Can I Touch a Projector Lamp?

It is important to know that projector lamps are similar to halogen lamps, but not identical. Halogen lamps strictly cannot be touched because the oil from your hands will create hotspots on the halogen lamp and cause it to fail. Projector lamp globes can be touched, but we recommend that you handle them as little as possible or not at all. 

It is strictly essential that you do not touch the ARC tube with your fingers; this will leave fingerprints and cause the ARC tube to burn hotter in the places where it was touched. Higher burning temperatures can destabilize the ARC tube and can cause it to explode.