 They will, however, lose their ability to produce a reasonable amount of UV after a short while.Typical lifespans for low-pressure lamps are from 300 to 1,600 hours of actual use although they may light and produce very little UV for as much as 5000 hours.High-pressure lamps range from 300 to 1,000 hours, and should be replaced when they have reached their maximum life to prevent any possible damage to the ballast, although this is very rare.