A review of available sources identified the following: Phosphorus white/yellow rat oral LD50 and human/dog oral LDLo doses, TLV-TWA and IDLH exposure limits, and red phosphorous (CAS: 7723-14-0) proposed AEGLs. Data sources were selected according to the hierarchy listed in Table 3.1. Toxicity data were selected based on the 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. Within the AEGL Technical Support Document, the comparison of white/yellow phosphorus was made to red, “…properties of red phosphorus are intermediate between those of white and black phosphorus (O’Neil, et al., 2001). Red phosphorus is more stable than white phosphorus and considered less toxic (Dalhamn and Holma, 1959)”. As such, the red phosphorous AEGLs were determined inappropriate for TEEL development. Evaluating the remaining data, exposure limits were chosen over toxicity data based on source preference. The IDLH was selected as the TEEL-3; the revised and original IDLH were considered. The original IDLH is listed as an “effective” basis, whereas the revised considers human toxicity. Therefore, the revised IDLH was selected as the TEEL-3. The TEEL-2 value was derived according to Table 3.5. The TLV-TWA was selected as the TEEL-1 basis.
• TEEL-1 = TLV-TWA (0.1 mg/m3) x 3
• TEEL-2 = TEEL-3/6
• TEEL-3 = IDLH (1994, 5 mg/m¬3)
This review generated TEEL-3 and TEEL-2 values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a dog oral LDLo, which was identified during current research but not selected due to the availability of a more preferred basis (exposure limit > toxicity basis). The Rev. 29A and current TEEL-2 methodology used is the same (Table 3.5), with differences due to the change in TEEL-3. The Rev. 29A and current TEEL-1 values, source, and methodology are consistent.