Thought that was entitled 'Rotting Frog' for a moment there. You might want to alter the name so that it isn't confused with SCP-352, which is in fact called 'Frog Rot'.
Also, the distance from the containment perimeter and the fog is really quite small in the image, which I found rather off-putting when reading the article. It looks like containment would be lost in the event of a slight breeze.
It's well-written, although at times I felt a few things would be worth moving around. For example, the containment procedures mention needing to destroy the fog but don't explain how that is supposed to be done. I had to trawl through the description to find it out, and it made me feel like the containment procedures are incomplete.