78-83 db C weighting
What I read from NIOSH: (National Institute for Occupational Safety and Health) and OSHA establishes permissible exposure limits based on a combination of intensity and duration:
85 dB: damage begins after 8 hours of continuous exposure
88 dB: damage threshold reached in 4 hours
91 dB: 2 hours
94 dB: 1 hour
97 dB: 30 minutes
100 dB: 15 minutes
110 dB: ~2 minutes
120 dB+: essentially immediate risk

