Phosphorus, (atomic number 15) is part of the nitrogen family and called "Light bearer" in it's Greek terminology as it reacts with oxygen to produce a faint white (sometimes yellow) light which is a by-product of it burning.
White/Yellow Phosporus is considered toxic, and was used as the ignitary agent in so-called "Molotov Cocktails" as well as being used to create the striking patches on match boxes amoungst other things.
So if a cloud heads your way, don't walk into it!
there was a fire in a chemical plant - the fire is out, but some chemicals have been released in this cloud thats heading that way. I'm not very scientific, but its not nice. Can irritate eyes, noses, throats - asthma sufferes are possibly at a risk I would think too.
I work in West Bromwich, about 2 miles from Langley, there have been many "leaks" from the factories, locals get used to it.( explains alot, lol) Doesn't usually make the news tho'
Apols to any blackcountry folks only joking!!