Tetrodotoxin is a biotoxin. A review of available sources identified acute toxicity data (LC50, LD50, and LDLo) for several species and routes. Data sources were selected according to the hierarchy listed in Table 3.1. Toxicity data were selected according to type of exposure, species, and route according to the hierarchies stated in Sections 3.6.3, 3.6.4, and evaluated using factors in Tables 3.2, 3.3, and 3.4. The available human toxicity data is estimated based on incidents of exposure and it was not selected for TEEL development. Instead, the most preferred species and route toxicity data, a mouse LD50, was selected as the TEEL-3 basis. TEEL-2 and TEEL-1 values were derived according to Table 3.5.
• TEEL-1 = TEEL-2/11
• TEEL-2 = TEEL-3/6
• TEEL-3 = Mouse oral LD50 (334 µg/kg)
This review generated TEEL values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a dog intravenous LD50 not found during the review; instead, a analysts selected a mouse oral LD50 for the TEEL-3 basis. The Rev. 29A and current TEEL-2 and TEEL-1 use the same methodology with differences due to the change in TEEL-3.