Strengthening Global Customs to Prevent Chemical Diversion

By Christina McAllister – Research by Braden Holt

From soaps, to fertilizers, to pigments, flame retardants, and more, chemicals underpin global agriculture, medicine, manufacturing, and everyday life. At the same time, some of the same chemicals so foundational to modern life can prove malign – damaging the environment if not managed responsibly, or risking diversion for illicit purposes – illegal manufacturing and trafficking of drugs or explosives, for example, even chemical weapons development. The availability of weapons or drugs precursor chemicals, especially the “dual-use” chemicals that have legitimate and even vital roles in the global economy, means we need constant vigilance against the illegitimate acquisition and use of such substances. In addition, growth in international chemical trade, valued at $2.39 trillion in 2022, and projected to expand by 2.6 percent a year globally between 2024 and 2031, makes the effort to control the chemical precursors of explosives, narcotics, and chemical weapons one of truly global scope and importance.

A number of international conventions, arrangements, and other legal and political regimes – as well as national legislation – contribute to the framework for the governance of international trade in chemicals for these different purposes. The Basel, Rotterdam, and Stockholm Conventions, for example, seek to control the trade in hazardous chemicals and wastes as characterized and listed in Annexes to each Convention, among other objectives. The Chemical Weapons Convention (CWC) controls transfers (as well as production and use) of chemicals covered by its three Schedules. The UN Convention Against the Illicit Traffic in Narcotic Drugs and Psychotropic Substance identifies narcotic precursors and obliges states parties to establish and maintain a system to monitor international trade in those substances.

And UN Security Council Resolution 1540 requires all UN member states, among other obligations, to establish export and trans-shipment controls to prevent access by proliferators to chemical and other weapons of mass destruction and related materials. Several voluntary multilateral arrangements complement these legally binding instruments and also feature lists of chemicals and other items of control. The Missile Technology Control Regime (MTCR), for example, a non-binding political understanding among 35 likeminded countries to adhere to a common export policy (the Guidelines) applied to a common list of items that includes propellant chemicals for missiles (fuels, oxidizers, and additives like binders, plasticizers, stabilizers, and burn-rate modifiers). The voluntary Wassenaar Arrangement and Australia Group also feature lists of chemicals and equipment that members undertake to control for export.

While not every country has fully enacted trade and licensing controls, countries that have done so rely on relevant national authorities (in most cases Customs supported by licensing authorities) to enforce compliance. Given the volume and pace of global trade, these officers are under significant pressure to determine – often in a matter of minutes – whether a chemical listed in trade documentation is potentially subject to import or export licensing requirements by checking the chemical identifying information provided against a national or international control list. Such lists typically feature a single name for each substance and/or a unique number assigned by the American Chemical Society’s Chemical Abstracts Service (CAS), known as the CAS Registry Number® (CAS RN®).

But what if trade documentation uses one of dozens or even hundreds of synonyms for the chemical? Or doesn’t include the CAS RN®? In fact, this is often the case. In a sample Bill of Lading (BoL) dataset consisting of 6,000 items, for example, only 10 percent of entries included the CAS RN® for the substance. And what if the chemical is a variant of the listed controlled chemical? Or a newly created member of a family of chemicals listed on one of the CWC’s Schedules? Even chemical experts, much less front-line officers without chemistry expertise, may be hard pressed to determine rapidly whether a particular chemical listed for export is part of a controlled family. And how is a non-specialist customs officer to distinguish the relevant identifiers from the wide variety of information our research indicates is provided to customs? A random sample of 100 entries, taken from one country’s customs declarations associated with chemical shipments, included information ranging from general descriptions (i.e. “reagents for lab research use”) to brand names to systematic chemical names (e.g. 1,3-Distearoyl-2-chloropropanediol-d5), in many cases mixed with a substantial amount of other information about the form, weight, and number of units of the substance. Similarly, the BoL dataset included information such as the number of bottles or tablets of a substance, the purpose of a shipment, and molarity (a measure of concentration) in the “Packages and description of goods” field.

Given the multitude and complexity of chemical control regimes that customs authorities enforce, states should consider imposing a legal obligation requiring inclusion of at least one of the two most precise chemical identifiers in the import or export customs declaration for chemicals—a systematic chemical name based on chemical structure or a CAS RN®—to help compliance officers determine whether the chemical is controlled. Ideally, a systematic name, such as the IUPAC name, should be the primary requirement, with the CAS RN® as the required backup. As part of this requirement, a systematic name and CAS RN® should be included for chemicals that meet or exceed the national concentration threshold for control as part of a formulation (mixture).

Many countries already require this information: several countries of the European Union (EU), which use the Single Administrative Document as a common customs declaration, require customs declarants to include the CAS RN® in the declaration’s box 44 (Additional information/Documents produced/Certificates and authorizations). India issued regulations in 2023 requiring CAS RN® and IUPAC names for all “bulk and basic chemicals” imported to the country and for the “main/active ingredient” of a formulation or mixture. For the sake of strengthening international regimes against toxic pollution, illicit trafficking of narcotics and explosives, and preventing the proliferation of chemical weapons, it is a change other countries should find worth making as well.