From that site it states this:
"There is a common misconception that all containers made of white plastic or HDPE plastic bearing the symbol are food grade containers. This is not true. If you are considering the purchase of a container from some place other than a kitchen or restaurant supply store, and the container is not clearly labeled as "food safe" or being made of food grade plastic, then you should assume that it is not food grade and you should not brine in it"
Your/my Ale Pail does not say it is "Food Safe". So it violates what this site is saying, yet most of us have all used an ale pail to ferment at some point. It's no different than the #2 HDPE buckets from home depot. I agree with Cidahmaster, you are free to make your own choice. Maybe the effects are like you said, not readily apparent. But I have a hard time believing that homebrew equipment stores would sell something that is harmful to us.