I normally don't write reviews on Amazon but the fact that this book is only rated a 2.5 stars is ridiculous. I've recently completed a project that had to do with quantifying the human effects of food additives. In the process, I've found that there is almost no scientific agreement on many of the popular additives like MSG. There are heated debates on either side and you never really know who is funding what website or what study. It is also equally frustrating that the FDA recommendations and ratings are horribly outdated.
What this book excels at is presenting all the available information. It does not give you recommendations or tell you what you do with your life. You can still eat as many products with BHT as you want but the book will tell you that the substance is already banned in the UK and it is reasonably anticipated to be a carcinogenic based on _____ studies. The book is basically a collection of all the important scientific studies about an additive in one place. Since it is fairly up to date compared so some of the other sources I've seen, I can say that it is reliable. If you don't believe any of the information in the book, you can easily look up the studies yourself and make your own judgements.
That said, I don't believe that people should base all of their information about food additives on one source, even a reliable one. For those who are interested, I also recommend the Center for Science in the Public Interest's food additives list, which you can find on the Internet. You can also look at the list of banned substance from Whole Foods as a general guide. Again, I encourage everyone to do their own research and make their own judgements about various substances in their diet. This book is a good way to start.