Home Improvement Questions? Ask a Handyman for Answers
All commercial flooring and paint should be fire retardant anyeway, there is clearly more of a need in an elevator since if some did decide to smoke inside and ash set light to the floor you have got smoke building up in a small confined area, and paint is more concerned with the fumes which are given off, and the risk is due to the time it could take for the elevator to reach its destination and the doors open.
The building regulators (code) will depend on your local by-laws, and local county building office or fire station can advise the minimum requirements you need to comply with.
In terms of a suitable flooring, I have often suggested to customers to go for commercial vinyl, its one of the cheapest materials, long lasting, fire retardant\resistant, and doesn't weight a great deal, however depending on the look of the building I have seen carpet, tile and even stone fitted.
In terms of paint I would be inclined to use something like Hammerite metal paint.
The paint I referenced is a European product, exported to the US, and as such doesn't have the certifications your seeking. I am surprised the service company haven't made a recommendation for the particular model of elevator and surface what paint would be best suited, as you would need to establish if they are suggesting to go back to metal and therefore need a primer or just add a top coat to the paint already in place.
I have however found a firm which provides a range of products, which meet the specification your seeking, details can be found here.