Compounds added and Antoine's coefficients corrected in TANKS 4.09D Distillate Fuel Oil No. 2 at 60 degrees Fahrenheit was corrected to 60 degrees of 0.0065 psia. Table 7.1-2 of AP-42 will be corrected when the section is updated. Chemical Abstract Series (CAS) numbers have been added for approximately 30 chemicals that were previously missing this information in the TANKS chemical database. Chemical property data and CAS number for Naphthalene were added to the chemical database. Chemical property data and CAS numbers for “p-xylene”, “gasoline oxygenated with ethanol”, “denatured ethanol”, “gasoline (RVP 7.8)”, “gasoline (RVP 8.3)”, “gasoline (RVP 11.5)”, “gasoline (RVP 13.5)”, and “gasoline (RVP 15.0) were added to the chemical database. The constants for propylene oxide (CAS 75 56 9) from "Lange's Handbook of Chemistry" are different from the information already contained in the Chemical Database for propylene oxide (CAS 75 66 9), which also has a different CAS number. A third set of Antoine constants appear in "The Properties of Gases and Liquids". We decided to use the same constants as the Water 9 database, so they were changed from [A: 8.2768; B:1656.884; C: 273.16] to [A: 7.0671; B: 1133.267; C: 236.1054]. We also changed the listed CAS number from 75-66-9 to 75-56-9. A discrepancy was also discovered in the Antoine constants for isopropylbenzene (cumene). Both AP-42 and TANKS show the value of "A" as 6.963, but according to API MMPMS 19.4 and Lange's Handbook of Chemistry, 15th Edition, the value is 6.93666. The chemical database has been changed to 6.93666. Another discrepancy was found between 2,2,4-trimethylpentane and isooctane. Even though they are synonyms of the same chemical, the vapor pressure for 2,2,4-trimethylpentane is calculated using Antoine constants and the vapor pressure for isooctane is calculated using vapor pressure option #1 (a list of vapor pressures and corresponding temperatures). The chemical database has been changed to exclude isooctane and change the name of 2,2,4-trimethylpentane to 2,2,4-trimethylpentane (isooctane) to avoid confusion. The same Antoine constants will be used because they match Lange's Handbook of Chemistry. An error was found in the meteorological data for Birmingham, Alabama. For December, the minimum and maximum temperatures were inadvertently switched. Instead of 35.2 being the maximum and 55.9 being the minimum, the two values have been switched. A discrepancy was found for methyl ethyl ketone. The Antoine constants in TANKS do not match the constants in the NIST Chemistry Webbook. The constants have been changed from [A: 6.9742; B: 1209.6; C: 216] to [A: 6.8645; B: 1150.207; C: 209.246] to match the NIST values. A user found a discrepancy in the chemical data used for isobutyl alcohol. The Antoine's constants in the database actually belong with secondary butyl alcohol. The constants were changed from [A: 7.4743; B:1314.19; C: 186.55] to [A: 7.30636; B: 1236.991; C: 171.622].