The European REACH legislation involves processes of Registration, Evaluation, Authorization and Restriction of Chemicals, hence its acronym. This strategic legislation is expansive and covers potential exposures ranging from consumer products to personal exposures. Each process was rigorously evaluated and serves as a framework for others considering a more logical and comprehensive risk assessment. We are fortunate to have a compilation of papers outlining the REACH process from scientists who were intimately involved in its development. Our guest editor for this issue is Dr. Joop Van Hemmen of TNO Laboratories in the Netherlands. Dr. Van Hemmen's relentless dedication to commissioning these manuscripts cannot go without recognition. In addition, we are grateful that others have seen the value of this collection of papers and have donated funds to secure its publication. We gratefully recognize ECETOC, the American Chemistry Council, the Centers for Disease Control and Prevention, and Dr. Joop Van Hemmen along with TNO Laboratories for their generous support. This issue of the Journal of Exposure Science and Environmental Epidemiology will certainly become an important reference document for risk assessors and others who may wish to thoughtfully evaluate exposures and implement measures to protect human health.