I will use one of the last tests when a facility has hit home runs in managing its Hazardous Communications program. They are great with their container labeling, pipe labeling, training, etc. They even could provide an SDS for all their significant chemicals; however, only a tiny percentage of these facilities can do this…
Provide an SDS for their gas detector calibration gas(s)
If you have SDS for your cal gases, you are rocking it!
And yes, these pressurized cylinders containing flammable, asphyxiants, toxic gases fall under HAZCOM.
Here is an example: http://www.msanet.com/prism/MSDSpages/msdscal5.htm