"What does the nfpa code state for storage height of plastic containers in a warehouse with a wet automatic fire protection system. This building is also used as a manufacturing faciltiy."
NFPA 13 says if storage is higher then five feet, which you say it is, then it must be designed for the hazard. Which others have pointed out, "it depends" on a lot of stuff. Unless the sprinkler system was designed for this hazard to begin with, most likely, the sprinkler protection will not be adequate.
So with this brief information you now know you have a potential problem. How to fix it may not be easy, cheap, or fast. AND for sure we can not help without looking at the sprinkler piping, water supply, etc, etc.
Time to hire a professional to start the process. As others have mentioned your insurance carrier MAY be able to help. if they have in-house engineering staff. They can at least give you a more educated guess then we can, and may be able to suggest changes. As an insurance professional I do evaluation of buildings and sprinkler protection everyday, so ask your carrier you maybe surprised at what service they can offer, many times at no cost to you. BUT once they do the engineering they will want you to spend the $$$ to upgrade, IF it possible to do so.