Recomended Exposure Time
Sound Level (Decibels)	Exposure Period/24 Hours
<80	No limit
85-90	8 hr.
92	6 hr.
95	4 hr.
97	3 hr.
100	2 hr.
102	1.5 hr.
105	1 hr.
110	.5 hr.
115	15 min.
120	7.5 min.

DECIBEL LEVELS OF COMMON SOUNDS
0	Acute threshold of hearing
15	Average threshold of hearing
20	Soft whisper
30	Leaves rustling
65	Normal conversation
70	Inside an automobile at 60 m.p.h.
80	Heavy traffic
90	Recommended level for 8 hour exposure
100	Tractor under load, motor cycle, snowmobile
120	Jack hammer, amplified rock music