The Philips MSD 250/2 discharge lamp has an average life of 3000 hours and a maximum service life of 3300 hours. Discharge lamps shall always be replaced when the maximum service life has been reached, even if they´re still working, due to the increased risk of lamp explosion as the quartz bulb becomes more brittle.
The average life specification for the MSD 250/2 was increased from the original 2000 hours long enough ago that lamps currently in use can be assumed to be 3000 hour lamps.
In general, the maximum service life of Philips long-life discharge lamps is 10 percent more than their average life.