January 19, 2023
Listed Chemicals and Federal Regulation of Controlled
Substance Precursors
The Controlled Substances Act (CSA) regulates
The CSA also imposes specific controls on scheduled listed
pharmaceutical and non-pharmaceutical drugs and other
chemical products, which are products lawfully sold as
substances that pose a risk of abuse and dependence. The
nonprescription drugs that contain any of the List I
CSA authorizes the manufacture, distribution, and
chemicals ephedrine, pseudoephedrine, or
possession of controlled substances for legitimate medical
phenylpropanolamine. 21 U.S.C. § 802(45). As one
and scientific purposes, subject to government registration
example, pseudoephedrine is sometimes sold without a
and regulatory controls designed to prevent misuse and
prescription as a nasal decongestant.
diversion. It also imposes criminal penalties for
unauthorized activities involving controlled substances.
While many listed chemicals are controlled substance
precursors, the CSA separately provides for control of
In addition to controlled substances, the CSA regulates
immediate precursors. To control a substance as an
listed chemicals—certain substances that can be used to
immediate precursor, DEA must find by regulation that the
illicitly manufacture controlled substances. Listed
substance is the “principal compound used” in producing a
chemicals include some controlled substance precursors as
controlled substance or made “primarily for use” in such
well as certain reagents and solvents used in the
production, is “an immediate chemical intermediary” used
manufacturing process. Like controlled substances, listed
to manufacture the controlled substance (essentially a
chemicals are subject to CSA regulatory requirements, and
chemical stepping stone to the controlled substance), and
unlawful activities involving listed chemicals may give rise
must be controlled to prevent or limit such manufacture. 21
to civil or criminal liability.
U.S.C. § 802(23). The CSA authorizes DEA to include an
immediate precursor in the same schedule as the controlled
What Are Listed Chemicals?
substance it is used to produce or in any less restrictive
The CSA divides listed chemicals into two categories,
schedule. Id. § 811(e). Scheduled immediate precursors are
known as List I and List II. List I chemicals are defined as
regulated as controlled substances, not as listed chemicals.
chemicals designated by the Drug Enforcement
For more information on regulation of controlled
Administration (DEA) that, in addition to legitimate uses,
substances under the CSA, see CRS Report R45948, The
are used in manufacturing a controlled substance in
Controlled Substances Act (CSA): A Legal Overview for the
violation of the CSA and are important to the manufacture
117th Congress, by Joanna R. Lampe.
of a controlled substance. 21 U.S.C. § 802(34). List II
chemicals are DEA-designated chemicals not included in
Regulation of Listed Chemicals
List I that, in addition to legitimate uses, are used in
Some of the CSA’s regulatory requirements for listed
manufacturing a controlled substance in violation of the
chemicals differ from the requirements for controlled
CSA (without the additional requirement of being important
substances, and some depend on whether a chemical is in
to the manufacture). Id. § 802(35).
List I or List II.
Many List I chemicals are precursor chemicals that are key
Under 21 U.S.C. § 822(a), “Every person who
ingredients used to produce controlled substances. For
manufactures or distributes any controlled substance or list
instance, ephedrine is a List I chemical that is a precursor to
I chemical,” or who proposes to do so, must register with
the Schedule II controlled substance methamphetamine.
DEA. 21 U.S.C. § 823(i) sets out specific criteria for
Other List I chemicals are precursors to controlled
registering applicants to distribute List I chemicals. DEA
substances such as fentanyl, lysergic acid diethylamide
may deny, revoke, or suspend a registration on various
(LSD), and 3,4-Methylenedioxymethamphetamine (known
grounds, including if a registrant has materially falsified
as MDMA, molly, or ecstasy). List I also includes
any application filed under the CSA; committed a felony
substances such as phosphorous and iodine, which are used
involving a controlled substance or List I chemical; had a
as reagents during controlled substance manufacturing.
state license or registration suspended, revoked, or denied;
While List II includes some precursor chemicals, most List
or committed acts that would render registration
II chemicals are either reagents or solvents used to produce
“inconsistent with the public interest.” Id. § 824(a). The
controlled substances. Examples include acetone,
CSA does not require DEA registration to manufacture or
hydrochloric acid, and sulfuric acid.
distribute List II chemicals.
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Listed Chemicals and Federal Regulation of Controlled Substance Precursors
Another section of the CSA, 21 U.S.C. § 830, imposes
amounts of a listed chemical in small units “with the intent
specific requirements on transactions involving listed
of causing the evasion of the [CSA’s] recordkeeping or
chemicals (as well as transactions involving machines used
reporting requirements.”
to form substances into tablets or capsules). Among other
things:
Under 21 U.S.C. § 841(f), possession of a listed chemical in
knowing violation of the applicable recordkeeping or
Regulated parties must maintain records of covered
reporting requirements is punishable by a fine and up to
transactions, 21 U.S.C. § 830(a);
year in prison. Knowing distribution of a listed chemical in
violation of any other provision of the CSA is punishable
Regulated parties must submit reports to DEA about
by a fine and imprisonment for up to five years.
suspicious transactions, including transitions “involving
an extraordinary quantity of a listed chemical” or “an
21 U.S.C. § 843(a)(4)(B) makes it an offense to present
uncommon method of payment or delivery,” id.
false or fraudulent identification when receiving or
§ 830(b)(1)(A);
purchasing a listed chemical. 21 U.S.C. § 843(a)(9) makes
it unlawful to distribute, import, or export a List I chemical
without the required registration. A first offense is
Sales of any scheduled listed chemical product to a retail
punishable by a fine and up to four years in prison. A
purchaser may not exceed set amounts in a single day,
person convicted of a felony violation of Section 843
id. § 830(d);
involving a listed chemical may also be enjoined from
engaging in any transaction involving a listed chemical for
Scheduled listed chemical products sold at retail must be
placed “b
not more than 10 years. Id. § 843(e).
ehind-the-counter,” meaning that “the seller
places the product such that customers do not have
Among other things, 21 U.S.C. § 844(a) makes it unlawful
direct access to the product before the sale is made” (the
for a person knowingly or intentionally to possess any List I
product need not actually be placed behind a counter
chemical obtained pursuant to a registration that is no
and may be “stored in a locked cabinet that is located in
longer effective. It also prohibits knowing or intentional
an area ... to which customers do have direct access”),
purchases of scheduled listed chemical products in excess
id. § 830(e)(1)(A)(i); and
of certain amounts. A first offense is subject to
imprisonment for not more than one year and a minimum
Most sales of scheduled listed chemical products must
fine of $1,000.
be recorded in a logbook—“a written or electronic list of
such sales that identifies the products by name, the
Considerations for Congress
quantity sold, the names and addresses of purchasers,
Controlled substance precursors have been regulated under
and the dates and times of the sales,” id.
the CSA since Congress enacted the statute in 1970, and
§ 830(e)(1)(A)(ii).
Congress has periodically modified the applicable
regulatory regime. For instance, Congress passed legislation
DEA has issued regulations to implement the CSA’s
imposing controls on scheduled listed chemical products in
requirements related to listed chemicals. See, e.g., 21 C.F.R.
2006, seeking to target List I chemicals that can be used to
Parts 1309, 1310, 1313 & 1314.
manufacture methamphetamine illegally. More recently,
listed chemical regulation has attracted attention in the
21 U.S.C. § 842(a)(12), (13), and (15) prohibit sales of
context of the opioid epidemic, as policymakers seek to
scheduled listed chemical products in violation of
control chemicals used to manufacture illicit fentanyl and
applicable regulatory requirements. 21 U.S.C. § 842(a)(14)
other synthetic opioids.
prohibits unauthorized disclosure of information in
logbooks of listed chemical transactions and refusal to
Congress has substantial power to change the laws that
provide a logbook to federal, state, or local law
apply to listed chemicals and could do so in several ways.
enforcement authorities. Violations may result in a civil
First, Congress could pass legislation to add or remove
fine of up to $25,000. DEA may also prohibit a regulated
specific substances from control as listed chemicals, and it
entity that violates 21 U.S.C. § 842(a)(12) or (13) from
has done so in the past. Second, Congress could change the
selling any scheduled listed chemical product. While most
substantive CSA provisions that apply to listed chemicals.
violations of Section 842 are not crimes, knowing
Third, Congress could enact legislation outside the scope of
violations may be prosecuted as criminal offenses, subject
the CSA to impose legal consequences for activities
to a fine and up to a year in prison. Id. § 842(c)(2)(A).
involving listed chemicals. As one example, the Fentanyl
Listed Chemical Offenses
Sanctions Act, 21 U.S.C. §§ 2301–2335, enacted as part of
the National Defense Authorization Act for FY2020, directs
In addition to the foregoing, some other unauthorized
the President to impose sanctions on foreign persons
activities involving listed chemicals are crimes that can lead
involved in trafficking “listed chemicals that are synthetic
to fines and imprisonment. Among other things, 21 U.S.C.
opioids” or “active pharmaceutical ingredients or chemicals
§ 841(c) prohibits possessing a listed chemical “with intent
that are used in the production of controlled substances that
to manufacture a controlled substance except as authorized”
are synthetic opioids.”
under the CSA. It also prohibits distributing reportable
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Listed Chemicals and Federal Regulation of Controlled Substance Precursors
IF12311
Joanna R. Lampe, Legislative Attorney
Disclaimer
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https://crsreports.congress.gov | IF12311 · VERSION 1 · NEW