Yesterday I went to the beach, and it turned into and impromptu photo-shoot (got to love all the free time on vacation). Putting on sunscreen got me thinking; what exactly are all these chemicals we are putting on our body. Now don’t get me wrong, I am a woman of science, and by no means promote a holistic approach. I believe in modern medicine, but none the less, I am still concerned by some of the things we use.


A while back, I watched a news segment that was quite alarming. They discussed the effects of a new compound that can be found in many of our every day personal care items. Being a microbiology student, this piqued my interest, and I figured I would share what I discovered. The culprits name is Methylisothiazolinone, also known, as MI. It’s a preservative that is used in products like cleansers, shampoos, creams and skincare items (such as sunscreen). Its main purpose is to eliminate bacteria in products that are susceptible to bacterial growth once opened. 

When you buy a lotion or personal care product, it is sterile (or is supposed to be manufactured in a sterile environment). There are actually many guidelines created for suppliers and retailers to see what quantity of bacteria is permitted for an item to be qualified as acceptable. The problem is if the product you are using is open to the air, or you have to reach into it (like a jar) you are essentially contaminating it. Hence, the need for companies to use these preservatives.

A few years ago, there was a study that came out saying that parabens could possibly have negative effects on specific hormones in the endocrine system (the system that regulates your hormones). Some data also claimed that these parabens could potentially lead to certain types of cancer, although this was never proven in rigorous clinical studies. Enter the media orchestrated war on parabens.

In response to this media attack on parabens, all the big player companies made major efforts to remove all of these preservatives from their products. Unfortunately, by removing these ingredients, they had to replace them with something else… enter MI. 

This new compound, MI, can cause something called contact dermatitis. According to the Mayo Clinic, it’s a red, itchy rash caused by a substance that comes in contact with your skin, a moderate – severe allergic reaction.

Some people are very allergic to this compound, and get extremely painful rashes and reactions (I will spare you the pictures I found). However, since it’s a rather new preservative on the market, when they see a doctor, the root cause of their symptoms often goes misdiagnosed.

I went through my arsenal of products, and was actually surprised to see that quite a few of the things I used daily contained MI. Included was my beloved Bath & Body Works hand soaps and shower gels, as well as my Dove Go Fresh body wash.

Because I have used these products daily without issues, I am luckily not someone that is affected by this compound. However, if you find that your skin is unusually dry or irritated, check the ingredients to see if MI could be the potential problem.

Dr. Denis Sasseville, the dermatologist reporting these findings, said that he would personally buy a product containing parabens rather than Methylisothiazolinone. So, from now on, I will be sure to check the ingredients of the products I use, and make a more conscious effort to learn about what I am putting on my body.

Well there is my little microbiology/chemistry tidbit of the day (first time my microbiology knowledge seems useful lol) and I hope this was insightful to some!