The authoritive reference on these iss
ues
is
Beta-white (hexagonal)
Alpha-white (cubic)< /font>
Brown (which converts to beta-while at T > -190 C) and
Red (amorphous)
The other forms are made from these fo rms.
Ignoring ‘Hittorf’s violet ’, which is crystallized from molten lead, the other stable forms at normal T and P are alpha-white, beta-white and red.
From:
Sent: Tuesday, August 16, 20
11
9:35 AM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: Re: [DCHAS-L] CAS #
s for
allotropes of phosphorus
Monona -
I work at the Pine Bluff Arsenal in
As I work with the Chemical Weapons destruction part of the Arsenal, not the production side of the house, I'm forwarding your email to the Industrial Hygienist on that side. She worked with us for many years before moving over there and I have hopes that she might be able to help a little bit.
I'd go ahead and send her email addres s to you, but I lost it and I'm waiting for one of my folks to send it to me so I can forward your email...confused yet?
Don
A. Long
CAIH, CEAS I
Southwest Research Institute Laborat
ory
870-541-4930
From:
Sent: Tuesday, August 16, 20
11
8:46 AM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: [DCHAS-L] CAS #s fo
r
allotropes of phosphorus
My old Hawleys gives on CAS # 7723-14-0 to all forms and says elemental
phosphorus can have allotropes that are "white (or yellow), red, and
black." Other references list a brown allotrope as well. <
br>
* White phosphorus CAS# 7723-14-0 which has no TLV, but a DFG MAK 0.05 mg/m
3.
* Yellow phosphorus CAS# 12185-10-3 has a TLV-TWA 0.1 mg/m3; MAK 0.05 and a
NIOSH REL of 0.1 mg/m3.
And there's no entry for red phosphorus or any other color.
Pyrotechs use white and red. And their suppliers as well as other exp
erts
list the White as CAS 7723-14-0 and Red as 12185-10-3. And if I googl
e
various sources I can get different CAS numbers almost at will. They all
contradict each other.
Does anyone know if white and yellow are really different
allotropes? Does anyone know which CAS # goes with
which? Specifically is the CAS# 12185-10-3 for yellow or
for
red? It's to look like ACGIH might be wrong on this one.
Thanks for thinking on this.
Monona
Is anyone out there, or does anyone know, an expert on the allotropes of
phosphorus?
I'm working on the health effects for the chemicals listed in the next edit
ion
of the Dictionary of Pyrotechnics--a freebie for a pal I work with on NFPA
1126, the standard of pyro before a proximate audience.
Here's the deal. ACGIH has two entries in their big exposure guide booklet:
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