An ionization smoke alarm that is 'certified' by a testing laboratory (eg, Underwriters Laboratories (UL)  British Standards or Standards Australia) affords no protection to any person who BOTH has power to swap these alarms for photoelectrics AND who is aware that Ionization alarms are not fit for purpose.  Note: In this Mercer v Pittway Corporation BRK case the Defendants were afforded no protection merely because the ionization alarms were compliant with UL217, America's current smoke alarm standard. Once a landlord, building owner, real estate agent, fire official etc, becomes aware of the fact that ionization alarms are not fit for purpose (as evidenced by the amended Australian Standard, AS3786, in acknowledgement of flawed testing) then 'prior knowledge' exists together with a duty of care to inform all home owners/tenants that their existing ionization alarms are dangerously deficient.  Failure to warn in these conditions may render the official liable for prosecution in the event of death, injury or loss of property.

See the Hosford vs BRK Brands Inc & UL et al case where it has been alleged that UL’s testing of ionization smoke alarms is flawed.