DIN EN ISO 24234:2015-08

The global use and emission of mercury (the only metal that is liquid at room temperature and readily evaporates and is also considered toxic) is to be restricted by the Minamata Convention. More than 140 countries agreed on this in 2013. This treaty describes the gradual elimination of household appliances containing mercury. From clinical thermometers and dental fillings to energy-saving lamps, emissions of the heavy metal are to be reduced. The use of mercury in gold mining is to be prohibited. The convention enters into force when 50 states have ratified it. According to UNEP (United Nations Environmental Program, 2013), dental amalgam requires about a quarter of the total amount of mercury used worldwide. ISO 24234 was revised in order to implement these requirements internationally in the field of dentistry. The International Standard has been prepared by ISO/TC 106/SC 1/WG 7 "Amalgam/Mercury" (secretariat: BSI, Great Britain) in collaboration with CEN/TC 55 "Dentistry" (secretariat: DIN). At DIN the responsible Working Committee is NA 014-00-17-05 AK "Metallic filling materials" of Working Committee NA 014-00-17 AA "Metalle" ("Metallic materials") of NADENT. In Germany, the number of amalgam fillings has fallen sharply in the past 20 years (in 2014 only about 10 % of all fillings made). The new international requirement to use only encapsulated amalgam has been complied with in Germany since 1993. The standard defines requirements and test methods for dental amalgam alloys suitable for the manufacture of dental amalgams, together with requirements and test methods for these dental amalgams and requirements for packaging and marking (including those for dental mercury). The standard applies to dental amalgam alloys supplied in the form of free-flowing loose powder, or as tablet powder, or as powder in a capsule (that is, pre-dosed capsule). It describes the chemical composition of the alloy, the exclusion of foreign objects and large particles in the alloy powder, the variation of the pre-dosed masses, the properties of amalgam such as creep, change in length during hardening, compressive strength after one hour and after 24 hours and the appearance of the mixed amalgam before hardening. The information required for packaging, marking, instructions for use and warnings on mercury are specified.