Any cons of using these beats

Do they harmful if i put them for 14 -16. Hours with some breaks

I use it at full volume it is pleasing and its audio is sooo clear 

I am from India
I m preparing for JEE exam
Yeah, that's a lot of hard work for your ears. Volume should be 20-40% max. I personally wouldn't study for more than 3 hours a day, but ... I don't have exams.
Saurav Maheshwari