Phosphorous containing glass having antimicrobial efficacy

A method for making strengthened antimicrobial glass, the method comprising:

• obtaining a glass article comprising:
• greater than or equal to about 50.0 mol. % to less than or equal to about 65.0 mol. % SiO2,
• greater than or equal to about 14.0 mol. % to less than or equal to about 22.0 mol. % Al2O3,
• greater than or equal to about 14.0 mol. % to less than or equal to about 22.0 mol. % R2O, wherein R is an alkali metal, and
• greater than or equal to about 4.0 mol. % to less than or equal to about 10.0 mol. % P2O5;
• strengthening the glass article by contact with a first ion-exchange liquid;
• and
• contacting the glass article with a second ion-exchange liquid comprising an antimicrobial agent, wherein:
• the glass comprises a compressive stress layer having a thickness of greater than or equal to about 20 μm to less than or equal to about 60 μm and having a compressive stress of greater than or equal to about 700 MPa;
• and
• the glass has an antimicrobial activity greater than or equal to about 1.0 log kill at about 23° C. and a relative humidity of about 40%.