One of the things you should always do after cleaning or any other disassembly of your firearm is to perform a safety check once it’s back together. We put a lot of rounds through our firearms and over time pieces wear or break. One of the things you should always check is if the primary safety, if your firearm came from the factory with one, is working properly.
The majority of the firearms we use in competition come with some sort of safety from the factory. The only exceptions are revolvers and selective action pistols with decocker levers instead of a safety. If your gun came with a factory safety, it must be functional. Some pistols have a safety lever and a grip safety and in divisions other than Production and Carry Optics, the grip safety can be disabled as long as the primary safety is functional. And yes, if you shoot Production or Carry Optics with a selective action pistol that has a factory safety, the safety must work even though you always start hammer down.
Chronograph officers are becoming more diligent about checking firearm safeties and over the last couple years have found quite a few guns with non-functional safeties. What does the chrono officer do? He/she declares the firearm unsafe and calls the RM. The RM then requires the competitor to repair the firearm or replace the firearm to complete the match. Want to avoid this hassle? Check the function of your firearm safety before you go to the match!