IT used to be safe contrator who most commercial work req'd, now if you want to win any goverment bodys work are most commercial CHAS is wot they want. But if you have held safe contracor for 12 months they would let you apply for CHAS n you could have that for 12 months under like grand father rights..Then at the end of 12months have to fill all the paper work in wait for an assessor to review all your paper work n then get back to ya,To tell ya wot lacking n wot extra ya need to document daily inspection of equipment wkly monthly ect so you have all the relevant docmentation n "proof" of your safe working methods n practices. Each time for a fee..And if your successful all well n good. Not bad if ya get the work after...