Shift work and fatigue: health and safety

If you are too tired to lift a patient safely, operate a forklift or drive home after nights, the rota needs attention. Your employer must manage fatigue risks. Free health assessments, limits on night work and rest rights give you ways to challenge an unsafe pattern, though exceptions matter, especially in care and security.

Are you a night worker?

The Working Time Regulations 1998 cover workers, including employees, agency staff and zero-hours workers. Genuinely self-employed people are outside them, but a “freelancer” label does not decide your status. Some jobs, including transport work, have separate or modified rules.

Under regulation 2, you are a night worker if you normally work at least 3 hours in the night period. That includes doing so on the majority of days you work. The default period is 11pm to 6am. A legally enforceable written agreement can change it to a period lasting at least 7 hours and including midnight to 5am. A collective or workforce agreement can also specify an annual night-work share that qualifies you.

A carer working 9pm to 7am or a warehouse picker on 10pm to 6am will normally meet the threshold. For rotating shifts, check the frequency of nights and any agreement.

How many hours can you work at night?

The standard limit is an average of 8 hours per 24 hours across all normal working hours. Daytime hours count too. Regular overtime counts; occasional overtime does not count towards this average. The usual reference period is 17 weeks, or the time you have worked for the employer if shorter. Your employer must take all reasonable steps to comply.

GOV.UK guidance describes agreed averaging periods of up to 52 weeks. Ask to see the terms rather than accepting “it averages out”.

There is no individual opt-out from the night-work limit. Signing the separate 48-hour working-week opt-out does not remove it. The exceptions below are different.

The stricter cap for hazardous or strenuous work

For work involving special hazards or heavy physical or mental strain, the standard cap is 8 hours in any 24-hour period in which you perform night work. No averaging. The hazards or strain must be identified in a collective or workforce agreement or your employer’s risk assessment. Regulation 6 sets both caps.

For example, a 12-hour warehouse shift breaches this cap if the risk assessment identifies night-time machinery work as involving special hazards and no exception or modifying agreement applies.

Exceptions that matter in care and security

Regulation 21 can disapply both caps in specified circumstances, including security requiring a permanent presence, continuity of hospital or residential care, uninterrupted production processes and exceptional events. Regulation 23 also permits collective or workforce agreements to modify or exclude them. Retail and catering are not automatically exempt sectors.

Where these exceptions displace rest periods or breaks, regulation 24 requires equivalent compensatory rest wherever possible. Only exceptional cases with objective reasons allow appropriate health-and-safety protection instead. An exception does not excuse an unsafe rota or remove the night-worker assessment duty.

The weekly limit and rest rights also need checking. See our guide to the Working Time Regulations.

Health checks and the move to days

Your employer must offer a free health assessment before you become a night worker and at regular intervals afterwards. A questionnaire prepared with health-professional input can suffice. You can decline; your employer cannot skip the offer. Confidential records of assessments and offers, and records showing compliance with night-work limits, must be kept for at least 2 years.

If a doctor advises that you have health problems connected with nights, your employer must transfer you to suitable day work where possible. This is a duty, not a guarantee that a suitable day job exists. See GOV.UK’s assessment guidance.

1. Request the assessment in writing. Ask when your free night-worker assessment will be offered. Keep the reply.
2. Take symptoms to your GP. Bring your rota and sleep notes. Ask whether the health problem is connected with nights.
3. Ask about day work. Send the medical advice to your employer. Ask what suitable work is possible and request written reasons for a refusal. Involve your union rep.

Acas offers free advice in Great Britain. Citizens Advice and law centres can help. Consider UNISON in care, Usdaw in retail and distribution, or Unite and GMB in hospitality, logistics and security. Check which union organises your workplace and its terms for helping with an existing dispute.

Rest you must still get

The standard adult rest rights below apply on nights as well as days, unless a lawful exception or agreement changes them. Weekly rest is normally separate from daily rest. A gap between shifts is time off work, not a guarantee that commuting and childcare leave you enough sleep.

Where the exceptions above displace rest, ask when you will receive compensatory rest. A care home cannot answer a missed break by saying “patients still need us” and ignore the replacement rest duty. See rest breaks at work for the rules on taking breaks.

What your employer must do about fatigue

Fatigue slows reactions and impairs judgement. A medication error, forklift collision or lapse while using food-factory cutting equipment can follow. Early starts and rotating shifts can cause fatigue too, even if you are not legally a night worker.

HSE puts the duty to manage fatigue on your employer, even if you volunteer for extra hours. Ask how the risk assessment addresses shift length, consecutive shifts, rotation, workload, breaks and recovery. It must reflect actual overtime and shift swaps. HSE warns that persistent overtime and swaps may indicate inadequate staffing. A break printed on the rota is no use without someone to cover it.

Report fatigue symptoms and near misses through the workplace safety system. If you are too sleepy to drive, arrange another way home. If sleepiness develops while driving, stop somewhere safe. For driving as part of your job, see your employer’s safety duties.

Protect the sleep you can get

HSE recommends a sleep schedule you can keep, a dark, quiet room and avoiding caffeine close to bedtime. Light meals may be easier before sleep; alcohol can worsen sleep quality. These can help, but cannot repair a rota with too little recovery time. Seek medical advice for persistent sleep problems.

What nights do to your health

Daytime sleep is often shorter, lighter and more disturbed. Repeated sleep loss builds fatigue. Shift work has been linked with cardiovascular and metabolic problems and depression, but associations do not predict an individual worker’s health.

In 2019, the International Agency for Research on Cancer classified night shift work as Group 2A, “probably carcinogenic to humans”, based on limited human evidence and sufficient animal evidence. That identifies a hazard, not your personal cancer risk or the cause of a particular cancer.

ONS counted 8.7 million people doing some night-time work in 2022. That broad statistical measure differs from the legal night-worker definition. TUC analysis in 2019 counted over 3 million regular night workers, nearly 1 million over 50.

For related problems, see long hours and health and work-related stress claims. If you are disabled, a rota change may be a reasonable adjustment. Age alone does not create that duty.

Do you get more pay for nights?

There is no statutory night premium. Extra pay can come from your contract or an applicable collective agreement. Two carers on the same hourly rate for the same 40 hours could have identical gross pay, despite one working nights. Check your agreement and payslips.

For sleep-ins, if you are expected to work for most of the shift, the whole shift counts for minimum wage, even if you can sleep between tasks. The sleep-in rule above applies where you are expected to sleep for most of it. It does not settle contractual pay or working-time rights. See minimum wage rates and rights and report suspected underpayment through GOV.UK’s pay-and-work-rights route.

Can 16 and 17-year-olds work nights?

Young workers over compulsory school age generally cannot work between 10pm and 6am. Where the contract provides for work after 10pm, the restricted period is 11pm to 7am.

Regulation 27A allows narrow exceptions for continuity or surges where no adult is available and education or training is not harmed. Retail, agriculture, postal or newspaper delivery, catering, hotels and bakeries still cannot use this exception between midnight and 4am. Hospitals and specified cultural, artistic, sporting or advertising activities have a wider exception. Equivalent compensatory rest and adult supervision where needed are required. Get advice before accepting an overnight shift.

Scotland, Wales and Northern Ireland

The main rules apply across England, Wales and Scotland. HSE or the relevant local authority enforces hours and assessment duties, depending on the workplace.

Northern Ireland’s separate Regulations provide similar protections. Use HSENI guidance and the Labour Relations Agency for disputes, not Acas. Do not assume the Great Britain reform dates below apply there. See Northern Ireland employment law.

What to do if your employer breaks the rules

Workers are protected against detriment for specified working-time reasons, including refusing unlawful requirements or asserting statutory rights. Employees also have dismissal protection. This is not a blanket right to refuse nights. Get advice before refusing contracted work or resigning. If shifts disappear after a complaint, save both rotas and check zero-hours rights.

Night-work limits and assessment duties go to the safety regulator. Refused rest, breaks or compensatory rest can go to a tribunal. Regulation 30 does not provide a direct tribunal claim simply for a missing assessment. Retaliation, discrimination or dismissal may create separate claims.

1. Record what happened. Save start and finish times, work done, breaks missed, rotas and messages. Note fatigue symptoms and near misses. Do not copy patient or customer information into your personal records.
2. Ask for a specific fix. Request the assessment, replacement rest or rota review in writing. Ask which exception applies. Set a reasonable reply date, but do not wait if there is an immediate safety risk.
3. Bring in your union or safety rep. Ask them to review the rota and fatigue assessment with you. Acas, Citizens Advice and law centres can help you identify the right complaint route.
4. Report safety breaches. Contact HSE or the relevant local authority about night-work limits or missing assessments. In Northern Ireland, use HSENI. See how safety enforcement works.
5. Protect any tribunal claim. For Great Britain working-time claims whose relevant date is on or after 1 October 2026, the normal limit is 6 months less a day. Earlier events can still have a 3-months-less-a-day limit. Start Acas early conciliation in time and get the deadline calculated for the actual claim. See bringing a tribunal claim.

What is in force and what is still scheduled

The position below is for Great Britain on 1 October 2026, using Acas’s timeline. The Employment Rights Act 2025 has not replaced the night-work caps or assessment duty, or introduced a night premium.

1. 6 Apr 2026In force. Sick pay from the first day

   Statutory Sick Pay is payable from the first day of illness, and the lower earnings limit has been removed. Other eligibility rules still apply. See Statutory Sick Pay.

2. 7 Apr 2026In force. Fair Work Agency established

   The agency brings enforcement bodies together and takes on rights such as holiday pay and sick pay. Do not assume it replaces HSE or local authorities for night-work safety complaints.

3. 1 Oct 2026In force. Longer tribunal time limits

   The normal working-time claim limit rises from 3 months to 6 months, subject to transitional rules and early conciliation.

4. 30 Oct 2026Scheduled. Stronger harassment duties

   The sexual-harassment prevention duty becomes “all reasonable steps”, with new third-party harassment liability. Relevant to lone workers dealing with customers. Not yet in force.

5. 1 Jan 2027Scheduled. Dismissal and union-rights changes

   The ordinary unfair-dismissal qualifying period falls from 2 years to 6 months and the compensation cap is removed. Employers must tell workers about union-membership rights. These are scheduled changes, not current rights.

6. 2027, exact date not setScheduled. Guaranteed hours and shift notice

   Planned rights cover guaranteed hours, reasonable shift notice and compensation for cancelled, shortened or moved shifts. Details remain subject to consultation.

Questions people ask

Can an adult night worker do a 12-hour shift?

Sometimes. The standard 8-hour limit is an average, so an individual 12-hour shift is not automatically unlawful. The stricter hazardous-work cap has no averaging, but statutory exceptions and collective or workforce agreements can change either limit. The employer must still assess fatigue and provide the rest the law requires.

Can you decline the night-worker health assessment?

Yes. Your employer must offer it free before night work and at regular intervals afterwards, but you do not have to accept. If a doctor links health problems to nights, ask for transfer to suitable day work where possible.

Must your employer pay extra for nights?

There is no statutory night premium. A contract or collective agreement can provide one. Sleep-ins have a separate minimum-wage calculation, depending on whether you are expected to sleep or work for most of the shift.

Can a 17-year-old work overnight in a shop or hotel?

The usual restricted period is 10pm to 6am, or 11pm to 7am where the contract provides for work after 10pm. Narrow exceptions exist for continuity or surges where no adult is available and education or training is not harmed. The midnight-to-4am prohibition remains for these sectors.

Does a 6-hour night shift give you a statutory break?

The standard adult entitlement to at least 20 minutes applies when your working day is longer than 6 hours, not exactly 6 hours. Your contract or the risk assessment may require more. The usual daily rest is 11 consecutive hours, with weekly rest as well. Young workers have different rules.

Who should you contact about an unsafe night rota?

Start with your manager and union or safety rep. Report hours-limit and assessment breaches to HSE or the relevant local authority. Refused rest or retaliation may need a tribunal claim; contact Acas promptly about the route and deadline. In Northern Ireland, use HSENI and the Labour Relations Agency.

Sources

1. Working Time Regulations 1998, legislation.gov.uk. In particular, regulations 2, 6, 7, 9, 10 to 13A, 21, 23, 24, 27A and 30.
2. Night working hours, GOV.UK. Hours, regular overtime, pay and sleep-ins.
3. Health assessments for night workers, GOV.UK.
4. Night workers, Acas.
5. Fatigue, Health and Safety Executive. Employer duties and the 20% major-road accident estimate.
6. Managing shift work, HSG256, Health and Safety Executive.
7. Hints and tips for shift-workers, Health and Safety Executive.
8. IARC Monographs Volume 124: night shift work, International Agency for Research on Cancer. Group 2A classification announced in 2019.
9. The night-time economy, UK, 2022, Office for National Statistics. The broad 8.7 million night-time-work measure.
10. Older workers powering an increase in night working, Trades Union Congress, 2019. Regular night-worker estimates.
11. Working Time Regulations (Northern Ireland) 2016, legislation.gov.uk.
12. Working at night, nidirect.
13. Working Time Directive, Health and Safety Executive for Northern Ireland.
14. Employment Rights Act 2025 implementation timeline, Acas.
15. Employment Rights Act 2025, legislation.gov.uk.
16. Tribunal time-limit transitional provisions, SI 2026/954, regulation 4, legislation.gov.uk.
17. Caring about workers’ rights, Focus on Labour Exploitation, July 2024. Exploitation risks in care.