From the Document: "According to the Global Public Policy Institute, there have been more than 330 chemical weapons attacks since 2012. Such attacks are prohibited under the Chemical Weapons Convention. A set of methods called forensic chemical attribution has the potential to trace the chemical agent used in such attacks to a source. For example, investigators could use these methods to identify the geographic sources of raw materials used to make the agent, or to identify the manufacturing process. Such information can aid leaders in deciding on whether or how to respond to a chemical weapons attack. Forensic chemical attribution is a three-step process, though the third step is being developed. First, a sample is taken from a victim or the site of an attack. Second, the sample's chemical components are analyzed and identified either at a mobile lab or at one of 18 authorized biomedical labs worldwide. [...] In the third step--still under development--investigators use the data from the forensic chemical identification and analysis methods from step two to develop a 'chemical fingerprint.' The fingerprint can be matched to a database of information on existing methods or known source to identify chemical agents. However, a comprehensive database containing complete, reliable data for known agents does not exist."
Government Accountability Office: https://www.gao.gov/