Underwriters Laboratories (UL), Northbrook, IL, warned that installing double-ended direct replacement LED lamps in energized luminaires powered by magnetic 40W ballasts may pose a shock hazard.
UL said in a release that its recent testing confirmed that luminaires with magnetic ballasts intended for F40T12 fluorescent lamps may pose a risk of electric shock during installation of LED lamps intended for direct substitution of a fluorescent lamp while the circuit is energized. To date, UL has not received any reports of persons receiving an electric shock while replacing lamps on these older magnetic 40W ballasts.
Magnetic ballasts for F40T12 fluorescent lamps have not been available in the marketplace for many years. However, given their prior widespread use, these magnetic ballasts may still be in service in some older installations. To enhance safety, UL always recommends that all luminaires be deenergized during lamp installation or replacement.