Liquids on a plane redux

I got home at 5:30 this morning from my trip to the LA region. The trip reiterated how superior the JetBlue experience can be if you are going to the right place. My colleague and I flew directly from Boston to Long Beach, had at the most an hour drive between Long Beach and our prospect in Pasadena (which mostly means we got lucky), and had two great cross country flights.

I also got to test the new revised rules about liquids on a plane (note: be careful on the TSA site! The home page crashes Safari!). My test apparatus was a quart sized ziplock bag containing a travel size tube of toothpaste and a travel size bottle of contact solution. The catch? My contact solution came in a 4 ounce bottle, and the rules state that anything 3 and under is safe.

First, from Logan on Tuesday (the first day of the new rules): before the ID check I was met by a screener, who asked if I was carrying liquids; I was and showed him the bag. He looked, made a note of the 4-ounce bottle on a paper form, and asked me to keep the plastic bag out of my baggage so that the security screeners could see it. I ran the bag through, and one of the screeners grabbed my bag and my form. He asked a supervisor about the four ounce bottle, got the OK, and handed it back.

On the way back, it was much the same process, except they made me put the bag in a tray instead of on the top of my duffle. Both times a supervisor had to step out and verify that my contact solution was OK.

Question: What is the difference between three ounces and 4? What is the impact of enforcing a one-ounce overage on our security teams? Why doesn’t contact lens solution come in a 3-ounce travel bottle? (It will now, I guess.)