On 24 April 2017, the US Treasury Department’s Office of Foreign Assets Control (OFAC) designated 271 persons working in the Syrian Scientific Studies and Research Center to be added to the agency’s Specially Designated Nationals (SDN) and Blocked Persons List. In its press release announcing the action, OFAC attributed the Syrian Scientific Studies and Research Center with developing and producing the country’s non-conventional weapons and delivery systems. The action is meant to respond to the Assad regime’s 4 April 2017 sarin attack in Khan Sheikhoun, Syria. It is one of the agency’s largest such single actions taken to date, more than doubling the number of Syrian’s on the OFAC SDN List. As a result, any property or interests in property of the designated persons held or under the control of US persons or in the US is blocked, and US persons are generally prohibited from dealing with the designated persons.