I was in New York City, recently, and came across two liquid nitrogen dewars on a street corner.  One had a regulator on it and tubing running into a manhole in the street.  I think the dewars had been there awhile as one had been tagged with graffiti.  No one in sight that might have anything to do with the dewars.

Gas cylinders get "managed" in creative ways, it would seem.  I guess chaining to a tree satisfies the "prevent from falling" requirement.  Rolling along the pavement - ill-advised, certainly.  I wonder what they were using the nitrogen for.

Debbie M. Decker, CCHO, ACS Fellow

Chair, Division of Chemical Health and Safety

University of California, Davis

(530)754-7964

(530)304-6728

dmdecker**At_Symbol_Here**ucdavis.edu

Birkett's hypothesis: "Any chemical reaction

that proceeds smoothly under normal conditions,

can proceed violently in the presence of an idiot."