For the first time, food irradiation techniques have been approved by the FDA for keeping salad clean and fresh.

Food irradiation is a controversy. Treatment of food with ionised radiation (which doesn't contaminate products with radioactivity, if you're wondering) stimulates the formation of molecules that blast away bacteria, ranging from salmonella to E. coli.

Irradiating is a good way to kill off micro-organisms...and there's the rub, because in doing so it's strong enough to change the chemical composition of foods and strip away nutrients. The European Union currently limits the authorized trade in irradiated food to dried spices and seasonings. One potential problem is that irradiation might encourage bad habits - sloppy food hygiene, in particular. And irradiation is used to extend shelf-life in the same way preservatives do, at the expense of nutritional content.

So what does this mean for shoppers in the U.S.? Just that they should be aware that in opening irradiation up for widespread use, the FDA is somewhat out on a limb - and consumer rights groups like Food & Water Watch are far from impressed.

Image: catsper