PAC Database - Detailed Chemical Data
Chemical Identity
| Chemical | CAS# | UN# | Health Code Numbers | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Methyl difluorophosphite; (Methylphosphonic difluoride) | 676-99-3 |
7.01
7.00
11.00
4.01
4.02
4.11
|
||||||||||
| Formula | Synonyms | |||||||||||
| CH3F2OP | ||||||||||||
Physical Properties
| Mol Wt | State | MP (°C) | BP (°C) | VP (Hg) | VP (°C) | SG | LEL (ppm) |
|---|---|---|---|---|---|---|---|
| 100.01 | L | 98 | 1.33 |
PAC Values
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.53 | 5.9 | 35 |
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.13 | 1.4 | 8.6 |
Technical Basis
A review of available data sources identified intravenous LD50 (dog, mouse, rat) and LCLo (dog, monkey, rat) toxicity data for multiple species. 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. Inhalation exposures were scaled to 60-minute equivalents using the ten Berge equation (Section 3.3.4).
Collected toxicity data were evaluated for their relative preference and the most preferred species, monkey, data 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 = Monkey LCLo (2608 mg/m3/30-min)
This review generated TEEL values that are inconsistent with Rev. 29A. In Rev. 29A, TEEL-3 was calculated using rat inhalation LCLo acute toxicity data, this review utilizes a data source that is more preferred due to the species used in the acute toxicity study (monkey is more preferable than rat).
Collected toxicity data were evaluated for their relative preference and the most preferred species, monkey, data 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 = Monkey LCLo (2608 mg/m3/30-min)
This review generated TEEL values that are inconsistent with Rev. 29A. In Rev. 29A, TEEL-3 was calculated using rat inhalation LCLo acute toxicity data, this review utilizes a data source that is more preferred due to the species used in the acute toxicity study (monkey is more preferable than rat).
References
Monkey LCLo: Toxicology and Applied Pharmacology., 15(131), 1969 [PMID:4979020] via PubChem; National Center for Biotechnology Information (2023). PubChem Compound Summary for CID 69610, Methylphosphonic difluoride. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Methylphosphonic-difluoride.