Biological toxins are poisonous substances, either naturally produced by an animal, plant or microbial source; or their analogs may be synthesized in a laboratory. Unlike most other biohazards, biotoxins cannot replicate, and they are not infectious. However, these toxins can be harmful at relatively low levels when inhaled, ingested, injected, or absorbed through the skin or mucous membranes. Depending on the toxin, amount, and route of exposure, health effects can range from minor (skin or eye irritation, headache, nausea) to severe (respiratory distress, muscle weakness, seizures, paralysis, death). Unlike most hazardous chemicals, biological toxins have no established safe exposure limits, and there is limited toxicological data applicable to human exposures.
Biotoxin Registration
Please include ALL toxins in your laboratory HCOC online inventory. In the case of an emergency in the lab, EH&S staff need to be able to communicate all potential hazards to emergency responders. For acute toxins and exempted select agents, please record all quantities procured and used, as well as volumes and concentrations of any diluted stocks using the Toxin Tracking Form (PDF).
Safe Handling
Laboratory exposure risks are primarily from accidental injection, absorption through skin or mucous membranes, inhalation, and ingestion. Typically, the amounts used in biomedical research laboratories can be handled safely by trained laboratory personnel. Handling of concentrated stocks poses the greatest risk to laboratory personnel. Even a seemingly tiny quantity of concentrated toxin may contain more than a lethal dose for a human.
Preparation of biotoxins should be performed in a Biosafety Cabinet or Chemical Fume Hood while wearing a lab coat/gown and gloves and may also require the use of respiratory protection. The use of latex gloves should be avoided, as they may not be impervious to all dermal hazards. When handling powdered toxins, select gloves that do not generate static electricity. For most toxin use, standard BSL-2 practices should be followed unless otherwise indicated by the Biosafety Office.
Higher risk procedures
- Use of aerosol or splatter generating procedures (e.g. vortexing, grinding, centrifuging, injection or intra-nasal inoculation of animals).
- Utilization of concentrated stocks or large quantities of toxins: beware that a vial could contain more than a LD50 for an average-sized person! Calculate in advance.
- Work with powdered or dried toxins, reconstitution of lyophilized toxin: highly concentrated material with high potential for inhalation and a tendency for electrostatic attachment to gloves, weighing spatulas, etc.
- Use of needles or sharps in experimental procedures
Store toxin stocks in secured storage rooms, cabinets, or freezers with restricted access. If toxins are stored in the laboratory, containers should be sealed, labeled, and secured to restrict access.
Inactivation and Disposal
Most acute toxins are stable proteins (or carbohydrates) requiring rigorous inactivation of contaminated surfaces, objects, and waste. Addition of a sodium hypochlorite solution is one of the easiest ways to inactivate many biotoxins. The final concentration for inactivation should be 50% bleach, or 2.5% sodium hypochlorite. Autoclaving for 60 minutes may also be effective, depending on the toxin. Alternative chemical destruction methods can be found in the BMBL, Appendix I (PDF). Make sure to check the toxin's SDS for recommended inactivation methods. Chemical inactivation procedures must be performed in a Biosafety Cabinet or Chemical Fume Hood while wearing the appropriate PPE.