Hi Jonnie
I won't bore everyone with too much detail, but S 15 is basically to enable Regulations to be issued.
The HSAW is an 'Enabling Act', aside from all the details about Powers of Inspectors etc, the key thing is that Regulations pertaining to 'health & safety' can be issued very easily.
An 'Act' has to go back and forward from Commons to Lords being debated and can take years to get through. Regulations are literally signed off by the Sec of State, and copies placed out for MPs to review. If no relevant complaints are received, then after 30 days they are law.
And that's really the purpose of S15.
As to 'deregulation' in 2010, the Coalition Government made a big deal about the 'Red Tape Challenge', but after 2 separate reviews, The government's 2010 Lord Young, "Common Sense, Common Safety" and the 2011 Independent Report "Reclaiming health and safety for all (Löfstedt report)", it was clear that there wasn't the problem they imagined, but there was a problem in some sectors.
The hundreds of Regulations they removed and consolidated were dross that should have already been sorted out.
For example, just some of the Regulations relating to mines:
Coal and Other Mines (Fire and Rescue) Order 1956
Coal and Other Mines (Fire and Rescue) (Amendment) Regulations 1980
Coal and Other Mines (General Duties and Conduct) Order 1956
Coal and Other Mines (Locomotives) Order 1956
Coal and Other Mines (Metrication) Regulations 1978
Coal and Other Mines (Safety-Lamps and Lighting) Order 1956
Coal and Other Mines (Sanitary Conveniences) Order 1956
Coal and Other Mines (Shafts, Outlets and Roads) (Amendment) Regulations 1968
Coal and Other Mines (Shafts, Outlets and Roads) Regulations 1960
Coal and Other Mines (Sidings) Order 1956
Coal and Other Mines (Ventilation) (Variation) Regulations 1966
Coal and Other Mines (Ventilation) Order 1956
The Coal and Other Safety-Lamp Mines (Explosives) Regulations 1993
Coal Mines (Cardrox and Hydrox) Regulations 1956
Coal Mines (Clearances in Transport Roads) Regulations 1959
The Coal Mines (Control of Inhalable Dust) Regulations 2007
Coal Mines (Firedamp Drainage) Regulations 1960
The Coal Mines (Owner’s Operating Rules) Regulations 1993
Coal Mines (Precautions against Inflammable Dust) (Second Amendment) Regulations 1974
Coal Mines (Precautions against Inflammable Dust) Amendment Regulations 1977
Coal Mines (Precautions against Inflammable Dust) (Variation) Regulations 1960
Coal Mines (Precautions against Inflammable Dust) Order 1956
Escape and Rescue from Mines Regulations 1995
Management and Administration of Safety and Health at Mines Regulations 1993
Mines (Control of Ground Movement) Regulations 1999
Mines (Manner of Search for Smoking Materials) Order 1956
Mines (Medical Examinations) Regulations 1964
Mines (Precautions Against Inrushes) Regulations 1979
Mines (Safety of Exit) Regulations 1988
Mines (Shafts and Winding) Regulations 1993
Mines and Quarries (Metrication) Regulations 1976
Mines and Quarries (Tipping Plans) Rules 1971
Mines and Quarries (Tips) Regulations 1971
Mines and Quarries Acts 1954 to 1971 (Repeals and Modifications) Regulations 1974
Mines and Quarries Acts 1954 to 1971 (Repeals and Modifications) Regulations 1975
Mines Miscellaneous Health and Safety Provisions Regulations 1995
Miscellaneous Mines (Explosives) Regulations 1959
Miscellaneous Mines (Metrication) Regulations 1983
Miscellaneous Mines (General) Order 1956
Stratified Ironstone, Shale and Fireclay Mines (Explosives) Regulations 1956
Classification and Labelling of Explosives Regulations 1983
And that's before we even get into the realm of all the other explosive regulations....
The level of safety regulation in the UK is probably the best in the world. In many places it is down to States or Regional Governments, not a national set of regulations at all.
When people have moaned about 'EU' H&S restrictions they have usually been originated by the UK.
Why do I know all this trivia?
I'm a chartered H&S practitioner, and I make it my job to make it simple for my clients, who are usually small business, local charities and the like.