Callaghan served on the Low Pay Commission from 1997 to 2000 and played a key role in the introduction of the National Minimum Wage in April 1999.
He helped establish the public inquiry into the crash by Lord Cullen and championed subsequent improvements in rail safety.
Following the 2007 release of Foot and Mouth virus from the Pirbright site, he led a review into the regulation of animal pathogens for DEFRA, publishing the results on 13 December 2007.
Callaghan is Chair of the British Occupational Health Research Foundation,[7] and has previously served on the board of Business in The Community.
[8] In June 2007, Callaghan received a knighthood in the Queen's Birthday Honours in recognition of his outstanding contribution to health and safety management at work.
[9] Callaghan received a Distinguished Service Award from The Royal Society for the Prevention of Accidents (RoSPA), in August 2007.