Tetrodotoxin (TTX)

Characteristics
Natural Source	TTX naturally occurs in the skin, intestine and liver of some fish in the order Tetraodontidae. Examples include puffer fish, porcupine fish, ocean sunfish, and some species of newts and salamanders. A paralytic marine alkaloid toxin that interferes with normal function of excitable cells in heart, muscle, and neuronal tissue, causing potentially lethal paralytic poisoning.
Laboratory Source	Isolated toxin
Characteristics	The toxin is a chemical with a molecular formula of C11H17N3O8. The formula weight is 319.27. TTX is a neurotoxin that blocks the flow of sodium ions in sodium channels. This blocks the conduction of nerve impulses. Can metabolized and rapidly excreted through the urine within 24-72 hours.

Health Hazards
Route of Entry	Inhalation, ingestion, absorption, and injection
Signs and Symptoms	Paresthaesias, dizziness, gastrointestinal symptoms, and ataxia. Toxication can progress to paralysis and death within hours of ingesting the naturally occurring toxin.
Toxicity Dose Data	Median LD50 for humans is 334 μg/kg

Medical Precautions/Treatment
Prophylaxis	None available
Vaccines	None available
Treatment	No antidote available. Administer supportive care (artificial respiration to support breathing). Activated charcoal and/or gastric lavage can be done if the patient presents within 60 minutes of ingestion.
Surveillance	Monitor for symptoms. Seek medical attention if symptoms arise
GWU Requirements	Report all incidents to the Office of Risk Management as well as the Office of Research Safety (ORS) IMMEDIATELY FOLLOWING THE OCCURRENCE.

Containment
BSL-2	BSL-2 practices are to be used under standard research uses of TTX. Containment equipment, and facilities are recommended, especially the wearing of a laboratory coat, safety glasses, and disposable gloves; the gloves must be impervious to organic solvents or other diluents employed with the toxin. The use of respiratory protection is considered if there is potential for aerosolization of the toxin.
BSL-3	For large scale production of TTX or activities with a high potential for aerosol or droplet generation.

Containment

BSL-2

BSL-2 practices are to be used under standard research uses of TTX. Containment equipment, and facilities are recommended, especially the wearing of a laboratory coat, safety glasses, and disposable gloves; the gloves must be impervious to organic solvents or other diluents employed with the toxin. The use of respiratory protection is considered if there is potential for aerosolization of the toxin.

BSL-3

For large scale production of TTX or activities with a high potential for aerosol or droplet generation.

Spill Procedures
Small Spills (<1 liter)	If the spill occurred inside a biological safety cabinet, close the sash and allow the cabinet to operate for 15 minutes before continuing with the spill cleanup. If a spill occurs outside of a BSC, aerosol exposure to TTX can occur. Leave the room immediately and allow the aerosols to dissipate for 15 minutes. Notify others working in the lab. Don appropriate PPE. Cover area of the spill with paper towels or any absorbent material and apply decontamination solution working from the perimeter towards the center. Allow 60 minutes of contact time before disposal and cleanup of spill materials.
Large Spills	Alert lab personnel in the laboratory to the spill and keep people out of the area to prevent spread of the contamination. Check if you have been contaminated or if any of your PPE has been breached. If so follow exposure procedures. Remove any contaminated clothing and place it the biohazard waste. Wash your hands and post a sign on the door. Notify your supervisor of the incident and call ORS (4-8258) for assistance. If the situation involves an imminently life-threatening injury or has catastrophic potential, call 911.

Spill Procedures

Small Spills (<1 liter)

If the spill occurred inside a biological safety cabinet, close the sash and allow the cabinet to operate for 15 minutes before continuing with the spill cleanup.

If a spill occurs outside of a BSC, aerosol exposure to TTX can occur. Leave the room immediately and allow the aerosols to dissipate for 15 minutes. Notify others working in the lab. Don appropriate PPE. Cover area of the spill with paper towels or any absorbent material and apply decontamination solution working from the perimeter towards the center. Allow 60 minutes of contact time before disposal and cleanup of spill materials.

Large Spills

Alert lab personnel in the laboratory to the spill and keep people out of the area to prevent spread of the contamination. Check if you have been contaminated or if any of your PPE has been breached. If so follow exposure procedures. Remove any contaminated clothing and place it the biohazard waste. Wash your hands and post a sign on the door. Notify your supervisor of the incident and call ORS (4-8258) for assistance. If the situation involves an imminently life-threatening injury or has catastrophic potential, call 911.

Exposure Procedures
Mucus Membrane	Flush eyes, mouth or nose for 15 minutes at eyewash station.
Other Exposure	Wash area with soap and water for 15 minutes.
Reporting	Report ALL injuries to the PI immediately and reported to the Office of Risk Management at [email protected] IMMEDIATELY FOLLOWING THE OCCURRENCE. Exposures that involve a bloodborne-pathogen or recombinant DNA also need to be reported to the Office of Research Safety at [email protected]. If the injury requires immediate medical attention, call GWPD at 202-994-6111 or call 911.
Medical Monitoring	Seek immediate medical evaluation, treatment, and post exposure follow-up at the Employee Health Office at GWU Hospital (900 23rd St., NW, Suite G-1090, Phone: 202-715-4275). Students should go to the Students Health Office at Marvin Center. After hours treatment can be received at the GWU hospital emergency room.

Stability
Decontamination	High molar concentrations of hydrochloric acid (1.0-2.5%). Hydrogen peroxide does cause some inactivation of tetrodotoxin but requires a 16-hour contact time in the presence of ultraviolet light.
Inactivation	Inactivated by Dry heat in excess of 260oC for 10 minutes can be used for inactivation

Personal Protective Equipment (PPE)
Minimum PPE Requirements	At minimum, personnel are required to don gloves, closed toed shoes, lab coat, and appropriate face and eye protection prior to working with TTX. Additional PPE may be required depending on lab specific SOPs
Additional Precautions	Additional protection may be worn over laboratory clothing when infectious materials are directly handled, such as solid-front gowns with tight fitting wrists, gloves, and respiratory protection.

References
CDC (https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750019.html) BMBL 6th Edition (https://www.cdc.gov/labs/BMBL.html) Tetrodotoxin Toxicity (https://www.ncbi.nlm.nih.gov/books/NBK507714/)