I'm not sure where you got that graph, but it's WRONG! The headwise article was wildly inaccurate in some places too.
The lowest (1st) entry on the graph lists exposure to 85dBA for 40 hours. In the European Union figures are used from the WHO who state that 85dBA for 8 hours is likely to cause hearing damage. Any workplace within the EU with a SPL of 85dBA (or higher) is required by law to have it's employee's wear hearing defenders.
Standard conversation is usually around 60-65dB although again, in the USA maybe it is 80dB
To be honest, most of the figures used throughout the world as "safe" hearing volumes are to an extent guess work. Different individual people experience hearing loss (and/or permanent damage) at different levels. The figure of 85dBA is often quoted by various government agencies but some audiologists believe that the figure should be 75dB. I doubt that there will ever be precise definitive figures.
The OP question is in fact flawed. It's not a question of "if" you will damage your hearing, more a question of when and how much. Just through everyday use our hearing deteriorates throughout our lifetimes. The more loud music you listen to, the more hearing damage you will experience at a younger age. If you are listening to loud music this could mean just a couple of years and profound deafness, extremely loud music could permanently damage your hearing in a far shorter period of time!!