Will that be with or without printing ink to your cereal, Madam? What, are you joking, you say? No, it is no joke but probably not much to worry about, although you might like to know.
You’re in the supermarket looking at the cereal choices. You want to buy some Swiss style muesli because you believe it is a healthy choice. There is a very attractive brand name package in red, green and gold that you favour and beside it there is an organic version in a bland brown box. Of course you pick the colourful package, that’s what the manufacturer is counting on. Isn’t muesli healthy enough without being organic? And besides, the picture of the muesli looks very appetising.
But what you are not counting on is the potential migration of printing ink components from the outside of the package, through the cardboard and into the plastic inner package. And before you know it the muesli also contains some printing ink. Sounds impossible, but that is what is happening all the time for plenty of packaged food. And this is the reason why printing inks should be safe to use according to the general food legislation in many countries.
So why even raising this? Well, in early February 2009, German authorities found 4-methylbenzophenone (4-MBP) migrated from the outside cardboard packaging at levels of almost 1 mg/kg into certain cereal products. They sent an alarming message to other European authorities because they had never seen this before. Other countries started their testing and Belgian authorities found even higher levels of close to 4 mg/kg in cereals. Problem was there was not enough toxicity data available to say if 4-MBP was safe at the levels found. 4-MBP is used to stabilise printing inks and lacquers applied on the surface of outer packages, mainly cardboard boxes. Since it is very volatile it may easily migrate into the package and contaminate even solid food inside an inner plastic bag. An inner aluminium bag would be safe but is not used that often.
At the end, the European Food Safety Authority (EFSA) issued a statement concluding that short term consumption of contaminated breakfast cereals should not pose a risk to most people. However, EFSA pointed out that should 4-MBP continue to be used with printing inks, more data on occurrence of the substance in foods should be provided as well as appropriate toxicity data corresponding to the level of exposure for a full risk assessment. So the alarm could be called off for this time.
But what do we know about printing inks in general? Are they all safe? Could there be an interaction between different chemicals that we have not yet studied? Maybe you should pick that brown box of muesli anyway, just to be on the safe side for now.