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.

Category

This identifier is not yet active.

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

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).

POTW PartitionSludge

Percent of total POTW removal efficiency attributable to sorption of the chemical to sewage sludge.

POTW PartitionVolat

Percent of total POTW removal efficiency attributable to volatilization of the chemical.

POTW PartitionBiod

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.

T33/50Flag

This flag is a marker which indicates that the chemical is included in EPA’s 33/50 program, a program in which facilities voluntarily reduce their chemical releases by 33 percent and 50 percent by certain dates.

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.

Metal

This flag indicates whether the chemicals are metals and also whether they are core chemicals. (Core chemicals are those that are common to all reporting years of TRI and which have had no modifications of reporting requirements.)

User Tags 1 through 5

Using these tags, you can select a set of chemicals based on your own selection criteria.

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).