Comparative assessment of food safety regulations and standards for arsenic, cadmium, lead, mercury and iodine in macroalgae used as food and feed in China and Europe

•Seaweed is a sustainable food source worldwide.•The potential food safety issues of particular concern in seaweeds are iodine, inorganic arsenic and cadmium.•Different MLs for arsenic, lead, cadmium, mercury and UL for iodine in seaweeds are established in national regulations.•There are currently no harmonized international standards for seaweed safety due to scarcity of occurrence and intakedata.