Advanced Chemical, Biological, and Radiological (CBR) Defense Person (DC 309) Practice Test

M-9 paper is a chemical detection indicator used primarily for identifying the presence of certain chemical agents. When M-9 paper comes into contact with a chemical agent, it undergoes a color change that indicates the type of agent present. The initial color that M-9 paper turns upon exposure to a chemical agent is green. This initial reaction signifies the detection of nerve agents or certain other chemical threats.

The importance of this color change is critical for personnel to quickly identify and confirm potential threats in a CBRN environment. Recognizing and understanding this response allows responders to take appropriate protective measures and adapt their tactics accordingly.