<p>A glass container (10) and a process for chemically modifying a surface portion (22) of the glass container using an ion-exchange process. At least a portion of the glass container is immersed in or in contact with an aqueous electrolyte solution comprising salts of at least one group IA alkali metal and having a temperature of 70 to 100 degrees Celsius such that exchangeable alkali metal ions in a surface portion of the glass container are exchanged or replaced by alkali metal ions in the electrolyte solution.</p>
