The present invention relates to an antimicrobial material consisting of particles comprising an antimicrobial agent (A) and a carrier (B), wherein: the antimicrobial material is a granular material; at least 90% w/w of the particles have a particle size in the range of from 1.0 mm up to and including 8.0 mm measured according to the method DIN 66165-1/-2; at least 90% w/w of the particles have an aspect ratio R, equal to or lower than 8; the antimicrobial agent (A) comprises elemental silver nanoparticles; the antimicrobial agent (A) is present in an amount in the range of from 0.001% w/w up to and including 2% w/w on antimicrobial material; the carrier (B) is a polymer comprising a polyamide; the carrier (B) is present in an amount in the range of from 98% w/w up to and including 99.999% w/w on antimicrobial material. The invention further relates to an article comprising the granular antimicrobial material, a device comprising the granular antimicrobial material or the article. The invention also relates to a process for preparing the granular antimicrobial material and use of the granular antimicrobial material or an article or a device comprising the granular antimicrobial material in water treatment systems/appliances, water filters, swimming pools, whirlpools, water supply containers, water storage and for treatment of drinking water.