Scientific communication is one of the most challenging aspects of volcanic risk management because the complexities and uncertainties of volcanic unrest make it difficult for scientists to provide information that is timely, relevant, easily comprehensible and trusted. When poorly handled, scientific communication can cause social, economic and political problems, and undermine community confidence in disaster management regimes. This is the first of two related papers that together investigate the interface between the scientific consideration of volcanic hazards and the governance of volcanic risks. Both papers are principally concerned with issues of risk governance, and their focus is hazard communication by volcanologists at this hazard-risk interface (the interface) during periods of volcanic unrest. In this paper, we argue that the working practices of contextualisation must be more methodical and propose four quality assurance standards that will enhance hazard assessments. To improve hazard communication between volcanologists and risk-mitigation decision-makers (decision-makers), we argue that volcanologists need to adopt a more iterative and structured approach that openly embraces the benefits, and confronts the challenges, of stakeholder-orientated 'contextualisation'. Our analysis of the published literature reveals evidence of a slow paradigm shift from practices based upon strict linear technocratic approaches to more iterative stakeholder participation. The extent of this shift varies in different regions, however, the rules and practices of deliberation often appear ad hoc and unstructured. Since there is currently insufficient guidance for managing the practicalities and standards of contextualisation, we introduce two novel concepts; the 'scrutiny dimension' of risk governance, which is the slow changing governance context that may influence the processes of contextualisation, and the dynamic 'equilibrium of contextualisation', which is the metastable product of regulatory standards, natural and organisational constraints, and stakeholder pressures. We argue that the working practices of contextualisation must be more structured and should strive to be open, transparent and fully articulated. Contextualisation, which meets proposed quality assurance standards of materiality, proximity, comprehensibility and integrity, will enhance hazard assessments and, thereby, the utility of their outputs. In our second paper (Bretton et al, J Appl. Volcanol.