Here's a pretty basic suggestion for improving 'use by' labelling on food.
Even food that's properly packaged and uncontaminated can still go bad well before its use by date.
For example, once a tub of tomato paste has been opened it needs to be used within a few weeks at most, even if its use by date is still more than a year away. And of course, it needs to be stored properly, in the fridge.
'use by' labelling unfortunately suggests that the food is ok to consume as long as that date hasn't passed, regardless of any other details. (the same applies for 'best before' dates).
Here's my suggestion for how the labels could look:
7 days after opening
and before 31 Mar 2012
Refrigerate after opening.
Packaging does often show 'time after opening' information and storage info, but they're usually in some fine-print separated from the (much more prominent) use by date. I think all this information should be shown right next to each other, as in the labelling suggested above.
With the way it currently is, you can easily just see the use by date by itself and draw the conclusion that if today's date is before then the food is ok.
You might think it'd be obvious how food needs to be stored, but people often put condiments that according to the labelling should be refrigerated in the pantry.
And even if you have stored it properly, the sight of the use by date being still months or years off can make it feel like the food must still be ok. I've seen someone who has, for this reason, used tomato paste that's been put in the fridge but since gone mouldy (first scraping the mould off).
Of course labelling is never going to *stop* people from doing anything, but that's not the point. It's to try and help reduce the chances of it happening, even if only by a relatively small amount.
Keep in mind, also, that it's not just about the one-off effects of eating unsafe foods, but whatever the cumulative effects of this may be.
Warning: the following is a bit rambly... where I try to think through some of the issues to do with human perception and psychology that underly labelling.
Labelling concerns human perception and psychology. It's not a matter of what information is, strictly speaking, available. It's about what information we'll notice and how we'll perceive it and how it can effect our actions.
The thing is that people aren't going to devote much time or effort to checking food safety info on labels.
The amount of time and effort and concentration we devote to a task tends to be proportional to how important it is to us at that point in time (and this is not usually the result of a conscious choice).
We don't fully consciously process the smaller things. To some extent we're always handling certain tasks on automatic, rather than giving them full conscious deliberation. We're creatures of habit, as they say.
While we're doing the little tasks we usually have our concentration focused more on the bigger tasks and concerns on our minds.
We're unlikely to ever devote that much time or effort or conscious thought to food labelling info.
As soon as a person finds something that seems like its telling them the whole story (the "use by" date) they're likely to stop their search.
Think what it'd actually take to actually find and process the other food safety information in addition to the use by date.
We'd have to think to look for it. We'd have to find it on the packet, then take the effort to read it. And then we'd have to reconcile that information with the use by date information. The latter is harder than it sounds. It took me a fair while to get clear how the use by date relates to the 'time after opening' info.
And we'd have to overcome our natural inclination to stop our search once we have found an answer (you can find a description of some research on this here. I can't recall where I had first heard about this, but I do remember that Dan Airely describes it in his book Predictably Irrational). We make swift, relatively sub-conscious judgements.
Where's the motivation in a normal situation to do these things? There doesn't seem to be one. There's always heaps of things you could be doing, but unless they're relevant to what you are doing or want to do they don't come to mind.
It may seem so "obvious" as something to focus upon because that's what we're doing right now in this bit of writing. Which is the 'paradox' of discussing aspects of tasks that you wouldn't think of when you were actually doing the task - when you're discussing it you're making yourself to focus on it.