I doubt there is anything official out there. People also can have different experiences... I see people swearing all the time that white rice stores "for decades" (without any special packaging), but I've had it turn rancid just months past the expiration date. I pack all, white rice in mylar with 02 absorbers.
Rancidity is unhealthy... can cause oxidative damage.
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I have a very sensitive smell detector for rancidity. But if you can't smell it, try putting a bit of suspect food on the tip of your tongue... rancidity causes dort of a tingle, and there's usually an off taste.
In a dire situation, avoid giving rancid foods to pregnant women or small children. And for everyone else, limit consumption as much as possible.
Summerthyme