I understand. When I drove with two barrels of Nitro in my wan I got the same worry. But the weight of the barrels were more dangerous so I fasted them really good.

When barrell of Nitro was dropped from helicopter it did not explode. Because there is a risk Angus company does add the marker product to Racing Fuel. I did read this from their or others "user manual"

You are able to buy without the marker for example using in painting because in some processes the purity is important.