I would check to see if what Turtle is saying is true. It seems to me that once cured, there wouldn't be any emission of chemicals from the floor paint that would affect food.

I like to think I know something about paint. The statement was made that acrylic floor paints consist of acrylic plastic resins and titanium dioxide. While all acrylic paints do contain gazillions of tiny hard spheres of a plastic called polymethyl methacrylate (otherwise known as Plexiglas), the titanium dioxide in paints is the white pigment that gives white, and pastel tint bases their white colour. You won't find titanium dioxide in "deep" or "accent" tint bases because the white titanium dioxide would prevent you from tinting such a base to a true red or blue colour. For example, the white titanium dioxide and the red pigments (typically Quinacridone red) combined would give you a pink paint instead of a red paint. Similarily, the white titanium dioxide combined with the blue pigment (typically phthalocyanine blue also called "Thalo Blue") would give you a "Powder Blue" paint instead of a true Royal blue paint.

In my humble opinion, NO latex paint, even the so called "Porch and Floor Latex Enamels" will stand up well on a floor. The harder the service the paint has to stand up to, the harder the paint you need. This is why Polyurethanes became the clear coat of choice over hardwood floors in the 1950's. The hardness of alkyd based polyurethane was much higher than that of the Carnauba Wax it replaced, and that meant that the floor stayed looking new much longer, and it was too hard to respond to polishing the way Carnuaba Wax would. Consequently, you didn't need to polish polyurethaned hardwood floors like you did with waxed hardwood floors.

If I was repainting a floor in a commercial application, I would shut down the freezers and allow the floor to warm up to room temperatures and have the old paint blasted off the concrete floor with baking soda or a more aggressive powder. Then I would apply either an epoxy floor paint or a moisture cure polyurethane floor paint.

I don't really know any big names in epoxy floor paints, but a company called Wasser is probably the biggest name in moisture cure polyurethane industrial coatings, and that would include factory and warehouse floor paints.

Moisture cure polyurethanes aren't polyurethanes at all. They're actually polyureas. But, since they compete with alkyd based polyurethanes and catalyzed water based polyurethanes in the market place, people call them "polyurethanes" just to keep things simple. A moisture cure polyurethane floor paint will stink to high heaven as it cures, but once cured shouldn't smell at all. It will give you a floor coating that's comparable to epoxy floor paints in hardness and durability.

Certainly, I'd check to see if the Health Department has any concern about the KIND of paint used in a walk in freezer, but in a commercial application like this, I think it would be better to use an industrial coating meant for factory and warehouse floors rather than a retail floor paint meant for residential applications.