Bunsen's burning orange

[RosalieL]

Our Bunsens have developed an orange glow around the blue flame. This has just happened during a class today where they were doing flame tests. Each chemical was set up at a different station so I don't think it's contamination as they are all doing it the same way. Our gas is off bottles. All I can think of is that the bottles might be running low? (I haven't gone to look at them yet - it is disgustingly windy and cold outside today!) Does this sound like a reasonable explanation or should I be looking for other problems? Has anyone else had this happen?

[bigmack]

Try a few bunsens from another set/room that wasn’t doing the flame test .