Fatigue Self-Assessment
Samn-Perelli + Sleep / Circadian Risk Factors
Method:
Combines the Samn-Perelli 7-point Fatigue Scale (Samn & Perelli, 1982 — validated in aviation, military, and shift-worker studies) with measurable risk factors: hours awake, sleep last night, sleep debt, time of day, and consecutive shifts.
Reference: 17 hours awake ≈ 0.05% BAC impairment · 24 hours awake ≈ 0.10% BAC (Dawson & Reid, 1997).
Reference: 17 hours awake ≈ 0.05% BAC impairment · 24 hours awake ≈ 0.10% BAC (Dawson & Reid, 1997).
⚠ Important — Self-Screening, Not a Medical Tool
This is a self-screening checklist, not a medical assessment. Workers may underestimate their own fatigue, especially under chronic sleep restriction. Persistent fatigue can signal underlying medical conditions (sleep apnea, thyroid disease, depression) — see a healthcare provider. For safety-critical workplaces, follow your employer’s Fatigue Risk Management System and stop-work authority. The author and FieldSafetyTalk.com assume no liability for decisions made using this tool.
1. Samn-Perelli — How do you feel right now?
2. Sleep & Wake
3. Work Pattern
Please answer the Samn-Perelli question and complete sleep/wake fields.
Fatigue Risk Score
—
out of 100
Impairment Equivalent
—
approx. BAC
Risk factor breakdown
Self-rated fatigue (Samn-Perelli)—
Time awake—
Sleep last night—
7-day sleep average—
Circadian timing—
Consecutive shifts—
Recommended actions
Sources: Samn SW, Perelli LP. (1982). USAF School of Aerospace Medicine Tech Report SAM-TR-82-21. Dawson D, Reid K. (1997). Fatigue, alcohol and performance impairment. Nature 388:235. FAA AC 120-115 Fatigue Risk Management. NIOSH/CCOHS Fatigue resources.
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