Maximum audible tolerance is:
A noise of 90 db, 8hrs a day for 5 days/week is maximum safe limit. No exposure in excess of 115 db is permitted. No impulse noise of intensity > 140 lb is permitted. Persons working in area where noise exceeds 85 db should have pre employment and annual audiograms. Ear plugs offer protection up to 35db and to be used where noise exceeds 85 db.
90 db for 6 hrs
90 db for 8hrs
85 db for 6 hrs
85 db for 8 hrs