The HSE guidance is now 18 years old — it was published in 2006 — and it is not keeping pace with evidence of harm. In June 2019, for example, the International Agency for Research on Cancer (IARC) published an evaluation of night shift work by a working group of 27 scientists from 16 countries which concluded that night shift work is probably carcinogenic to humans, with limited evidence of a link to breast, prostate and colorectal cancers.