1
\$\begingroup\$

If the bulb fails and outer glass envelope becomes detached is there a safety issue with the inner exposed wires between the small inner bulb and the bayonet cap?

exposed wires halogen bulb

\$\endgroup\$
1
\$\begingroup\$

Yes, there are safety issues.

Firstly those wires are connected to the cap of the bulb which will be connected to the mains.

Secondly the outer cover acts as a UV filter, so if the halogen bulb is still working but the outer cover has come off the bulb will produce high levels of UV which are bad for your eyes.

You should treat the bulb the same as you would treat a conventional incandescent bulb whose glass envelope has broken or fallen off. Isolate the circuit (do not rely on lightswitches for safety isolation) and then carefully remove the bulb.

\$\endgroup\$
3
  • \$\begingroup\$ Yes indeed - as I suspected. \$\endgroup\$
    – flash
    Feb 17 '17 at 16:21
  • \$\begingroup\$ The reason for my question is that I have recently witnessed the outer envelope detaching from a halogen bulb. It occurs to me that if the user is unsure whether or not the light switch is off eg in the case of a push button switch or possible a ganged switch then there is a danger from electrocution from the exposed wires. \$\endgroup\$
    – flash
    Feb 17 '17 at 16:26
  • \$\begingroup\$ continuing from my previous comment: unlike standard light bulbs halogen bulbs appear to retain their integrity when broken thus posing an additional risk to the unwary. \$\endgroup\$
    – flash
    Feb 17 '17 at 16:34
0
\$\begingroup\$

Risks include electrical shock from the more exposed wires, UV emission and possible injury from shards of hard glass or quartz if the pressurized capsule ruptures.

Aside from the other issues, the operating surface temperature of the quartz or glass of the halogen capsule is likely high enough to ignite flammable materials. So it is potentially a serious fire hazard.

More in this NEMA document entitled

Tungsten-halogen Lamps (Bulbs): Ultraviolet, Rupture, And High Temperature Risks

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.