This post is about toxic adhesives used to apply labels to food packaging and whether or not those chemicals can migrate into our foods. But it’s also a convoluted story about the foul odor emanating from the general direction of my dishwasher.
Stinky Dishwasher Smell
If you’re my Facebook friend, you may be waiting impatiently to hear the conclusion to the following status update:
Our kitchen smells like dead animal ass. Literally. We’ve searched for weeks to find the source of the smell. Today, I’m pretty sure it’s the Seventh Generation dishwasher powder we switched to. Is that possible? The dishwasher’s running now, and the smell is definitely coming from there. I stuck my nose in the [detergent] box, a…n…d it’s not good. Anyone else noticed this or am I crazy?
Yes, this is the type of tasteful, articulate status update you can except from me if you choose to be my Facebook friend. And I owe Seventh Generation a big apology because, while I’m not crazy about the smell of their dishwasher detergent, I’m happy to report that it was not the source of the funk under the kitchen counter. It turns out, however, that the smell did originate from behind the dishwasher filter screen. Unfortunately, said filter was not made to be removed by anyone but a trained professional or at least someone with tools. Darn you General Electric! So, after I posted the following photo with a second status update:
Can someone please tell me what tool I need to remove a bolt like this from inside my dishwasher? It’s holding on the filter thingie, which I would like to access so I can see if it’s where the dead animal smell is coming from. (Sadly, this cheapo dishwasher, which was already here when we moved in, does not have any easily removable parts. In fact, I think the filter is not even meant to be removed by the dishwasher owner.)
and after I received a billion suggestions from Facebook friends, Michael went out and bought a nut driver to remove the filter. What we found? I didn’t take a picture because it was just too gross. Actually, that’s a lie. I would have taken a picture anyway. The truth is that I forgot to do it. So I’ll try and describe to you the mass of wet, stinky paper pulp, mixed with slimy bits of rotting food, clogging up the filter. Paper pulp? Um sometimes (okay more often than sometimes) we put empty jars — pasta sauce, peanut butter, pickles, etc — into the dishwasher without removing the labels. But seriously, paper is biodegradable, right? Shouldn’t it have just gone through the disposal like food? Well, not if it’s all stuck together with non-water soluble adhesives. Did I mention that the stinky mass was sticky too?
Well, okay, so we cleaned out the filter and promised each other we would never do this again:
The problem was inconvenient but no big deal, right? Well, turns out it was perhaps a bigger deal than we thought.
Toxic Food Label Adhesives
interesting new study on leaching of adhesive compounds from labels on food into foods . . .
Whatever you think of social media, it sure is useful. So anyway, thanks to Jennifer I learned about a new study published in The Journal of Materials Chemistry: Partition and diffusion of volatile compounds from acrylic adhesives used for food packaging multilayers manufacturing. What the heck does that mean? Well, WebMD has a nice article explaining the study in English, and I did a little research on my own to try to understand the study (PDF) itself. That was fun. Once again, I turned to a Facebook friend who is a doctor to help me understand some of the chemistry.
Basically, the researchers studied 11 compounds from four different adhesives used to apply labels to several different kinds of packaging: two kinds of plastic — polyethylene and polypropylene — as well as two different kinds of paper, to see if the chemicals from the adhesives could migrate through the packaging into the food. Of the 11 compounds they studied, four migrated into the food. And of those four, the chemical 2,4,7,9-Tetramethyldec-5-yne-4,7-diol is highly toxic to humans.
What’s more, researchers discovered that packaging made from polyethylene plastic was the most likely to allow chemicals from the adhesives to migrate through into the contents. What’s made from polyethylene? Plastic beverage bottles, plastic bags, as well as flexible Mylar food packages, some prepared food or frozen dinner trays, and many non-PVC plastic wraps.
Toxic Glue in my Dishwasher?
So what do I know now about the funky mess in my dishwasher? Nothing for certain. First of all, the labels in my dishwasher were applied to glass, a strong barrier for protecting food. However, when subjected to hot water and detergent, those chemicals would have come into contact with all the rest of my dishes. And since they were trapped behind the filter screen, I assume this happened every time I washed dishes. What’s more, I would have been flushing those chemicals into our water ways. I’ve been so careful to buy the least toxic dishwasher detergent, never dreaming there were other sources of toxic chemicals to consider.
But do I know whether my jar labels were afixed with the most toxic adhesives? I do not. And I probably never will because the manufacturers certainly are not going to tell me what chemicals they used in their glue, if I could even determine who the manufactures of the labels and glues actually are. So this is another case where the Precautionary Principle is in order.
First, if only to avoid clogging up the dishwasher, we won’t be putting jars with labels in there anymore. And second, after soaking the jars to loosen the labels, I’ll be wearing rubber gloves to remove them.
Oh, and by the way, if you’re one of the people since the oil spill counting the number of products we use that are derived from petroleum, go ahead and include label adhesives to your list. Unless we grow and prepare all our foods from scratch, it’s pretty hard to get away from petroleum products.