At a local hardware store the battery recycling bin has a sign asking that only 9V batteries be taped since there is a much more likely hazard of their side-by-

At a local hardware store the battery recycling bin has a sign asking that only 9V batteries be taped since there is a much more likely hazard of their side-by-side terminals being directly shorted from inadvertent contact than for those with polar opposite terminals. The mess and hassle of untaping non-9v batteries for recycling centre workers was the cited reason, so my guess is that the fire risk is seen as much less important than the work required to untape them.