Anyone seen anything like this before?

https://youtube.com/shorts/xKejh6rIAqY?si=T4bclOKIAZ3UF5J9

Wow, that is impressive. I don't think that fire was likely to spread (unless the flaming plastic was dripping onto something flammable), but it was very close to a sprinkler which could heat up and go off. Not a fun situation, that could have been a lot worse.

This is the reason why plastic refractors shouldn’t be used on MH fixtures. All MH fixtures should have a glass refractor. Assuming these were 250 or 400 watts.

Otherwise, these fixtures should use open rated lamps with arc tube shrouds.

Yes, and I also think all metal halide fixtures should have a GLASS refractor. Using a plastic refractor on a metal halide fixture is stupid to begin with. Plastic refractors should only be used in MV or HPS fixtures or lower wattage.

But yes, using a protected lamp might’ve prevented this.

I thought all low bay fixtures are made from glass rather than plastic.

Yes, and I also think all metal halide fixtures should have a GLASS refractor. Using a plastic refractor on a metal halide fixture is stupid to begin with. Plastic refractors should only be used in MV or HPS fixtures or lower wattage.

But yes, using a protected lamp might’ve prevented this.

Yes, and specially so in a lamp burning BASE UP. If I had a say in the matter, it would be glass/porcelain for any lamp >100W. Metal halides have the greatest risk of non-passive failure so using flammable palstic right next to it doesn't seem too bright.

How coincidental! I just DM'd a forums member who i hold in high esteem about how to deal with (small) exploding MH lamps (James), that i want to use inside my house. I have a few specific ones i want to use, instead of the ones that are designed to fail safe in open luminaires, because of their technical peculiarities not found in the fail safe ones.
For protection 4mm tempered glass panes he recommended, or quarz tube but that is likely very expensive. My goal is to just be able to hang it from the ceiling. A glass box with overlapping panes will be suitable for that. Only issue is that tempered glass is even harder to cut than normal stuff...

E: with regards to that video - it is why in many countries polystyrene thermal isolation is not allowed for overhead use (like roof isolation). Even if it is self extinguishing, it oozes hot, possibly still burning sticky messes of plastic that are incompatible with human skin.