[wolfcreek]

I wouldn’t want ‘that’ beer.

Regardless, why would there be that much pressure in ANY keg?

[Calvin Locke]

Plastic has been used for a while, especially for export. I vaguely recall buying a small plastic "keg" - < gallon - of Japanese beer 30 years ago.

I'm surprised that there isn't the equivalent of a burst disk as a safety precaution to relieve excess pressure