I think we should treat the combustible dust power like an industry power page. Change the title to Combustible Dust (currently combustible dust vacuum cleaners) and link it to either explosion proof vacuum cleaners or vacuum cleaners. We can use this article to show the imporance of manufacturers using vacuum cleaners. No new sub category would be needed.
If we were to create a new subcat called "Combustible Dust Vacuum Cleaners", we would have to make some changes to the power page content and have Don edit the content he originally wrote for me since it was about combustible dust and not combustible dust vacuum cleaners.