On the helpful surveys that some of you completed awhile back, many people said they would not reuse their plastic grocery bags at the store because they felt they would be unsanitary. This is an interesting question, and one of our Bag-It team members (Sam) wanted to learn if this is true of not. He did a lot of research on this subject and found that while there is a lot of research on microbial growth on water bottles, water treatment places, and water pipes (and more), there is almost no research on the HDPE bags themselves. This is probably because they've been named "single use" and so why would we want to know?? Well, we want to know since we're telling you that you should reuse them at the store.
With the help of a couple of mentors, Sam designed an experiment using a technique called Presence/Absence testing -- it's a protocol that can be used for testing of water and food contamination. There were many, many test tubes and swabs and lots of learning. It turns out that when the HDPE bags are used once, there are microbes living on them. But after a week's time, most of the microbes didn't find the environment good for growing and multiplying, and died. This is important research because it supports our idea that it's pretty safe to reuse your plastic grocery bags for food. Now, if there was a bad spill in one of the bags (with meat or something else), you might not want to reuse that for food. And to make the bags even more sanitary, simply exposing them to air will most likely take care of things -- microbes mostly like wet, dark and moist places with a food source. HDPE plastic bags don't really do it for them -- they kind of don't like it.
How about that for science detectives?
Here is the link to the video he created to explain the story:
And some charts and a graph with data ...
