http://www.ime.org/subsections/subsection.asp?IdSection=4&IdSubSection=46&memb=1

Switzerland is the only country in the world to require taggants in explosives. The Swiss experience is often cited as evidence that taggants are safe and effective. However, the Swiss Police readily admit that their program is nothing like that being proposed in the United States, nor is their explosives industry anything like the industry in this country.

The Swiss law was adopted primarily to stop undesirable trans-border trade in explosives. Imported explosives must be tagged only if competing products are also made in Switzerland.

Swiss manufacturers are required to change the taggant code in their products only every six months. Proposals in the United States typically require daily changes in order to achieve any meaningful specificity. The Swiss do not require the maintenance of distribution records or the purging of equipment between batches to avoid contamination. In the United States, these measures would be required to achieve specificity for definitive tracing.