Disposal
Never put fireworks, even those which are fully spent, on the bonfire.
Never dispose of them by burying.
Soak fully spent fireworks in a container of water after use (till soaked right though, this could take several hours), then put in your household rubbish bin.
Soak misfired or partly spent fireworks in a container of water in an area where they cannot be tampered with (preferably away from the display site) and contact the manufacturer or supplier for advice on disposal.