g>± hhhijk United States
wcnPi Environmental Protection Agency
EPA 743B18001, June 2018
Office of Chemical Safety
and Pollution Prevention
Guidance for Creating Generic Names
for Confidential Chemical Substance Identity
Reporting under the Toxic Substances
Control Act
June 2018

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Preface
This guidance provides information to assist companies in creating structurally descriptive
chemical names for chemical substances whose specific chemical identities are claimed
confidential, for purposes of protecting the specific chemical identities from disclosure while
describing the chemical substance as specifically as practicable, and for listing substances on the
Toxic Substances Control Act (TSCA) Chemical Substance Inventory.
The Frank R. Lautenberg Chemical Safety for the 21st Century Act amends TSCA Section
14(c)(4) to require EPA to "develop guidance regarding - (A) the determination of structurally
descriptive generic names, in the case of claims for protection from disclosure of specific
chemical identity..The Act also amends TSCA Section 14(c)(1)(C) to require submitters who
assert a confidentiality claim for specific chemical identity to include a structurally descriptive
generic name for the chemical substance that EPA may disclose to the public, which is consistent
with EPA's guidance and which describes the chemical structure of the substance as specifically
as practicable while protecting those features of the chemical structure that are claimed as
confidential, and the disclosure of which would be likely to cause substantial harm to the
competitive position of the claimant. Consistent with the TSCA Section 14(c)(4) and (c)(1)(C)
requirements, this guidance updates and replaces the 1985 guidance published in the TSCA
Inventory, 1985 Edition (Appendix B: "Generic Names for Confidential Chemical Substance
Identities").
Also consistent with the TSCA Section 14(c)(4) and (c)(1)(C) requirements, EPA will be
reviewing generic names upon receipt in TSCA filings where chemical identity is claimed as
confidential for consistency with the guidance. Companies are encouraged to consult with the
Agency prior to the submission of TSCA filings about creating generic names generally and in
particular instances. Companies are particularly encouraged to consult the Agency (Office of
Pollution Prevention and Toxics/Industrial Chemistry Branch; telephone (202) 564-8740) if they
feel that it will be necessary to mask more than one structural element of a specific chemical
name in order to mask a confidential chemical identity.
Disclaimer
This Guidance does not constitute rulemaking by the United States Environmental Protection
Agency (EPA), and cannot be relied on to develop a substantive or procedural right enforceable
by any party in litigation with the United States. Non-mandatory language such as "should"
provides recommendations and does not impose any legally binding requirements.
The TSCA statutory provisions described in this document contain legally binding requirements
relating to claims for protection from disclosure of a specific chemical identity. This document is
not a regulation itself, nor does it change or substitute those provisions or other EPA regulations.
While EPA has made every effort to ensure the accuracy of the discussion in this guidance, the
obligations of EPA and the regulated community are determined by statutes, regulations, or other
legally binding requirements, which supersede this guidance document.

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Interested persons are free to raise questions and objections about the substance of this guidance
and the appropriateness of the application of this guidance to a particular situation. EPA may
make changes in this document at any time without public notice.
Background
A specific chemical name identifies every structural feature of a chemical substance possible,
i.e., a specific chemical name is a structurally specific and descriptive chemical identifier. A
generic name is the nonconfidential substitute for a specific chemical name that is treated as
confidential. A generic name should also be structurally descriptive, i.e., a generic name should
reveal the chemical identity of a substance to the maximum extent practicable while masking
only those structural elements that are confidential. Generic names allow EPA to publicly
identify confidential chemical substances. For example, generic names are routinely used to
publicly identify the thousands of confidential substances on the TSCA Inventory.
This guidance and the 1985 guidance that it is replacing are based on the approach that an
appropriate generic name generally starts with the specific Chemical Abstracts (CA) Index name
and then masks only the structurally descriptive element(s) (or the compositionally descriptive
element(s) or other element(s) for substances with variable or unknown structural features) of
that name that are confidential; an appropriate generic name generally does not start with a very
generic name to which some additional structural information is then reintroduced. Additionally,
when masking a confidential element, it generally is not just removed from the name but is
substituted with a more generic structural descriptor. Furthermore, because generic names, like
CA Index names, are generally structure-based names, trade names generally are not acceptable
as generic names, nor are names that mask confidential elements by substituting with non-
structural descriptors, e.g., use or function information.
This guidance provides examples of the process for masking the structurally descriptive (or
other) element(s) of the specific CA Index name for a chemical substance. Although examples
primarily include masking one structural element, masking more than one structural element can
be acceptable, provided that the submitter can justify their need for any additional masking.
Because of inherent differences in naming class 1 organic chemical substances, class 2
(including UVCB) organic substances, and inorganic substances, the guidance addresses each
separately.
Class 1 Organic Chemical Substances
A class 1 organic chemical substance can be represented by a definite molecular formula and
chemical structure diagram. A generic name is created for a class 1 organic chemical substance
by masking the confidential elements of its specific chemical name. Masking is accomplished by
substituting more generic structural descriptors for the confidential elements. The specific
chemical name of a class 1 chemical substance generally discloses the following structure
information:
1. Identity of the parent structure for a substance of a certain chemical class (e.g., alcohols,
alkenes) which often also describes a chain of carbon atoms or a ring system.

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2.	Identity, number, and position of chemical group(s) that are attached to the parent structure
or to other chemical groups.
3.	Identity and number of counter ion(s) for salt(s).
4.	Stereochemical relationship(s).
The structural elements of a class 1 organic chemical substance name that can be masked when
creating a generic name therefore include the following:
1.	Identity of a parent structure.
2.	Identity of an attached chemical group.
3.	Number or multiplicative prefix (e.g., di-, tri-, tetra-) of an attached chemical group.
4.	Position or locant of an attached chemical group.
5.	Identity or number (multiplicative prefix) of the cation(s) or anion(s) of a salt.
6.	Stereochemical or isomeric identifiers (e.g., D- or L-, R- or S-, E- or Z-, cis- or trans-).
Parent Structure Masking
A parent structure describing a certain chemical class - often including a chain of carbon atoms
or a ring system - can be masked in the specific chemical name by substituting the following
examples of more generic descriptors:
•	"alkane" for saturated carbon chains (e.g., butane, octane)
•	"alkene" or "alkyne" for unsaturated carbon chains (e.g., 1-butene, 2-butyne)
•	"cycloalkane" or "carbomonocycle" for non-aromatic, carbon-based, single ring systems
(e.g., cyclohexane)
•	"carbomonocycle" for aromatic, carbon-based, single ring systems (e.g., benzene)
•	"carbopolycycle" for aromatic or non-aromatic, carbon-based fused, bridged, or spiro ring
systems (e.g., lH-indene, bicyclo[2.2.2]octane, spiro[5.5]undecane)
•	"heteromonocycle" for aromatic or non-aromatic, carbon-based, single ring systems that
contain at least one additional atom (heteroatom) in the ring (e.g., pyrrolidine; 1,4-dioxane)
•	"heteropolycycle" for aromatic or non-aromatic, carbon-based, fused, bridged, or spiro ring
systems that contain at least one additional atom (heteroatom) in the ring(s) (e.g., lH-indole;
l,4-diazabicyclo[2.2.2]octane; 2,4,8,10-tetraoxaspiro[5.5]undecane)
Chemical Group Masking
An attached chemical group can be carbon-based (carbon chain or carbon-based ring system),
heteroatom-based (e.g., hydroxyl, amino, nitro, chloro), or both (e.g., alkoxyl, acyl, amido,
cyano). The attachment can be on the parent structure or on another chemical group. Similar to
masking a parent structure, the identity of an attached chemical group can be masked in the
specific chemical name by substituting the following examples of more generic descriptors:
•	"alkyl," "alkenyl," or "alkynyF for saturated or unsaturated carbon chains (e.g., butyl, 1-
butenyl, 1-butynyl)
•	"carbomonocyclic" or "carbopolycyclic" for carbon-based ring systems (e.g., cyclohexyl,
phenyl, indenyl, bicyclooctyl, spiroundecyl); "aryt' also can be used for aromatic ring
systems

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•	"heteromonocyclic" or "heteropolycyclic" for carbon-based ring systems that contain at least
one additional atom (heteroatom) in the ring (e.g., pyrrolidinyl, indolyl, diazabicyclooctyl,
tetraoxaspiroundecyl)
•	"halo" for halogens (e.g., chloro, bromo)
•	"nitrogen-substitutedfor nitrogen containing chemical groups (e.g., nitro, azo);
"heteroatom-substituted" also can be used for heteroatom-based chemical groups
Masking the number (multiplicative prefix) or position (locant) of an attached chemical group
is illustrated in the examples below.
Examples
The generic names provided for the examples below illustrate only some of the possible ways
that structural elements in class 1 organic chemical substances can be masked.
Example 1
Specific chemical name: "2-Pentenoic acid, 2,4-dimethyl-, ethyl ester, (2E)-"
Appropriate generic names:
•	"alkenoic acid, 2,4-dimethyl-, ethyl ester, (2E)-" or "unsaturatedcarboxylic acid, 2,4-
dimethyl-, ethyl ester, (2E)-" masks the identity of the 2-pentenoic acid parent group
•	"2-pentenoic acid, 2,4-dialkyl-, ethyl ester, (2E)-" masks the identity of the methyl groups
(but not the number and positions)
•	"2-pentenoic acid, methyl substituted, ethyl ester, (2E)-" masks the locants and
multiplicative prefix of the methyl groups (but not the identity)
•	"2-pentenoic acid, 2,4-dimethyl-, alkyl ester, (2E)-" masks the identity of the ethyl ester
group (but not the stereochemistry)
•	"2-pentenoic acid, 2,4-dimethyl-, ethyl ester, single isomer" masks the stereochemistry
Example 2
Specific chemical name: "Benzenesulfonic acid, 3-amino-5-chloro-4-ethyl-"
Appropriate generic names:
•	"carbomonocycle hetero-acid, 3-amino-5-chloro-4-ethyl-" or "arylhetero-acid, 3-amino-5-
chloro-4-ethyl- " masks the identity of the benzenesulfonic acid parent group
•	"benzenesulfonic acid, 3-nitrogen-substituted-5-chloro-4-ethyl- " or "Benzenesulfonic acid,
3-heteroatom-substituted-5-chloro-4-ethyl- " masks the identity of the amino group (but not
the number and position)
•	"benzenesulfonic acid, 3-amino-5-halo-4-ethyl- " masks the identity of the chloro group (but
not the number and position)
•	"benzenesulfonic acid, 3-amino-5-chloro-4-alkyl- " masks the identity of the ethyl group (but
not the number and position)

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Example 3
Specific chemical name: " 1,l'-Biphenyl, 2,2',3,3',5,5',6,6'-octafluoro-"
Appropriate generic names:
•	"carbopolycycle, 2,2',3,3' 5,56,6'-octafluoro- " masks the identity of the 1,1 -biphenyl parent
group
•	"1,1 '-biphenyl, 2,2', 3,3', 5,5' 6,6'-octahalo- " masks the identity of the fluoro groups (but not
the number and positions)
•	"1,1 '-biphenyl, polyfluoro- " masks the locants and multiplicative prefix of the fluoro groups
(but not the identity)
Example 4
Specific chemical name: " IH-Imidazole, 4,5-dihydro-2-(phenylmethyl)~, hydrochloride (1:1)"
Appropriate generic names:
•	"heteromonocycle, 2-(phenylmethyl)~, hydrochloride (1:1) " masks the identity of the 4,5-
dihydro-lH-Imidazole parent group
•	"lH-imidazole, 4,5-dihydro-2-carbomonocyclic-, hydrochloride (1:1) " masks the identity of
the phenylmethyl group (but not the position)
•	" lH-imidazole, 4,5-dihydro-2-(phenylmethyl)~, 1:1 salt" masks the identity of the
hydrochloride salt
Class 2 Organic Chemical Substances
A class 2 organic chemical substance cannot be represented by a definite chemical structure
diagram and may or may not be able to be represented by a definite molecular formula.
Class 2 organic chemical substances include less complex substances that have variable chemical
structure diagrams in which the variability is known. Some have definite molecular formulas
such as "Benzene, dimethyl(or xylene) in which the location of the attached methyl chemical
group is variable resulting in three possible structural isomers: 1,2-dimethylbenzene, 1,3-
dimethylbenzene, and 1,4-dimethylbenzene. The molecular formula for all three isomers is
C6H4(CH3)2 or CsHio. Other class 2 organic chemical substances that have variable chemical
structure diagrams in which the variability is known do not have definite molecular formulas. An
example is "Alkanes, C2-3" which is comprised of ethane and propane.
Class 2 organic chemical substances also include more complex substances, such as those of
Unknown or Variable Composition, Complex Reaction Products and Biological Materials
(UVCBs). These substances do not have definite molecular formulas or definite chemical
structure diagrams. UVCBs often have variable structural elements that are not defined or have
unknow structural elements. An example is "Extracts (petroleum), light naphthenic distillate
solvent' which has the definition "A complex combination of hydrocarbons obtained as the
extract from a solvent extraction process. It consists predominantly of aromatic hydrocarbons

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having carbon numbers predominantly in the range of C15 through C30. This stream is likely to
contain 5 wt. % or more of 4- to 6-membered condensed ring aromatic hydrocarbons. "
A generic name is created for a class 2 organic chemical substance by masking the confidential
elements of its specific chemical name which, for a class 2 organic substance, will often include
variable or unknown structural elements. In instances where a variable structural element is
known, the guidance presented above for creating generic names for class 1 substances may be
applied in order to mask the variable structural element. For example, if a class 2 organic
substance has a variable parent structure or a variable chemical group attached and the variability
is known, such structural elements can be masked in a similar way as described for class 1
substances. To further illustrate, the substance "Pyridine, Cl-3-alkyl derivshas the variable
chemical group "Cl-3-alkyl derivs " that could be masked by substituting with "alkyl
derivatives," just as "methyl," "ethyl," and "propyF can be masked by substituting with "a/Ay/."
If a class 2 organic chemical substance with more complex structural variability or with an
unknown structural element can be represented by a partial or representative (e.g., predominant
component) chemical structure diagram, the specific chemical name for the substance is
generally a more common name that encompasses the variable or unknown element of the
structure. In such instances, the variable or unknown structural element in the common name
can be substituted with a more generic descriptor of the partial or representative structure by
applying the guidance for class 1 substances. For example, the substance "Resin acids and rosin
acids" is a common name representing a mixture of carboxylic acids generally comprised of the
same fused ring parent structure that could be masked by substituting with "polycyclic acids "
Similarly, "Lignin" is a common name representing a plant-based polymer generally comprised
of crosslinked phenols that could be masked by substituting with "polyphenols" or
"polyarylalcohols."
In other instances, the specific chemical name for a class 2 organic chemical substance with
more complex structural variability or with an unknown structural element may include
manufacturing, chemical processing, or related information as a means to identify the substance.
Such information can include natural source material, synthetic precursors (e.g., monomers) or
other reactants, or manufacturing or chemical processing methods. To mask precursors or other
reactants in the specific chemical name, the guidance for creating generic names for class 1
substances may be directly applied. For example, the " 1-chloronaphthalene" reactant in
"Formaldehyde, reaction products with 1-chloronaphthalene" could be masked by substituting
with "halocarbopoly cycle" To mask source information, a more generic descriptor of the source
should be substituted. For example, "Oils, catnip" could be masked by substituting with "plant-
based oils" and "Fatty acids, tallow, sodium salts" could be masked by substituting with
"animal-basedfatty acid salts." Finally, to mask manufacturing or chemical processing
methods, either a more generic structure-based descriptor or a more generic descriptor of the
method could be substituted. For example, "methoxylated' or "ethoxylated' could be masked by
substituting with "alkoxylated," "oxidized' or "hydrogenated' could be substituted with
"modified" and ''fumerated' or "maleated' could be substituted with "functionalized"

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Examples
The generic names provided for the examples below illustrate only some of the possible ways
that structural elements in class 2 organic chemical substances can be masked.
Example 1
Specific chemical name: "Nonanedioic acid, polymer with 1,2-ethanediamine, 1,6-
hexanediamine and (9Z,12Z)-9,12-octadecadienoic acid dimer"
Appropriate generic names:
•	"alkanedioic acid, polymer with 1,2-ethanediamine, 1,6-hexanediamine and (9Z,12Z)-9,12-
octadecadienoic acid dimer" or "dicarboxylic acid, polymer with 1,2-ethanediamine, 1,6-
hexanediamine and (9Z,12Z)-9,12-octadecadienoic acid dimer" masks the identity of the
nonanedioic acid starting material
•	"nonanedioic acid, polymer with mixed alkyldiamines and (9Z, 12Z)-9,12-octadecadienoic
acid dimer" masks the identity of the two diamine monomers
•	"nonanedioic acid, polymer with 1,2-ethanediamine, 1,6-hexanediamine and a (Z,Z)~
alkanedienoic acid dimer" masks the identity of the 9,12-octadecadienoic acid dimer starting
material (but not the stereochemistry)
•	"nonanedioic acid, polymer with 1,2-ethanediamine, 1,6-hexanediamine and a single isomer
of octadecadienoic acid dimer " masks the stereochemistry
Example 2
Specific chemical name: "Hydrogenated palm-oil fatty acids, esters with D-mannitol,
ethoxylated'
Appropriate generic names:
•	"hydrogenated plant oil fatty acids, esters with D-mannitol, ethoxylated' masks the natural
source of the fatty acids parent group
•	"modified palm-oil fatty acids, esters with D-mannitol, ethoxylated' masks that the fatty acid
parent group is hydrogenated
•	"hydrogenated palm-oil fatty acids, esters with polyhydroxyalkane, ethoxylated' masks the
identity of the D-mannitol reactant
•	"hydrogenated palm-oil fatty acids, esters, with D-mannitol, alkoxylated' masks that the
chemical substance is ethoxylated
Example 3
Specific chemical name: " Waste plastics, pyrolyzed, C5-12 fraction"
Appropriate generic names:
•	"waste polymers, pyrolyzed, C5-12 fraction" or "waste solids, pyrolyzed, C5-12 fraction" or
"wastes, pyrolyzed, C5-12 fraction" masks the identity of the waste source of the starting
material

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•	"waste plastics, pyrolyzed, fractionated' masks the specific carbon range of the fraction
Similarly, specific chemical name: "Tires, wastes, pyrolyzed, C6-39 oil fraction"
Appropriate generic names:
•	"waste polymers, pyrolyzed, C6-39 oil fraction" or "waste solids, pyrolyzed, C6-39 oil
fraction" or "wastes, pyrolyzed, C6-39 oil fraction" masks the identity of the waste source of
the starting material
•	"tires, wastes, pyrolyzed, fractionated' masks the specific carbon range of the fraction
Inorganic Chemical Substances
Inorganic chemical substances (which, for the purposes of this guidance, includes organometallic
substances) may or may not include metals. In the case of metal-containing inorganic
compounds or complexes, the identity of the metal atom can be masked by substituting with
more generic terms such as "meto/," "transition metaF, "alkali metal," or "alkaline earth metal"
Similarly, the identity of a metalloid atom can be masked by substituting with the more generic
term "metalloidNon-metal elements can be masked by applying the guidance for class 1
substances. For example, the metal in "Potassium bromide" can be masked by substituting
"alkali metal" ("alkali metal bromide") and the bromide group can be masked by substituting
"halide" ("potassium halide").
For mixed metal-containing inorganic compounds or complexes, the identity of one metal atom
can be masked by substituting with more the generic term "metal," or the identities of two or
more metal atoms can be masked by substituting with more the generic term "mixed metal." For
example, one metal in "Cadmium zinc sulfide" can be masked by substituting "transition metaF
("transition metal zinc sulfide" or "cadmium transition metal sulfide") or both metals can be
masked by substituting "mixed metal" or "mixed transition metaF ("mixed transition metal
sulfide").
For inorganic substances with more complex structural elements (such as inorganic UVCB
substances), such elements can be masked by applying the guidance for class 2 substances. For
example, manufacturing, chemical processing, or related information used as a means to identify
more complex structural variability or unknown structural elements of inorganic substances can
be masked by substituting either a more generic structure-based descriptor or a more generic
descriptor of the method. To mask source information, a more generic descriptor of the source
should be substituted. To further illustrate, "acid-leached' or "sintered' could be substituted
with "modified' or "treated," "copper ore" could be substituted with "ore," and "copper
refinery" could be substituted with "metal refinery."
Examples
The generic names provided for the examples below illustrate only some of the possible ways
that structural elements in inorganic chemical substances can be masked.

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Example 1
Specific chemical name: "Silicic acid, aluminum calcium salf
Appropriate generic names:
•	"metalloid acid, aluminum calcium salf or "inorganic acid, aluminum calcium salf
masks the identity of the silicic acid parent group
•	"silicic acid, mixed metal salf masks the identity of the aluminum calcium salt
Example 2
Specific chemical name: "Copper(2+), tetraammine-, carbonate hydroxide (2:1:2)"
Appropriate generic names:
•	"transition metal, tetraammine-, carbonate hydroxide " masks the identity of the copper
metal
•	"Copper(2+), nitrogen-substituted, carbonate hydroxide" masks the identity of the tetramine
group
•	"Copper(2+), tetraammine-, salt complex" masks the identity of the carbonate hydroxide salt
Example 3
Specific chemical name: "Zinc ores, cones., preleached'
Appropriate generic names:
•	"ores, cones., preleached' masks the identity of the zinc ores
•	"zinc ores, cones., modified' masks that the zinc ores are preleached
Example 4
Specific chemical name: "Copper, [2,9,16,23-tetrachloro-29H,3lH-phthalocyaninato(2-)~
.kappa.N29,.kappa.N30,.kappa.N31,.kappa.N32]-, (SP-4-1)-"
Appropriate generic names:
•	"transition metal, [2,9,16,23-tetrachloro-29H,3lH-phthalocyaninato(2-)~
.kappa.N29,.kappa.N30,.kappa.N31 ,.kappa.N32]-, (SP-4-1)-" masks the identity of the
copper metal
•	"copper, [2,9,16,23-tetrahalo-29H,3lH-phthalocyaninato(2-)-
.kappa.N29,.kappa.N30,.kappa.N31 ,.kappa.N32]-, (SP-4-1)-" masks identity of the chloro
groups (but not the number and positions)
•	"copper, [polychloro-29H,31H-phthalocyaninato(2-)~
.kappa.N29,.kappa.N30,.kappa.N31 ,.kappa.N32]-, (SP-4-1)-" masks the locants and
multiplicative prefix of the chloro groups (but not the identity)
•	"copper, [2,9,16,23-tetrachloro-heteropolycyclic]-" masks identity of the phthalocyaninato
group

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