One job, one standard: how the revised NFPA standard 1580 alters firefighter fit for duty status across age

The National Fire Protection Association (NFPA) sets operational standards for fire departments, including criteria for evaluating firefighters' readiness and fit for duty status. The recently revised NFPA 1580 standard replaces absolute aerobic capacity threshold with the American College of Sports Medicine's general population, percentile-based classification system. The purpose of this study was to compare classification outcomes between the previous NFPA 1582 and the revised NFPA 1580 to examine whether age, sex, or body mass index (BMI) were associated with differing fit for duty status' by age classifications. Retrospective data were analyzed from 6009 career firefighters (366 females). Aerobic capacity was directly assessed via a cycling-based protocol. Participants were classified under the previous NFPA 1582 and the revised NFPA 1580 standards. Ordinal logistic regression models estimated the odds of being categorized into a restricted duty classification (RDC), using age, BMI, and sex as predictors. Odds ratios with 95% confidence intervals were calculated. Under the previous NFPA 1582, increased age, higher BMI, and being female were associated with lower odds of being classified as fit for duty. Under the revised NFPA 1580, older age groups, especially those aged 60-69 years, were ∼38× more likely (OR = 37.48) to be classified as fit for duty, despite lower aerobic capacity. RDC likelihood increased among younger, male firefighters. The transition to a percentile-based framework may misalign fit for duty classification with unchanging job demands and compromise occupational safety. Future standards should prioritize task-based validations to ensure occupational readiness reflect the actual physiological demands of firefighting.