Appendix E Guidelines for work with toxins of biological origin

Biological toxins comprise a broad range of poisons, predominantly of natural origin but increasingly
accessible by modern synthetic methods, which may cause death or severe incapacitation at relatively
low exposure levels. Laboratory work with most toxins, in amounts routinely employed in the
biomedical sciences, can be performed safely with minimal risk to the worker and negligible risk to the
surrounding community. Toxins do not replicate, are not infectious, and are difficult to transmit
mechanically or manually from person to person. Many commonly employed toxins have very low
volatility and, especially in the case of protein toxins, are relatively unstable in the environment; these
characteristics further limit the spread of toxins.
Toxins can be handled using established general guidelines for toxic or highly-toxic chemicals with the
incorporation of additional safety and security measures based upon a risk assessment for each specific
laboratory operation. The main laboratory risks are accidental exposure by direct contamination of
mouth, eyes or other mucous membranes; by inadvertent aerosol generation; and by needle-sticks or
other accidents that may compromise the normal barrier of the skin.
A risk assessment should be conducted to develop safe operating procedures before undertaking
laboratory operations with toxins; suggested “pre-operational checklists” for working with toxins are
available. For complex operations, it is recommended that new workers undergo supervised practice
runs in which the exact laboratory procedures to be undertaken are rehearsed without active toxin. If
toxins and infectious agents are used together, then both must be considered when containment
equipment is selected and safety procedures are developed. Likewise, animal safety practices must be
considered for toxin work involving animals.
Detailed information and guidance is contained in BMBL 5th Edition Appendix I:
https://www.cdc.gov/labs/pdf/CDC-BiosafetyMicrobiologicalBiomedicalLaboratories-2009-P.PDF