When a specification is revised, manufacturers will need to have existing models certified to the new specification, however, certification bodies (CBs) may accept existing test data, so long as the testing requirements have not changed, and the test data is from an EPA-recognized lab. To avoid the costs and administrative burdens associated with retesting and certification, EPA encourages manufacturers to certify products to the highest specification version possible, and to work with CBs to determine if additional testing will be needed. A complete list of EPA-recognized CBs can be found here.