> You're appealing to a need for safety, but where you draw the line is arbitrary. I am only demonstrating that, following the same logic you are using, I draw the line somewhere else which results in a completely different, though absurd, outcome. What is the principle which makes where you drew the line correct and where I drew the line incorrect?

Maybe there is no first-principles answer here (certainly either of the obvious principles-based approaches gives absurd results). Maybe we do just have to weigh up the costs and benefits of individual cases as best as we can.

> You also suggest that because transporting these materials in an unsafe manner is illegal and punishable by a fine, that that is somehow a bigger deterrent to businesses than the threat of a lawsuit. How so, and why is the illegality of it supposed to be a bigger deterrent than a lawsuit?

Leaving it up to lawsuits to enforce public safety doesn't square very well with the limited-liability corporation. Imagine ten companies engaging in dangerous shipping practices, and one of them actually having an incident. If we only fine the one that had the incident, we bankrupt it and don't recover the full public-health cost.