How to tell chrome language of your web site (as a hint to the translate bar)

I have a web app that is in queens engrish but the chrome translate bar pops up and tells me that its in Estonian.

I have tried lang and xml:lang but the google translation bar seems to ignore these.

Note: The web application is totally Ajax and the content that causes the bar to pop up is dynamic content that can appear long after the page load. So perhaps I have to add a header to my Ajax responses??

Anyone ever had issues like this?

Guido