The SHP magazine they issue monthly to members has dozens of jobs in the back, also on the web site is web forum.
If you fancy overseas try worldwideworker.com and oilcareers.com
Not to rain on your parade so to speak but a NEBOSH general is the bottom end of the quals market.... Most decent management type posts look for the diploma or equivilent. Check out the NVQ route ? you may get your grad IOSH out of it ? bcs.co.uk
While the IOSH site is good, it does not allow job advertising as such. Try this new site for a different approach. I have no connection with the site owners, but I'm looking for another safety job too and have found this site useful for contacts.
Certainly worth trying. You're right that he won't find it that easy getting a safety job at the moment with no prior experience outside HM Forces. It's the perennial Catch-22 I'm afraid - "sorry mate you don't have enough experience" - so how's he supposed to get any if he can't get a job... H&S forums are full of people offering to do "shadowing" work for free to get experience.