The rates of emission of formaldehyde from five domestic gas appliance burners have been determined as a function of both heat input and primary aeration. These emission rates range from 0.2 to 20 ng/J (based on the lower heating value), depending on the operational parameters and the design of the burners. Conventional blue flame burners generally produce <2 ng/J unless subject to impingement or operating under conditions leading to flame lift when emission rates increase substantially. The highest formaldehyde emission rates (6 to 20 ng/J) found in this study were produced by an inverted radiant griller (broiler) burner. Probe measurements of formaldehyde distributions within a bunsen burner flame show peak concentrations around 120 ppm occurring just inside the inner cone, decreasing very rapidly into the burnt gases. High concentrations of formaldehyde (>20 ppm) occur outside the outer cone of the bunsen burner flame only in the quenched regions near the base. This effect is believed to be responsible for the baseline emissions from domestic blue flame burners also.