Hi Jay,

The 10 ppm of oxygen is probably OK with respect to flammability.  The 
limiting oxygen concentration from many hydrocarbons is in the 10% range.

However, the nitrogen gas containing the flammables might become 
flammable when they are discharged from the glove box and mixed with air.

That is a bigger problem.

Dan Crowl
Michigan Tech University

Saldivar, Jay wrote:
> One of our scientists has asked for guidance in the use of inert (N2)
> atmosphere glove boxes for processes utilizing flammable liquids and
> electrical appliances. Details of the process of concern follow:
> *	Dispersed (in xylenes) silicon nanoparticles are to be further
> dispersed using a SS ultrasonic wand (20 kHz)
> *	Process to be performed in a N2 atmosphere glove box
> *	Monitored O2 levels will not exceed 10ppm in the box
> *	All power to the glove box (including the wand) is cut upon
> exceeding 10ppm O2 concentration in the box
> *	The lab bldg is provided with a fire sprinkler system as well as
> CO2 extinguishers within 10 ft
> 
> Questions:
> *	Is there a (any) concern regarding the use of a wand-type
> ultrasonic to agitate a flammable solvent in an inert atmosphere?
> *	Should this level of O2 ( flammability perspective?
> *	Under this scenario, at what O2 levels should fire reasonably be
> a concern?
> 
> I appreciate any and all feedback on this topic.
> Regards,
> 
> I Jay Saldivar
> Sr Safety Administrator
> Sharp Microelectronics of the Americas
> NW Pacific Rim Blvd
> Camas, WA  98607
>  
> 360/834-8734 (o)
> 360/772-4502 (c)
> saldivarj**At_Symbol_Here**sharpsec.com
> 

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