RSEI Data Dictionary: Chemical Data
The following tables provide descriptions for each field in each table. Note that for the Microdata, "Other Geographies" includes block groups, census tracts, and ZIP code files. For more information, see the RSEI methodology document and the RSEI Microdata documentation.
The chemical table contains data for chemicals reported to TRI, including toxicity, physico-chemical properties, and flag fields to facilitate user selections. The chemical table is also available in EasyRSEI.
Additional data tables containing chemical flags and various chemical categories can be found in the documentation for TRI Explorer.
These tables are from RSEI Version 2.3.12 (RY 2022) and cannot be used with tables from any other version.
RSEI Chemical Table (Spreadsheet) (xlsx)
RSEI Chemical Table (Text Format) (csv)
Chemical Data |
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|---|---|
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Field Name |
Field Description |
| CASNumber | Chemical Abstracts Service Registry Number, which identifies a unique chemical. For chemical categories, CAS Numbers begin with “N”, followed by three digits. |
| CASStandard | The Chemical Abstracts Service Registry Number identifies a unique chemical. The standard format contains three sets of numbers divided by hyphens (00-00-0). |
| ChemicalNumber | Unique internal identifier. |
| TRIChemID | Chemical Abstracts Service (CAS) Registry Number formatted with leading zeroes to match other TRI datasets. |
| MetalCombinedChemNum | Same values as ChemicalNumber, except for metals and their associated compounds, where the number is duplicative. For example, "lead" and "lead compounds" have different Chemical Numbers, but the same MetalCombinedChemNum. |
| SortCAS | Chemical Abstracts Service Registry Number, which identifies a unique chemical, formatted as numbers for sorting (no hyphens). For chemical categories, CAS Numbers do not include the “N”. |
| SortNameKey | Numeric field that can be used to sort the Chemical field in alphabetical order excluding initial modifiers. |
| Chemical | Name of the chemical as listed in the Toxics Release Inventory. |
| FirstReportingYear | The first year that the chemical was reportable to the Toxics Release Inventory. |
| ToxicitySource | All sources used for toxicity data, and date of addition to database. |
| RfCInhale | The inhalation reference concentration (RfC) is defined as “an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious noncancer health effects during a lifetime”. Units are mg/m3. |
| RfCUF | The uncertainty factor (UF) is applied to the no-observed-adverse-effect level (NOAEL) upon which the RfC is based, thereby reducing the dose. The UF accounts for uncertainties in extrapolation from experimental data to an estimate appropriate to humans. |
| RfCMF | The modifying factor (MF) is a value applied to the NOAEL when scientific uncertainties in the study chosen for estimating the RfC are not explicitly addressed by the standard UFs. |
| RfCConf | Confidence levels are assigned to the study used to derive the RfC, the overall database, and to the RfC itself. |
| RfCSource | Source used for the RfC value. |
| RfCListingDate | Date that RfC was listed, if available. |
| RfCToxWeight | Toxicity weight based on the RfC (RfCToxWeight = 3.5/RfC). Noncancer/inhalation. |
| RfDOral | The oral reference dose (RfD) is “an estimate (with uncertainty spanning perhaps an order of magnitude) of a daily exposure [by ingestion] to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime”. (mg/kg-day) |
| RfDUF | The uncertainty factor (UF) is applied to the no-observed-adverse-effect level (NOAEL) upon which the RfD is based, thereby reducing the dose. The UF accounts for uncertainties in extrapolation from experimental data to an estimate appropriate to humans. |
| RfDMF | The modifying factor (MF) is a value applied to the NOAEL when scientific uncertainties in the study chosen for estimating the RfD are not explicitly addressed by the standard UFs. |
| RfDConf | Confidence levels are assigned to the study used to derive the RfD, the overall database, and to the RfD itself. |
| RfDListingDate | Date that RfD was listed, if available. |
| RfDSource | Source used for the RfD value. |
| RfDToxWeight | Toxicity weight based on the RfD (RfDToxWeight = 1/RfD). Noncancer/oral. |
| UnitRiskInhale | The unit inhalation risk is the excess lifetime risk due to a “continuous constant lifetime exposure of one unit of carcinogen concentration”(51 FR 33998). (1/mg/m3) |
| QSTAROral | The oral cancer slope factor (q1*) or oral slope factor (OSF): a measure of the incremental lifetime risk of cancer by oral intake of a chemical, expressed as risk per mg/kg-day. (1/mg/kg-day) |
| WOE | Weight of evidence (WOE) categories indicate how likely a chemical is to be a human carcinogen, based on considerations of the quality and adequacy of data and the type of responses induced by the suspected carcinogen. EPA WOE classifications include the following categories and associated definitions (51 FR 33996):
|
| UnitRiskListingDate | Date that Unit Risk was listed, if available. |
| UnitRiskSource | Source used for the Unit Risk value. |
| IURToxWeight | Toxicity weight based on the IUR (IURToxWeight = IUR/2.8e-7). Cancer/inhalation. |
| QStarListingDate | Date that QStar was listed, if available. |
| QStarSource | Source used for the QStar value. |
| OSFToxWeight | Toxicity weight based on the QStar or OSF (OSFToxWeight = QSTAROral/1e-6). Cancer/oral. |
| WOEListingDate | Date that WOE was listed, if available. |
| WOESource | Source used for the WOE classification. |
| ITW | Inhalation Toxicity Weight: the RSEI toxicity weight for a chemical for the inhalation pathway. |
| OTW | Oral Toxicity Weight: the RSEI toxicity weight for a chemical for the oral pathway. |
| ToxicityClassOral | This indicates whether the toxicity weight for the oral pathway is based on cancer or noncancer health effects. |
| ToxicityClassInhale | This indicates whether the toxicity weight for the inhalation pathway is based on cancer or noncancer health effects. |
| ToxicityCategory | This indicates whether the oral and inhalation toxicity weights are based on cancer health effects, non-cancer health effects, or both. |
| AirDecay | The rate at which a chemical degrades in air, due primarily to photooxidation by radicals (hr-1). |
| Koc | The organic carbon-water partition coefficient, used in estimates of chemical sorption to soil (mL/g). |
| H2ODecay | The rate at which a chemical degrades in water, due to abiotic hydrolysis, biodegradation, or photolysis (hr-1). |
| LOGKow | The logarithm of the octanol-water partition coefficient. Kow is the ratio of a chemical’s concentration in the octanol phase to its concentration in the aqueous phase at equilibrium in a two-phase octanol/water system. |
| Kd | The soil-water partition, or distribution, coefficient. For organics, the value is often estimated as the product of Koc and foc (the fraction of organic carbon in the soil) (L/kg). |
| WaterSolubility | The amount of chemical that dissolves in water at a particular temperature (mg/L). |
| POTWPartitionRemoval | Percent of chemical removed from the wastewater by the POTW (Publicly Owned Treatment Works). |
| POTWPartitionSludge | Percent of total POTW removal efficiency attributable to sorption of the chemical to sewage sludge. |
| POTWPartitionVolat | Percent of total POTW removal efficiency attributable to volatilization of the chemical. |
| POTWPartitionBiod | Percent of total POTW removal efficiency attributable to biodegradation of the chemical. |
| IncineratorDRE | Destruction/removal efficiencies, expressed as the percent of chemical fed to the incinerator that is not released to the air. |
| BCF | Bioconcentration factor: the ratio of a chemical’s concentration in fish to its concentration in water at equilibrium (L/kg). |
| Henrys | Henry’s law constant: the ratio of a chemical’s concentration in the air to its concentration in the water at equilibrium (atm·m3/mol). |
| MCL | Maximum Contaminant Level, which is EPA’s national primary drinking water standard for the chemical. This is the current value; historical data are contained in the table, ‘MCL.’ |
| Molecular Weight | The mass in grams of one mole of molecules of the chemical. |
| HAPFlag | This flag marks the chemicals that are hazardous air pollutants, as defined by the Clean Air Act. |
| RMPFlag | This flag marks the chemicals for which facilities are required to Risk Management Plans (RMPs) under section 112(r) of the Clean Air Act. |
| PriorityPollutantFlag | This flag marks the chemicals that are priority pollutants, as defined by the Clean Water Act. |
| SDWAFlag | This flag marks the chemicals that have national primary or secondary drinking water standards under the Safe Drinking Water Act. |
| CERCLAFlag | This flag marks the chemicals that are regulated under Superfund (CERCLA—the Comprehensive Environmental Response, Compensation, and Liability Act). |
| OSHACarcinogens | This flag indicates whether the chemical is a known or suspect human carcinogen based on OSHA criteria. Known human carcinogens are defined as those that have been shown to cause cancer in humans. Suspect human carcinogens have been shown to cause cancer in animals. The list of chemicals flagged as OSHA carcinogens is based on the list of carcinogens provided in the 1997 TRI Public Data Release.* |
| ExpansionFlag | This flag marks the chemicals that were added to the Section 313 toxic chemical list for the 1995 Reporting Year. |
| Core88ChemicalFlag | This flag marks the chemicals that are common to all reporting years of TRI and that have had no modifications of reporting requirements, as determined by the 1988 Core Chemical List found on the TRI Explorer website. |
| Core95ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 1995 through the current year and that have had no modifications of reporting requirements in that time period, as determined by the 1995 Core Chemical List found on the TRI Explorer website. |
| Core98ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 1998 through the current year and that have had no modifications of reporting requirements in that time period, as determined by the 1998 Core Chemical List found on the TRI Explorer website. |
| Core00ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2000 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core01ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2001 through the current year and that have had no modifications of reporting requirements in that time period. The only difference between this flag and the Core00ChemicalFlag is the inclusion of lead and lead compounds. |
| Core11ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2011 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core12ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2012 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core14ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2014 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core15ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2015 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core16ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2016 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core17ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2017 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core19ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2019 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core20ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2020 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core21ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2021 through the current year and that have had no modifications of reporting requirements in that time period. |
| Core22ChemicalFlag | This flag marks the chemicals that are common to TRI reporting years 2022 through the current year and that have had no modifications of reporting requirements in that time period. |
| HPVFlag | Indicates whether the chemical is designated as a High Production Chemical. |
| HPVChallengeValue | Describes the value or combination of values assigned to the chemical by EPA’s HPV Challenge program to describe the chemical’s status under the program. |
| PBTFlag | Indicates whether EPA has designated this chemical as a priority chemical under the Persistent Bioaccumulative and Toxic (PBT) Chemical Program. |
| TSCAFlag | Indicates whether the chemical is a Work Plan Chemical under the Toxic Substances Control Act (TSCA). |
| PFASFlag | Indicates whether the chemical is a polyfluoroalkyl substance. |
| Metal |
Indicates whether the chemical is a metal. 0 = Not a metal 1 = Elemental metal (e.g., "Lead") 2 = Metal compound categories (e.g., "Lead Compounds") 3 = Metals with qualifiers (e.g., "Aluminum (fume or dust)") 4 = Individually-listed compounds that contain metal (e.g., "Lithium carbonate") 5 = May contain metal (e.g., copper cyanide is reportable under TRI-listed chemical category "Cyanide compounds") |
| HasTox | Indicates that the chemical has a toxicity weight (either oral or inhalation) in the data set. |
| MaxTW | Shows the greater of the two possible toxicity weights (oral or inhalation). |
| MaxNC | Shows the greater of the two possible toxicity weights for noncancer endpoints (RfDToxWeight or RfCToxWeight). |
| MaxC | Shows the greater of the two possible toxicity weights for cancer endpoints (OSFToxWeight or IURToxWeight). |
| Notes | Additional information regarding assignment of toxicity or physiochemical data, or listing/delisting dates. |