Risk analysis and safety evaluation of biomass cookstoves

Combustion of biomass in open fires and ad hoc unventilated stoves is the primary form of household energy for two to three billion people worldwide. These cookstoves have significant health, social, and economic impacts on poor families in developing countries. These impacts include disease, injury, excess time spent gathering fuel, deforestation, and high fuel costs relative to income. In an attempt to address many of these problems numerous non-governmental organizations have developed several biomass cookstove designs in the past five to ten years. These designs have generally focused on increasing fuel efficiency, and to a lesser degree, reducing particulate emissions. This emphasis has been driven largely by the availability of relatively straight forward fuel efficiency tests for biomass cookstoves developed 10-20 years ago and the ability of researchers to adapt current air pollution testing methods for stoves. In contrast there are no safety standards or hazard evaluations available for biomass cookstoves. Because of this the safety of the cookstove is seldom explicitly considered as a part of the design process. This paper addresses the basic safety issues that should be considered in the design of biomass stoves used in developing countries, describes the reasoning behind these safety issues, and proposes a set of safety guidelines for testing and evaluating stove safety. These guidelines are intended for testing and evaluating in the field as well as in the design lab.