You will need to spawn in as either Class-D or as a Scientist. SCP-207 will be in several small glass cases in different locations within Light and Heavy Containment and will resemble a glass soda bottle. You will need a keycard with Containment Access Level 2 and Checkpoint Access. There are multiple instances of SCP-207 within the facility.
Once you drink SCP 207, your HP will slowly degrade as you walk and run but will boost your speed. Drinking more bottles of SCP 207 will degrade your health even as you stand still, but will allow you to run even faster. To ensure you do not die before escaping, pick up as many HP-giving items as you can carry. You could also save SCP 207 in your inventory, and drink it right before you pass the escape line.