Why does touching halogen bulbs shorten their life?

(Lansing State Journal, Feb. 23, 1994)

Halogen bulbs burn much brighter and produce much more heat than standard incandescent bulbs.

When you touch one of these bulbs (never touch a light bulb while it is on), oil from your skin leaves a residue on the glass shell to the bulb. When the bulb is turned on, it begins to get hot. Much of this heat is dumped into the air around the bulb and is carried away.

However, when there is oil on the bulb, it begins to get heated as well. The heat is actually enough to cause the oil to boil and its temperature can reach near 1,100 degrees Fahrenheit.

This "hot spot" puts a great deal of heat near the glass bulb and can cause the glass in the hot spot to warp and stretch. This causes a weak spot in the glass bulb which can break and thus shorten the life time.

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