I'm a little skeptical that there aren't side-effects, but still...

[acroyear]

Which Cut Is Older? (It's a Trick Question) - New York Times:

If some of the meat in supermarkets is looking rosier than it used to, the reason is that a growing number of markets are selling it in airtight packages treated with a touch of carbon monoxide to help the product stay red for weeks.

Comments

[eac.livejournal.com]

And as of yesterday, other treated meat bought at the same time was still red despite having been left unrefrigerated on a kitchen counter since Feb. 14.

Ugh.