Where:  D = density of deicing fluid, expressed in pounds per gallon.  D$_{w }$= density of water, expressed as 8.345 pounds per gallon.  C = concentration of component in deicing fluid (i.e., water, ethylene glycol, propylene  glycol, urea, polymer additives, etc.), expressed as a percent.  SG = specific gravity of component in deicing fluid; specific gravity is a dimensionless ratio of  the weight of the chemical to the weight of water.  𝑨 =  𝑨 𝒘 × ( 𝑪 𝟏𝟎𝟎 ⁄ ) ×  𝑺𝑮 APPENDIX A5$_{ }$ Equation A5-13. Density of Deicing Fluid  Table A5-8. Specific Gravity of Common Deicing Fluid Components  Concentration of chemical in deicing fluid (by weight) should be obtained from MSDS sheets,  deicing contractor, or fluid manufacturer. Common solutions are 50 percent propylene glycol in  water or 50 percent ethylene glycol in water. In many cases, different chemical formulations are  used for runway and aircraft deicing.  Emission factors for an ethylene glycol solution applied to a runway and to aircraft have been  calculated. An emission factor of 0.0067 pounds VOC emissions per pound of ethylene glycol  and propylene glycol applied should be used for runway and taxiway surface deicing, and an  emission factor of 0.00011 pounds VOC emissions per pound of ethylene glycol and propylene  glycol applied should be used for aircraft deicing. 33  One should be careful to note that emissions  are given per pound of ethylene glycol rather than per pound of deicing fluid, which contains water.  Equation A5-13  ( Density of Deicing Fluid ) takes this into account by employing  a concentration factor. The emission  factors given for ethylene glycol solutions may also be  33 Garska, Dan, Union Carbide Corporation. Letter to Terrence J. Godar, Virginia Department of Environmental  Quality, dated August 22, 1995.  40$_{ }$ A5.3.4.2  Emission Factors  Fluid Component  Specific Gravity  Water  1.000  Ethylene Glycol  1.119  Propylene Glycol  1.036  Urea  1.323  Source: CRC Handbook of Chemistry and Physics.  Specific gravity for common deicing fluid components is given in  Table A5-8  ( Specific Gravity  of Common Deicing Fluid Components ). 