From: Tammy M. Lutz-Rechtin <tlutzrec**At_Symbol_Here**UARK.EDU>
Subject: Re: [DCHAS-L] Auto-ignition temperatures
Date: Tue, 11 Sep 2018 15:30:27 +0000
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Message-ID: BN7PR04MB40514096E051DE4D055A7DF2BA040**At_Symbol_Here**

For aluminum, classification depends on the size and shape of aluminum particles and most importantly, whether the particles have been exposed to air to create an oxidized coating.  For instance, unoxidized nm spherical aluminum under Argon should be handled as a pyrophoric substance as they can spontaneously ignite when exposed to air.  Oxidized aluminum particles of larger sizes is what is used in pyrotechnics.




From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Jeffrey Lewin
Sent: Tuesday, September 11, 2018 9:42 AM
Subject: Re: [DCHAS-L] Auto-ignition temperatures


The Alcoa GHS SDS I have for aluminum powder lists:


Product identifier ATOMIZED ALUMINUM POWDER   


Auto-ignition temperature 1202 F (650 C) layered


Hazard statement May form combustible dust concentrations in air.   


However, they also list DOT as not regulated.  


The DOT Hazard Material Table lists:


Aluminum powder, coated as DOT 4.1 (Flammable Solid)


Aluminum powder, uncoated as DOT 4.3 (Dangerous when wet)




On Tue, Sep 11, 2018 at 5:34 AM Debbie M. Decker <dmdecker**At_Symbol_Here**> wrote:

Hi All:


We're working through a list of materials classified as H250 (pyrophoric) but are having a terrible time finding auto-ignition data to back up that classification.  It appears to have evaporated off Sigma SDS' and other sources (CRC, PubChem, ChemSpider, CAMEO) don't seem to have it either.  Most irritating, to me, is the classification of powdered aluminum as pyrophoric with no auto-ignition data to back it up - just a note "ignites on contact with air."  If that were the case, the entire pyrotechnic and propellant industries would have folded up by now.


Does anyone out there have auto-ignition data in a format they're able/willing to share? Or have any insight into where the data has gone off to?


Thanks mucho,



Debbie M. Decker, CCHO, ACS Fellow

Past Chair, Division of Chemical Health and Safety

Councilor and Programming Co-Chair

University of California, Davis





Birkett's hypothesis: "Any chemical reaction

that proceeds smoothly under normal conditions,

can proceed violently in the presence of an idiot."



--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here** Follow us on Twitter **At_Symbol_Here**acsdchas


Jeff Lewin

Chemical Safety Officer

Compliance, Integrity, and Safety

Environmental Health and Safety

Michigan Technological University

Houghton, MI 49931


O 906-487.3153

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