Elution of Metals with Artificial Sweat/Saliva from Inorganic Antimicrobials/Processed Cloths and Evaluation of Antimicrobial Activity of Cloths

Abstract

Inorganic agents, such as Ag, Cu, and Zn compounds, are known to be relatively safe, and these agents are used in many products. In Europe, the standard levels of heavy metals eluted with artificial sweat and saliva are specified in the self-imposed safety criteria (OEKOTEX Standard) for textile products. We prepared metal zeolites (Ag, Cu, Zn, and Cr) and standard cloths loaded with these zeolites and a silver antimicrobial agent, AG300. The agents, standard processed cloths, and regions of commercially available products in which metals were detected at a high concentration were subjected to metal elution with artificial sweat (JIS L 0848: 2004), saliva (BS 6684: 1987), and purified water according to the JIS shake-flask antimicrobial test method (JIS L 1902–1900). The metal concentrations in the extracts were measured using an inductively coupled plasma-mass spectrometry (ICP-MS). A similar tendency was noted in elution from the agents, standard processed cloths, and commercial products. No metals were eluted with purified water alone, while the metals were eluted with artificial sweat and saliva. Large amounts of Cu and Zn were eluted, the elution of Ag was low, and almost no Cr was eluted. Furthermore, the antimicrobial activity of the standard processed cloths was evaluated in the antimicrobial test (JIS L 1902: 2002) using Staphylococcus aureus (S. aureus )a ndKlebsiella pneumoniae (K. pneumoniae). Cu- and Ag (Ag zeolite and AG300)-processed cloths exhibited strong antimicrobial activities against both bacteria. Zn-processed cloth also showed antimicrobial activity against S. aureus.