Know the difference: epoxy-coated vs. PVC-coated closet shelving

One subtle difference between the ventilated wire closet organizer products that you will find on the market is the type of process that is used at the manufacturer to coat the wire in order to color it and protect it from rusting and wear. It's worth your time to understand the basics of these processes, as the finishing process used at the manufacturer will impact quality and durability of the shelving over time.
Epoxy-Coated Wire Shelving
This type of wire shelving is finished at the manufacturer with a process known as "powder-coating". During the powder coating process, small particles of powered paint are deposited on the unfinished wire shelf. The shelf is sent through a large furnace where the paint particles melt and adhere to the shelf. The result is a "painted" shelf that has a smooth, consistent, durable finish that resists scratches, scrapes, and rusting. Closet organizers that use epoxy-coated wire shelving include Rubbermaid and Elfa.
PVC-Dipped Wire Shelving
An alternate method used by some manufacturers to finish wire shelving is called PVC-dipping. During this process, unfinished wire shelving is dipped into a pool of heated, liquid PVC. When the shelf is removed and cooled, the PVC hardens on the shelf and results in a smooth, consistent finish that protects the wire. Closetmaid is one of the major manufacturers who uses the PVC-dipping process.
Why You do NOT Want to Choose PVC-Dipped Shelving
There are two reasons that you will want to choose an epoxy-coated wire shelving system and NOT PVC-dipped shelving. First, when you consider the environmental impact of the two processes, epoxy-coating has a much more favorable impact than does the PVC-dipping process. You can do a quick search in your favorite search engine to find a wealth of information on the dangers of PVC product.
Secondly, epoxy-coated shelving outperforms PVC-dipped shelving over time. Specifically, there are oils present in the PVC coating that "leach out" to the surface of the PVC coating over the course of a few years. The oils are present in the PVC coating in order to make the coating more flexible and to keep it from cracking when it dries during the manufacturing process. However, these oils will eventually reach the surface of the PVC coating and attract dirt and grime that you can NOT remove from the shelving. This leaves your shelves in a constant state of disgustingly dirty! Here is an image of a PVC-coated kitchen shelf just before I replaced it for a client several years ago:

In this image, you can see the dirt, grime, and even hair that is permanently adhered to the oils on the surface of the PVC-coated wire shelving! This particular client lived in Florida. The hot and humid Florida climate accelerated the migrating of the oils to the surface of the PVC coating and this shelf started to look dirty only after a few years.
Net, I highly recommend that you seek out closet systems that use epoxy-coated shelving and not PVC-coated shelves. Rubbermaid systems use epoxy-coating exclusively and are the systems that I recommend. For further information on epoxy-coated closet systems, check out the following products on Amazon: