I started using SoClean 2 about 3 months ago. Within the past 2 weeks I have been sick with cold like symptoms and started have chest pains. After doing research I found that Ozone (they call it activated oxygen) is 3 oxygen atoms. We breathe O2 (2 oxygen atoms). In addition, oxygen poisoning is a thing. I immediately stopped using it and now 4 days later I am not longer have chest pains and my cold is going away. I see my doctor in 2 weeks and he will refer me to a cardiologist to check for permanent damage. I am surprised that this product is allowed to be sold. I wish that I had researched more before buying it.