I have tried this product several times with no ill effects. It does a good job of covering the gray. The color lasts approximately six weeks and I am satisfied with the results. It is permanent color and has Color-blend technology. This involves the expert blending of 3 tones for natural color with highlights and long-lasting, 100%Gray Coverage. This product identification number for the user is 104. It is a Natural Medium Golden Blond and is enough for one application. It is very easy to apply although I find I must cover the counter and floor so as to protect it in case some drops should spill. This is a concern of mine because if I don't immediately wipe up the drops that spill, I will have a difficult time cleaning up any dried solution. This product does contain skin irritants which is printed on the box. My main concern is to make certain that I do not get this in my eyes because to do so may cause blindness. This in itself scares me and this makes me apprehensive throughout the process until I have thoroughly rinsed my hair and shampooed it.