewed and approved by the Institutional Biosafety Committee (IBC) prior to initiation of the activity. Biologically-derived toxins include all naturally occurring molecules produced by animals, plants, microorganisms or other biological agents that have a median lethal dose (LD50) value of less than 50 mg/kg (as determined for rats).
Prior to initiation of a project, the PI should complete the appropriate IBC registration form(s) and submit it to the Biosafety Office for review by the committee.
Common Biologically-Derived Toxins*
|Clostridium difficile enterotoxin A||Pseudomonas aeruginosa toxin A|
|Clostridium difficile cytotoxin B||Shiga toxin|
|Clostridium perfringens lecithinase||Shigella dysenteriae neurotoxin|
|Clostridium perfringens kappa toxin||Streptolysin O|
|Clostridium perfringens perfringolysin O||Streptolysin S|
|Clostridium perfringens beta toxin||T-2 toxin|
|Clostridium perfringens delta toxin||Taipoxin|
|Clostridium perfringens epsilon toxin||Tetanus toxin|
|Leukocidin||Yersinia pestis murine toxin|
Select Agent Toxins
|Staphylococcal enterotoxins||T-2 toxin|
*This is not an exhaustive list. Other biologically-derived toxins may be subject to IBC oversight.
Permissible Amounts of Select Agent Toxins
The use of select agent toxins may be exempt from the federal select agent regulations if the toxin quantity, per investigator, does not exceed a specified permissible amount.
Working Safely with Toxins
Biologically-derived toxins can be extremely hazardous, even in very small quantities. However, toxins can typically be handled using established guidelines for highly-toxin chemicals with the incorporation of additional safety and security measures based upon a risk assessment of each laboratory procedure. Exposure to toxins may occur by 1) direct contamination of mouth, eyes, or other mucous membranes; 2) by inadvertent aerosol generation; and 3) by needle-sticks or other accidents that may compromise the normal barrier of the skin.
Work with toxins should be conducted only in designated rooms with controlled access and at a pre-determined bench area. When toxins are in use, signage should be clearly posted to indicated that toxins are present and that unauthorized personnel should not enter.
A certified biosafety cabinet (BSC) or chemical fume hood must be used for routine activities with most protein toxins. Solutions containing low molecular weight toxins or work involving chemicals or radionucleotides combined with toxins may require the use of a charcoal hood filter in addition to HEPA filtration. Appropriate PPE must be worn at all times when handling toxins.
The stability of a toxin can vary widely depending upon environmental conditions such as temperature, pH, etc. General standards for decontamination of selected toxins can be found in the 6th Edition of Biosafety in Microbiological and Biomedical Laboratories. Inactivation procedures should always be validated using specific toxin bioassays.
Contaminated materials and toxin waste solutions can be inactivated by incineration or prolonged autoclaving, or by prolonged soaking in a suitable disinfectant. All disposable materials, equipment, and protective clothing that may be contaminated or potentially contaminated must be decontaminated by a suitable method before disposal, repair, or cleaning.