PAC Database - Detailed Chemical Data

Chemical Identity
Chemical CAS# UN# Health Code Numbers
Sodium thiosulfate pentahydrate 10102-17-7
4.08
11.00
4.05
7.00
Formula Synonyms
H10Na2O8S2
Physical Properties
Mol Wt State MP (°C) BP (°C) VP (Hg) VP (°C) SG LEL (ppm)
248.2 S 48 1.69
PAC Values
PAC Values (Original Units: ppm)
PAC-1 PAC-2 PAC-3
4.9 54 320
Converted PAC Values (mg/m3)
PAC-1 PAC-2 PAC-3
50 550 3200
Technical Basis
A review of available data sources identified the following: LDLo1, LD502, and TDLo3 exposures for intravenous and oral routes. Each was evaluated using the guidelines for calculating equivalent values in the TEEL Handbook. A compound adjusted TEEL derived for sodium thiosulfate (CASRN: 7772-98-7) was also evaluated, but ultimately not selected4. Toxicity data were evaluated for their relative preference ranking (Section 3.3.2, Table 3.1). The most preferred exposure of dog, intravenous LDLo data was the starting point to estimate a TEEL-3. Although a TDLo is preferred as the basis for a TEEL-2, it was not selected because its results were one to two orders of magnitude less than all other TEEL-2s calculated, and it was oldest data (1957.) Instead, TEEL-2 and TEEL-1 values were calculated from the TEEL-3 value, according to Table 3.5.
• TEEL-1 = TEEL-2/11
• TEEL-2 = TEEL-3/6
• TEEL-3 = Estimated from dog, intravenous LDLo (3000 mg/kg)
This review generated TEEL values consistent with those published in Rev. 29A.
References
Dog, intravenous LDLo: Cancer Chemotherapy Reports, 50(255), 1966; via PubChem: https://pubchem.ncbi.nlm.nih.gov/compound/61475#section=Acute-Effects
Rat, intravenous LD50: Yakkyoku. Pharmacy, 31(959), 1980; via PubChem: https://pubchem.ncbi.nlm.nih.gov/compound/61475#section=Acute-Effects
Human male, oral TDLo: Tohoku Journal of Experimental Medicine, 63(383), 1956 [PMID:13371588]; via PubChem: https://pubchem.ncbi.nlm.nih.gov/compound/61475#section=Acute-Effects
This value was estimated from compound adjustment factor (CAF) using sodium thiosulfate as a basis. The sodium thiosulfate TEEL values were estimated using the methods: TEEL-2/11, TEEL-3/6, Dog intravenous, LD50. This resulted in TEEL values approximate 20% greater than the selected method for the chemical of interest. (Nutritional and Gross Metabolic; via PubChem: https://pubchem.ncbi.nlm.nih.gov/compound/24477#section=NIOSH-Toxicity-Data)
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PAC values marked with a subscript "A" correspond to 60-minute AEGL values.
PAC values marked with a subscript "E" correspond to ERPG values.
PAC values marked by * are >= 10% lower explosive limit (LEL) but < 50% LEL.
PAC values marked by ** are > 50% LEL but < 100% LEL.
PAC values marked by *** are >= LEL.