Appendix F: Guidelines for Work with Toxins of Biological Origin

Biological toxins are poisons, either naturally produced by living organisms including animals, plants, or microbial sources that cause death or severe incapacitation at relatively low exposure levels. Biological toxins do not replicate and are not infectious. In amounts used most typically in biomedical research laboratories, biological toxins can be handled safely by trained laboratory personnel and they are a low risk to the local community. Biological toxins are difficult to transmit from person-to-person, they are non-volatile, and usually are not dermally active (mycotoxins are an exception). They tend to be more toxic per weight than many chemical agents. These guidelines are intended for biological toxins recommended to be handled under BSL2 conditions. Personnel using biological toxins listed by CDC and USDA under the Federal Select Agent Program (such as Botulinum neurotoxins, Staphylococcal enterotoxins, ricin, tetrodotoxin and selected low molecular weight toxins), should follow additional safety, handling and inventory practices appropriate for the higher biosafety level and detailed elsewhere under BSL3 practices. The federal list of select agents and toxins and exemptions can be found here.

A PI should expect that storage and use of a biological toxin(s), including the select agent toxins, will need approval by the IBC. Please check with IBC if you have questions on a particular biological toxin.

Select agent toxins are not regulated under the Federal Select Agent Program if the amount stored and possessed by the lab at any given time does not exceed the permissible toxin amounts. The permissible amount for each select agent toxins is listed here.

The following guidelines are intended to provide general safety requirements for the use of such toxins.

General Information

Working with biologically-derived toxins may present health risks due to routes of exposure that are not always taken into consideration. The laboratory facilities, equipment, and procedures for work with toxins must reflect the intrinsic level of hazard posed by a particular toxin, as well as the potential risks inherent in the operations being performed.

If both toxins and infectious agents are used, both must be considered when containment equipment is selected and policies and procedures are written. If animals are used, animal safety practices must also be considered. IBC will evaluate all such uses and determine if the proposed safeguards are adequate or not.

Standard Practices

Provide all laboratory personnel with biosafety training specific for the toxins being used. Training is documented and repeated annually or as needed for new personnel before use. Toxin-specific training should include description of the toxin, its importance to public health and/or research priorities, medical consequences of any exposure, appropriate lab safety measures including decontamination policies, and instructions for how to deal with accidental exposure. If needed and when requested by the PI, toxin-specific training can be provided by the ROHP and the EHS.

For Select Agent Toxins and selected low molecular weight toxins, an inventory control system should be in place to account for toxin use and disposition according to the CDC BMBL (6th edition) Appendix I- Guidelines for Work with Toxins of Biological Origin. Select Agent Toxins require inventory detail to ensure that total quantities remain below the regulated amount. Select Agent Toxin inventories should include date and quantity of each acquisition (purchase, transfer, etc.), use and disposal. For other biological toxins, an inventory control system is not required unless mandated by the IBC.

Biological toxins have varying susceptibility to inactivation and decontamination measures. For example, most are resistant to freeze-thaw, but susceptible to 10% (v/v) fresh bleach solutions. Refer to the CDC BMBL (6th Edition) Appendix I Guidelines for tables detailing toxin-specific inactivation and decontamination recommendations as appropriate.

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; refrigerators and other storage containers should be clearly labeled and provide contact information for trained, responsible laboratory staff.

Dry forms of toxins present a high aerosol risk. Primary containers of dry forms of toxins should be handled in a chemical fume hood, a glove box, or a biological safety cabinet or equivalent containment system. All work should be done within the operationally effective zone of the hood or biological safety cabinet, and each user should verify the inward airflow before initiating work, and whenever possible, reconstitute entire vial of powdered toxin by injecting diluent through septum. HEPA and/or charcoal filtration of the exhaust air may be required, depending on the toxin.

If infectious agents and biological toxins are used together in an experimental system, consider both when selecting protective clothing and equipment.

Glove selection: If powdered toxin must be handled, select gloves that do not generate static electricity. Do not use latex. When handling toxins that are percutaneous hazards (irritants, necrotic to tissue, or extremely toxic from dermal exposure), select gloves that are known to be impervious to the toxin. Additional PPE such as disposable, long-sleeved gown may be necessary.

Standard practices listed under BSL2 and/or BSL3 should be reviewed and incorporated as appropriate into protocols for work with toxins.

Standard Laboratory Practices

Appropriate laboratory practices will depend on a number of parameters, such as the toxin used or the type of operations performed. General guidelines below are for biological toxins recommended to be handled under BSL2 conditions. In addition to standard BSL2 PPE, other protective equipment may be required depending on the characteristics of the biological toxin and the containment system. For example, additional respiratory protection may be necessary if aerosols may be generated and it is not possible to use containment equipment or other engineering controls.

Each laboratory should develop Standard Operating Procedures (SOPs) for toxin handling and policies (or a chemical hygiene plan specific to the toxin(s) used in that laboratory). If necessary, IBC will assist the PI with development of SOPs appropriate for the toxin(s). The SOPs should include:

• Description of hazards that will be encountered during expected use of the toxin and those that could be encountered in case of a spill or other accident. This is typically a summary of the biosafety training for that toxin.
• Policies and practices to be used to minimize risks such as:
  • Containment and personal protective equipment.
  • Toxin-appropriate methods for decontamination of PPE, equipment, and bench areas.
  • Transport of toxin outside the laboratory. Toxins should be transported only in leak-/spill-proof secondary containers.
  • Management of spills.
  • Medical surveillance.
  • Procedure for accidental exposure.
• Safety receipt, inspection, storage, and disposal of the toxin used.

All high-risk operations (e.g., use of toxin at levels considered to be unusually high) should be conducted with two knowledgeable individuals present. Each must be familiar with the applicable procedures, maintain visual contact with the other, and be ready to assist in the event of an accident.
When biological toxins are in use, the room should be posted to indicate “Biological Toxins in Use ­ Authorized Personnel Only.” Any special entry requirements should be posted at the entrance(s) of the room. Only personnel whose presence is required should be in the room while toxins are in use.

Laboratory Facilities

Laboratory facility recommendations listed under BSL2 and BSL3, as well as OSHA standards should be reviewed and incorporated as appropriate into protocols for work with toxins.

When vacuum lines are used with systems containing toxins, they should be protected with a HEPA filter to prevent entry of toxins into the lines. Water aspirators should be avoided.