A review of available sources identified the following for a similar chemical, ethylenimine (CASRN: 151-56-4): rat and mouse acute toxicity data (LC50, LD50) for various routes, and an AEGL-2 and AEGL-3. 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 3.3.1, 3.3.2, and evaluated using factors in Tables 3.2, 3.3, and 3.4. The AEGLs were selected as the TEEL-2 and TEEL-3 due to their priority among the emergency exposure limits (Section 1). Due to insufficient data, an AEGL-1 does not exist for this chemical; therefore, the TEEL-1 value was derived according to Table 3.5.
• TEEL-1 = TEEL-2/11
• TEEL-2 = AEGL-2
• TEEL-3 = AEGL-3

This review generated TEEL values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a mouse 10-min LCLo that was not identified during this review. Instead, the AEGLs of a chemical that is the backbone of the chemical of interest were selected as the TEEL-3 and TEEL-2 due to their priority (Section 1). The TEEL-1 methodology remains consistent, with the change in values due to the change in the TEEL-2 basis.