LLNL-TR-625492 Physical Properties of Chemicals in PAC Revision 27 Listing M. A. Johnson March 8, 2013 Disclaimer This document was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor Lawrence Livermore National Security, LLC, nor any of their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or Lawrence Livermore National Security, LLC. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or Lawrence Livermore National Security, LLC, and shall not be used for advertising or product endorsement purposes. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Physical Properties of Chemicals in PAC Revision 27 Listing 1 Purpose The purpose of this chemical physical property listing is to provide data required to apply the DOE SCAPA Protective Action Criteria (PAC) values to calculation of the LLNL Quantity (Q) Value thresholds for facility chemical hazard classification. This chemical physical property listing based on the DOE SCAPA Protective Action Criteria (PAC) Revision 27 listing Identifies: 1. Physical state at 25°C (i.e. solid, liquid, or gas) 2. Vapor pressure of liquids at 25°C 2 Summary of Process 1. Start with PAC Input Data (table 1). a. Eliminate data columns not required for Q-Value threshold calculations. b. Add additional, necessary data columns. 2. Modify data format as needed 3. Filter out gases and solids based upon data provided in table 1 4. Utilize reference materials to: a. Further weed out gases & solids b. Identify VP at 25°C for liquids c. Fill in data gaps 2.1 PAC Input Data (table 1) 2.1.1 Eliminate Unnecessary Data Columns Only those values necessary to accomplish the stated purpose of this listing are utilized from table 1; these are: 1. PAC Revision 27 Chemical Identification Number (No.); which is required to maintain continuity between listings. 2. Chemical Compound Description; which is required to maintain continuity between listings. 3. Chemical CAS Number (CASRN); which is required for chemical identification. 4. Molecular Weight; which is required for chemical identification. 5. (Physical) State at 25°C. 6. Melting Point (MP); which is useful in identifying physical state at 25°C. 7. Boiling Point (BP) (sometimes given with a pressure other than 760 mmHg). 8. Vapor Pressure (VP). 9. Temperature at which Vapor Pressure has been provided. 2.1.2 Add in Needed Data Columns Some additional data columns have been added; these include: 1. Modified-format CAS numbers (sort-able). 2. Boiling Point data separated into Boiling Point Temperature (°C) and Boiling Point Pressure (mmHg) 3. Added a column to document reference sources for VP at 25°C. 2.2 Modify Data Format Much of the PAC Revision 27 table 1 content formatting has been modified in this listing to make the data more useful; modifications include: 1. Physical state values simplified (limiting choices to S, L, or G) 2. Numerical data reformatted to numerical values (much of the data was in text format). a. This primarily applies to data for chemicals existing as liquids at 25°C. 2.3 Exclusion of Solids and Gases from Further Evaluation Auto-filter function of spreadsheet is applied to eliminate from further evaluation all but those chemicals either identified as liquids, or not having an identified physical state. 2.4 Reference Material Data 2.4.1 Application of Referenced Data for Further Exclusion of Solids and Gases In some instances, assignment of physical form data (i.e. S, L, or G) provided by SCAPA in table 1 (input data) of the PAC listing is based upon conditions inconsistent with the LLNL Q-value calculation process. In these cases, it is sometimes possible to use additional data to better align physical form of the chemicals to 25°C. In instances where the chemicals are clearly a solid or gas at 25°C, these chemicals may be excluded from further evaluation of physical properties. 1. Chemicals assigned a physical state of “L” in the table 1 listing, but having a melting point equal to or greater than 25°C have been reassigned a physical state of “S.” a. This only applies to experimentally derived, published melting point data. 2. Chemicals assigned a physical state of “L” in table 1 but having a boiling point (temperature) at 760 mmHg equal to or less than 25°C have been reassigned a physical state of “G.” a. This only applies to experimentally derived, published boiling point data. 3. Chemical assigned a physical state of “L” in table 1 but found to have a vapor pressure at 25°C equal to or greater than 760 mmHg have been reassigned a physical state of “G.” a. This applies to both experimentally derived and estimated vapor pressure data. 2.4.2 Application of Referenced Data for Vapor Pressure Determinations All liquids are required to have a vapor pressure identified at 25°C; each of these will have a documented reference or source. The hierarchy for referenced data is: 1. First priority is given to values provided by SCAPA in table 1 (input data) of the PAC listing, as these values have been vetted by the DOE SCAPA working group and have been derived from reputable published sources. For those liquids not having a vapor pressure at 25°C identified in table 1 of the PAC listing, it is necessary to fill in the gaps utilizing other data sources. Where data ranges are provided, the mean of the range is utilized for calculations. 2. Second priority is given to experimental data derived from other published data sources, including: a. The EPA’s Estimation Program Interface (EPI) Suite Experimental Data Table b. EPI Suite chemical searches c. Published Industry technical papers or data sheets d. MSDSs 3. Third priority is given to modeled or estimated data. This is arrived at through: a. The EPA’s EPI Suite – either: i. Through direct use of the EPI Suite program (available from EPA’s website: http://www.epa.gov/oppt/exposure/pubs/episuitedl.htm ii. By proxy, using the Royal Society of Chemistry (RSC) “ChemSpider” free chemical database b. The ACD I-Lab Physical Chemistry Model – by proxy using the Royal Society of Chemistry (RSC) “ChemSpider” free chemical database c. Logarithmic interpolation between the chemical’s boiling point and a second known vapor pressure & temperature data set. [see section 3] d. Aqueous solutions for which the MSDS shows no contribution other than density in physical properties (i.e. VP, BP, MP are that of water) are assigned a hazardous component VP of 1E-05 for calculation purposes. 4. Last priority is given to values approximated from analogous materials. It is understood that such values are approximations only; however these are useful in that (in this PAC revision) these values have been applied only to chemicals having VPs below 1mmHg. In the Q-value threshold calculation process, it is not relevant how far the VP is below 1mmHg. 2.4.3 Application of Referenced Data to Fill in Gaps In many instances, it is possible to utilize data from the sources described in 2.4.2 to fill in data gaps present in the PAC input table. 1. In all instances where this data is used to re-assign physical form, only experimentally-derived data is applied. 2. In all instances where experimental data is available to fill in gaps, these values will be added to the listing. 3. In instances where EPI Suite-estimated values for MP & BP are available to fill in gaps, these values will be added to the table only if they are both credible & consistent with experimentally- derived data. 4. In instances where table 1 data is significantly at odds with published data for a chemical, corrections applied will also be noted in the Reference Documentation field. 3 Model for Estimation of Vapor Pressure Using Boiling Point and a Known Vapor Pressure Point 3.1 Basis and Equations The basis for this model is linear interpolation of the natural log of vapor pressure (VP) with the inverse of absolute temperature. ln( ) = + Equation 1 1 =푉푃ln ( 퐵 푇 퐴) Equation 2 퐵 ( ) ( ) 퐴 = 퐵푃푃 − 퐵푃 ( ) ( ) Equation 3 ln 퐵푃푃 − ln VP1 −1 −1 Where 퐵 퐵푃 − 푇1 VP = Desired Vapor Pressure [mmHg] T = Temperature for desired vapor pressure [°K] A and B are coefficients in equation 1, represented by equations 2 and 3 respectively And BPP = Boiling Point Pressure [mmHg] BP = Boiling Point [°K] VP1 = known VP [mmHg] T1 = Temperature for known VP [°K] 3.2 Sample Calculation Ethyl acetate has a VP of 118.3 mmHg at 29.5°C and a normal boiling point of 77.1°C. Vapor pressure at 25°C may be estimated as follows: ( ) ( . ) = ( . ) ( . ) = -4142.351 ln 760 − ln 118 3 ( −1 . ) −1 퐵 = ln77 (7601+273 15 − 29 5+273 15 ( . ) ) = 18.460 −4142 351 퐴 ( ) = ( −414277 1.351+273)15 + 18.460 = 4.566 ( . ) 1 푙푛 푉푃= 96.22− 25+273 15 The published,푉푃 experimentally푚푚퐻푔 -derived VP for ethyl acetate at 25°C is 93.2 mmHg. The percent error for this method in this instance is: .