HSE would become involved if an accident was reported under RIDDOR, or they received information (whistleblower or a visitor who spoke out of turn and was overheard) or if they made one of their random checks which are a lot less frequent these days due to the pressure of business through the accidents that are reported and also their constant attendance at Building Sites looking for misdemeanours. Unfortunately there is so much statute legislation now that most firms do maintain there own H & S departments and if you have the relevant qualifications NEBOSH/ IOSHH et al and have the additional knowledge of the businesses you can help. there is a great deal of money to be made, setting up your own H & S firm and take the business on as a sub contractor. So all the major construction companies maintain their own H & S Departments, but smaller firms find it more efficient to off load it to one of these H & S companies who also often run all the training records. Pedro is spot on everything stems from HASAW 1974 and all subsequent amendments and yes Guilbert Cadburys would have their own H & S Dept, but possibly did not consider picking something off the conveyor belt dangerous, because remember all of us who were children years ago were much more sensible than the snowflakes of today...and we had stricter parents who did not worry about the nanny state punishing you for slapping your badly behaved child...earhole and clip were the usual remedy. The great thing about today is that it is a maze of initials...NEBOSH, IOSHH, RIDDOR, HASAW. LOLER. PUWER, BS7121 Parts 1 to 4, ALLMI, IPAF, NPORS, CPCS, CSCS, RTITB, ITTSAR, Lantra, PASMA and the list goes on.