Long hours, hard work, and giving everything 110% are usually considered virtues in manufacturing and production facilities. Instead, they should be considered giant red flags, especially in critical safety roles. For food manufacturing and production facilities, where food safety is imperative and every role is a critical safety role, worker fatigue is often the most significant and least recognized food safety risk.
In this article, we'll look at why your food safety team should be taking worker fatigue much more seriously, how fatigue fits into regulatory and compliance frameworks, and how to build food safety programs that actively reduce fatigue-induced food safety risk in your facilities.
… This Is Your Brain on Lack of Sleep
Virtually every manufacturing plant acknowledges and accounts for impairment from drugs and alcohol. Employees might be randomly drug tested and supervisors trained to recognize signs of drug use; accidents and incidents often come with mandatory drug and alcohol testing; and policies are written into employee handbooks and contracts warning about consequences for non-compliance. It's an obvious and preventable hazard that food safety professionals take seriously.
By comparison, worker fatigue seems harmless. Lack of sleep is a personal issue, not a work issue, and employees can deal with it on their own time. That's a common line of thinking among foremen and FSQAs alike. Unfortunately, it couldn't be further from the truth. Fatigue-induced impairment can be just as dangerous as drug- or alcohol-induced impairment, with a much higher food safety risk because it's much harder to spot and mitigate.
Fatigue Myths: Debunked
Most common “knowledge” surrounding worker fatigue is outdated or simply incorrect. From the causes of worker fatigue to its potential effects on food safety, the science of sleep and fatigue is complex and often misunderstood. Some common myths include:
"People need 8 hours of sleep to feel well-rested."
The "correct" amount of sleep is actually a broad range that varies from person to person and across life stages. This myth is particularly dangerous in facilities with younger employees; the common-sense belief is that teenagers and young adults can function on less sleep, when in reality they need much more than their more senior coworkers. In general, chronic sleep restriction is defined as multiple consecutive nights of less sleep than an individual needs, which could range from as low as 6 hours a night to 8 to 10 hours.
"Sleep loss only matters if it's chronic/goes on for multiple consecutive nights."
While cognitive impairment does increase with repeated sleep loss, even missing a single night's good rest is enough to create an acute sleep loss impairment situation that could reduce attention to detail, time awareness, and executive functions. One bad night is enough to affect food safety outcomes.
"As long as workers get enough sleep every day, worker fatigue isn't an issue."
While sleep loss is one of the most common causes of worker fatigue, it's far from the only one.
- The Circadian Trough is the lowest point in the body’s circadian rhythm that governs sleep and wakefulness, typically between 4 and 6 a.m., when alertness and performance are at their lowest. Employees who are at work at this time are more likely to be impaired, regardless of their sleep schedules and work hours.
- Circadian misalignment happens when workers' schedules don't align with their natural sleep patterns, creating significant discrepancies between the performance and alertness required of them and what they can realistically achieve. This is especially dangerous for third-shift or night-shift employees and workers on irregular shifts who may be chronically out of alignment with their natural needs. On average, night shifts have a 30% higher rate of injuries and incidents, per the National Safety Council.
- Task fatigue and biomechanical fatigue are the products of working for too long, exceeding the energy a worker can output in a day, or performing repetitive and unengaging tasks for extended periods. This kind of fatigue can escalate quickly: The National Safety Council found that 10-hour shifts increase injury/incident rates by 10%, while shifts over 12 hours see a 30% increase.
What Happens When You Miss a Good Night's Sleep?
The first and most reliable symptoms of fatigue are vigilant attention deficits, impaired reaction times, and degraded time awareness. Workers might not realize they've had a freezer door open long enough for temperatures to creep into the danger zone, or they may misread a solution-testing strip and under- or over-concentrate sanitizer. Anything that requires careful attention to detail and timeliness — that is, the entirety of food safety — starts to slip.
Executive functions — the thought processes that help make good decisions — are the next to go, along with rule-compliance. Research by Cambridge University has demonstrated that fatigue leads to significant drift in hygiene compliance as shifts wear on. As shift hours and task fatigue accumulate, employees in high-tempo food operations begin to wash their hands less often and less thoroughly. Workers finishing up late shifts, especially late evening and overnight ones, perform much worse at close-out and pre-prep tasks (like cleaning, sanitation, and equipment maintenance) than workers just starting their shifts.
These factors combine to dramatically increase error rates. As mentioned earlier, going from a 10- to a 12-hour shift increases the error rate by 3x compared to an eight-hour shift.
Worker fatigue is not a character flaw, personal problem, or moral failing: It's a serious risk to food safety operations in manufacturing facilities. The problem is serious enough that the UK's Health and Safety Executive explicitly frames it as a human-factors hazard. Food safety professionals must do the same: explicitly acknowledge fatigue in their food safety plans, and design preventive controls and programs to address this very real risk.
Finding Worker Fatigue Guidance
Part of the problem with integrating worker fatigue into food safety plans and programs has been the lack of clear guidance from regulatory and standards bodies. While ISO 45001 offers a framework for Fatigue Risk Management (FMR) — auditable and ready for FSMS-grade controls — most regulators see worker fatigue as a culture issue best left to individual manufacturers and food safety managers. This, even though fatigue-related impairment has been linked to the 2005 Texas City refinery explosion, the Colgan Air crash, the explosion of the Challenger space shuttle, and the nuclear accidents at Chernobyl and Three Mile Island.
The FDA Food Safety and Modernization Act (FSMA), as an example, doesn't explicitly mention worker fatigue, though some have interpreted language around "competent, trained personnel" to include "non-fatigue impaired." GFSI, BRCGS, SQF, and FSSC are placing larger expectations on how manufacturers integrate culture, management, and data, but also lack many guidelines for evaluating or validating fatigue-related risks.
The problem, in short, is that food safety regulations lump fatigue in with "soft risks." That kind of treatment deprioritizes the threat worker fatigue poses to food safety and reinforces the laissez-faire attitude many manufacturers take toward employees bringing their "personal problems" into the workplace. Even when food safety professionals understand the risks posed by worker fatigue, they find little guidance from regulators on how to track, measure, and address it.
Fatigue Risk Management: A Practical Approach
While guidance from governing bodies may be hard to come by, food safety professionals can take immediate steps today to mitigate risk.
Adjust culture and governance plans
Adding fatigue as an explicit agenda item during Food Safety Culture and Management reviews helps to surface the risk and break down some of the reluctance to address it as a real problem. Tracking absenteeism, near misses, sanitation rework, and contamination positives and cross-referencing against shift, overtime, staffing, and time of day can turn a vague problem into a real one. Adding it as a known human-factor hazard in HACCP/PC helps start the accountability machine.
Measure and analyze precursors and circumstances
Certain correlated risk factors can help predict fatigue-induced risk. Measure and track hours worked, shift and line rotation patterns, shift turnaround times, consecutive nights, and overtime density. Correlate these warning factors against defect rates, deviations, and disciplinary reports to create risk bands that may require extended oversight or corrective action.
Add red zones around known common periods when fatigue tends to peak: the window between 2 a.m. and 6 a.m., end-of-shift, and any period where workers exceed 10 hours on shift. Use spot screening with the Karolinska Sleepiness Scale (KSS) to validate red-zone selection and identify periods where fatigue may be higher than anticipated.
Create controls for fatigue
- Schedule for Safety: As much as possible, cap routine shifts to safe windows of no more than 10 hours and require food safety sign-off for any shifts that exceed those safe limits. Restrict turnaround windows to at least 12 hours and reduce consecutive nights worked. Work with plant supervisors to reduce shift irregularity.
- Lighting: Align lighting use with evidence-based best practices like bright-light intervention during night shifts. Require minimum lumens and add brightness to critical control point (CCP) checks.
- Task Rotation: Integrate mandatory micro-breaks and task rotation, especially for workers performing attention-heavy, monotonous work, like CCP monitoring. Bias microbreak and rotation timing towards the red zones you identified earlier.
- Training and Process: Build fatigue-awareness SOPs that both reinforce the risk posed by fatigue-related impairment and account for it when performing key risk-reduction tasks. Create risk-based sequencing processes for close-out and pre-prep, and add enhanced verification and validation for end-of-shift sanitation and hygiene tasks.
Don't Sleep on Worker Fatigue
Fatigue risk management rarely gets the attention it deserves in food safety, even though it is a major contributor to risk. The good news is that it's also one of the easiest risks to reduce, with proven, effective mechanisms that can be implemented quickly and with few resources. Relatively minor modifications to scheduling, process, and governance all go a long way.
If you're ready to tackle fatigue risk in your food manufacturing and reduce your facility’s deviations and corrective actions from tired workers, contact AIB International. Our Ask an Expert program can pair you with an experienced, trained food safety pro who will work with your staff to build a fatigue risk management program that pays off in safer food, fewer work stoppages, and reduced regulatory actions.
