I have a small compressor. I mainly use it to blow dust and chips off before I leave the shop. I've heard of eye and ear injury by getting the nozzle to close. Even a death by horseplay when a nozzle was used to " goose" someone and his guts got blown out. I was amazed to learn it's so dangerous it's banned in many work places.
This Canadian website http://www.ccohs.ca/oshanswers/safet...essed_air.html says :
Second, compressed air itself is also a serious hazard. On rare occasions, some of the compressed air can enter the blood stream through a break in the skin or through a body opening. An air bubble in the blood stream is known medically as an embolism, a dangerous medical condition in which a blood vessel is blocked, in this case, by an air bubble. An embolism of an artery can cause coma, paralysis or death depending upon its size, duration and location. While air embolisms are usually associated with incorrect diving procedures, they are possible with compressed air due to high pressures. While this seems improbable, the consequences of even a small quantity of air or other gas in the blood can quickly be fatal.
So, I'll be more careful.