Incandescent lamps are void of air. At least, this is what some people think. But this is not the case for halogen lamps at all. They have no vacuum like the one found primarily in classic household light bulbs. By contrast, halogen lamps are filled with a gas. And it is under pressure. A pretty fair amount of it, at that. It can range between 10 bars to 15 bars. The gas can contain elements like fluorine, chlorine, bromine and, above all, iodine. These chemical elements are called halogens, the name given to the entire technology.
Diving goggles to the rescue
The high levels of pressure create risks. The gas can explode if the lamp is damaged. Such blasts do not occur frequently. But when they do occur, glass splinters can fly everywhere. People’s eyes are particularly vulnerable. Individuals who wear glasses already have a certain line of defense. But they, just like other people, would also be well-advised to wear safety glasses when they work with halogen lamps. Diving goggles will do in a pinch.
An explosion of new brand-name lamps like those made by Osram is a very rare occurrence. But it is a different story for used lamps. The frequent change of temperature during operation and jolts the lamps have experienced while in service can make the glass bulb brittle. In such cases, it only takes a small touch or bump into the headlight casing during removal, and the damaged structure in the glass will give way.
Never touch the glass with your fingers!
There are also other reasons why a glass bulb can explode. If a person touches it with his or her bare fingers, the individual will leave behind traces of sebum or sweat. Aggressive substances are created during interaction with the heat generated by operations. These substances facilitate the embrittlement process of the glass. This is why the warning on the package to never touch the glass body with a finger is so important. There is also a second reason for the warning. The combination of sebum and sweat will partially evaporate – once again because of the heat. It will then condense on the headlight’s reflector, where it could also cause damage.
It really makes a whole lot of sense to observe the warnings on the packaging of car lamps – even if the message of the internationally standardized symbols may not be so clear at first.