All aspects of the safety of engineered systems. Readers: 6100 (0.1%) {25%} Mesgs per month/day: 173/6 {27%} Crossposting: 17% {57%} Megs per month/day: 0.2/0.007 {26%} Sites reciving this Group: 47% Cost ratio ($US/month/rdr): 0.01