Health Assessments for Night Workers

Information Update: 10/2023 • Issue Date: 09/05/2023

By way of general reminder, employers are required by law to offer free health assessments to night workers before they start working at night and on a regular basis thereafter.  The obligation is for the employer to offer a free health assessment: the worker is not obliged to accept.

Night Workers

Night workers are those who regularly work at least 3 hours during the ‘night period’.

The night period is 11pm to 6am, unless the worker and employer agree a different night period. If they do, it must be 7 hours long and include midnight to 5am. It must be agreed in writing. Workers may also be night workers if there’s a collective agreement (for example, trade union agreement) that states their work is night work.

Health Assessment

These assessments may be in the form of a questionnaire or a medical assessment.

The assessment must be written by a qualified health professional. It can be in the form of a questionnaire.

The purpose of the assessment is to determine whether the employee is medically fit to undertake night work or has any underlying conditions that may be affected by working nights.

Employers must take into account that night work might increase a worker’s stress levels.

If the assessment raises concerns, employers should refer the employee to a doctor. If a doctor determines that the employee has health problems caused by night work, the employer must transfer the employee to daytime work if possible.

A repeat assessment must be offered regularly.


Employers must keep confidential records of:

  • The health assessments (keep for 2 years)
  • Dates when assessments were offered (if a worker did not want one)

Young Workers

Young workers (16 and 17 year olds) must not work during the ‘restricted period’. The restricted period is:

  • Between 10pm and 6am if their contract does not say
  • Between 11pm and 7am if their contract allows for them to work after 10pm

However, they can work until midnight or from 4am onwards if it’s necessary in the following types of work:

  • Advertising
  • Agriculture
  • A bakery
  • Catering
  • A hospital or similar
  • A hotel, pub or restaurant
  • Post or newspaper delivery
  • Retail

But this is only if:

  • There are no adult workers available to do the work
  • Working those hours will not have a negative effect on the young person’s education or training.

If they do need to work after 10pm or before 7am, the employer must make sure the young worker:

  • Is supervised by one or more adult workers where necessary for their protection
  • Has enough rest at another time if they need to work during their normal rest breaks or rest periods

It’s against the law for anyone aged under 18 to work between midnight and 4am, even if they do one of the jobs above.