What Is The Danger Of Class 3b Laser Radiation?

nearly 2 weeks ago i went my friends’..Their computer’s cd writer driver’s front cover (which has button to open) FELL DOWN TO THE FLOOR and beams escaped….I couldn’t realize..If i realize i wouldn’t allow it.And cd’s laser worked..Nearly 5 minutes i stayed (i have cds read) in there..There is no damage on my eyes but just wanna ask it these radiation emit from the laser in 5 minutes how harmful can be?And my legs was opposite of the cd drivers..These radiation has many doses must be to cause cancer?And is cd burners send less powerfull laser beam while they were reading instead of burning?there is no harm on my skin and eyesight but just wanna know it these radiation is reli dangerous for 5 min..?