The ingredients are listed right on the can: Celery Salt (salt, celery seed), Spices (including red pepper and black pepper) and paprika. The formula of how much of what, and what are the unnamed spices, resides with the manufacturer, McCormick of Hunt Valley MD. (In my workin'-at-the-courthouse days, if the wind was blowing right, one could catch an early-morning whiff of what was going on up there; it was right down the road a piece from the factory. Oregano, Italian Seasoning, or Old Bay in the air was a treat for the schnozz.)
I have a friend who moved to Pound, Virginia for a new job, and the first thing she did after getting home from her first grocery shopping foray was to send home for Utz Potato Chips, Tastykakes and Old Bay...three things Baltimore cannot live without. We even take it on the road. I do not leave home with my shaker bottle in the car. Just like Selena's husband in the movie, who carried his hot sauce in a little holster, I know that when I cross the Maryland state line headed north, Old Bay is as unknown as the idea of remaining quiet about things one knows nothing about is to Pat Sajak, so I go packin' the pepper.
If you go to one of those friendly restaurants that hand out free highly-salted snacks like popcorn or pretzels, you do realize that they know you'll be apt to drink more as a result, right? That's sort of how Old Bay got its start. You see, there was a time that blue crabs and shrimp were so plentiful in the Chesapeake Bay that saloons gave them away to patrons with their beers...and the saltier and spicier the seafood, the drink-ier the patrons and the higher the sales on suds!
Today, with crabs so expensive as to be something for which you might have to part with a week's salary for a bushel, we sprinkle the Old Bay on any kind of seafood - even a McFish!, and on fried chicken and french fries and popcorn and baked potatoes and veggies and deviled eggs and tunafish salad and chicken salads and Bloody Marys and I don't know what-all else.
When everyone knows you just sprinkle some in your National Bohemian beer anyway. No problem!