Review of Restricted Experiment Requests, Division of Select Agents and Toxins, Centers for Disease Control and Prevention, 2006-2013.

The Centers for Disease Control and Prevention (CDC) Division of Select Agents and Toxins (DSAT) regulates laboratories that possess, use, or transfer select agents and toxins in the United States. DSAT also mitigates biosafety risks through the review of "restricted experiments," which under the select agent regulations are experiments that pose heightened biosafety risks. From January 2006 through December 2013, DSAT received 618 requests from 109 entities to perform potentially restricted experiments. Of these requests, 85% were determined not to meet the regulatory definition of a restricted experiment, while 15% of the requests met the definition of a restricted experiment. Of the 91 restricted experiments proposed, DSAT approved 31 (34%) requests because the biosafety conditions proposed were commensurate with the experiments' biosafety risk. All 31 approved restricted experiments were for work with select toxins. DSAT did not approve 60 restricted experiment requests due to potentially serious biosafety risks to public health and safety. All 60 denied restricted experiments proposed inserting drug resistance traits into select agents that could compromise the control of disease. The select agents and toxins associated most frequently with requests that met the regulatory definition of a restricted experiment are Shiga toxin (n = 16), Burkholderia mallei (n = 15), Botulinum neurotoxin (n = 14), and Brucella abortus (n = 14). In general, all restricted experiment decisions are determined on a case-by-case basis. This article describes the trends and characteristics of the data associated with restricted experiment requests among select agents that have an impact on public health and safety (HHS only agents) or both public health and safety and animal health or products (overlap agents). The information presented here, coupled with the information published in the restricted experiment guidance document ( www.selectagents.gov ), is intended to promote awareness among the research community of the type of experiments that meet the regulatory definition of a restricted experiment as well as to provide a greater understanding of the restricted experiment review process.