You should know first aid at work for many reasons. Put another way, there isn't one good reason not to know first aid anywhere, including the workplace. Many people are afraid that learning first aid procedures will be difficult and if it came time to use them they wouldn't be able to save a life. This is just fear talking, as you will be tested by a trained instructor who will make sure you do master first aid at work or anywhere else before passing you. Plus, that fear is illogical, because if you didn't learn first aid then you definitely wouldn't be likely to save a life.
Many companies will offer free training to employees so they will know first aid at work. This may involve a trainer coming into the workplace to teach lifesaving techniques or paying for interested employees to take first aid courses on their own time. Either way, learning first aid is the right thing to do.
Knowing what to do in a medical emergency will have you prepared inside and outside the work place. It may be a family member or friend's life you end up saving rather than a co-worker's. You may not ever need to use the first aid techniques you learn, but, like having insurance, you'll be prepared in case of an emergency.
Most workplaces are required by law to have a first aid kit. In learning first aid at work, you'll know how to properly use the kit. This knowledge can also be used in your home, as you should have a first aid kit there. If you engage in outdoor recreation such as camping, fishing, hiking or cycling, you should carry at least a small first aid kit. Along with learning how to effectively use the kit in an emergency, if you take first aid training, you'll know how to perform cardiopulmonary resusitation (CPR) if someone has stopped breathing and what to do if a person is choking.
If you don't know proper first aid procedures and the unexpected happens, such as a person choking, you may panic in trying to think how to handle the situation. Some people may think of a stomach thrusting technique called the Heimlich maneuver that they've seen done in movies and try it on the choking person. In reality, this is the wrong thing to do because the thrusting may cause further injury to the chocking person. Getting the person to cough or drink fluids may work more effectively; if these don't help, then the Heimlich maneuver might be able to be performed. The thing to realize is that procedures change and if you take first aid at work, you'll learn the techniques considered to be the safest as well as the most effective.