The determination of dose equivalents from environmental radiation is most frequently performed on a TLD basis. As a matter of common language between authorities, customers and manufacturers of TLD systems, recommendations and standards are being set up by international and national bodies. Here, comments are made on the present state of standardisation by focussing attention on the energy range required. The different lower energy limits found are reviewed and discussed in terms of the metrologically feasible and with reference to a dose equivalent quantity as stated in ICRU 39.