Well, on average resin is said to contain over 50% THC, some say it is over 60%. Resin is concentrated THC TAR! I know, I said it, TAR! It is tar, and it can very easily be considered dirty, but the damage to the lungs is not that much higher than smoking weed. Smoke is smoke, but resin smoke is just more concentrated. It might taste like shit, but no more than smoking stems does. I've ground up stems and smoked them, they didn't get me high. But, I have smoked resin and it has got me very high.