There is no set requirement, because who the hell knows what some idiot may hang on their key-chain! All the while, it has to be loose enough that a 90+year old weakling can turn it with ease and start the car.
Exactly how do you figure that “standard?”
The person who wants to hang pictures, keyfobs, mementos, store passes, etc... is going to need a switch that will handle 25 pounds of resistance.
The 90+ year old weakling needs it to have no more than a 2-5 pound resistance.
Easy to do if the ignition switch had worked properly. My previous GM cars (I own none now, and never will own another, commie bastards that they are...) all had to have a deliberate press motion to turn off the ignition. It was much less than my current Honda Civic Si and Nissan Titan 4x4, but none the less, it was required (the Japanese value tactile feel).
This switch malfunctioned when enough off angle force was supplied to override the push-to-unlock feature, then when the inevitable accident occurred, the pendulum effect of a decelerating car would allow the weight of the keychain to act like a pendulum, turning off the ignition just at the time you need the safety equipment most!
There is a upper limit to key chain weight, but it should not be determined as the weight of a theoretically heavy keychain. As a matter of fact, I’d set that limit somewhere above the weight of a 8 year old child, since that is one of the situations the feature is meant to curtail occurring, since taking out of on also locks the steering wheel.
GM was negligent and they need to pay up.