If my previous post came across as snarky or accusatory I apologize. What I really wanted to know is the exact set of circumstances that caused the tank contamination. The intent was to be a learning moment for all on this forum. If it was containers mislabeled or re-purposing it is a valuable thing to be passed along. I am in aviation (flight testing) and we are always trying to learn from error (often fatal). The toughest thing I have ever seen is a presentation by people that had their coworkers killed by a mistake...for the sake of others to not screw up.
