Its china, you really think they have regulations? And if they did they would be enforced if the system is making money?

But I agree, hydrogen is way cheaper and more efficient for unmanned dirigibles. Also I wonder how well it would burn at super high altitude w/ the limited oxygen?

And even if it did burn the fire would be out well before it hit the ground. Not like the Hindenburg that was low to the ground and its outer coating was massively flammable.

Fun Fact: The reason why they had to use hydrogen was we (the US) clocked them as an enemy prior and refused to sell helium to them. Sound familiar?