Latchy look on the membership page which is accessible via the home page for all the details. I got TECH IOSH status by passing the NVQ Diploma in occupational health and the environment, you can also gain it through passing the NEBOSH general certificate. You also need to show you have experience of working in H&S for a few years and give evidence. Good luck

Tech IOSH require you to have an approved level 3 H&S qualification, coupled with a few years practical experience in an H&S role. As sean says, check the membership section on IOSH homepage.