It is argued that dose equivalent and effective dose equivalent are scientifically undesirable, are unstable, are largely unnecessary, are confusing, are potentially wasteful of radiobiological data, attempt to achieve the impossible and are abandoned when of greatest importance. It is stated that the place for judgemental factors is in the setting of limits, not in the definition of quantities. Proposals are made that absorbed dose, or a specially qualified absorbed dose, be used as the quantity in terms of which dose limits are set, and that different limits are laid down for high and low LET radiations.