Backed up drain, is our freshly packaged product safe for consumption?
My question is, is our freshly packaged product safe for consumption, or should it be marked DNS?
Test it.
My answer would be "it depends". How risky is your product? Is there a chance contamination could have moved from the floor? Or are your controls on floor and food contact excellent? Can you hold and test the environment and product as suggested above? Are there risks aerosols could have been generated (often the case if someone attempted to unblock it before production finished.) If we're talking a block in the drain which had just happened but no water flowed up out of the drain during production and all production was moved out before cleaning, unless you have a very sensitive product, I'd be inclined to release.
The risk may also depend on the intended consumer..