Vapor Pressure of Organic Material or Solvent

Section 219 Section 219.110  Vapor Pressure of Organic Material or Solvent a)         If the organic material or solvent consists of only a single compound, the vapor pressure must be determined by ASTM Method D2879-86 (incorporated by reference in Section 219.112 of this Part) or the vapor pressure may be obtained from a publication such as:  Boublik, T., V. Fried and E. Hala, "The Vapor Pressure of Pure Substances," Elsevier Scientific Publishing Co., New York (1973); Perry's Chemical Engineer's Handbook, McGraw-Hill Book Company (1984); CRC Handbook of Chemistry and Physics, Chemical Rubber Publishing Company (1986-87); and Lange's Handbook of Chemistry, John A. Dean, editor, McGraw-Hill Book Company (1985). b)         Except as provided in subsection (d), if the organic material or solvent is in a mixture made up of both organic material compounds and compounds which are not organic material, the vapor pressure must be determined by the following equation: where: P om = Total vapor pressure of the portion of the mixture which is composed of organic material; n = Number of organic material components in the mixture; i = Subscript denoting an individual component; P i = Vapor pressure of an organic material component determined in accordance with subsection (a); X i = Mole fraction of the organic material component of the total organic mixture. c)         If the organic material or solvent is in a mixture made up only of organic material compounds, the vapor pressure must be determined by ASTM Method D2879-86 (incorporated by reference in Section 219.112) or by the above equation. d)         For hand-wipe cleaning solvents used at aerospace facilities subject to Section 219.219(g)(2), the composite vapor pressure of a cleaning solvent consisting of multiple components must be determined by the following equation: where: PP c = Composite vapor pressure of the cleaning solvent in mmHg at 20 °C; n = Number of components in the cleaning solvent; i = Subscript denoting an individual VOM-containing component; j = Subscript denoting an individual non-VOM component; W i = Weight of a VOM-containing component in grams; W j = Weight of a non-VOM component in grams; W w = Weight of water in grams; MW i = Molecular weight a VOM-containing component in grams per gram-mole; MW j = Molecular weight of a non-VOM component in grams per gram-mole MW w = Molecular weight of water in grams per gram-mole; VP i = Vapor pressure of a VOM-containing component in mmHg at 20 °C.