1. Be sure the plan doesn't create more problems. For instance, your plan may say that in the event of a catastrophe you will have your product co-packed by another firm. You will want to fully vet that firm before using them so they do not make unsafe/poor quality items for you. Controls could include documenting the firm's last 3rd party GMP/HACCP/GFSI audits, 2nd party audits you undertake to look more closely at capabilities related to product specifications and so on.
2. SQF requires you have a product hold/release program. This should be put into play to quarantine the items you have on hand until such time that you can make sure they meet product specification. Placed into quarantine, labeled with hold tags and documented in your hold log.
3. Measures taken to identify products affected by a crisis start with a visual inspection and work your way to lab tests against product specifications. You will be looking for obvious signs of damage or distress - easily identified and quarantines. after that you will have to apply a testing protocol to ensure that the product that is not visibly damaged is still good to go. If the product is temperature sensitive, was that affected? Exposure to sunlight? Exposure to toxic fumes? all the usual suspects.
Your BCP committee can help you brain-storm the solutions to each of the above. Your mock BCP exercises can help refine your responses. Good luck!