We experienced an industrial accident at work - we have theorized that the welder placed the oxyacetylene torch inside of the pipe that he had burned a 4" hole just 40 minutes earlier. The pipe, a 14" steel pipe pile is driven into bedrock and capped with concrete.

We believe that the employee set the torch head into the pipe with the acetylene valve partially open.

When he returned from lunch he removed the torch from the pipe, lite the torch and while he was pulling himself up close to the pipe pile passed the flame of the torch by the hole. A flash of fire shot out and his face and eye was burned.

The welder has denied that the torch was placed into the pipe pile hole during the lunch break.

We obtained water samples from the interior of the pipe the day after the incident. Incidentally, the welder will be ok.

The results indicate 1 ppm of acetone in the water. Does the presence of acetone suggest that gaseous acetylene was inside the pipe? Does gaseous acetylene break done into acetylene and acetone at ambient pressure? Acetone is 2 times heavier than air.

Thanks for the consideration of your reply!