I see on facebook today that a Ham Radio site is publicizing a dangerous antenna launcher, and there are many designs and products available like this. It is important to understand what the safety issues are when you are choosing, building and using an antenna launcher.
Dangerous Launchers often use Non-Pressure-Rated PVC components. These are PVC parts that are not rated for pressure service. They are designed for drain system usage, and are not designed or tested for pressure use. A common example is a 3″ to 1 1/2″ reducer coupling, or endcaps that are flat rather than domed. Pressure rated fittings are much thicker, heavier and have much longer gluing surfaces. Make sure any launcher you pressurize is constructed from 100% pressure rated components! (Our PVC components are pressure rated for a minimum 130 psi operating pressure, and minimum burst pressures of 700 psi. Most models have pressure safety valves.)
Dangerous Launchers often use threaded holes drilled in single thickness PVC material. We have seen launchers fail catastrophically from a crack radiating out from a hole drilled in the curved portion of an endcap. Never use a hole in PVC that is a single thickness, it should be backed up with another layer of PVC to protect against cracks causing material failures. In our launchers the holes in the thick schedule 40 PVC are either in double thick areas, or are backed up by another PVC layer to protect against failure.
Dangerous Launchers often use hard projectiles, such as PVC plastic or lead. These projectiles can do a great deal of damage to whatever they strike. This dangerous even in remote areas because they can bounce back or deflect in unexpected directions and damage equipment, vehicles or even cause injury. Soft projectiles such as tennis balls can get the job done without such risks.