I read a lot of NIOSH reports on Fire Fighter fatalities and injuries, but had never read the industrial ones. EVERYONE SHOULD READ SOME OF THESE. It will make you think twice.
Here's one that struck me as odd that is pertinant:
On November 8, 1996, a 48-year-old male crew member (the victim) died from injuries after he was struck by a grease fitting propelled through the air while performing maintenance on a vessel steering quadrant. The victim was part of a six-person crew of a fishing vessel performing various duties including routine maintenance and repair of the vessel's equipment. At the time of the incident, the vessel was moored at a local harbor. The victim had been on duty for 2 hours and was completing maintenance on the steering quadrant and related assembly in the vessel's aft (rear) storage compartment (lazarette). As part of the maintenance procedure, the victim was greasing the rudder shaft by pumping grease into the rudder shaft tube (or trunk). Assuming the grease connector (or zirk) had malfunctioned, the victim attempted to remove the grease fitting from the trunk. The grease fitting struck and entered the victim near the center of his chest. The victim was able to climb to the vessel deck where he collapsed. Co-workers radioed for emergency medical services. Due to the condition of the victim and the nature of his injury, he was transported by the responding police officer to the local medical clinic. The victim was pronounced dead at the medical clinic. It is surmised that the victim thought the grease fitting had failed and attempted to remove it without realizing the pressure exerted from the grease within the rudder shaft tube.
On edit, a little more info: The victim had been performing maintenance on the steering quadrant and rudder mechanism and had been adding grease to the rudder trunk using a manual grease gun. Normally, grease emerged from the top of the trunk when filled to capacity, having flowed around the thrust bearing and out top grease channel; in this case, the victim reported to fellow crew members that no grease emerged and the fitting was not taking any grease. The victim requested a crew member to try to pump grease through the zirk. After exiting the lazarette, the victim stated to a crew member (the witness) on deck that he would change the fitting, assuming the zirk had malfunctioned. The victim returned to the lazarette, positioned himself in front of the fitting, and began using a wrench to remove the fitting. The fitting was released from the trunk with a great force, impacting and penetrating the victim's mid-chest area. At this time the witness who was still on deck heard a loud "pop" above the regular on deck noise.
A manual grease gun with a total capacity of 20 oz. bulk fill can deliver 10,000 pounds per square inch (psi) 1. The available information suggested that pressure in the rudder trunk could have been that high since the grease gun had been pumped more than 100 times. Although verbal procedures were discussed for the maintenance of the steering assembly, inspection guidelines could help employees understand and recognize potential problems.
Wow, 10,000 psi. I knew it was high but I didn't think it was that high. So in an attempt to apply this to something we might everyday use would the piston you pump with grease to tighten up tracks on equipment do the same thing. Do those hold pressure like that.