The International Technical Commission (ITC) published the first European standard IEC 62368–1 on personal audio systems in 2010.[42] It defined safe output levels for PLSs as 85 dB or less, while allowing users to increase the volume to a maximum of 100 dBA. However, when users raise the volume to the maximum level, the standard specifies that an alert should pop up to warn the listener of the potential for hearing problems.[31]