One thing you can do is by taking full size pictures of existing signs on construction sites put on your pc adjust the size and print it,very primative but it works,or contact other safety professionals most of them usually have some signs that you can copy from them and print,HSE also have some Posters you can print from thair webpage.If you have good skills with pc drawing programs you can look on the web for safety signs and try to duplicate it.hope this helps a little

Copy without my permission original material from my website, my lab etc that I have produced or paid for and you will be at serious risk of a nasty legal challenge. You will probably breach copyright and you will certainly be guilty of theft!

K I advise that you cost out/ assess [Time, effort, money, work stoped to progress making the sign, whould your efforts be better spent elsewhere etc] your actions in the light of what you do and go from there as its probably not cost effective to DIY such areas these days especially so when noting the copyright situation and the need to comply with Brit / ISO/ UN standards