An update on REACH toxicity legislation and its impact on SMT companies and their customers are discussed. Most U.S. companies, including SMT manufacturers and their customers, will need to contend with toxic substances that are in the articles or products that they sell. Article manufacturers are affected by REACH if their article contains substances that will be intentionally released during normal conditions of use and more than one ton of the substance is put on the EU market within a one-year period. A key difference between REACH and previous toxicity legislation such as EU and China RoHS is the method used to calculate the MCV of a substance in an article. The REACH MCV approach is more helpful to article manufacturers, as it is easier to be compliant when the substance weight is a percentage of article weight, not a percentage of homogeneous material weight. SMT companies will be asked by their customers to provide substance-level information for the articles they sell.