I personally have given hundreds upon hundreds of injections to tons of people at work and let me tell you, you will not die from either injecting small bubbles of air into a muscle or even into a vein, there is no way it can kill you, I've done it to myself and others and ...nothing. You'd have to inject a good 3cc's with a lot of force into a main artery, otherwise..forget it. As for aspirating and hitting veins, good luck. How will you know when you hit a vein? You won't, aspirating won't and doesn't do anything. Next time you shoot in your quad and you aspirate, tell me if you don't get blood in the syringe, you definately will, 'cause there is blood there, that's why. Even if you were to hit a vein chances are you'd pass the needle right through it, it's unlikely that you'd hit right on and be able to inject right into it, most junkies can't even hit there veins properly. If your good at injecting in proper sights, then there is little if any risk of hitting veins. And even in the unlikely event that you did, believe me the worst thing that would happen is maybe a little nausea or dizziness. I give at least 5 injections/ day of POWERFUL mind sedating anti-psychotics and nobody has ever died in front of me or had any problems.