The present guidelines on the use of hepatitis B vaccine in mental handicap hospitals dictate the need for an a priori identification of occupational risk, but fail to clarify how this risk should be defined. The ethical requirement of a respect for autonomy however demands that in offering vaccine as a means of protection, the choice of options must be "informed'. The determinants of institutional transmission have not been clearly defined and it is therefore difficult to inform client groups as to the degree or nature of their occupational risk. It is questionable whether the literature can support the recommendations in their present form, and supposedly "cost-effective' solutions to the problem, pay scant regard to the fact that in risk management, the relative desirability of options is conditional on the alternatives considered, how they are framed, what evidence is consulted and how consequences are weighed. In informing the policy making process, it is imperative that the values of those whose voice is seldom heard, are considered.