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Risk-Screening Environmental Indicators (RSEI) Model

RSEI Data Dictionary: Chemical Data

                                                               Tables in the RSEI Data Dictionary
Facility NAICS Submission Disaggregated Microdata Census Crosswalks
EPA Program IDs (Reporters) Chemical Release Aggregated Microdata Population Data
Offsite MCL Elements Block Group Microdata Shapefiles
EPA Program IDs (Off-sites) Media Category Water Microdata  

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 on the TRI supplementary data page.

RSEI Chemical Table (Spreadsheet)(207 K, December 2018)

RSEI Chemical Table (Text Format)(244 K, December 2018)

Chemical Data

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 for sorting (no hyphens). For chemical categories, CAS Numbers begin with “N”, followed by three digits.
SortName Common name of chemical, with initial modifiers moved to end of name. Used for internal sorting purposes.
FullChemicalName Full scientific name(s) of the chemical.
Chemical Common name(s) of the chemical.
Added The year the chemical was added to the Toxics Release Inventory. This field is blank when Chemical is invalid, mixture, or trade secret.
Toxicity Source 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):
  • A- Carcinogenic to humans
  • B- Probable carcinogen based on:
    • B1- Limited human evidence
    • Sufficient evidence in animals and inadequate or no evidence in humans.
  • C- Possible carcinogen
  • D- Not classifiable
  • E- Evidence of non-carcinogenicity
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.
CAAFlag This flag marks the chemicals that are Clean Air Act pollutants.
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.
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.
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.