# thermo.environment module¶

thermo.environment.GWP(CASRN, AvailableMethods=False, Method=None)[source]

This function handles the retrieval of a chemical’s Global Warming Potential, relative to CO2. Lookup is based on CASRNs. Will automatically select a data source to use if no Method is provided; returns None if the data is not available.

Returns the GWP for the 100yr outlook by default.

Parameters: Returns: CASRN : string CASRN [-] GWP : float Global warming potential, [(impact/mass chemical)/(impact/mass CO2)] methods : list, only returned if AvailableMethods == True List of methods which can be used to obtain GWP with the given inputs Method : string, optional The method name to use. Accepted methods are IPCC (2007) 100yr’, ‘IPCC (2007) 100yr-SAR’, ‘IPCC (2007) 20yr’, and ‘IPCC (2007) 500yr’. All valid values are also held in the list GWP_methods. AvailableMethods : bool, optional If True, function will determine which methods can be used to obtain the GWP for the desired chemical, and will return methods instead of the GWP

Notes

All data is from [R292297], the official source. Several chemicals are available in [R292297] are not included here as they do not have a CAS. Methods are ‘IPCC (2007) 100yr’, ‘IPCC (2007) 100yr-SAR’, ‘IPCC (2007) 20yr’, and ‘IPCC (2007) 500yr’.

References

 [R292297] (1, 2, 3) IPCC. “2.10.2 Direct Global Warming Potentials - AR4 WGI Chapter 2: Changes in Atmospheric Constituents and in Radiative Forcing.” 2007. https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-10-2.html.

Examples

Methane, 100-yr outlook

>>> GWP(CASRN='74-82-8')
25.0

thermo.environment.ODP(CASRN, AvailableMethods=False, Method=None)[source]

This function handles the retrieval of a chemical’s Ozone Depletion Potential, relative to CFC-11 (trichlorofluoromethane). Lookup is based on CASRNs. Will automatically select a data source to use if no Method is provided; returns None if the data is not available.

Returns the ODP of a chemical according to [R295299] when a method is not specified. If a range is provided in [R295299], the highest value is returned.

Parameters: Returns: CASRN : string CASRN [-] ODP : float or str Ozone Depletion potential, [(impact/mass chemical)/(impact/mass CFC-11)]; if method selected has string in it, this will be returned as a string regardless of if a range is given or a number methods : list, only returned if AvailableMethods == True List of methods which can be used to obtain ODP with the given inputs Method : string, optional The method name to use. Accepted methods are ‘ODP2 Max’, ‘ODP2 Min’, ‘ODP2 string’, ‘ODP2 logarithmic average’, and methods for older values are ‘ODP1 Max’, ‘ODP1 Min’, ‘ODP1 string’, and ‘ODP1 logarithmic average’. All valid values are also held in the list ODP_methods. Method : string, optional A string for the method name to use, as defined by constants in ODP_methods AvailableMethods : bool, optional If True, function will determine which methods can be used to obtain the ODP for the desired chemical, and will return methods instead of the ODP

Notes

Values are tabulated only for a small number of halogenated hydrocarbons, responsible for the largest impact. The original values of ODP as defined in the Montreal Protocol are also available, as methods with the ODP1 prefix.

All values are somewhat emperical, as actual reaction rates of chemicals with ozone depend on temperature which depends on latitude, longitude, time of day, weather, and the concentrations of other pollutants.

All data is from [R294299]. Several mixtures listed in [R294299] are not included here as they are not pure species. Methods for values in [R295299] are ‘ODP2 Max’, ‘ODP2 Min’, ‘ODP2 string’, ‘ODP2 logarithmic average’, and methods for older values are ‘ODP1 Max’, ‘ODP1 Min’, ‘ODP1 string’, and ‘ODP1 logarithmic average’.

References

 [R294299] (1, 2, 3) US EPA, OAR. “Ozone-Depleting Substances.” Accessed April 26, 2016. https://www.epa.gov/ozone-layer-protection/ozone-depleting-substances.
 [R295299] (1, 2, 3, 4, 5) WMO (World Meteorological Organization), 2011: Scientific Assessment of Ozone Depletion: 2010. Global Ozone Research and Monitoring Project-Report No. 52, Geneva, Switzerland, 516 p. https://www.wmo.int/pages/prog/arep/gaw/ozone_2010/documents/Ozone-Assessment-2010-complete.pdf

Examples

Dichlorotetrafluoroethane, according to [R295299].

>>> ODP(CASRN='76-14-2')
0.58

thermo.environment.logP(CASRN, AvailableMethods=False, Method=None)[source]

This function handles the retrieval of a chemical’s octanol-water partition coefficient. Lookup is based on CASRNs. Will automatically select a data source to use if no Method is provided; returns None if the data is not available.

Parameters: Returns: CASRN : string CASRN [-] logP : float Octanol-water partition coefficient, [-] methods : list, only returned if AvailableMethods == True List of methods which can be used to obtain logP with the given inputs Method : string, optional The method name to use. Accepted methods are ‘SYRRES’, or ‘CRC’, All valid values are also held in the list logP_methods. AvailableMethods : bool, optional If True, function will determine which methods can be used to obtain the logP for the desired chemical, and will return methods instead of the logP

Notes

$\log P_{ oct/wat} = \log\left(\frac{\left[{solute} \right]_{ octanol}^{un-ionized}}{\left[{solute} \right]_{ water}^{ un-ionized}}\right)$

References

>>> logP('67-56-1')