DCHAS-L Archives May 18 2011 - Re: Piranha solution

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All, The fact there are two types of Piranha solutions certainly should call int o question the wisdom of using such trival names for hazardous chemicals. Rudy Gerlach -----Original Message----- From: David Bunzow To: DCHAS-L Sent: Wed, May 18, 2011 8:44 am Subject: Re: [DCHAS-L] Piranha solution All, Please be aware there are TWO kinds of Piranha solutions =E2=80=93 the one focused on thus far is referred to as =E2=80=98acidic=E2=80=99 piranha=E2 =80=99. There is also a =E2=80=98basic piranha=E2=80=99 solution to consider as wel l in terms of dangers and risk of use in specific circumstances. David From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**list.uvm.edu] On Behalf Of IL PI Sent: Tuesday, May 17, 2011 7:00 PM To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU Subject: Re: [DCHAS-L] Piranha solution I've said it before on this list, so I will simply reference the previous d iscussion(s) and say here that Piranha solution is exceedingly dangerous an d, in all but carefully controlled and highly limited circumstances, poses an unacceptable risk in synthetic research labs. The near miss you describ e and the apparently limited knowledge of those who were using it serves to reinforce my argument. http://list.uvm.edu/cgi-bin/wa?A2=ind1101&L=DCHAS-L&D=0&T =0&P=48619 http://list.uvm.edu/cgi-bin/wa?A2=ind1101&L=DCHAS-L&D=0&T =0&P=52225 http://yarchive.net/chem/piranha_solution.html Rob Toreki ======================== ========================= ===== Safety Emporium - Lab & Safety Supplies featuring brand names you know and trust. Visit us at http://www.SafetyEmporium.com esales**At_Symbol_Here**safetyemporium.com or toll-free: (866) 326-5412 Fax: (856) 553-6154, PO Box 1003, Blackwood, NJ 08012 On May 17, 2011, at 4:20 PM, Johnson, Amy Carr wrote: I have been reading about how to make Piranha solution and I keep coming ac ross this statement, "Add the acid to the peroxide, although some authorities disagree=" Why would authorities not agree that adding acid to water instead of water to acid is best? I have seen some say add acid to peroxide for initial solution, but when re freshing, add aliquots of hydrogen peroxide to Piranha mixture. Is that ok ? We recently had an incident when Piranha came in contact with ferric chlori de and instantly reacted violently Was this due to the metal, the fact that both are oxidizers, both , or something else? I have read that neoprene gloves should always be worn. True? What type of glass is appropriate for containment? ----------MB_8CDE3854BD24071_1158_29182_Webmail-d115.sysops.aol.com

All,

The fact there are two types of Piranha solutio ns certainly should call into question the wisdom of using such triva l names for hazardous chemicals.

Rudy Gerlach

-----Original Message-----
From: David Bunzow <davidbunzow**At_Symbol_Here**COMCAST.NET>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Sent: Wed, May 18, 2011 8:44 am
Subject: Re: [DCHAS-L] Piranha solution

All,< /SPAN>

Pleas e be aware there are TWO kinds of Piranha solutions =E2=80=93 the one focus ed on thus far is referred to as =E2=80=98acidic=E2=80=99 piranha=E2=80=99.

There is also a =E2=80=98basic piranha=E2=80=99 solution to consider as well in terms of dangers and risk of use in specific circumstances.

;

David

;

Fr om: DCHAS-L Discu ssion List [mailto:DCHAS-L**At_Symbol_Here**list.uv m.edu] On Behalf Of ILPI
Sent: Tuesday, May 17, 2011 7:00 PM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: Re: [DCHAS-L] Piranha solution

I've said it before on this list, so I will simply r eference the previous discussion(s) and say here that Piranha solution is e xceedingly dangerous and, in all but carefully controlled and highly limite d circumstances, poses an unacceptable risk in synthetic research labs . The near miss you describe and the apparently limited knowledge of those who were using it serves to reinforce my argument.

; http://list.uvm.edu/cgi-bin/wa?A2=ind1101&L=DCHAS-L &D=0&T=0&P=48619

; http://list.uvm.edu/cgi-bin/wa?A2=ind1101&L= DCHAS-L&D=0&T=0&P=52225

; http://yarchive.net/chem/piranh a_solution.html

Rob Toreki

======================= ========================= ======

Safety Emporium - Lab & Safety Supplies featuring brand names

you kn ow and trust. Visit us at http://www.SafetyEmporium.com

esales**At_Symbol_Here**safetyemporium.com or toll-free: (866) 326-5412

Fax: ( 856) 553-6154, PO Box 1003, Blackwood, NJ 08012

On May 17, 2011, at 4:20 PM, Johnson, Amy Carr wrote :

I hav e been reading about how to make Piranha solution and I keep coming across this statement, "Add the acid to the peroxide, although some authorities disagree=" Why would authorities not agree t hat adding acid to water instead of water to acid is best?

;

I hav e seen some say add acid to peroxide for initial solution, but when refreshing, add aliquots of hydrogen peroxide to Piranha mixture. Is that ok?

;

We re cently had an incident when Piranha came in contact with ferric chloride an d instantly reacted

viole ntly Was this due to the metal, the fact that both are oxidizers, both, or something else?

;

I hav e read that neoprene gloves should always be worn. True?

;

What type of glass is appropriate for containment?

;

----------MB_8CDE3854BD24071_1158_29182_Webmail-d115.sysops.aol.com--

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