Level 83 spoilers

Is there a difference between heating grade ceruleum and airship grade ceruleum? Felt really silly scavenging for those cartridges when I have a stack of 500 ceruleum tanks in my inventory since I run the FC submarines. The airship tanks say they are suitable for the ships, but it would have been an interesting data point if Julius explained that the airship grade stuff emits too many poisonous fumes to be used to heat homes.... or something.