ALL cars with them fitted do a self test and if anything is defective in the system there will be a warning light to tell you there is a problem.
Watch the dash on start up. The air bag test light should illuminate for a second or so then extinguish. That's the test for function.
Look-up the list. DON'T TRY TO OPEN IT, as it may explode in your face... Also, call the local car dealer of your car & ask him.
if the CEL is not on, then the air bags should be ok. any fault in that system should trigger that light.
Slam that sucker into a brick wall.
You can look it up by your VIN.
http://www.safercar.gov/Vehicle+Shoppers...