Compressors, presses, looms and DG sets can push a shop floor well past safe noise levels. Here is a small Python helper to estimate how long people can stay in an area and how much hearing protection helps.

Allowed time at a given level

The NIOSH recommended limit is 85 dBA for 8 hours, with a 3 dB exchange rate: every 3 dB more halves the allowed time.

def allowed_hours ( dba , limit = 85 , exchange = 3 ): return 8 / 2 ** (( dba - limit ) / exchange )

for level in ( 85 , 88 , 91 , 94 , 100 ): print ( level , " dBA -> " , round ( allowed_hours ( level ), 2 ), " h " )

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85 dBA -> 8.0 h 88 dBA -> 4.0 h 91 dBA -> 2.0 h 94 dBA -> 1.0 h 100 dBA -> 0.25 h

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Daily noise dose

Most people move between areas during a shift. The dose adds up each part: hours spent divided by hours allowed at that level.…