Select Agent List

The Select Agent List is the roster of biological agents and toxins that the U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA) have jointly determined pose a severe threat to human, animal, or plant health, or to animal or plant products. Any entity that possesses, uses, or transfers a listed agent or toxin above the regulatory exclusion thresholds must register with the Federal Select Agent Program (FSAP) and comply with federal biosafety, security, personnel-screening, and reporting requirements, regardless of funding source. The list and its regulatory apparatus sit under three parallel, harmonized regulations: 42 CFR Part 73 (HHS select agents and toxins), 7 CFR Part 331, and 9 CFR Part 121 (USDA select agents and toxins). See CASRAI’s Dual-Use Research of Concern (DURC) entry for a related but narrower oversight category, and Institutional Biosafety Committee (IBC) for how select-agent compliance sits alongside routine biosafety review.

Who administers the program

The Federal Select Agent Program is run jointly by two agencies, each with its own lane: CDC’s Division of Regulatory Science and Compliance regulates HHS/human-pathogen select agents and toxins, and USDA’s Animal and Plant Health Inspection Service (APHIS), through its Division of Agricultural Select Agents and Toxins, regulates agents and toxins that primarily threaten livestock, poultry, or plants. A subset — “overlap select agents” — pose a threat to both humans and animals/agriculture and are jointly regulated by both agencies (42 CFR 73.4). This dual structure is why the program is often referred to as “CDC/APHIS” jointly rather than as a single regulator.

What makes an agent “select”

Agents and toxins are added to or removed from the list through formal rulemaking; HHS and USDA are required to conduct a biennial review of the list and publish any changes in the Federal Register. Listing criteria weigh factors such as the agent’s or toxin’s effect on human, animal, or plant health, its virulence and transmissibility, the availability of medical countermeasures, and the history and feasibility of its use as a bioweapon. Most listed agents and toxins also carry an exclusion, such as attenuated or non-toxin-producing strains, or a permissible toxin amount below which the regulations do not apply (42 CFR 73.3-73.4). Confirming exclusion status is a normal part of an institution’s registration and inventory process, not something to assume from an agent’s common name alone.

Tier 1: the highest-consequence subset

Within the broader list, a smaller subset is designated Tier 1 — agents and toxins the regulations identify as presenting the greatest risk of deliberate misuse, with the potential for mass casualties or a devastating effect on the economy, critical infrastructure, or public confidence, a designation established by a 2012 rulemaking. Tier 1 agents and toxins carry the program’s most stringent security, biosafety, and personnel-suitability requirements on top of the baseline select-agent rules. Widely cited examples include Bacillus anthracis, Ebola virus, Marburg virus, Variola major and Variola minor virus, and Yersinia pestis, among others enumerated in 42 CFR 73.3; because the list is revised periodically, the current, authoritative version is maintained at selectagents.gov and in the regulatory text itself.

Registration and the APHIS/CDC Form 1

An entity intending to possess, use, or transfer a select agent or toxin must submit an APHIS/CDC Form 1 (Application for Registration) to the Federal Select Agent Program and receive approval before beginning work; registration is not self-certifying. Registration requires the entity to designate a Responsible Official (and at least one alternate) who is personally accountable for the entity’s compliance, and to submit biosafety, security, and incident-response plans covering the specific agents to be possessed. Registration is entity- and agent-specific, tied to particular registered space, subject to renewal (typically every three years), and subject to unannounced inspection.

Personnel security and suitability

Before any individual, including students, postdocs, and visiting researchers, not only principal investigators, may access a select agent or toxin, the entity must submit that person’s identifying information to HHS/CDC or USDA/APHIS, which forwards it to the FBI’s Criminal Justice Information Services (CJIS) Division for a Security Risk Assessment (SRA). The SRA checks the individual against the “restricted person” criteria set out in federal law, originally established by the USA PATRIOT Act and now codified alongside the select agent statutes, and against terrorism screening records. Access cannot be granted until the SRA clears. For Tier 1 agents specifically, the entity must additionally operate a pre-access suitability assessment program that goes beyond the baseline SRA, including ongoing monitoring for the duration of an individual’s access rather than a one-time check.

How this differs from DURC and from BSL containment

The Select Agent List, DURC, and biosafety-level (BSL) containment practice are frequently confused because they all attach to the same high-consequence pathogens, but each answers a different question:

• Select Agent List: is this specific agent or toxin on the regulated roster, and does the entity and individual meet the registration and personnel-screening requirements to possess or access it at all? This is a threshold, entity-and-person-level gate.
• DURC: a narrower, experiment-level question — does a specific proposed study, involving one of a defined subset of select agents, meet a two-part test (listed agent AND one of seven defined categories of experiment of concern)? A lab can hold a fully compliant select-agent registration and never trigger DURC review, because most select-agent work does not meet the second part of that test.
• Biosafety Level (BSL): a physical and procedural question — what containment practices, engineering controls, and PPE does this specific agent and activity require, independent of whether the agent happens to be a listed select agent? Not every BSL-3 or BSL-4 agent is a select agent, and not every select agent requires BSL-3/4 containment; the two lists overlap heavily but are not identical.

An institution’s Institutional Biosafety Committee (IBC) and its Responsible Official typically coordinate select-agent compliance, DURC/institutional-review-entity review, and BSL-appropriate protocol review as related but distinct approval tracks for the same project.

Frequently asked questions

Is the Select Agent List the same thing as DURC? No. The Select Agent List is the regulated roster of specific agents and toxins itself, governing who may possess or access them at all. DURC is a narrower, US-government oversight category that applies to a subset of experiments involving certain listed agents when those experiments are reasonably anticipated to produce one of seven defined categories of concerning outcomes. See CASRAI’s DURC entry for the full two-part test.

Who has to register with the Federal Select Agent Program? Any entity, academic, government, or commercial, that possesses, uses, or transfers a listed select agent or toxin above the applicable exclusion threshold, regardless of whether the work is federally funded.

What happens if my agent is a lab-adapted or attenuated strain? Many attenuated, non-pathogenic, or non-toxin-producing strains are explicitly excluded from regulation under 42 CFR 73.3-73.4 and the parallel USDA provisions, but the exclusion must be confirmed and documented through the institution’s registration and inventory process, not assumed from the strain’s common name.

Does select-agent registration replace IBC or IRB review? No. Select-agent registration, IBC biosafety review, and (where human or animal subjects are involved) IRB/IACUC review are separate, complementary approval tracks administered by different bodies; a project involving a select agent typically needs all of the applicable ones, not just registration.