# The Railways (Safety Critical Work) Regulations 1994, Regulation 4: Hours of work


(1) Every employer shall ensure, so far as is reasonably practicable, that no employee of his undertakes any safety critical work for such number of hours as would be liable to cause him fatigue which could endanger safety; and in determining whether he would be so liable regard shall be had to the length of time between periods on duty.
(2) For the purposes of paragraph (1) a person shall be regarded as undertaking work throughout the period he is on duty.

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Source: https://www.legislation.gov.uk/uksi/1994/299/regulation/4 (the official version)
Page: https://openlegislation.uk/railways-safety-critical-work-regulations-1994/regulation-4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.