Q. Can closed cell spray foam walls in a food processing facility be adequately cleaned?
A. Absolutely, a closed cell foam sprayed wall can be cleaned adequately -- if you are willing to invest the additional labor to insure the microbial load that may remain on the wall is below the FDA established upper limits or if you are willing to use a cleaning solution that has a high oxidation capacity (e.g. ozonated water, chlorinated rinse). As we all know "The devil is in the details."
The closed cell approach is by far the most cost effective short-term solution, and is the best solution for mitigating an existing concern at the least cost. However, keep in mind that all materials have a shelf life and are also susceptible to the rigors of your plant's operation. The security that closed cell applications offer could, in the short term, easily be compromised by fork-lift drivers or workers that may scrape the side of the wall and compromise the protection this type of surface originally offered. If this is not a concern, closed cell could be the most economical solution.
If considering new construction for the wall is an option, I would suggest using an IMP (insulated metal panel), which has a greater ease of cleaning and is much more compatible with a myriad of cleaning agents. Typically, they are installed with a protective 2-3 foot base to prevent damage and are USDA and FDA approved. If expansion calls for it, the panels can be removed and reused. This really works well for growing companies that need to make every dollar count.