PAC Database - Detailed Chemical Data

Chemical Identity
Chemical CAS# UN# Health Code Numbers
Methamidophos 10265-92-6
6.00
7.00
15.01
11.00
4.05
4.01
7.01
4.06
4.07
8.00
Formula Synonyms
C2H8NO2PS METHAMIDOPHOS, ACEPHATE-MET, BAY 71628, BAYER 5546, BAYER 71628, CHEVRON 9006, CHEVRON ORTHO 9006, CKB 1220, ENT 27,396, FILITOX, HAMIDOP, METAMIDOPHOS, METHYL PHOSPHORAMIDOTHIOATE ((MEO)(MES)P(O)(NH2)), MONITOR, MONITOR (INSECTICIDE), MONITOR(INSECTICIDE), O,S-DIMETHYL ESTER AMIDE OF AMIDOTHIOATE, O,S-DIMETHYL PHOSPHORAMIDOTHIOATE, O,S-DIMETHYL PHOSPHORAMIDOTHIOLATE, O,S-DIMETHYL THIOPHOSPHORAMIDE, ORTHO 9006, ORTHO MONITOR, PHOSPHORAMIDOTHIOIC ACID, O,S-DIMETHYL ESTER, RE 9006, SRA 5172, TAMARON
Physical Properties
Mol Wt State MP (°C) BP (°C) VP (Hg) VP (°C) SG LEL (ppm)
141.14 S 40 0.0003 25 1.31 @ 44.5°C
PAC Values
PAC Values (Original Units: mg/m3)
PAC-1 PAC-2 PAC-3
0.11 1.2 7.1
Converted PAC Values (ppm)
PAC-1 PAC-2 PAC-3
0.019 0.21 1.2
Technical Basis
Technical Justification A review of available sources identified several human (male, female) and rat acute toxicity data (TDLo, LD50, LC50) for inhalation and oral routes, and exposure limits (LOC, AEGLs). 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. Although AEGLs are high priority (Section 1), they were not selected for further evaluation since they were proposed values, or values are still under review by the public and committee; however, upon completion of review TEEL values may need to be re-evaluated. The data of the most preferred route and species, a 4-hour rat LC50, was selected as the TEEL-3 basis and scaled to 60-minute equivalent using the ten Berge equation (Section 3.3.4) The LOC was deemed more preferential to the human TDLo toxicity data (whose endpoints may not be appropriate), however the LOC was not selected since the basis could not be found. TEEL-1 and TEEL-2 values were derived according to Table 3.5.
• TEEL-1 = TEEL-2/11
• TEEL-2 = TEEL-3/6
• TEEL-3 = Rat LC50 (162 mg/m3/4H)
This review generated TEEL values that are consistent with Rev. 29A.
References
Chemical information: https://pubchem.ncbi.nlm.nih.gov/compound/Methamidophos.
Rat LC50: Agrochemicals Handbook, with updates, Hartley, D., and H. Kidd, eds., Nottingham, Royal Soc of Chemistry, 1983-86, A265(1984). Retrieved from: National Center for Biotechnology Information (2024). PubChem Compound Summary for CID 4096, Methamidophos. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Methamidophos.
LOC: Retrieved from Appendix C (page C-6); https://www.epa.gov/sites/default/files/2015-09/documents/technical_guidance_for_hazard_analysis.pdf
AEGLs: https://www.epa.gov/aegl/methamidophos-results-aegl-program
Search Again
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.