Wayno I agree with you the rule book offers up minimums. You shouldn't be shy about going beyond.
What do you think about the following?
HIGH RESILIENT (HR) is a foam material that is produced to offer a longer useful life than non-HR foam. HR foam is often also rated as fire resistant (FR). Tell your Upholsterer that you are concerned about fire safety and long life of your new foam and ask him to verify that your new foam is rated both HR and FR. Most States have Furniture Flamibility Laws that will require the use HR-FR foam materials.
Some foams contain Fire retardant additives I also found theres fire retardant classifications for the various types of foams. The denser foams like the HR seem to have the FR clasification and the added benifit of a longer life span for deteriation.
