Tenne, if nitric acid burned the eyes and throats of desperate hikers who were so numb they couldn't feel their hands, then biting one's knuckle in agony of eye pain would be excusable. I mentioned it because the subject of errant rocketry has just surfaced in the DPI news. I mention it because nitric, sulphuric, and hydrochloric acid are harsh on the body. Shoot, even vinegar is,hard on the eyes. Personally, I do not believe a Russian missile went 900 miles in the wrong direction to precipitate the DPI. Then again, I haven't been chewing my knuckles with worry about that possibility, just yet. Hope that helps.