The lecture series “Limits for Metals – Trace Elements or Poison?” aims to provide insights into the occurrence, technical applications, presence in food, and physiological effects of various metals on the human body. This fourth installment addresses five additional elements: silver, barium, manganese, zinc, and the newly included zirconium.
Previous lectures covered six elements in Florence (boron, cobalt, nickel, molybdenum, cadmium, and lead), four in Chicago (lithium, aluminium, copper, and antimony), and four in Kyoto (vanadium, chromium, arsenic, and tin).
With this lecture, the series completes the review of the 17 elements regulated by Resolution CM/Res(2020)9 on metals and alloys used in food contact materials and articles, adopted by the Committee of Ministers on 11 June 2013 during the 1173rd meeting of the Ministers’ Deputies (Council of Europe), and by EN ISO 4531. The currently applicable limits under EN ISO 4531 are:
Al: 1000 µg/l
Ag: 80 µg/l
As: 2 µg/l
Ba: 1200 µg/l
Cd: 5 µg/l
Co: 100 µg/l
Cr: 250 µg/l
Cu: 4000 µg/l
Li: 480 µg/l
Mn: 1800 µg/l
Mo: 120 µg/l
Ni: 140 µg/l
Pb: 10 µg/l
Sb: 40 µg/l
V: 10 µg/l
Zn: 5000 µg/l

An upcoming revision of EN ISO 4531 will introduce the following changes:
Chromium: limit increased from 250 µg/l to 1000 µg/l
Manganese: limit reduced from 1800 µg/l to 550 µg/l
Zirconium: newly included with a limit of 2000 µg/l. It is therefore recommended that all future certificates according to EN ISO 4531 already include zirconium as a monitored element, to ensure continued validity after the forthcoming revision.