I hope someone can answer this.

I am using table rate shipping when adding products to the shopping cart. I have two tables, one set up for First Class Post and one set up for Royal Mail Track and Trace. For most products it is ok to show both shipping options, however we have just discovered that certain items require special insurance as they are flammable products. The insurance has already been added onto the prices of these products so not a problem there and it doesn't affect the shipping price. But on items where insurance has been applied to the price I need to be able to display Royal Mail Track and Trace only as a shipping option. All other products will display both First Class Post and Royal Mail Track and Trace, it is only the flammable items where I need to disable the First Class Post. So how would I go about doing this?

I have seen similar posts but none of them really fit.

This one is close

http://www.zen-cart.com/forum/showthread.php?t=175429


But ideally I would like to be able to control it from the admin as not all products are listed yet so I don't know what the product ID's or Category ID's will be for each flammable product so I don't know which one's need to have First Class Post Disabled on.