Recommended volume level iem gr07&j3

Hi, i do notice the difference in isolation of my iems vs earbuds, they rock at semiquiet places where i can feel all the detail at very low volume(6 to 8). In the train, even though they isolate quite a lot, i loose much detail, whisperings being very hard to hear I wonder how much volume would be healthy for my ears. Ill be listening to it for 2hrs daily. So j3 users do you think 1+1hrs of say level 12 or 14 would cause me hear loss or something? The rest of time(4 to 5 hrs) ill listen at vol. 6 or 8 the most. Physicians advices welcome, specially j3/gr07 owners. Thanks.

I don't know what you mean, my source is a cowon j3, my iems are gr07, and the volume, i don't know. Never measured dB levels before. That's why i asked people who own the same playback set. If you need any more data let me know. Thanks :)