I often purchase prepared white sushi rice at my local Whole Foods.I used to store it in the frig, but lately I have been keeping it on the counter in its original closed plastic container. I use it up in 3-6 days, usually in maki. I did once see it go visually moldy after 1+ weeks. Per normal, the sushi rice consists of cooked white rice that has been tossed w/ rice vinegar and a little sugar. With specific regard to this product, I am wondering what significant health hazards I may not be aware of. I am far from an alarmist in this but am curious. The vinegar and sugar seem to have a preservative effect on the stability of the rice when held at room temp. Thanks much.