Thanks for the response.Actually,I am with Louisiana DOTD and trying to compile the list for DOTD use on field projects. In the past we qualified all ourselves,but workforce has trimmed to the point that we don`t have the time. Was hoping to find what agency might list "certified" labs.I saw ASTM had a list ,but,I didn`t want to invest the amount they wanted to purchase it without knowing if it would contain useful entries.