Tenability Criteria Calculator

Evaluate tenability conditions for temperature, visibility, CO exposure, and O2 depletion per NFPA 92/SFPE

Input Parameters

Results

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Temperature Status
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Visibility Status
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CO Fractional Effective Dose
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Oxygen Status
Note: Tenability criteria per SFPE Handbook and NFPA 92. FED (Fractional Effective Dose) of 1.0 represents incapacitation for average population. Design typically targets FED < 0.3 for safety margin. Consider combined effects of heat, toxicity, and visibility.

Reference

SFPE/NFPA 92 Tenability Criteria: Temperature: <60C safe, 60-100C marginal, >100C untenable Visibility: >10m safe, 3-10m marginal, <3m untenable CO FED = (CO_ppm x Time_min) / 35000; FED >= 1.0 = untenable Oxygen: >15% safe, 12-15% marginal, <12% untenable, <6% lethal