Analytical smoking has been daily routine in the tobacco laboratories for many years. The smoking processes have been specified by CORESTA and ISO and international harmonisation and collaborative studies have been performed several times by the cigarette industry.

The need for consistent and reliable results has over the years grown together with increased export to often quite remote foreign countries and regulatory control by equally remote laboratories. This control has more often than not been performed without a structured contact between the laboratories from the industry and the regulatory authorities.

Along with this, the international standardisation has offered improved specifications of the analytical procedures and accreditation of smoking laboratories has become normal in many parts of the world. But still we may meet problems in reaching the needed and wanted concord.

Seen from the outside it would be assumed that well-defined analytical procedures could secure unambiguous results but practical life has shown us that it is not always so.

Why is that so? Why do we see unexpected variation between good and well-experienced laboratories?

This presentation intends to give an overview of the practical experiences gained from many years organisation of comparative studies and standardisation work in CORESTA and ISO.