The CITB Test(Health, Safety and Environment (HS&E)) is an important way for construction workers to show that they can be safe on the job when gaining their CSCS Card. It's also a way for them to know that their fellow workers are as safe on the site and not put them at risk of injury. For this reason, employers are increasingly making CSCS cards mandatory to enable you to work on construction sites. Regular checks are carried out on CSCS card holders to ensure the card is valid. If you are holding the wrong type of card for the type of job you are doing, you may be asked to leave the site.